Rick Magun MBBS MScChris P Verschoor PhDDawn ME Bowdish

PhDJohn Provias FRCP MD

Correspondence toRick Magunrmagungmailcom

Mycoplasma pneumoniae a trigger forWeston Hurst syndrome

ABSTRACT

Objective We report a case of Mycoplasma pneumoniae infection as one possible trigger forWeston Hurst syndrome (acute hemorrhagic leukoencephalitis) a rare disorder of microvascularinjury often described as a postinfectious complication of an upper respiratory illness

Methods This is a case of a 27-year-old man presenting with a Glasgow Coma Scale score of 3and an acute head CT revealing extensive vasogenic edema in the right hemisphere associatedwith mass effect in the context of a recent upper respiratory illness Right frontal biopsy was per-formed on day 2 which showed acute cerebritis and the patient was aggressively treated withantibiotics However over the next 5 days from presentation the vasogenic edema increasedleading ultimately to brain herniation and death

Results A full autopsy was performed at 5 days from presentation which showed areas of vessel wallfibrinoid necrosis throughout the right hemisphere as well as but less so in the left frontal lobe andpons Chest x-ray on presentation revealed atypical pneumonia blood tests were positive for cold ag-glutinins and at full autopsy there wasmyocarditis all in keepingwith recentMpneumoniae infectionDNAobtained from lung and diseased brain (postmortem)was positive forMycoplasmaprovidingmoredirect evidence for brain invasion by this organism as the ultimate trigger for Weston Hurst syndrome

Conclusions This is a rare case report of Weston Hurst syndrome having both initial brain biopsyon day 2 and full autopsy results on day 5 of presentation revealing important clinical clues aboutthe pathogenesis of this often fatal disorder Neurol Neuroimmunol Neuroinflamm 20163e187 doi

101212NXI0000000000000187

GLOSSARYAHLE 5 acute hemorrhagic leukoencephalitis HSV 5 herpes simplex virus Ig 5 immunoglobulin

Weston Hurst syndrome is a rare acute disorder characterized by diffuse fibrinoid necrosis ofvessels andor perivascular demyelination in the CNS Previous reports suggest it is a hyperacuteform of acute disseminated encephalomyelitis Also known as acute necrotizing encephalopathyacute hemorrhagic encephalomyelitis acute hemorrhagic leukoencephalitis (AHLE) Weston-Hurst syndrome or Hurst disease AHLE is a rare disorder with fewer than 100 cases reportedin the medical literature as of 201412

The initial presentation of AHLE involves a rapid deterioration and often death occurringwithin days to weeks of the first symptom signifying the poor prognosis for this disorder Itis believed to be a postinfectious encephalopathy but the trigger thought to be a viral or bacterialrespiratory infection remains unclear It is thought that the pathogen induces an autoimmunecross-reaction against myelin andor other antigens however this has yet to be fully proven3

Pathologic features previously described include vascular necrosis focal demyelination edemainflammatory meningeal infiltrates and focal hemorrhagic areas The prognosis remains poormost patients die within 2 to 4 days after symptom onset

From the Department of Neurology (RM) McMaster Immunology Research Centre (CPV DMEB) and Department of Pathology andMolecular Medicine (Neuropathology) (JP) McMaster University Hamilton Ontario Canada

Funding information and disclosures are provided at the end of the article Go to Neurologyorgnn for full disclosure forms The Article ProcessingCharge was paid by the authors

This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License 40 (CCBY-NC-ND) which permits downloading and sharing the work provided it is properly cited The work cannot be changed in any way or usedcommercially

Neurologyorgnn copy 2016 American Academy of Neurology 1

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

To date the pathogenesis of this disorderhas remained elusive Herein we describeMycoplasma pneumoniae with brain invasionas a trigger for Weston Hurst syndrome Thisfirst triggers a neutrophil reaction as seen atbiopsy on day 2 followed by a macrophagepredominant immune reaction at autopsy onday 5

CASE This is a case of a 27-year-old man with a 2-day history of cough headache and coryza anddocumented temperature of 395degC Before this hehad been well with no preexisting medical problemsHe did not drink alcohol had no history of IV druguse and was a nonsmoker He emigrated fromTaiwan to Canada in 1993 There was no recenttravel or sick contacts and no family history ofneurologic disorders He was seen by an outpatientfamily medicine clinic and received antibiotics(clarithromycin) and 4 hours later presented to the

emergency room with a Glasgow Coma Scale score of3 requiring immediate intubation Head CT showedright frontal edema with mass effect (figure 1A)Examination revealed a temperature of 391degCblood pressure of 15070 mm Hg and oxygensaturation of 95 His neurologic examinationshowed midsized nonreactive pupils normal cornealreflex no gag reflex and extension of all 4 limbs topainful stimuli A head CT showed extensivevasogenic edema in the right frontal-parietal regiona focal hypodensity in the right frontal area associatedwith mass effect and subfalcine herniation to the leftwith early central downward herniation (figure 2)Therefore an urgent right-sided craniectomy wasperformed with a partial right frontal lobectomyand insertion of a ventricular drain As expected hisintracranial pressure was raised Initial brain biopsy ofthe right frontal region on day 2 showed acutecerebritis (figure 3)

He was admitted to intensive care postoperativelyand our infectious disease team was consulted andsuggested a differential diagnosis of pneumonia withhematogenous spread to the brain or a primaryencephalitis CSF was taken on day 2 from the ventri-cle drain and sent to microbiology only and unfortu-nately no biochemistry was obtained includingprotein level glucose and cell count CSF was nega-tive for Gram stain and culture as well as for herpessimplex virus (HSV)-1 and -2 via PCR Bloodcultures were also taken on day 2 via line and periph-erally and showed no growth after 5 days Nasopha-ryngeal swab taken on day 2 was negative forrespiratory viruses via PCR HIV serology tested onday 3 was negative for HIV p24 antigen and negativefor HIV-1HIV-2 antibodies Nevertheless given hislung x-ray showed consolidation (figure 1B) he wasplaced on the following antimicrobials ceftriaxone 2g IV twice a day vancomycin 1 g IV every 8 hoursand acyclovir 1 g IV every 8 hours (HSV status at thetime was pending) The patient also received dexa-methasone 4 mg IV every 8 hours to reduce vasogenicedema and phenytoin (Dilantin) 300 mg IV daily forseizure prophylaxis Propofol and fentanyl were alsoused in the intensive care unit for sedation and anal-gesia effect His hemoglobin dropped to 74 gL froma postoperative value of 90 gL Cold agglutinins wereidentified but because the bilirubin was normal itwas thought to be secondary to infection rather thanhemolytic anemia International normalized ratioliver function testing and creatine were all normalWhite blood cell count was 19 3 109L with anabsolute neutrophil count of 177 3 109L and pla-telets were 165 3 109L Despite aggressive therapyhe lost his brainstem reflexes over the next 48hours and developed diabetes insipidus He wasunfortunately declared brain dead the next day on

Figure 1 Summary of clinical presentation

(A) Head CT on days 1 and 2 showed extensive vasogenic edema in the right temporal-pari-etal region a focal hypodensity in the right frontal region associated with mass effect andsubfalcine herniation to the left with early central downward herniation Therefore an urgentright-sided craniectomy was performed to relieve the pressure and obtain a biopsy of theright frontal region (B) Chest x-ray on day 2 showed patchy congestion consistent with aright lower lobe pneumonia as well as pulmonary edema Later autopsy results at day 5 con-firmed these findings and also showedmucoid purulent secretions in the bronchial tree Myo-carditis was also noted at autopsy with a primary neutrophilic reaction Nasopharyngealswab was negative for enteroviruses and respiratory viruses via PCR Cold agglutinins werepositive at a titer of 64 when tested against adult cells at 4degC

2 Neurology Neuroimmunology amp Neuroinflammation

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

day 5 Postmortem cultures were taken on day 6including CSF for Gram stain and culture as well aslung tissue from the right side in the area of consol-idation and from the left lung Brain tissue in the areaof hemorrhage purulent fluid which was noted inthe bladder and peripheral blood cultures were alsosent on day 6 (postmortem) These were all negativefor culture and Gram stain

METHODS Biopsy tissue was placed in 10 formalin for pro-

cessing for light microscopy The brain was fixed in 10 formalin

for approximately 3 weeks and it was then examined grossly and sec-

tioned at 15-cm intervals Sections of the lesions in the white

matter the cerebral cortex thalamus basal ganglia hippocampus

cerebellum midbrain pons and medulla were taken for histologic

evaluation DNA was isolated from lung and brain A Mycoplasma

PCR Detection Kit from ZmTech Scientifique (Montreal Canada)

was used which screens up to 117 species of Mycoplasma Severalantibodies were used for immunohistochemistry as follows a

monoclonal mouse anti-human neurofilament immunoglobulin G

(IgG) antibody reacting to 70-kDa subunit was used at 1200

dilution Rabbit polyclonal myelin basic protein IgG antibody

(Ab-1) was obtained from Neo Markers Inc and used at a 1100

dilution A rabbit polyclonal anti-glial fibrillary acidic protein

antibody from Dako (Carpinteria CA) was used at 1200

dilution A rabbit polyclonal anti-water channel aquaporin 4

antibody at 1200 to 1400 dilution was used (Sigma-Aldrich St

Louis MO) A Monoclonal mouse anti-human CD5 antibody

was used at 1200 (Dako) CD3 CD4 CD8 CD20 and

CD68 monoclonal mouse antibodies were also ordered from

Dako and used as per manufacturerrsquos protocol Rabbit anti-

human ferritin antibody from Dako was used at 1100 dilution

Polyclonal rabbit HSV-1 and HSV-2 antibodies were used at a

dilution of 1100 (Dako)

Figure 2 Gross autopsy findings

A full Autopsy was performed after the patient died on Day 5 and the brain weight was 1600 grams There is evidence of a previous right frontal biopsy siteOn external examination of the brain there was hemorrhagic necrosis and swelling noted along the right lateral edge of the frontaltemporalparietal area(arrows A CndashF H) with evidence of flattening of the right olfactory tract secondary to increase intracranial pressure (arrow B) There was subfalcineherniation to the left with herniation of the cingulate gyrus underneath the edge of the falx cerebri (arrow G) There was also transtentorial herniation on theright with early signs of Duretrsquos hemorrhages in the pons (arrows I J) A normal pons is shown for comparison (I) There was also cerebellar tonsillar herniationnoted on the right which was likely the fatal complication

Neurology Neuroimmunology amp Neuroinflammation 3

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

BIOPSY RESULTS Brain biopsy on day 2 of theright frontal lobe showed acute cerebritis as shownin figure 3 There is a marked acute inflammatorycell reaction most consistent with an acute infectiousprocess The neutrophil predominance was deter-mined to be consistent with a pyogenic processalthough the Gram stain was negative Silver stainwas also negative for fungus There was no neoplasmgranulomatous inflammation or evidence of vasculi-tis present

AUTOPSY RESULTS A full autopsy was performedwith the brain being removed and formal-fixed in a

routine fashion The brain weight was 1600 g Onexternal examination of the brain there washemorrhagic necrosis and edema noted along theright lateral edge of the frontaltemporalparietal area(figure 2) There was subfalcine herniation andcerebellar tonsillar herniation There was also uncalherniation noted on the right causing Durethemorrhages in the pons which was likely the fatalcomplication Hemorrhagic necrosis was seen in theright hemisphere in multiple sections from frontal totemporal lobes No space-occupying lesion or abscesswas noted Inspection of the vessels showed no evidenceof thrombus or embolic events Inspection of themeninges showed no evidence of infection Inspectionof the right hippocampus showed minute darkhemorrhages in the posterior portion reflecting uncalcontusion

Microscopic examination There were multiple areas ofperivascular ring-like hemorrhages with surroundinginflammation of both acute (neutrophils) butpredominantly a chronic macrophage reaction(figure 3) These were seen predominantly in theright and less so in the left orbital frontal areas aswell as the right frontal-parietal specimens Nomicroglial nodules were noted A multicentricfibrinoid necrosis was seen within these vessels withsurrounding edema and hemorrhages noted Theseinvolved predominantly the smaller arteriolar andvenule type vessels No vasculitic changes werepresent Examination of the hippocampuscerebellum and pons showed evidence of terminalhypoxic ischemic encephalopathy with selectiveneuronal necrosis Examination of brainstemshowed areas of Duret hemorrhages in midbrainand pons secondary to brain herniation as well asareas of ring-like hemorrhages and perivascularinflammatory macrophage reaction were noted

Gram and silver stain were performed whichwere negative for bacteria and fungi The trichromestain confirmed fibrinoid necrosis (figure 3) in mul-tiple vessels of the right orbital frontal and rightfrontoparietal areas Staining for ferritin confirmedthe presence of macrophages surrounding ring-likehemorrhages Staining for HSV-1 and HSV-2 wasnegative

Immunohistochemistry for myelin basic proteinshowed areas of reduced staining in a perivascular distri-bution throughout the white matter (figure 4) The Ufibers were spared There was perivascular edema notedas well as axonal damage Immunohistochemistry forIgG and IgM showed a perivascular pattern consistentwith autoimmune inflammatory reaction or ldquoleakyrdquo ves-sels CD68 confirmed macrophage infiltration aroundthese vessels T cell markers CD3 and CD8 were neg-ative CD20 a B cell marker was also negative

Figure 3 Initial brain biopsy and autopsy microscopic findings

Initial brain biopsy on day 2 of the right frontal region showed acute cerebritis There was amarked acute inflammatory cell reaction most consistent with an acute infectious processnoted in lower (A) and higher (B) magnification The neutrophil predominance was determinedto be consistent with a pyogenic process although the Gram stain was negative Silver stainwas also negative for fungus There was no neoplasm granulomatous inflammation or vas-culitis present (C D) Hematoxylin amp eosin stain at autopsy showed punctate ring-shapedfoci of perivascular hemorrhage and edema localized to the white matter This was sur-rounded by inflammation with a predominantly macrophage reaction in the right and leftorbital frontal areas as well as right frontal-parietal sections (E F) Trichrome stain confirmedfibrinoid necrosis in multiple vessels in the right orbital frontal and frontal-parietal areasThere was no lymphocytic infiltration and no microglial nodules as seen in vasculitis and viralencephalitis respectively There was no inflammation in the vessel walls Thromboemboliviral cytopathologic effects foreign abscesses and granulomas were not seen

4 Neurology Neuroimmunology amp Neuroinflammation

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

We isolated DNA from formalin-fixed brain andlung tissue (figure 5) PCR test for MycoplasmaDNA was positive in the right lung field and the rightfrontal lobe of the brain (sample taken from the areaof hemorrhage)

DISCUSSION Case reports showing both biopsy andfull autopsy results from the same case of AHLE arerare Seven previous autopsies have been reportedhowever2ndash8 In this case the biopsy and full autopsywere performed within 5 days from presentationwhich revealed a chronological change that has pro-vided clues to the pathophysiology of this rare disor-der There still remain several areas of uncertaintyregarding AHLE This case not only provides moreconcrete evidence that M pneumoniae is a trigger butwe can also learn more about the pathophysiologyincluding why there were differences seen in thebiopsy of the brain vs autopsy at day 5 In additionis this truly a demyelinating disorder

Regarding antigenic infectious causes for AHLEseveral have been identified and in this case we con-firmed M pneumoniae involving the right lung asthe trigger Since it was first reported in 1941 byHurst9 AHLE remains a rare disorder with a poorprognosis and to date Epstein-Barr virus10ndash13

HSV1415 and M pneumoniae3 have been identifiedas causes We reported positive DNA via PCR fromlung and diseased brain for M pneumoniae (figure 5)This is in keeping with the chest x-ray findings

showing atypical pneumonia the autopsy resultsshowing myocarditis and positive cold agglutininstest all in keeping with recent M pneumoniae infec-tion The significance of identifying MycoplasmaDNA via PCR in brain indicates that brain invasionhad occurred This has been previously describedusing immunohistochemistry on autopsy specimensfrom brain tissue in a patient with AHLE3 Threeother previous reports of M pneumoniae triggeringAHLE have been reported which showed positiveserology including both IgG and IgM as well as coldagglutinin positivity1116 however positive serologysimply indicates past exposure and is not specific fora recent infection

In previous studies it is hypothesized that Mpneumoniae triggers a cross-reaction to antigens formyelin to account for the demyelination3410 How-ever there is no direct evidence for this Whether theimmune response is toward M pneumoniae or actualneural antigens also remains unclear Pathologic fea-tures include focal hemorrhages with perivasculardemyelination These findings were seen in boththe right and left hemisphere in our case more soon the right in the large area of hemorrhage as wellas small areas in the pons In areas of vessel wallfibrinoid necrosis there were perivascular areas ofdemyelination and edema noted as shown in figure4 Immunohistochemistry showed lack of staining formyelin basic protein around vessel walls but the pres-ence of neurofilament staining throughout which

Figure 4 Autopsy immunochemistry results

CD68 (A) and ferritin (B) stain showed the presence of scattered microglial cells foamy macrophages and rare hemosiderin-laden macrophages CD4 wasnegative for T cells (C) Other tests performed include staining T cell markers CD3 CD4 CD5 and CD8 as well as B cell marker CD20 (data not shown) all ofwhich were negative These results indicated a primarily macrophage reaction vs lymphocytic Immunohistochemistry for immunoglobulin G (IgG) and IgMshowed a perivascular double ring-like effect consistent with an autoimmune inflammatory reaction or leakage (arrows D) Immunohistochemistry for myelinbasic protein (MBP) showed areas of reduced staining in a perivascular distribution throughout the white matter (E) The U fibers were spared There wasperivascular edema gliosis and mild axonal damage seen on glial fibrillary acidic protein (GFAP) (F) and neurofilament stain (G) Of note neurofilament stainshowed minimal axonal damage in contrast to the MBP stain which was most consistent with demyelination Herpes simplex virus 1 and 2 staining was neg-ative Gram stain and silver stain were also performed which were negative for infection

Neurology Neuroimmunology amp Neuroinflammation 5

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

signified that the axons were relatively intact but somedemyelination had occurred Nevertheless althoughwe have postulated that demyelination had occurredin our case we were not able to determine whetherthere was a separate mechanism causing demyelina-tion or if this was a cross-reaction toM pneumoniae aspreviously proposed3

The core diagnostic feature of AHLE is the fibrin-oid necrosis of vessel walls Although we showedbrain invasion by M pneumoniae a direct infectioncausing an encephalitis by this bacteria wouldunlikely cause fibrinoid necrosis and such vessel walldamage at day 517 This is central to the pathophys-iology of AHLE and the immunologic cascade lead-ing to this terminal event can be postulated to bedivided into 2 phases An initial ldquoMycoplasma phaserdquois predominantly a neutrophil reaction with no fibrin-oid necrosis of the vessel walls as seen on the day 2biopsy result and in a previous study18 This likelyrepresents a direct immunologic reaction to CNSinvasion by Mycoplasma pneumonia This is followedby a quick second phase an ldquoimmune phaserdquo whichis macrophage-predominant leading to degranula-tion cytokine release and ultimately vessel wallnecrosis the fatal response in this disorder Thiswas seen at day 5 at autopsy in this case and of note

was previously reported23 Further evidence for acti-vation of the innate immune system was proposed ina recent report19 that postulated that the complementcascade is involved in the pathogenesis of AHLE Ithas been suggested that deposition of immune com-plexes on vessel walls triggers complement activationand ultimately recruitment of macrophages in thissecond phase Whether this second phase representsa distinct autoimmune phase has been hypothesizedbut to date there is no evidence for immunocomplexdeposition or direct activation of complement in thiscondition This is in contrast to acute disseminatedencephalomyelitis which is a lymphocytic (T cell orhumoral B cell) predominant response that we didnot see in our case

Similar to our case an initial neutrophil responsefollowed by macrophage reactions has been continuallyreported in previous case reports21120 Unfortunatelythe primary neutrophil response with no fibrinoidnecrosis of vessel walls obscured the diagnosis at theday 2 biopsy result and the patient was aggressivelytreated for infection and not an autoimmune reactionon presentation Survivors of this disorder have rarelybeen reported In a previous report18 successful treat-ment involved quick recognition of the disorder de-compressive craniotomy followed by 10 treatments oftherapeutic plasma exchange leading to a successful out-come with full reversal of presenting neurologic deficitsIn another recent study19 2 patients of Filipino descentwere shown to have partial complement factor I defi-ciency and responded successfully to a novel drug ana-kinra an interleukin 1 receptor antagonist Anakinracan serve to control inflammation via complement-mediated effects by reducing interleukin 1b signalingand thus is another possible treatment for AHLE thatshould be explored

AUTHOR CONTRIBUTIONSRick Magun manuscript concept and design performed autopsy analysis

and interpretation of test results constructed and wrote manuscript Chris

P Verschoor performed DNA analysis figure 5 reviewed manuscript

regarding immunologic response Dawn ME Bowdish critical revision of

manuscript for immunologic intellectual content John Provias manuscript

concept and design performed autopsy analysis and interpretation of test

results critical revision of manuscript for intellectual content

STUDY FUNDINGNo targeted funding

DISCLOSUREThe authors have no disclosures Go to Neurologyorgnn for full disclo-

sure forms

Received July 14 2015 Accepted in final form November 3 2015

REFERENCES1 Dos Santos MP Martin J Woulfe J et al Autopsy-proven

acute hemorrhagic leukoencephalitis in an elderly patient

Can J Neurol Sci 20144199ndash102

Figure 5 Autopsy Mycoplasma DNA analysis

DNA was isolated from the right hemisphere of the brain in an area of hemorrhage and nor-mal brain from the autopsy of our patient as well as the right lung PCR test forMycoplasmaDNA is shown above A corresponding 167ndashbase pair (bp) band as seen in the control isnoted in all the right lung fields (upper middle and lower) and diseased brain consistent withamplification of Mycoplasma DNA No band for Mycoplasma DNA was seen in normal areasof the brain The results indicate a recent Mycoplasma pneumoniae infection with braininvasion which ultimately led to Weston Hurst syndrome

6 Neurology Neuroimmunology amp Neuroinflammation

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

day 5 Postmortem cultures were taken on day 6including CSF for Gram stain and culture as well aslung tissue from the right side in the area of consol-idation and from the left lung Brain tissue in the areaof hemorrhage purulent fluid which was noted inthe bladder and peripheral blood cultures were alsosent on day 6 (postmortem) These were all negativefor culture and Gram stain

METHODS Biopsy tissue was placed in 10 formalin for pro-

cessing for light microscopy The brain was fixed in 10 formalin

for approximately 3 weeks and it was then examined grossly and sec-

tioned at 15-cm intervals Sections of the lesions in the white

matter the cerebral cortex thalamus basal ganglia hippocampus

cerebellum midbrain pons and medulla were taken for histologic

evaluation DNA was isolated from lung and brain A Mycoplasma

PCR Detection Kit from ZmTech Scientifique (Montreal Canada)

was used which screens up to 117 species of Mycoplasma Severalantibodies were used for immunohistochemistry as follows a

monoclonal mouse anti-human neurofilament immunoglobulin G

(IgG) antibody reacting to 70-kDa subunit was used at 1200

dilution Rabbit polyclonal myelin basic protein IgG antibody

(Ab-1) was obtained from Neo Markers Inc and used at a 1100

dilution A rabbit polyclonal anti-glial fibrillary acidic protein

antibody from Dako (Carpinteria CA) was used at 1200

dilution A rabbit polyclonal anti-water channel aquaporin 4

antibody at 1200 to 1400 dilution was used (Sigma-Aldrich St

Louis MO) A Monoclonal mouse anti-human CD5 antibody

was used at 1200 (Dako) CD3 CD4 CD8 CD20 and

CD68 monoclonal mouse antibodies were also ordered from

Dako and used as per manufacturerrsquos protocol Rabbit anti-

human ferritin antibody from Dako was used at 1100 dilution

Polyclonal rabbit HSV-1 and HSV-2 antibodies were used at a

dilution of 1100 (Dako)

Figure 2 Gross autopsy findings

A full Autopsy was performed after the patient died on Day 5 and the brain weight was 1600 grams There is evidence of a previous right frontal biopsy siteOn external examination of the brain there was hemorrhagic necrosis and swelling noted along the right lateral edge of the frontaltemporalparietal area(arrows A CndashF H) with evidence of flattening of the right olfactory tract secondary to increase intracranial pressure (arrow B) There was subfalcineherniation to the left with herniation of the cingulate gyrus underneath the edge of the falx cerebri (arrow G) There was also transtentorial herniation on theright with early signs of Duretrsquos hemorrhages in the pons (arrows I J) A normal pons is shown for comparison (I) There was also cerebellar tonsillar herniationnoted on the right which was likely the fatal complication

Neurology Neuroimmunology amp Neuroinflammation 3

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

BIOPSY RESULTS Brain biopsy on day 2 of theright frontal lobe showed acute cerebritis as shownin figure 3 There is a marked acute inflammatorycell reaction most consistent with an acute infectiousprocess The neutrophil predominance was deter-mined to be consistent with a pyogenic processalthough the Gram stain was negative Silver stainwas also negative for fungus There was no neoplasmgranulomatous inflammation or evidence of vasculi-tis present

AUTOPSY RESULTS A full autopsy was performedwith the brain being removed and formal-fixed in a

routine fashion The brain weight was 1600 g Onexternal examination of the brain there washemorrhagic necrosis and edema noted along theright lateral edge of the frontaltemporalparietal area(figure 2) There was subfalcine herniation andcerebellar tonsillar herniation There was also uncalherniation noted on the right causing Durethemorrhages in the pons which was likely the fatalcomplication Hemorrhagic necrosis was seen in theright hemisphere in multiple sections from frontal totemporal lobes No space-occupying lesion or abscesswas noted Inspection of the vessels showed no evidenceof thrombus or embolic events Inspection of themeninges showed no evidence of infection Inspectionof the right hippocampus showed minute darkhemorrhages in the posterior portion reflecting uncalcontusion

Microscopic examination There were multiple areas ofperivascular ring-like hemorrhages with surroundinginflammation of both acute (neutrophils) butpredominantly a chronic macrophage reaction(figure 3) These were seen predominantly in theright and less so in the left orbital frontal areas aswell as the right frontal-parietal specimens Nomicroglial nodules were noted A multicentricfibrinoid necrosis was seen within these vessels withsurrounding edema and hemorrhages noted Theseinvolved predominantly the smaller arteriolar andvenule type vessels No vasculitic changes werepresent Examination of the hippocampuscerebellum and pons showed evidence of terminalhypoxic ischemic encephalopathy with selectiveneuronal necrosis Examination of brainstemshowed areas of Duret hemorrhages in midbrainand pons secondary to brain herniation as well asareas of ring-like hemorrhages and perivascularinflammatory macrophage reaction were noted

Gram and silver stain were performed whichwere negative for bacteria and fungi The trichromestain confirmed fibrinoid necrosis (figure 3) in mul-tiple vessels of the right orbital frontal and rightfrontoparietal areas Staining for ferritin confirmedthe presence of macrophages surrounding ring-likehemorrhages Staining for HSV-1 and HSV-2 wasnegative

Immunohistochemistry for myelin basic proteinshowed areas of reduced staining in a perivascular distri-bution throughout the white matter (figure 4) The Ufibers were spared There was perivascular edema notedas well as axonal damage Immunohistochemistry forIgG and IgM showed a perivascular pattern consistentwith autoimmune inflammatory reaction or ldquoleakyrdquo ves-sels CD68 confirmed macrophage infiltration aroundthese vessels T cell markers CD3 and CD8 were neg-ative CD20 a B cell marker was also negative

Figure 3 Initial brain biopsy and autopsy microscopic findings

Initial brain biopsy on day 2 of the right frontal region showed acute cerebritis There was amarked acute inflammatory cell reaction most consistent with an acute infectious processnoted in lower (A) and higher (B) magnification The neutrophil predominance was determinedto be consistent with a pyogenic process although the Gram stain was negative Silver stainwas also negative for fungus There was no neoplasm granulomatous inflammation or vas-culitis present (C D) Hematoxylin amp eosin stain at autopsy showed punctate ring-shapedfoci of perivascular hemorrhage and edema localized to the white matter This was sur-rounded by inflammation with a predominantly macrophage reaction in the right and leftorbital frontal areas as well as right frontal-parietal sections (E F) Trichrome stain confirmedfibrinoid necrosis in multiple vessels in the right orbital frontal and frontal-parietal areasThere was no lymphocytic infiltration and no microglial nodules as seen in vasculitis and viralencephalitis respectively There was no inflammation in the vessel walls Thromboemboliviral cytopathologic effects foreign abscesses and granulomas were not seen

4 Neurology Neuroimmunology amp Neuroinflammation

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

We isolated DNA from formalin-fixed brain andlung tissue (figure 5) PCR test for MycoplasmaDNA was positive in the right lung field and the rightfrontal lobe of the brain (sample taken from the areaof hemorrhage)

DISCUSSION Case reports showing both biopsy andfull autopsy results from the same case of AHLE arerare Seven previous autopsies have been reportedhowever2ndash8 In this case the biopsy and full autopsywere performed within 5 days from presentationwhich revealed a chronological change that has pro-vided clues to the pathophysiology of this rare disor-der There still remain several areas of uncertaintyregarding AHLE This case not only provides moreconcrete evidence that M pneumoniae is a trigger butwe can also learn more about the pathophysiologyincluding why there were differences seen in thebiopsy of the brain vs autopsy at day 5 In additionis this truly a demyelinating disorder

Regarding antigenic infectious causes for AHLEseveral have been identified and in this case we con-firmed M pneumoniae involving the right lung asthe trigger Since it was first reported in 1941 byHurst9 AHLE remains a rare disorder with a poorprognosis and to date Epstein-Barr virus10ndash13

HSV1415 and M pneumoniae3 have been identifiedas causes We reported positive DNA via PCR fromlung and diseased brain for M pneumoniae (figure 5)This is in keeping with the chest x-ray findings

showing atypical pneumonia the autopsy resultsshowing myocarditis and positive cold agglutininstest all in keeping with recent M pneumoniae infec-tion The significance of identifying MycoplasmaDNA via PCR in brain indicates that brain invasionhad occurred This has been previously describedusing immunohistochemistry on autopsy specimensfrom brain tissue in a patient with AHLE3 Threeother previous reports of M pneumoniae triggeringAHLE have been reported which showed positiveserology including both IgG and IgM as well as coldagglutinin positivity1116 however positive serologysimply indicates past exposure and is not specific fora recent infection

In previous studies it is hypothesized that Mpneumoniae triggers a cross-reaction to antigens formyelin to account for the demyelination3410 How-ever there is no direct evidence for this Whether theimmune response is toward M pneumoniae or actualneural antigens also remains unclear Pathologic fea-tures include focal hemorrhages with perivasculardemyelination These findings were seen in boththe right and left hemisphere in our case more soon the right in the large area of hemorrhage as wellas small areas in the pons In areas of vessel wallfibrinoid necrosis there were perivascular areas ofdemyelination and edema noted as shown in figure4 Immunohistochemistry showed lack of staining formyelin basic protein around vessel walls but the pres-ence of neurofilament staining throughout which

Figure 4 Autopsy immunochemistry results

CD68 (A) and ferritin (B) stain showed the presence of scattered microglial cells foamy macrophages and rare hemosiderin-laden macrophages CD4 wasnegative for T cells (C) Other tests performed include staining T cell markers CD3 CD4 CD5 and CD8 as well as B cell marker CD20 (data not shown) all ofwhich were negative These results indicated a primarily macrophage reaction vs lymphocytic Immunohistochemistry for immunoglobulin G (IgG) and IgMshowed a perivascular double ring-like effect consistent with an autoimmune inflammatory reaction or leakage (arrows D) Immunohistochemistry for myelinbasic protein (MBP) showed areas of reduced staining in a perivascular distribution throughout the white matter (E) The U fibers were spared There wasperivascular edema gliosis and mild axonal damage seen on glial fibrillary acidic protein (GFAP) (F) and neurofilament stain (G) Of note neurofilament stainshowed minimal axonal damage in contrast to the MBP stain which was most consistent with demyelination Herpes simplex virus 1 and 2 staining was neg-ative Gram stain and silver stain were also performed which were negative for infection

Neurology Neuroimmunology amp Neuroinflammation 5

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

signified that the axons were relatively intact but somedemyelination had occurred Nevertheless althoughwe have postulated that demyelination had occurredin our case we were not able to determine whetherthere was a separate mechanism causing demyelina-tion or if this was a cross-reaction toM pneumoniae aspreviously proposed3

The core diagnostic feature of AHLE is the fibrin-oid necrosis of vessel walls Although we showedbrain invasion by M pneumoniae a direct infectioncausing an encephalitis by this bacteria wouldunlikely cause fibrinoid necrosis and such vessel walldamage at day 517 This is central to the pathophys-iology of AHLE and the immunologic cascade lead-ing to this terminal event can be postulated to bedivided into 2 phases An initial ldquoMycoplasma phaserdquois predominantly a neutrophil reaction with no fibrin-oid necrosis of the vessel walls as seen on the day 2biopsy result and in a previous study18 This likelyrepresents a direct immunologic reaction to CNSinvasion by Mycoplasma pneumonia This is followedby a quick second phase an ldquoimmune phaserdquo whichis macrophage-predominant leading to degranula-tion cytokine release and ultimately vessel wallnecrosis the fatal response in this disorder Thiswas seen at day 5 at autopsy in this case and of note

was previously reported23 Further evidence for acti-vation of the innate immune system was proposed ina recent report19 that postulated that the complementcascade is involved in the pathogenesis of AHLE Ithas been suggested that deposition of immune com-plexes on vessel walls triggers complement activationand ultimately recruitment of macrophages in thissecond phase Whether this second phase representsa distinct autoimmune phase has been hypothesizedbut to date there is no evidence for immunocomplexdeposition or direct activation of complement in thiscondition This is in contrast to acute disseminatedencephalomyelitis which is a lymphocytic (T cell orhumoral B cell) predominant response that we didnot see in our case

Similar to our case an initial neutrophil responsefollowed by macrophage reactions has been continuallyreported in previous case reports21120 Unfortunatelythe primary neutrophil response with no fibrinoidnecrosis of vessel walls obscured the diagnosis at theday 2 biopsy result and the patient was aggressivelytreated for infection and not an autoimmune reactionon presentation Survivors of this disorder have rarelybeen reported In a previous report18 successful treat-ment involved quick recognition of the disorder de-compressive craniotomy followed by 10 treatments oftherapeutic plasma exchange leading to a successful out-come with full reversal of presenting neurologic deficitsIn another recent study19 2 patients of Filipino descentwere shown to have partial complement factor I defi-ciency and responded successfully to a novel drug ana-kinra an interleukin 1 receptor antagonist Anakinracan serve to control inflammation via complement-mediated effects by reducing interleukin 1b signalingand thus is another possible treatment for AHLE thatshould be explored

AUTHOR CONTRIBUTIONSRick Magun manuscript concept and design performed autopsy analysis

and interpretation of test results constructed and wrote manuscript Chris

P Verschoor performed DNA analysis figure 5 reviewed manuscript

regarding immunologic response Dawn ME Bowdish critical revision of

manuscript for immunologic intellectual content John Provias manuscript

concept and design performed autopsy analysis and interpretation of test

results critical revision of manuscript for intellectual content

STUDY FUNDINGNo targeted funding

DISCLOSUREThe authors have no disclosures Go to Neurologyorgnn for full disclo-

sure forms

Received July 14 2015 Accepted in final form November 3 2015

REFERENCES1 Dos Santos MP Martin J Woulfe J et al Autopsy-proven

acute hemorrhagic leukoencephalitis in an elderly patient

Can J Neurol Sci 20144199ndash102

Figure 5 Autopsy Mycoplasma DNA analysis

DNA was isolated from the right hemisphere of the brain in an area of hemorrhage and nor-mal brain from the autopsy of our patient as well as the right lung PCR test forMycoplasmaDNA is shown above A corresponding 167ndashbase pair (bp) band as seen in the control isnoted in all the right lung fields (upper middle and lower) and diseased brain consistent withamplification of Mycoplasma DNA No band for Mycoplasma DNA was seen in normal areasof the brain The results indicate a recent Mycoplasma pneumoniae infection with braininvasion which ultimately led to Weston Hurst syndrome

6 Neurology Neuroimmunology amp Neuroinflammation

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

BIOPSY RESULTS Brain biopsy on day 2 of theright frontal lobe showed acute cerebritis as shownin figure 3 There is a marked acute inflammatorycell reaction most consistent with an acute infectiousprocess The neutrophil predominance was deter-mined to be consistent with a pyogenic processalthough the Gram stain was negative Silver stainwas also negative for fungus There was no neoplasmgranulomatous inflammation or evidence of vasculi-tis present

AUTOPSY RESULTS A full autopsy was performedwith the brain being removed and formal-fixed in a

routine fashion The brain weight was 1600 g Onexternal examination of the brain there washemorrhagic necrosis and edema noted along theright lateral edge of the frontaltemporalparietal area(figure 2) There was subfalcine herniation andcerebellar tonsillar herniation There was also uncalherniation noted on the right causing Durethemorrhages in the pons which was likely the fatalcomplication Hemorrhagic necrosis was seen in theright hemisphere in multiple sections from frontal totemporal lobes No space-occupying lesion or abscesswas noted Inspection of the vessels showed no evidenceof thrombus or embolic events Inspection of themeninges showed no evidence of infection Inspectionof the right hippocampus showed minute darkhemorrhages in the posterior portion reflecting uncalcontusion

Microscopic examination There were multiple areas ofperivascular ring-like hemorrhages with surroundinginflammation of both acute (neutrophils) butpredominantly a chronic macrophage reaction(figure 3) These were seen predominantly in theright and less so in the left orbital frontal areas aswell as the right frontal-parietal specimens Nomicroglial nodules were noted A multicentricfibrinoid necrosis was seen within these vessels withsurrounding edema and hemorrhages noted Theseinvolved predominantly the smaller arteriolar andvenule type vessels No vasculitic changes werepresent Examination of the hippocampuscerebellum and pons showed evidence of terminalhypoxic ischemic encephalopathy with selectiveneuronal necrosis Examination of brainstemshowed areas of Duret hemorrhages in midbrainand pons secondary to brain herniation as well asareas of ring-like hemorrhages and perivascularinflammatory macrophage reaction were noted

Gram and silver stain were performed whichwere negative for bacteria and fungi The trichromestain confirmed fibrinoid necrosis (figure 3) in mul-tiple vessels of the right orbital frontal and rightfrontoparietal areas Staining for ferritin confirmedthe presence of macrophages surrounding ring-likehemorrhages Staining for HSV-1 and HSV-2 wasnegative

Immunohistochemistry for myelin basic proteinshowed areas of reduced staining in a perivascular distri-bution throughout the white matter (figure 4) The Ufibers were spared There was perivascular edema notedas well as axonal damage Immunohistochemistry forIgG and IgM showed a perivascular pattern consistentwith autoimmune inflammatory reaction or ldquoleakyrdquo ves-sels CD68 confirmed macrophage infiltration aroundthese vessels T cell markers CD3 and CD8 were neg-ative CD20 a B cell marker was also negative

Figure 3 Initial brain biopsy and autopsy microscopic findings

Initial brain biopsy on day 2 of the right frontal region showed acute cerebritis There was amarked acute inflammatory cell reaction most consistent with an acute infectious processnoted in lower (A) and higher (B) magnification The neutrophil predominance was determinedto be consistent with a pyogenic process although the Gram stain was negative Silver stainwas also negative for fungus There was no neoplasm granulomatous inflammation or vas-culitis present (C D) Hematoxylin amp eosin stain at autopsy showed punctate ring-shapedfoci of perivascular hemorrhage and edema localized to the white matter This was sur-rounded by inflammation with a predominantly macrophage reaction in the right and leftorbital frontal areas as well as right frontal-parietal sections (E F) Trichrome stain confirmedfibrinoid necrosis in multiple vessels in the right orbital frontal and frontal-parietal areasThere was no lymphocytic infiltration and no microglial nodules as seen in vasculitis and viralencephalitis respectively There was no inflammation in the vessel walls Thromboemboliviral cytopathologic effects foreign abscesses and granulomas were not seen

4 Neurology Neuroimmunology amp Neuroinflammation

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

We isolated DNA from formalin-fixed brain andlung tissue (figure 5) PCR test for MycoplasmaDNA was positive in the right lung field and the rightfrontal lobe of the brain (sample taken from the areaof hemorrhage)

DISCUSSION Case reports showing both biopsy andfull autopsy results from the same case of AHLE arerare Seven previous autopsies have been reportedhowever2ndash8 In this case the biopsy and full autopsywere performed within 5 days from presentationwhich revealed a chronological change that has pro-vided clues to the pathophysiology of this rare disor-der There still remain several areas of uncertaintyregarding AHLE This case not only provides moreconcrete evidence that M pneumoniae is a trigger butwe can also learn more about the pathophysiologyincluding why there were differences seen in thebiopsy of the brain vs autopsy at day 5 In additionis this truly a demyelinating disorder

Regarding antigenic infectious causes for AHLEseveral have been identified and in this case we con-firmed M pneumoniae involving the right lung asthe trigger Since it was first reported in 1941 byHurst9 AHLE remains a rare disorder with a poorprognosis and to date Epstein-Barr virus10ndash13

HSV1415 and M pneumoniae3 have been identifiedas causes We reported positive DNA via PCR fromlung and diseased brain for M pneumoniae (figure 5)This is in keeping with the chest x-ray findings

showing atypical pneumonia the autopsy resultsshowing myocarditis and positive cold agglutininstest all in keeping with recent M pneumoniae infec-tion The significance of identifying MycoplasmaDNA via PCR in brain indicates that brain invasionhad occurred This has been previously describedusing immunohistochemistry on autopsy specimensfrom brain tissue in a patient with AHLE3 Threeother previous reports of M pneumoniae triggeringAHLE have been reported which showed positiveserology including both IgG and IgM as well as coldagglutinin positivity1116 however positive serologysimply indicates past exposure and is not specific fora recent infection

In previous studies it is hypothesized that Mpneumoniae triggers a cross-reaction to antigens formyelin to account for the demyelination3410 How-ever there is no direct evidence for this Whether theimmune response is toward M pneumoniae or actualneural antigens also remains unclear Pathologic fea-tures include focal hemorrhages with perivasculardemyelination These findings were seen in boththe right and left hemisphere in our case more soon the right in the large area of hemorrhage as wellas small areas in the pons In areas of vessel wallfibrinoid necrosis there were perivascular areas ofdemyelination and edema noted as shown in figure4 Immunohistochemistry showed lack of staining formyelin basic protein around vessel walls but the pres-ence of neurofilament staining throughout which

Figure 4 Autopsy immunochemistry results

CD68 (A) and ferritin (B) stain showed the presence of scattered microglial cells foamy macrophages and rare hemosiderin-laden macrophages CD4 wasnegative for T cells (C) Other tests performed include staining T cell markers CD3 CD4 CD5 and CD8 as well as B cell marker CD20 (data not shown) all ofwhich were negative These results indicated a primarily macrophage reaction vs lymphocytic Immunohistochemistry for immunoglobulin G (IgG) and IgMshowed a perivascular double ring-like effect consistent with an autoimmune inflammatory reaction or leakage (arrows D) Immunohistochemistry for myelinbasic protein (MBP) showed areas of reduced staining in a perivascular distribution throughout the white matter (E) The U fibers were spared There wasperivascular edema gliosis and mild axonal damage seen on glial fibrillary acidic protein (GFAP) (F) and neurofilament stain (G) Of note neurofilament stainshowed minimal axonal damage in contrast to the MBP stain which was most consistent with demyelination Herpes simplex virus 1 and 2 staining was neg-ative Gram stain and silver stain were also performed which were negative for infection

Neurology Neuroimmunology amp Neuroinflammation 5

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

signified that the axons were relatively intact but somedemyelination had occurred Nevertheless althoughwe have postulated that demyelination had occurredin our case we were not able to determine whetherthere was a separate mechanism causing demyelina-tion or if this was a cross-reaction toM pneumoniae aspreviously proposed3

The core diagnostic feature of AHLE is the fibrin-oid necrosis of vessel walls Although we showedbrain invasion by M pneumoniae a direct infectioncausing an encephalitis by this bacteria wouldunlikely cause fibrinoid necrosis and such vessel walldamage at day 517 This is central to the pathophys-iology of AHLE and the immunologic cascade lead-ing to this terminal event can be postulated to bedivided into 2 phases An initial ldquoMycoplasma phaserdquois predominantly a neutrophil reaction with no fibrin-oid necrosis of the vessel walls as seen on the day 2biopsy result and in a previous study18 This likelyrepresents a direct immunologic reaction to CNSinvasion by Mycoplasma pneumonia This is followedby a quick second phase an ldquoimmune phaserdquo whichis macrophage-predominant leading to degranula-tion cytokine release and ultimately vessel wallnecrosis the fatal response in this disorder Thiswas seen at day 5 at autopsy in this case and of note

was previously reported23 Further evidence for acti-vation of the innate immune system was proposed ina recent report19 that postulated that the complementcascade is involved in the pathogenesis of AHLE Ithas been suggested that deposition of immune com-plexes on vessel walls triggers complement activationand ultimately recruitment of macrophages in thissecond phase Whether this second phase representsa distinct autoimmune phase has been hypothesizedbut to date there is no evidence for immunocomplexdeposition or direct activation of complement in thiscondition This is in contrast to acute disseminatedencephalomyelitis which is a lymphocytic (T cell orhumoral B cell) predominant response that we didnot see in our case

Similar to our case an initial neutrophil responsefollowed by macrophage reactions has been continuallyreported in previous case reports21120 Unfortunatelythe primary neutrophil response with no fibrinoidnecrosis of vessel walls obscured the diagnosis at theday 2 biopsy result and the patient was aggressivelytreated for infection and not an autoimmune reactionon presentation Survivors of this disorder have rarelybeen reported In a previous report18 successful treat-ment involved quick recognition of the disorder de-compressive craniotomy followed by 10 treatments oftherapeutic plasma exchange leading to a successful out-come with full reversal of presenting neurologic deficitsIn another recent study19 2 patients of Filipino descentwere shown to have partial complement factor I defi-ciency and responded successfully to a novel drug ana-kinra an interleukin 1 receptor antagonist Anakinracan serve to control inflammation via complement-mediated effects by reducing interleukin 1b signalingand thus is another possible treatment for AHLE thatshould be explored

AUTHOR CONTRIBUTIONSRick Magun manuscript concept and design performed autopsy analysis

and interpretation of test results constructed and wrote manuscript Chris

P Verschoor performed DNA analysis figure 5 reviewed manuscript

regarding immunologic response Dawn ME Bowdish critical revision of

manuscript for immunologic intellectual content John Provias manuscript

concept and design performed autopsy analysis and interpretation of test

results critical revision of manuscript for intellectual content

STUDY FUNDINGNo targeted funding

DISCLOSUREThe authors have no disclosures Go to Neurologyorgnn for full disclo-

sure forms

Received July 14 2015 Accepted in final form November 3 2015

REFERENCES1 Dos Santos MP Martin J Woulfe J et al Autopsy-proven

acute hemorrhagic leukoencephalitis in an elderly patient

Can J Neurol Sci 20144199ndash102

Figure 5 Autopsy Mycoplasma DNA analysis

DNA was isolated from the right hemisphere of the brain in an area of hemorrhage and nor-mal brain from the autopsy of our patient as well as the right lung PCR test forMycoplasmaDNA is shown above A corresponding 167ndashbase pair (bp) band as seen in the control isnoted in all the right lung fields (upper middle and lower) and diseased brain consistent withamplification of Mycoplasma DNA No band for Mycoplasma DNA was seen in normal areasof the brain The results indicate a recent Mycoplasma pneumoniae infection with braininvasion which ultimately led to Weston Hurst syndrome

6 Neurology Neuroimmunology amp Neuroinflammation

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

We isolated DNA from formalin-fixed brain andlung tissue (figure 5) PCR test for MycoplasmaDNA was positive in the right lung field and the rightfrontal lobe of the brain (sample taken from the areaof hemorrhage)

DISCUSSION Case reports showing both biopsy andfull autopsy results from the same case of AHLE arerare Seven previous autopsies have been reportedhowever2ndash8 In this case the biopsy and full autopsywere performed within 5 days from presentationwhich revealed a chronological change that has pro-vided clues to the pathophysiology of this rare disor-der There still remain several areas of uncertaintyregarding AHLE This case not only provides moreconcrete evidence that M pneumoniae is a trigger butwe can also learn more about the pathophysiologyincluding why there were differences seen in thebiopsy of the brain vs autopsy at day 5 In additionis this truly a demyelinating disorder

Regarding antigenic infectious causes for AHLEseveral have been identified and in this case we con-firmed M pneumoniae involving the right lung asthe trigger Since it was first reported in 1941 byHurst9 AHLE remains a rare disorder with a poorprognosis and to date Epstein-Barr virus10ndash13

HSV1415 and M pneumoniae3 have been identifiedas causes We reported positive DNA via PCR fromlung and diseased brain for M pneumoniae (figure 5)This is in keeping with the chest x-ray findings

showing atypical pneumonia the autopsy resultsshowing myocarditis and positive cold agglutininstest all in keeping with recent M pneumoniae infec-tion The significance of identifying MycoplasmaDNA via PCR in brain indicates that brain invasionhad occurred This has been previously describedusing immunohistochemistry on autopsy specimensfrom brain tissue in a patient with AHLE3 Threeother previous reports of M pneumoniae triggeringAHLE have been reported which showed positiveserology including both IgG and IgM as well as coldagglutinin positivity1116 however positive serologysimply indicates past exposure and is not specific fora recent infection

In previous studies it is hypothesized that Mpneumoniae triggers a cross-reaction to antigens formyelin to account for the demyelination3410 How-ever there is no direct evidence for this Whether theimmune response is toward M pneumoniae or actualneural antigens also remains unclear Pathologic fea-tures include focal hemorrhages with perivasculardemyelination These findings were seen in boththe right and left hemisphere in our case more soon the right in the large area of hemorrhage as wellas small areas in the pons In areas of vessel wallfibrinoid necrosis there were perivascular areas ofdemyelination and edema noted as shown in figure4 Immunohistochemistry showed lack of staining formyelin basic protein around vessel walls but the pres-ence of neurofilament staining throughout which

Figure 4 Autopsy immunochemistry results

CD68 (A) and ferritin (B) stain showed the presence of scattered microglial cells foamy macrophages and rare hemosiderin-laden macrophages CD4 wasnegative for T cells (C) Other tests performed include staining T cell markers CD3 CD4 CD5 and CD8 as well as B cell marker CD20 (data not shown) all ofwhich were negative These results indicated a primarily macrophage reaction vs lymphocytic Immunohistochemistry for immunoglobulin G (IgG) and IgMshowed a perivascular double ring-like effect consistent with an autoimmune inflammatory reaction or leakage (arrows D) Immunohistochemistry for myelinbasic protein (MBP) showed areas of reduced staining in a perivascular distribution throughout the white matter (E) The U fibers were spared There wasperivascular edema gliosis and mild axonal damage seen on glial fibrillary acidic protein (GFAP) (F) and neurofilament stain (G) Of note neurofilament stainshowed minimal axonal damage in contrast to the MBP stain which was most consistent with demyelination Herpes simplex virus 1 and 2 staining was neg-ative Gram stain and silver stain were also performed which were negative for infection

Neurology Neuroimmunology amp Neuroinflammation 5

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

signified that the axons were relatively intact but somedemyelination had occurred Nevertheless althoughwe have postulated that demyelination had occurredin our case we were not able to determine whetherthere was a separate mechanism causing demyelina-tion or if this was a cross-reaction toM pneumoniae aspreviously proposed3

The core diagnostic feature of AHLE is the fibrin-oid necrosis of vessel walls Although we showedbrain invasion by M pneumoniae a direct infectioncausing an encephalitis by this bacteria wouldunlikely cause fibrinoid necrosis and such vessel walldamage at day 517 This is central to the pathophys-iology of AHLE and the immunologic cascade lead-ing to this terminal event can be postulated to bedivided into 2 phases An initial ldquoMycoplasma phaserdquois predominantly a neutrophil reaction with no fibrin-oid necrosis of the vessel walls as seen on the day 2biopsy result and in a previous study18 This likelyrepresents a direct immunologic reaction to CNSinvasion by Mycoplasma pneumonia This is followedby a quick second phase an ldquoimmune phaserdquo whichis macrophage-predominant leading to degranula-tion cytokine release and ultimately vessel wallnecrosis the fatal response in this disorder Thiswas seen at day 5 at autopsy in this case and of note

was previously reported23 Further evidence for acti-vation of the innate immune system was proposed ina recent report19 that postulated that the complementcascade is involved in the pathogenesis of AHLE Ithas been suggested that deposition of immune com-plexes on vessel walls triggers complement activationand ultimately recruitment of macrophages in thissecond phase Whether this second phase representsa distinct autoimmune phase has been hypothesizedbut to date there is no evidence for immunocomplexdeposition or direct activation of complement in thiscondition This is in contrast to acute disseminatedencephalomyelitis which is a lymphocytic (T cell orhumoral B cell) predominant response that we didnot see in our case

Similar to our case an initial neutrophil responsefollowed by macrophage reactions has been continuallyreported in previous case reports21120 Unfortunatelythe primary neutrophil response with no fibrinoidnecrosis of vessel walls obscured the diagnosis at theday 2 biopsy result and the patient was aggressivelytreated for infection and not an autoimmune reactionon presentation Survivors of this disorder have rarelybeen reported In a previous report18 successful treat-ment involved quick recognition of the disorder de-compressive craniotomy followed by 10 treatments oftherapeutic plasma exchange leading to a successful out-come with full reversal of presenting neurologic deficitsIn another recent study19 2 patients of Filipino descentwere shown to have partial complement factor I defi-ciency and responded successfully to a novel drug ana-kinra an interleukin 1 receptor antagonist Anakinracan serve to control inflammation via complement-mediated effects by reducing interleukin 1b signalingand thus is another possible treatment for AHLE thatshould be explored

AUTHOR CONTRIBUTIONSRick Magun manuscript concept and design performed autopsy analysis

and interpretation of test results constructed and wrote manuscript Chris

P Verschoor performed DNA analysis figure 5 reviewed manuscript

regarding immunologic response Dawn ME Bowdish critical revision of

manuscript for immunologic intellectual content John Provias manuscript

concept and design performed autopsy analysis and interpretation of test

results critical revision of manuscript for intellectual content

STUDY FUNDINGNo targeted funding

DISCLOSUREThe authors have no disclosures Go to Neurologyorgnn for full disclo-

sure forms

Received July 14 2015 Accepted in final form November 3 2015

REFERENCES1 Dos Santos MP Martin J Woulfe J et al Autopsy-proven

acute hemorrhagic leukoencephalitis in an elderly patient

Can J Neurol Sci 20144199ndash102

Figure 5 Autopsy Mycoplasma DNA analysis

DNA was isolated from the right hemisphere of the brain in an area of hemorrhage and nor-mal brain from the autopsy of our patient as well as the right lung PCR test forMycoplasmaDNA is shown above A corresponding 167ndashbase pair (bp) band as seen in the control isnoted in all the right lung fields (upper middle and lower) and diseased brain consistent withamplification of Mycoplasma DNA No band for Mycoplasma DNA was seen in normal areasof the brain The results indicate a recent Mycoplasma pneumoniae infection with braininvasion which ultimately led to Weston Hurst syndrome

6 Neurology Neuroimmunology amp Neuroinflammation

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

signified that the axons were relatively intact but somedemyelination had occurred Nevertheless althoughwe have postulated that demyelination had occurredin our case we were not able to determine whetherthere was a separate mechanism causing demyelina-tion or if this was a cross-reaction toM pneumoniae aspreviously proposed3

The core diagnostic feature of AHLE is the fibrin-oid necrosis of vessel walls Although we showedbrain invasion by M pneumoniae a direct infectioncausing an encephalitis by this bacteria wouldunlikely cause fibrinoid necrosis and such vessel walldamage at day 517 This is central to the pathophys-iology of AHLE and the immunologic cascade lead-ing to this terminal event can be postulated to bedivided into 2 phases An initial ldquoMycoplasma phaserdquois predominantly a neutrophil reaction with no fibrin-oid necrosis of the vessel walls as seen on the day 2biopsy result and in a previous study18 This likelyrepresents a direct immunologic reaction to CNSinvasion by Mycoplasma pneumonia This is followedby a quick second phase an ldquoimmune phaserdquo whichis macrophage-predominant leading to degranula-tion cytokine release and ultimately vessel wallnecrosis the fatal response in this disorder Thiswas seen at day 5 at autopsy in this case and of note

was previously reported23 Further evidence for acti-vation of the innate immune system was proposed ina recent report19 that postulated that the complementcascade is involved in the pathogenesis of AHLE Ithas been suggested that deposition of immune com-plexes on vessel walls triggers complement activationand ultimately recruitment of macrophages in thissecond phase Whether this second phase representsa distinct autoimmune phase has been hypothesizedbut to date there is no evidence for immunocomplexdeposition or direct activation of complement in thiscondition This is in contrast to acute disseminatedencephalomyelitis which is a lymphocytic (T cell orhumoral B cell) predominant response that we didnot see in our case

Similar to our case an initial neutrophil responsefollowed by macrophage reactions has been continuallyreported in previous case reports21120 Unfortunatelythe primary neutrophil response with no fibrinoidnecrosis of vessel walls obscured the diagnosis at theday 2 biopsy result and the patient was aggressivelytreated for infection and not an autoimmune reactionon presentation Survivors of this disorder have rarelybeen reported In a previous report18 successful treat-ment involved quick recognition of the disorder de-compressive craniotomy followed by 10 treatments oftherapeutic plasma exchange leading to a successful out-come with full reversal of presenting neurologic deficitsIn another recent study19 2 patients of Filipino descentwere shown to have partial complement factor I defi-ciency and responded successfully to a novel drug ana-kinra an interleukin 1 receptor antagonist Anakinracan serve to control inflammation via complement-mediated effects by reducing interleukin 1b signalingand thus is another possible treatment for AHLE thatshould be explored

AUTHOR CONTRIBUTIONSRick Magun manuscript concept and design performed autopsy analysis

and interpretation of test results constructed and wrote manuscript Chris

P Verschoor performed DNA analysis figure 5 reviewed manuscript

regarding immunologic response Dawn ME Bowdish critical revision of

manuscript for immunologic intellectual content John Provias manuscript

concept and design performed autopsy analysis and interpretation of test

results critical revision of manuscript for intellectual content

STUDY FUNDINGNo targeted funding

DISCLOSUREThe authors have no disclosures Go to Neurologyorgnn for full disclo-

sure forms

Received July 14 2015 Accepted in final form November 3 2015

REFERENCES1 Dos Santos MP Martin J Woulfe J et al Autopsy-proven

acute hemorrhagic leukoencephalitis in an elderly patient

Can J Neurol Sci 20144199ndash102

Figure 5 Autopsy Mycoplasma DNA analysis

DNA was isolated from the right hemisphere of the brain in an area of hemorrhage and nor-mal brain from the autopsy of our patient as well as the right lung PCR test forMycoplasmaDNA is shown above A corresponding 167ndashbase pair (bp) band as seen in the control isnoted in all the right lung fields (upper middle and lower) and diseased brain consistent withamplification of Mycoplasma DNA No band for Mycoplasma DNA was seen in normal areasof the brain The results indicate a recent Mycoplasma pneumoniae infection with braininvasion which ultimately led to Weston Hurst syndrome

6 Neurology Neuroimmunology amp Neuroinflammation

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

2 Gillies CG Grunnet M Hamilton CW Tubular inclu-

sions in macrophages in the brain of a patient with acute

hemorrhagic leukoencephalitis (Weston Hurst syndrome)

Ultrastruct Pathol 19941819ndash22

3 Stamm B Moschopulos M Hungerbuehler H et al

Neuroinvasion by Mycoplasma pneumoniae in acute dissem-

inated encephalomyelitis Emerg Infect Dis 200814641ndash643

4 Donnet A Dufour H Gambarelli D et al Acute Weston

Hurst necrotizing hemorrhagic leukoencephalitis Rev

Neurol 1996152748ndash751

5 Tshibanda L Nchimi A Otte M et al Hurst acute hae-

morrhagic leukoencephalitis MRI findings [in French]

JBR-BTR 200790290ndash293

6 Lann MA Lovell MA Kleinschmidt-DeMasters BK et al

Acute hemorrhagic leukoencephalitis a critical entity for

forensic pathologists to recognize Am J Forensic Med

Pathol 2010317ndash11

7 Abou Zeid NE Burns JD Wijdicks EF et al Atypical

acute hemorrhagic leukoencephalitis (Hurstrsquos disease) pre-

senting with focal hemorrhagic brainstem lesion Neuro-

crit Care 20101295ndash97

8 Pinto PS Taipa R Moreira B et al Acute hemorrhagic

leukoencephalitis with severe brainstem and spinal cord

involvement MRI features with neuropathological confir-

mation J Magn Reson Imaging 201133957ndash961

9 Hurst EW Acute hemorrhagic leukoencephalitis a previ-

ously undefined entity Med J Aust 194111ndash6

10 Hofer M Weber A Haffner K et al Acute hemorrhagic

leukencephalitis (Hurstrsquos disease) linked to Epstein-Barr

virus infection Acta Neuropathol 2005109226ndash230

11 Francisci D Sensini A Fratini D et al Acute fatal necro-

tizing hemorrhagic encephalitis caused by Epstein-Barr

virus in a young adult immunocompetent man

J Neurovirol 200410414ndash417

12 Befort P Gaillard N Roubille C et al Hemorrhagic leu-

koencephalitis linked to Epstein-Barr virus in an adult

patient Clin Neurol Neurosurg 2010112829ndash831

13 Takeuchi S Takasato Y Masaoka H et al Hemorrhagic

encephalitis associated with Epstein-Barr virus infection

J Clin Neurosci 201017153ndash154

14 SF An Groves M Martinian L et al Detection of infec-

tious agents in brain of patients with acute hemorrhagic

leukoencephalitis J Neurovirol 20028439ndash446

15 Martins HM Teixeira AL Jr Lana-Peixoto MA et al

Acute hemorrhagic leukoencephalitis mimicking herpes

simplex encephalitis case report Arq Neuropsiquiatr

200462139ndash143

16 Catalan M Naccarato M Grandi FC et al Acute hem-

orrhagic leukoencephalitis with atypical features Neurol

Sci 20093055ndash57

17 Payne ET Rutka JT Ho TK et al Treatment leading to

dramatic recovery in acute hemorrhagic leukoencephalitis

J Child Neurol 200722109ndash113

18 Ryan LJ Bowman R Zantek ND et al Use of therapeutic

plasma exchange in the management of acute hemorrhagic

leukoencephalitis a case report and review of the literature

Transfusion 200747981ndash986

19 Broderick L Gandhi C Mueller JL et al Mutations of

complement factor I and potential mechanisms of neuro-

inflammation in acute hemorrhagic leukoencephalitis

J Clin Immunol 201333162ndash171

20 Bitnun A Richardson SE Mycoplasma pneumoniae inno-

cent bystander or a true cause of central nervous system

disease Curr Infect Dis Rep 201012282ndash290

Neurology Neuroimmunology amp Neuroinflammation 7

ordf 2016 American Academy of Neurology Unauthorized reproduction of this article is prohibited

DOI 101212NXI000000000000018720163 Neurol Neuroimmunol Neuroinflamm

Rick Magun Chris P Verschoor Dawn ME Bowdish et al a trigger for Weston Hurst syndromeMycoplasma pneumoniae

This information is current as of January 21 2016

2016 American Academy of Neurology All rights reserved Online ISSN 2332-7812Published since April 2014 it is an open-access online-only continuous publication journal Copyright copy

is an official journal of the American Academy of NeurologyNeurol Neuroimmunol Neuroinflamm

ServicesUpdated Information amp

httpnnneurologyorgcontent31e187fullhtmlincluding high resolution figures can be found at

References httpnnneurologyorgcontent31e187fullhtmlref-list-1

This article cites 20 articles 0 of which you can access for free at

Citations httpnnneurologyorgcontent31e187fullhtmlotherarticles

This article has been cited by 1 HighWire-hosted articles

Subspecialty Collections

httpnnneurologyorgcgicollectionencephalitisEncephalitis

httpnnneurologyorgcgicollectioncritical_careCritical care

httpnnneurologyorgcgicollectionbacterial_infectionsBacterial infections

httpnnneurologyorgcgicollectionautoimmune_diseasesAutoimmune diseases

myelitishttpnnneurologyorgcgicollectionacute_disseminated_encephaloAcute disseminated encephalomyelitisfollowing collection(s) This article along with others on similar topics appears in the

Permissions amp Licensing

httpnnneurologyorgmiscaboutxhtmlpermissionsits entirety can be found online atInformation about reproducing this article in parts (figurestables) or in

Reprints

httpnnneurologyorgmiscaddirxhtmlreprintsusInformation about ordering reprints can be found online

2016 American Academy of Neurology All rights reserved Online ISSN 2332-7812Published since April 2014 it is an open-access online-only continuous publication journal Copyright copy

is an official journal of the American Academy of NeurologyNeurol Neuroimmunol Neuroinflamm

DOI 101212NXI000000000000018720163 Neurol Neuroimmunol Neuroinflamm

Rick Magun Chris P Verschoor Dawn ME Bowdish et al a trigger for Weston Hurst syndromeMycoplasma pneumoniae

This information is current as of January 21 2016

2016 American Academy of Neurology All rights reserved Online ISSN 2332-7812Published since April 2014 it is an open-access online-only continuous publication journal Copyright copy

is an official journal of the American Academy of NeurologyNeurol Neuroimmunol Neuroinflamm

ServicesUpdated Information amp

httpnnneurologyorgcontent31e187fullhtmlincluding high resolution figures can be found at

References httpnnneurologyorgcontent31e187fullhtmlref-list-1

This article cites 20 articles 0 of which you can access for free at

Citations httpnnneurologyorgcontent31e187fullhtmlotherarticles

This article has been cited by 1 HighWire-hosted articles

Subspecialty Collections

httpnnneurologyorgcgicollectionencephalitisEncephalitis

httpnnneurologyorgcgicollectioncritical_careCritical care

httpnnneurologyorgcgicollectionbacterial_infectionsBacterial infections

httpnnneurologyorgcgicollectionautoimmune_diseasesAutoimmune diseases

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is an official journal of the American Academy of NeurologyNeurol Neuroimmunol Neuroinflamm