syringobulbia: a surgical appraisal

12ournal of Neurology, Neurosurgery, and Psychiatry 1992;55: 1132-1141

Syringobulbia: a surgical appraisal

David Morgan, Bernard Williams

AbstractSyringobulbia is a term which has beenclinically applied to brain stem symptomsor signs in patients with syringomyelia.Syringobulbia clefts are found on inves-tigation or at necropsy caused by cuttingoutwards of the CSF under pressure fromthe fourth ventricle into the medulla.These should be differentiated from theascending syringobulbia which may occurfrom upward impulsive fluid movementsin a previously established syringomyelia.Clinical analysis of 54 patients suggeststhat bulbar features are most often foundwith neither of the above mechanisms butare due to the effects of pressure differ-ences acting downward upon the hind-brain with consequent distortion of thecerebellum and brainstem, traction oncranial nerves or indentation ofthe brain-stem by vascular loops. The commonestsymptoms in the 54 patients were head-ache (35), vertigo (27), dysphonia or dys-arthria (21), trigeminal paraesthesiae(27), dysphagia (24), diplopia (16), tinni-tus (11), palatal palsy (11) and hypo-glossal involvement (11). Carefulattention to hydrocephalus is advisablebefore craniovertebral surgery, but thedecompression of the hindbrain and thecorrection of craniospinal pressure dis-sociation remains the mainstay ofsurgicaltreatment. The results of careful surgeryare good, 45 of the 54 cases reportedimprovement. Most of the reported dete-rioration occurred in a few patients whodid conspicuously badly.

(3 Neurol Neurosurg Psychiatry 1992;55:1132-1141)

Material and methodsFifty four patients were selected because - ofhindbrain problems. Tumour cases have beenexcluded. All cases had clinical involvement ofthe brain stem and had craniovertebral decom-pression (CVD) between 1962-88. Hindbrainhernia headache has not been used on its ownas a selection criterion neither has syncope nornystagmus. There were 34 females and 20males. Forty four patients were available forreview. Of the remainder, two had died ofunrelated causes and 8 were untraceable orlived an excessive distance away. The age atdiagnosis for females was 10-58, a mean of37-3, and males 18-61, a mean of 44. Thesymptoms often started many years beforediagnosis. The mean follow up period from theoriginal operation was 14-2 years, range 3-39.Thirty four patients had either radiological orclinical evidence of syringomyelia, 20 cases hadhindbrain features without syringomnyelia.

Skull radiographs show basilar impression in26 cases and CT scanning and myelography orMRI showed that 46 had tonsillar descent, 28had a demonstrable syrinx in the spine. Twodid not undergo CT scanning, myelography orMRI.

All patients had CVD. The techniqueincluded a small craniectomy decompressingthe tonsils usually by removing the arachnoidand often by sucking away part of the tissue ofthe tonsils, and always stitching the dura backand leaving it widely open. Five patients hadventriculo-atrial shunting (VEA) followingpostoperative deterioration, one of these had asyringopleural shunt at the time of the CVDand two had late syringopleural shunting.At review each patient completed a ques-

tionnaire and had a neurological and otolar-yngological (ENT) examination.

Department ofOtorhinolaryngology,East BirminghamHospital,Birmingham, UKD MorganMidland Centre forNeurosurgery andNeurology, Holly Lane,Smethwick, WestMidlands B67 7JX, UKB WilliamsCorrespondence to:Mr Bernard WilliamsReceived 2 January 1991and in final revised form 13January 1992Accepted 17 January 1992

It is not uncommon for patients with syr-ingomyelia or hindbrain herniation, to havedysfunction of the lower cranial nerve andbrainstem. Such symptoms are often ascribedto "syringobulbia". Syringobulbia, however, isan uncommon lesion of the central nervoussystem; it may be defined as a pathologicalcavitation in the brain stem. There are severalpossibilities for the pathology and little agree-ment about what syringobulbia is.We have reviewed patients with bulbar

symptoms encountered in a neurosurgicalpractice expressing an interest in hindbrainherniation. The patients with adequate followup have been selected from a database ofpatients with syringomyelia and related dis-orders.

CLINICAL FEATURESOccipital headachesOccipital headache was the commonest pre-senting symptom and occurred in 35 patients.In seven patients the headache persisted post-operatively, but was less. The headache wasmost characteristically a pounding pain usuallyposterior and bilateral, sometimes ascending tothe vertex or present mostly unilaterally or inthe neck. Typically this beat in time with thepulse, coming on two or three seconds after astrain, rising to a crescendo after a few moreseconds and then dying away within half aminute. This is the "hindbrain hernia head-ache" stressed byWilliams.`3 It may be testedfor in the clinic by asking the patient to blowinto a mouthpiece attached to a sphygmoman-

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ometer to a pressure of 50 mm Hg or so for fiveseconds and then suddenly relaxing. Observa-tion of the patient usually makes the diagnosisbut the patient may be asked to draw a graph ofthe pain.

VertigoTwenty seven subjects complained of inter-mittent vertigo. Ten patients were symptomfree postoperatively, while the vertigo persistedin 9. In 2 cases, 1 and 2, persistent vertigooccurred postoperatively which was relievedfollowing ventriculo-atrial shunting.

Voice disturbanceTwenty one patients had voice disturbance,either dysphonia due to cord palsy or in 5 ofthem, slurring of speech. Ten patients hadconfirmed vocal cord palsies. 1 of which was abilateral abductor palsy and presented withstridor. Four unilateral and 1 bilateral recov-ered following operation. Only in 7 cases didthe voice disturbance persist following CVD.However, 2 patients developed a cord palsyimmediately postoperatively. Following ven-triculo-atrial shunting the cord palsy com-pletely recovered in one and in the other thesymptoms resolved, although the cordremained immobile. Another patient devel-oped a vocal cord palsy some years afteroperation.

ParaesthesiaeOf 27 patients with disordered trigeminalsensation, 1 of which was bilateral, 18 showeda complete resolution. In 8 the numbnesspersisted at least partially and in only 1 of thesewas there deterioration in symptoms. Only 1case had trigeminal pain associated with para-esthesiae, this was the presenting symptom andwas severe. This woman was completely curedby CVD, at which a loop of artery was foundfirmly pressed into the side of the medulla andwas lifted out.

DysphagiaTwenty four patients had pre-operative dys-phagia, some had palatal regurgitation. In 18cases the dysphagia resolved postoperatively.In most of the others there was some improve-ment but in one there was no change. Fourpatients developed postoperative dysphagia, 1recovered following ventriculo-atrial shunting.One patient had cricopharyngeal myotomywith improvement.

TinnitusEleven patients complained of tinnitus, 5bilateral and 6 unilateral. Two patients withunilateral tinnitus became worse postoper-atively. Out of the patients with bilateraltinnitus, 4 showed complete resolution whileone persisted. Only one patient complained ofpersistent postoperative tinnitus, others saidthat it was present but unobtrusive.

Hearing difficultyOf 9 patients complaining of hearing difficulty,all but one improved postoperatively; only onedeveloped unilateral impairment postopera-tively.

NystagmusTwenty six patients were noted to have nys-tagmus pre-operatively. Thirteen had rotatorynystagmus, which improved after CVD innine, with marked amelioration of ocillopsia ordizziness in those who had symptoms. In onlyone case did severe rotatory nystagmus resolvepostoperatively. Four patients developed nys-tagmus postoperatively, three of whom com-plained of ocillopsia, possibly contributing todifficulty in walking. Ocillopsia improved afterVEA shunting in two of these and in none didit remain prominent.

PtosisOf 11 patients with ptosis in 5 it appeared to bedue to a partial unilateral Horner's syndromeand in one a bilateral Horner's syndrome. In 2cases unilateral Horner's syndrome persistedas did one with unilateral ptosis. Completerecovery occurred in 8 cases. A postoperativeunilateral Horner's syndrome developed in onewhich resolved following VEA.

DiplopiaSixteen patients complained of diplopia appar-ently due to abducent nerve palsies. 4 persistedpostoperatively. In one of these, case 2, theparalysis was considerably worse after CVDand subsequent hydrocephalus but improvedafter VEA, although it remained a subjectiveproblem. In 1 patient Myodil (Pantopaque)which had been used in the myelogram couldbe seen in the cavity of the syrinx in theimmediate the post-myelogram period. Laterradiographs showed that some of the contrastmaterial was in the pons. This indicated thatfluid had ascended from the cervical syrinx andthe sixth nerve palsy may have been due tonuclear involvement.

Facial NerveFive patients had a pre-operative lower motorneuron (LMN) palsy of the facial muscles and1 patient an upper motor neuron palsy. One ofthe patients with LMN features had a historyof 6 episodes of facial palsy before the diag-nosis was made. All but 1 LMN palsy recov-ered postoperatively. One patient had an acuteherpes zoster of the left facial nerve a few daysafter discharge from hospital with temporarycomplete paralysis.

Palatal palsyEleven patients had a unilateral and 2 abilateral palatal palsy associated with an absentgag reflex and analgesia of the palate. Sixcompletely recovered including one with bilat-eral palsy and in the other bilateral case therewas improvement in one side only, includingrestoration of the gag reflex.One patient developed persistent palatal

analgesia and an absent gag reflex immediatelypostoperatively, which resolved after VEA.

Accessory nerve palsyOnly 1 patient had a unilateral accessory nervepalsy, which recovered postoperatively.

Hypoglossal PalsyEight patients had pre-operative unilateral

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Figure 1 Preoperation MRI scans ofpatient EM T2 weighted image (TE500, TR20)suggests flow void in the fourth ventricle indicating the energetic nature ofpulsation.

Figure 2 Transverse MRI scan through the fourth ventricle ofpatient EM. T2 weightedto show flow void. This was taken at the same time as 3 & 4, after operation, at a timewhen hydrocephalus had advanced.

hypoglossal palsy, and 1 bilateral palsy. Twounilateral persisted postoperatively and 3patients developed unilateral persistent hypo-glossal palsy postoperatively.

SUBJECTIVE IMPROVEMENTSPatients were asked to grade their clinicalcourse postoperatively between "greatimprovement, some improvement, unchangedand worse". Great improvement was claimedby 31 patients, 14 reported some improve-ment, 5 were unchanged and 4 said they wereworse. The subjective views correlated wellwith objective findings.

POSTOPERATIVE DETERIORATIONFive patients deteriorated considerably imme-diately postoperatively, at least two of themdue to mismanagement, and they warrantfurther discussion. Most of the deterioration inthe individual features described above occur-red in these cases.

Case 1A 34 year old female presented with syr-ingomyelia and hoarseness due to a left cordpalsy. She had marked basilar impression andarachnoiditis at the foramen magnum. AfterCVD combined with syringopleural drainagethe patient was well for 6 days but then becamesuddenly worse. She became hoarse and devel-oped total dysphagia. Her gait became con-siderably worse and she tended to fall overbackwards and could not sit up on her own.She had severe nystagmus and ocillopsia.There was acute urinary retention. Combinedventricular and intraspinal pressure studiesshowed that she had impacted her hindbrainmore severely then pre-operatively. This resultwas probably contributed to because the syr-ingopleural shunt which had been used wasover draining the spinal compartment, prob-ably including the spinal subarachnoid space.Hydrocephalus was present. The syringo-pleural drain was therefore removed and aTorkildsen's shunt from lateral ventricle to theupper spinal subarachnoid space was per-formed which resulted in slow improvement,eventually complete recovery of her dysphagia,ocillopsia and urinary retention. The voicerecovered only to its original state with persist-ence of the original cord palsy and some ataxia.Over subsequent years she has progressivelydeteriorated to become quadriplegic.

Case 2This was a 40 year old woman who hadsuffered since the age of 19. She had headache,vertigo, diplopia, gait disturbance, dysphagia,dysphonia, and impaired mobility andhypoaesthesia of the hands. On examinationshe had weakness of abduction of both eyes,rotatory nystagmus and spasticity of all limbs.Investigation showed a basilar impression,hindbrain herniation but no syringomyelia orhydrocephalus. After CVD the patient was wellfor a few hours and then had a catastrophicdecline. The CT scan showed a small haemor-rhage at the site of the tonsillar removal and asizeable haemorrhage around the front of thecorpus callosum. She required tracheostomyand respiratory support and seemed likely todie.The cause of the cerebral haemorrhages was

unclear, it may have been related to platelet

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Figure 3 Sagittal MRI scans (TE500, TR20) and adjacent to the midline to show theexcavation of the floor of the fourth ventricle by clefts arising as a result of thecombination of raised intraventricular presuure and probably low intraspinal pressure.

abnormalities. Angiography was negative. Shedid not have severe hydrocephalus at the timeofher discharge back to another hospital whereshe convalesced for several weeks. Her gradualrecovery was marred by the development of ahydrocephalus which was not acted upon for afurther nine months. She did not activelydeteriorate during this phase of the illness, buther recovery must have been delayed. BeforeVEA shunting she had total failure of abduc-tion of both eyes, and all the symptoms withwhich she had presented were worse. The MRIscans showed a severe hydrocephalus with flowvoid in the third and the centre of the fourth,indicating marked pulsatile movement (fig 1 &2). The fourth was particularly dilated andshowed clefts in the sites normally associatedwith syringobulbia (fig 3 & 4). After VEA thepatient's symptoms were all improved, but shedid not recover to be better than before theCVD.

Case 3A 68 year old woman complained of vertigoand had an ataxic gait with signs consistentwith a syringomyelia. Investigations showedhydrocephalus and hindbrain herniation withsome arachnoiditis. After CVD, she developedpersistent vertigo, tinnitus, horizontal nys-tagmus, dysphasia, left vocal cord palsy, absentgag reflex, palatal palsy and unilateral hypo-glossal palsy. She had severe ataxia and was

wheelchair bound thereafter. She refused fur-ther investigation or operation. It seems likelythat hydrocephalus could have been shuntedwith good effect.

Case 4A 38 year old woman, presented with occipitalheadache, nystagmus, facial numbness, tinni-tus, giddiness, Horner's syndrome, dissociatedsensory and tendon reflex loss and a Charcot'sjoint at the right shoulder. Investigationsshowed bilateral tonsillar descent with noarachnoiditis. Postoperatively she developedvertigo and a left sided Horner's syndrome, hersyringomyelic signs and symptoms becameworse. After initial but partial recovery shegradually deteriorated over many years. Re-investigation showed no hydrocephalus butthere was a sizeable syrinx. A syringopleuralshunt was performed 10 years later which ledto the disappearance of the vertigo, tinnitusand Horner's syndrome and improvement ingait, although fine horizontal nystagmus per-sisted.

Case SA man aged 32 years, presented with stridordue to bilateral vocal cord abductor palsies inassociation with occipital headaches, tinnitus,dysphagia and rotational vertigo. He had basi-lar impression, assimilation of the atlas into theskull and congenital fusion of 3 cervical verte-brae with impression of the front of thebrainstem by the odontoid peg (fig 5). AfterCVD he was acutely ill with a spastic triplegia,and was slow to recover consciousness, therewas slight improvement in the bilateral vocalcord palsy eventually, but the patient haddeveloped a bilateral hypoglossal palsy. Somespastic weakness persisted affecting the leftfoot severely. The right side of the tongueimproved. Postoperative investigation showeda right anterior cerebral artery area infarctionand deformation changes in the stem. Thecause of this infarction is obscure. An anteriorapproach might have given a better result butthis does not seem probable.

DiscussionThe ideas expressed about syringobulbia in theliterature are often obscure. Syringobulbia wasreviewed by Jonesco Sisesti in 1932 and thiswork has been republished.4 He restricted hisaccount to syringobulbia clefts and describedsuch "syringobulbia" as normally associatedwith syringomyelia. Syringobulbia in isolationhas been described.5-7There is a long established tradition for

regarding syringobulbia as a "developmental"lesion with the inference that it may be relatedto dysraphism. This attitude was taken bypathologists working in an era before modernimaging and surgery. More recently a hydro-dynamic approach has proved helpful inunderstanding and managing syringomyelia,syringobulbia and related diseases. Never-theless, perusal of the literature often reveals

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Figure 4 Sequential MRIscans (TE500, TR20)through the mid-fourthventricle a), through thelower part of the fourthventricle to show theforamina of Luschka at b).Bigfissures in the usualsite for fourth ventricularclefts are shown on eachside of c). Extension welldown into the medulla isseen on d). Note thesimilarity of the clefts tothose shown in figure 6.These clefts are widelyopened, unlike those in thehistological section.

-uImImmc

findings that are difficult to explain on hydro-dynamic grounds8 and odd syrinx cavitiesoccasionally occur with no blockage of theCSF pathways to suggest an hydrodynamiccause. Some of these cases, however, areassociated with dysraphic features. The major-ity of cases seen in clinical practice have ahydrodynamic component and this will bediscussed.

Pathologists, surgeons and other cliniciansdiffer in their concepts of syringobulbia. Path-ologists concentrate on clefts running out ofthe fourth ventricle (as in fig 6). The lines of

structural weakness coincide with develop-mental planes and this has sometimes seemedto support the "developmental" school. It isproposed to call such fissures "syringobulbiaclefts".

Surgeons are often more impressed by cav-ities running upwards from syrinx cavities inthe cord (as in fig 7). These cavities may befound under the floor of the fourth ventricleand are readily displayed by MRI techniques.The fluid filling the syrinx in such cases may benot only CSF or fluid indistinguishable fromCSF, but also sometimes proteinaceous fluid

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Figure 5 CT scans afterwater soluble intrathecalcontrast. Note theencroachment upon theforamen magnum by themalformed odontoid pegshown on the reformattedpictures (a). Angulation ofthe medullocervicaljunction was marked inthis case but the impactionof the tonsils was thoughtto justify a posteriorapproach. The axial cutsb) appear to show theprimacy of the hindbrainin deforming the medulla.note the deformity of theleft side of the medulla andthe proximity of thevertebral artery.

E}

Figure 6 Histological section at the level of the hypoglossal and trigeminal nw

illustrate the traditional sites of clefts from the fourth ventricle. Note the destruc

trigeminal nerve nucleus on the right of the picture and the way that the seepaAreaches to the subarachnoid space.In another section there was a communicatiosite.

from tumours. To differentiate them fromsyringobulbia clefts it is proposed to callcavities of this kind "ascending syringobulbia".It is possible to find combination of syr-ongobulbic clefts and ascending syringomyeliawith communication between the cavities as infig 8.Many clinicians, particularly before modern

imaging, used the term syringobulbia to meanany symptom complex in association withsyringomyelia which suggested bulbar involve-ment. Modern imaging and surgery indicatethat syringobulbic clefts and ascending syr-ingobulbia are less common than bulbarsymptoms.

Pathogenesis of syringobulbiaSyringomyelia is not a disease, but is a condi-tion with many possible causes. There are twomain groups of cases, those in which thecausative anomaly is at the foramen magnumlevel and those with a primarily spinal abnor-mality.The cases with partial blockage of the CSF

pathways at the level of the foramen magnumare the commonest and most important group.These may be called "hindbrain related" cases.Lesions at this level produce direct changes inthe medulla, cerebellar tonsils, lower cranialnerves, posterior inferior cerebellar and verte-bral arteries; this leads to difficulties in assess-ing the part played by intramedullary or

I pontine cavities.The commonest lesion at the foramen mag-

num is downward herniation of the tonsils.Although commonly termed the Arnold-Chiarideformity, the non-eponymous term "hind-brain hernia" seems preferable. There is evi-dence that the main mechanism is thegeneration of pressure difference acting down-wards across the foramen magnum, craniospi-nal pressure dissociation, or "suck". Thecramming of hindbrain tissues into the fora-men magnum has many effects. First, itmaintains the morphology of the herniationand its valvular configuration, thus perpetuat-ing the disease process. Second, it producesdownward sliding and compression of thetissues. The dorsal regions of the cord movedown relative to the front of the cord, the planeof weakness across the middle of the cordbeing accentuated by the actions of the dentateligament. One side may slip down more thananother and asymmetries and rotationaldeformities are common.The most probable pathological explanation

for ascending syringomyelia, the cavities occur-ring in the medulla and sometimes extendinginto the pons and beyond, is that upwardmovement of fluid occurs within the syr-ingomyelia and this dissects along the tissueplanes of least resistance, particularly into greymatter. Schliep"' has shown that extension of asyrinxc from the cervical spine into the brainstem may occur. Such extension may be seenon investigation or at operation. Extension

clei to cephalad to the pons has been repor--tion of the ted8 10-12 18'e offlihad The cause of upward movement of fluid

within syringomyelia cavities has been exten-

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Figure 7 Unenhanced Ti weztwelve year old boy with a spinarea seems crowded because ofsymptoms in this case. The opesyringopleural shunt, producedhindbrain.

Morgan, Williams

recovery of well formed glial lined cavities ofsyringobulbic clefts or ascending syringobul-bia.

.s..l l E The clinical featureA natural subdivision of brain stem features

-.\a j l . ,would be cranial nerve dysfunction and effects- -°Jil11e}SSuponthe stem itself. It is unclear, however,

how this applies to complex symptoms such asnystagmus, vertigo and tinnitus.

Nevertheless, cases with correlationsbetween the clinical state and the occurrence

A >_of clefts have been reported.' 46 192023

ightdMIst

ghvedmRIscntosowaCendingth syringobulbia ina

alslpoma a no hudbanc henaton.hes ind rarintexsfzeof the snobulbia Theeweresnobular i

raioqautee botomenof the tetawheredhcor,icuing avgru grsltooftcavityandhidecomdthspression atthefr ' .

sienlflwptaydi SFtscusend.b Williasa-iX.'2 131 Themovecmpesint of CS nthe spinal canal ihn th- :o

rspuons toi sudenachingesyringpbruressioin t

eample,afenhcohinghe . Thep istrains

squeezingof thedyinourba. Whene there isbularszalcravity withitheotmedordthispehreovd,idesdinaprf-tiecmressluion of theduratandthenpesiotheth

phvenomenonusmay be calleda"sloh.fi) Themovements of CFithefludpaybewel seena onradiological studies ndhchanges indrsueiam-h

radiological studies and the changes in diam- . : e_eter of the cavities may be seen on staticradiographs or CT scans. Patients may report .._Isymptoms such as upward advance of pain orsensory loss or neurological features such as Figure 8 Unenhanced Ti weighted MRI scans of adiplopia experienced immediately after a patient with severe syringobulbia of mixed type, a) coronal

14 15 17 18 ...and b) sagittal. There were three cavities incough or sneeze. communication, one outside the fourth ventricle dorsal toBenefits from operation, seem more likely to the tonsils, the next one was the dilated bottom end of the

relate to reversible neurological mechanisms, fourth and the deepest cavity was deep within the medullacommunicating with the main syringomyelia. The tissuessuch as traction upon nerves or compression of were all thin and mobile which may account for thebrain stem in the foramen magnum, than to difficulty in obtaining a clear image.





Figure 9 The phase ofupward movement of theCSF in response to asudden rise in intracoelomicpressure. This gives rise tothe most energetic phase ofthe slosh mechanism andthe impulsive ascendingsurge offluid may cut intothe bulbo-pontine tissues asshown in (a). Note theway in which thehindbrain is lifted off thebone of the foramenmagnum, the subarachnoidspaces are thus opened upto allow free movement ofthe CSF into the head. Thephase of downwardmovement after a rise ofintra-coelomic pressure isshown in (b). The close fitof the hindbrain in thispart of the phenomenonprovides the valvularmechanism and producesthe suck phase of thephenomenon. Thedownward pressure of CSFacross the foramenmagnum in this part of thecycle ofpressure changescauses cramming of thehindbrain into the upperspine, the overfolding of themedulla and traction onlower cranial nerves.

A B

Cranial nerves

Involvement of the third and fourth nerves isuncommon but disordered eye movement canoccur from a lesion of the posterior longitudi-nal fasciculus.23 Twelve of our patients com-

plained of diplopia on lateral gaze. One 1 case

of combined facial and abducent nerve

involvement was seen, despite the relationshipof the seventh nerve fibres to the sixth nucleus.Only 2 had clinical evidence of an abducentpalsy at follow up. The abducent involvement isthought by Schliep to be due to destruction ofits fibres in the pons but involvement of thenucleus seemed likely in one of our cases and itis possible that traction on the nerves resultsfrom the downward movement of the brain-stem.

Trigeminal nerve disorders are commonlyreported but it is likely that the nerve itself israrely directly affected.24 25 In one patient witha vascular loop trigeminal dysfunction was theonly symptom; an uncommon event. In twocases reported by Lapresle and Metreau thepresentation was of trigeminal type.25 Trigemi-nal symptoms probably often originate fromthe spinal sensory nucleus in the upper cervicalcord and the accompanying fibres which formthe descending trigeminal roof. These mayinitially be involved in syringomyelia, wherethe syrinx involves first the fibres representingthe most caudal part of all three divisions, not

necessarily from ascending syringobulbia or asyringobulbia cleft. Extension of the syrinxupwards may cause dissociated sensory loss toprogress in all three divisions, converging uponthe tip of the nose and upper lip, due to thesegmental pattern of facial sensory innerva-tion.Only 4 facial nerve palsies were seen, 3 of

which were of lower motor neuron type. Thesignificance of the relapsing case is unclear.

Deafness is an uncommon finding in syr-ingobulbia according to Schliep,'0 and Barnettet a1f4 do not mention it. Five cases out of six inthe present series improved following opera-tion. Tinnitus was not associated with thedeafness in these patients. Improvement wasreported in 4 out of 6 cases. These symptomsmay be due to traction and angulation of thenerves at the pons or at the porus acousticus.Alternatively the problem may lie in thebrainstem.24 30Vagus dysfunction is common and may

manifest as a breathing disorder4 31 vocal prob-lems6 or swallowing difficulty.20 32 Others havereported improvement after operation.2'The tongue is frequently involved in syr-

ingobulbia, especially in the latter stages of thedisease; inducing atrophy and fascicula-tion. o 22 24 Only 2 out of 6 palsies persistedfollowing CVD.5 It may result from a syr-ingobulbic cleft developing in the plane of




Morgan, Williams

weakness down the middle of the brainstem.Bilateral Horner's syndrome was present in 1patient who had bilateral lower cranial nerveinvolvement. Complete recovery occurred fol-lowing decompression.Nystagmus and ocillopsia are common

accompaniments of hindbrain herniation.33-35Improvement in nystagmus following opera-tion has been reported.'7 27 33-36 Nystagmus inour patients was more common than in someearlier series and improved less often afteroperation. Three patients developed nystagmuspostoperatively. Vertigo commonly improvedafter operation.7 (10 of 15 patients.)

Occipital headache is common in syringo-myelia and syringobulbia26 and responds bestto operation if there is a hindbrain her-

5 27-29nia. Only 4 patients complained of occip-ital headaches at review.

PrognosisSyringobulbia is sometimes rapidly progressiveand may be responsible for death in patientswith syringomyelia.37 The survival of syr-ingobulbic patients varies from 6 years 3236 to27 years404' following the onset of brainstemsigns. Brainstem dysfunction may result inswallowing and respiratory problems whichthreaten life.6 7 10 19 31 38 39 Sudden death isreported due to bleeding into a syringobulbiccleft.39 It seems that syringobulbic clefts aremore dangerous than the ascending syringo-bulbia. Jonesco Sisesti, however, consideredthat syringomyelia clefts are surprisinglybenign.4

It is believed that prognosis is improved byoperation with the objective of deflating hydro-cephalus9 13 21 43 44 and then carefully correct-ing craniospinal pressure dissociation at theforamen magnum.13 24 2728 38 43-45 We recom-mend that operation should include carefulremoval of the arachnoid and sometimes alsoof the tonsils.The dura must not be closed, lestsuck be re-established, and a graft is notnecessary. '3 It is probable that part of thebenefits ofCVD are gained by the "depulsat-ing" provided by a sizeable artificial cisternamagna.

Previous reports of the effect of CVD haveusually concentrated on the syringomyelicsymptoms or those from the hindbrain herniasuch as headache.527 Banerjee and Millar26studied 8 patients with syringobulbia who hadCVD. Six improved but there were no detailsof the pre- or postoperative signs or symptoms.Seaz et a128 studied 60 operations on patientswith Arnold-Chiari deformity, and showedthat 65% improved. Over a longer period manyof the patients with cord or brainstem cavitieshad a further deterioration. Hadj-Djilani andZander36 reported a study of 12 patients for 12years with cervicobulbar syringohydromyelia.They gave a qualitative assessment with fewclinical details.

ConclusionOf our 54 patients with features of bulbarinvolvement, commonly diagnosed as syr-ingobulbia, 45 improved after operation. Dete-

rioration after operation was uncommon; itoccurred immediately postoperatively, but latehydrocephalus developed insidiously. Posteriorfossa decompression improved lower cranialnerve dysfunction associated with syringomye-lia and hindbrain herniation, usually ascribedto syringobulbia. Nevertheless, it remainsunclear to what extent improvement is due tocollapsing of cavities or clefts and the extent towhich it may be attributable to mechanisms,such as, relieving compression and distortionof stem structures or traction upon nerves orvessels.

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2 Williams B. On the pathogenesis of syringomyelia: a review.J R Soc Med 1980;73:798-806.

3 Nightingale S, Williams B. Hindbrain hernia headache.Lancet 1987;1:731-4.

4 Jonesco-Sisesti B. Syringobulbia: a contribution to thepathophysiology of the brainstem (1932). Translation andupdating by Ross RT. New York: Praegear. 1986.

5 Cramer FJ. Surgical treatment of syringobulbia and syr-ingopontia. Arch Neurol Psychiat (Chic). 1946;56:442-53.

6 Duffy PE, Ziter FA. Infantile syringobulbia. Neurology(Minneap) 1964;14:500-9.

7 Kirgis HD, Echols DH. Syringo-encephalomyelia. J Neu-rosurg 1949;6:368-75.

8 Samples JR, Howard FM, Okazaki H. Syringomesencepha-lia. Arch Neurol 1983;40:757-9.

9 West RJ, Williams B. Radiographic studies of the ventriclesin syringomyelia. Neuroradiology 1980;20:5-16.

10 Schliep G. Syringomyelia and syringobulbia. In: Vinken PJ,Bruyn GW, eds. Handbook of clinical neurology, vol 32

11 Okada S, Nakagawa Y, Hirakawa K. Syringomyelia extend-ing to the basal ganglia. J Neurosurg 1989;71:616-7.

12 SpillerWG. Syringomyelia, extending from the sacral regionof the spinal cord through the medulla oblongata, rightside of the pons and right cerebral peduncle to the upperpart of the right internal capsule (Syringobulbia). BMJ1906;2: 1017-22.

13 Williams B. Progress in syringomyelia. Neurol Res1986;8: 139-45.

14 Williams B, Terry AF, Jones HWF, McSweeney T. Syr-ingomyelia as a sequel to traumatic paraplegia. Paraplegia1981 ;19:67-80.

15 Williams B. Post traumatic syringomyelia, an update.Paraplegia 1990;28:296-313.

16 Williams B, Page N. Surgical treatment of syringomyeliawith syringopleural shunting. Br J Neurosurg1987;1:63-80.

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18 Williams B, Timperley WR. Three cases of communicatingsyringomyelia secondary to midbrain gliomas. Jf NeurolNeurosurg Psychiatry 1977;40:80-8.

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22 Seiben RL, Hamida MB, Shulman K. Multiple cranialnerve deficits associated with the Arnold-Chiari malfor-mation. Neurology 1971;21:673-81.

23 Wilson SAK. Syringomyelia; syringobulbia. In: Bruce AN,ed. Neurology, Vol 11, (facsimile of 1940 ed). New York:Hajner, 1970:1389-405.

24 Barnett HJM, Foster JB, Hudgson P. Syringomyelia. Lon-don:Saunders, 1973.

25 Lapresle J, Metreau R. Atteintes trigeminales revelatricesd'une syringomelie et d'une malformation de la charniereoccipito-vertebrale. La Naivelle Presse Medicale1978;7: 103-4.

26 Banerjee NF, Millar JHD. Chiari malformation presentingin adult life-its relationship to syringomyelia. Brain1974;97: 157-68.

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29 Waveren LEAK Van. De misvorming van Arnold-Chiari bijolwassenen (Thesis). University of Utrecht. 1975.

30 Rudge P. Clinical neurotology, in clinical neurology andneurosurgery (monographs vol 4). London: ChurchillLivingstone, 1983.

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33 Cogan DG. Downbeat nystagmus. Arch Ophthalmol 1968;80:757-68.

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The signs of Kernig and Brudzinski

"I have observed for a number of years in cases ofmeningitis a symptom which is apparently rarelyrecognised although it is, in my opinion, of sig-nificant practical value. I am referring to theoccurrence of flexion contractures in the legs oroccasionally also in the arms which become evidentonly after the patient sits up.

Disregarding for a moment the infrequent cases ofacute meningitis without contractures (particularlypurulent secondary meningitis), one may find, as iswell known, in the vast majority of cases oftuberculous and epidemic spinal meningitis theclassic more or less prominent stiffness of the neckand back. Only in some of these patients while theyare lying supine, may contractures of the extremitymuscles be noted ... If one has the patient sit up onthe edge of the bed, his legs dangling... thestiffness of the neck and back will ordinarily becomemuch more severe and only now will a flexioncontracture occur in the knee and occasionally alsoin the elbow joints. If one attempts to extend thepatient's knees one will succeed only to an angle ofapproximately 135°. In cases in which this phenom-enon is very pronounced, the angle may even remainat 900. "

Vladimir Mihailovich Kernig (1840-1917) firstbrought these observations to the medical public at ameeting of physicians in St Petersburg in 1882. On 29December 1884 his work was published.' Born inLepaia, Latvia, Kernig graduated in 1864, receiving adoctorate one year later. He obtained a post at the

Obuhovsk Hospital in St Petersburg, reaching thehighest professional rank and continued his work untilhis retirement in 191 1. Kernig's account followed oneyear after that of the often confused Lasegue's signdescribed in his thesis by Lasegue's pupil J-J Forst in

.21881 .

J6sefBrudzinski (1874-1917) was a Polish paedia-trician. Dean of the University ofWarsaw, he describedseveral signs, but the one known in meningeal irritationwas published in 1909.3

"I have noted a new sign in cases of meningitis:passive flexion of the neck causes the lower extrem-ities to flex at the knees and the pelvis ... Thetechnique of examination is very simple. With thechild in the supine position, the examiner flexes theneck of the child with the left hand while resting hisright hand on the patient's chest to prevent it fromrising. This examination is generally not difficultexcept in the very young who because of restlessnessmay not be able to maintain the lower extremities inextension. In such a case, the examiner shouldgently restrain the legs at the knees. To preventerrors, it is important to do repeated examina-tions."

JMS PEARCE

1 Kernig W. Ueber ein wenig bemerktes Meningitis-Symptom. Berlin Klin Wschr 1884;21:829-32.

2 Pearce JMS. J Neurol Neurosurg Psychiatry 1988;51:1157.

3 Brudzinski J. Un signe nouveau sur les membresinferieurs dans les meningites chez les enfants (signede la nuque). Arch med Enf 1909;12:745-52.




Syringobulbia: a surgical appraisal.

D Morgan and B Williams

doi: 10.1136/jnnp.55.12.11321992 55: 1132-1141 J Neurol Neurosurg Psychiatry

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syringobulbia: a surgical appraisal

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