Primary Care Conference

May 25, 2005Becky Byers MDGuest patient Charlie Byers PhD

ENCEPHALITIS: An Inside Account

Physician/Spouse

Professor/Patient

Clinical Case

Patient is now a 58 year old professor. He had had a viral syndrome for approximately one week, then on 3/6/03 felt feverish and chilled; helped kids with homework, then went to bed early.

Awoke 3/7/03 with mental status changes including confusion and inability to answer questions appropriately.

Past Medical History

Asthma, chronic; well-controlled on Advair 100/50 BID, albuterol prn (seldom needed).

Dyslipidemia (baseline HDL 18); on statin and Niaspan.

Non-smoker.

No hypertension, DM.

ER and Stroke Team

Normal enhanced head CT without acute bleed.

IV Heparin.

Normal head MRI without evidence of acute stroke or perfusion abnormality.

Normal MRA of the neck without evidence of focal stenosis.

EEG - abnormal, but non-diagnostic.

Lumbar Puncture

Nucleated cells 7, 82% lymphocytes, 18% macrophages. No RBCs.Protein 70 (15-45)Glucose 68 (40-80)Gram stain - negative.Admitted to Neuro ICU with probable viral encephalitis.

Neuro ICU

Empiric IV ceftriaxone and ampicillin.Empiric IV acyclovir.ID Consult - recommended stopping antibiotics; continue acyclovir 10 mg/kg Q 8 hours. Send CSF for viral culture, HSV PCR, Enteroviruses, LCM, Mycoplasma, AFB/ fungal culture and smear.

Serology for coccidioidomycosis, HIV ELISA, serum cryptococcal antigen, Mycoplasma serology, Enterovirus, and LCM serology.

CXR.

Consider repeat CSF if not improving over next 24 hours.

Objectives

Brief review of causes of encephalitis.

Patient perspective of the illness and the recovery process.

Living with uncertainty; the power/anxiety of knowing/not knowing “the cause”.

Encephalitis

Infection involving brain parenchyma, characterized by cognitive deficits.20,000 annual viral cases in U.S.Primary vs postinfectious (viral invasion vs immune-mediated disease).Often few, if any, CSF abnormalities with a pure encephalitis (small increase in WBC/ lymphocytes and protein concentration, normal glucose, absence of RBCs).

Viral Infections of the CNS

Enteroviruses - Coxsackie A and B Echoviruses Polioviruses

Arthropod-borne viruses West Nile virus

St. Louis encephalitis virus California encephalitis virus Eastern/Western e.v.

Herpesviruses - Herpes simplex 1 Herpes simplex 2

Cytomegalovirus

Varicella zoster virus Epstein Barr virus

Simian herpes B virus

Other Viruses

HIV

Rabies virus

Lymphocytic choriomeningitis virus

Influenza virus

Mumps virus

Measles

Diseases Mimicking Viral CNS Infections - Infectious Causes

Tuberculosis Partially treated bacterial meningitisListeria meningitisSpirochetal infection (syphilis, Lyme disease, leptospirosis)Rocky Mountain spotted feverFungal (cryptococcosis, coccidioidomycosis, histoplasmosis)

Mycoplasma pneumoniae

Parameningeal infection (brain abscess, epidural or subdural abscess)

Amebic infection

Trypanosomiasis

Toxoplasmosis

Cerebral malaria

Disseminated cat-scratch disease

Whipple’s Disease

Legionellosis

Noninfectious Causes

Tumor

Dural venous sinus thrombosis

Sarcoidosis

Cerebral vasculitis

Behcet’s disease

Drug-induced meningitis (NSAIDs, sulfa)

Migrainous syndromes with pleocytosis

Patient Perspective

Anomaly between patient’s ability to understand vs communicate verbally.

Comprehension vs emotional response by the patient; associated difficulty for family and doctor to understand patient’s mental state.

Patient Perspective 2

Prolonged nature of rehabilitation; difference between test results and patient perspective.Effect on the patient of the expectation of family and friends to be told definitive etiology.