HERPES SIMPLEX ENCEPHALITIS ENCEPHALITIS M.RASOOLINEJAD, MD DEPARTMENT OF INFECTIOUS DISEASE TEHRAN UNIVERCITY OF MEDICAL SCIENCE

HERPES SIMPLEX ENCEPHALITIS ( HSE ) A SERIOUS ILLNESS WITH SIGNIFICANT RISKS OF MORBIDITY & MORTALITY TREATABLE ENCEPHALITIS

EPIDEMIOLOGY Incidence: 1/ 250,000 to 500,000/ year Morbidity: Untreated patients, 70% Treated patients, 19% Treated patients, 19% Morbidity: > 50% of survivors are left with moderate or severe with moderate or severe neurologic deficits neurologic deficits Sex: In male & female is equal Age: Peaks in childhood & middle-aged

HSE Acute or Subacute Illness General & Focal Cerebral Dysfunction Sporadic W ithout Seasonal Pattern W ithout Seasonal Pattern HSV-1 in 95% cases

PATHOGENESIS  Children & young adult: Primary HSV infection Brain  Adult: Prior HSV-1 infection ( Ab +ve ) Reactivation in Trigeminal or Autonomic roots Autonomic roots Brain Brain Olfactorybulb

PATHOLOGY Edema & Congestion & Hemorrhage & Necrosis Intense Hemorrhagic necrosis In Temporal & Frontal lobe Hallmark of HSE: Bilateral Asymmetrical Anterior Temporal lobe inflammation

CLINICAL MANIFESTATIONS NO PATHOGNOMONIC CLINICAL FINDING  Typical symptoms: Fever 90%Fever 90% Headache 81%Headache 81% Psychiatrics symptoms 71%Psychiatrics symptoms 71% Seizures 67%Seizures 67% Vomiting 46%Vomiting 46% Focal weakness 33%Focal weakness 33% Memory loss 24%Memory loss 24% Altered mental status & photophobiaAltered mental status & photophobia

CLINICAL MANIFESTATIONS NO PATHOGNOMONIC CLINICAL FINDING  Typical finding on P/E: Alteration of consciousness 97%Alteration of consciousness 97% Fever 92%Fever 92% Dysphasia 76%Dysphasia 76% Seizures 38% (Focal 28%, General 10%)Seizures 38% (Focal 28%, General 10%) Hemiparesis 38%Hemiparesis 38% Cranial nerve defect 32%Cranial nerve defect 32% Visual field loss 14%Visual field loss 14% Papilledema 14%Papilledema 14%

DIFFERENTIAL DIAGNOSIS Brain abscess Brain abscess Epidural & Subdural abscess Epidural & Subdural abscess Neoplasms, Brain Neoplasms, Brain Pediatric febrile seizures Pediatric febrile seizures Stroke & Hemorrhagic or Ischemic Stroke & Hemorrhagic or Ischemic

WORK-UP  Lab Studies: CSF  Mononuclear pleocytosis Elevated protein Elevated protein Nl or reduce glucose Nl or reduce glucose Initial may be Nl Initial may be Nl Hemorrhagic nature  Elevated RBC Hemorrhagic nature  Elevated RBC HSV is rarely cultured HSV is rarely cultured CSF/PCR  Sensitive & Specific

WORK-UP Imaging Studies:  MRI ( Preferred mainly imaging ) Bilateral Temporal & Inferior Frontal Changes Bilateral Temporal & Inferior Frontal Changes  CT-Scan ( much less sensitive than MRI ) Other tests:  EEG  Focal abnormalities Slow-wave or periodic sharp-wave Slow-wave or periodic sharp-wave Over temporal lobe Over temporal lobe Sensitive Not Specific Sensitive Not Specific

TREATMENT Goals of therapy: 1.Shorten the clinical course 2.To prevent complications 1.To prevent subsequent recurrence

TREATMENT ASYCLOVIR The drug of choice 10mg/kg (or 500mg/m2 ) IV q8h Each dose infused over 1 hour Duration: 10 to 14 days