HERPES SIMPLEXHERPES SIMPLEX ENCEPHALITISENCEPHALITIS

M.RASOOLINEJAD, MDM.RASOOLINEJAD, MDDEPARTMENT OF INFECTIOUS DISEASEDEPARTMENT OF INFECTIOUS DISEASETEHRAN UNIVERCITY OF MEDICAL SCIENCE TEHRAN UNIVERCITY OF MEDICAL SCIENCE

HERPES SIMPLEX ENCEPHALITISHERPES SIMPLEX ENCEPHALITIS( HSE )( HSE )

A SERIOUS ILLNESS A SERIOUS ILLNESS WITH SIGNIFICANT RISKSWITH SIGNIFICANT RISKS

OF MORBIDITY & MORTALITYOF MORBIDITY & MORTALITY

TREATABLE ENCEPHALITISTREATABLE ENCEPHALITIS

EPIDEMIOLOGYEPIDEMIOLOGYIncidence: 1/ 250,000 to 500,000/ yearIncidence: 1/ 250,000 to 500,000/ yearMorbidity: Untreated patients, 70%Morbidity: Untreated patients, 70% Treated patients, 19%Treated patients, 19%Morbidity: > 50% of survivors are left Morbidity: > 50% of survivors are left with moderate or severewith moderate or severe neurologic deficitsneurologic deficitsSex: In male & female is equalSex: In male & female is equal

Age: Peaks in childhood & middle-aged Age: Peaks in childhood & middle-aged

HSEHSEAcute or Subacute IllnessAcute or Subacute IllnessGeneral & Focal Cerebral DysfunctionGeneral & Focal Cerebral Dysfunction

SporadicSporadic WWithout Seasonal Patternithout Seasonal Pattern

HSV-1 in 95% casesHSV-1 in 95% cases

PATHOGENESISPATHOGENESISChildren & young adult:Children & young adult:Primary HSV infection BrainPrimary HSV infection Brain

Adult:Adult:Prior HSV-1 infection ( Ab +ve )Prior HSV-1 infection ( Ab +ve )Reactivation in Trigeminal or Reactivation in Trigeminal or Autonomic rootsAutonomic roots

BrainBrain

OlfactoryOlfactorybulbbulb

PATHOLOGYPATHOLOGYEdemaEdema && CongestionCongestion && HemorrhageHemorrhage &&NecrosisNecrosis

Intense Hemorrhagic necrosis Intense Hemorrhagic necrosis InIn

Temporal & Frontal lobeTemporal & Frontal lobe

Hallmark of HSE:Hallmark of HSE:Bilateral AsymmetricalBilateral Asymmetrical

Anterior Temporal lobe inflammationAnterior Temporal lobe inflammation

CLINICAL MANIFESTATIONSCLINICAL MANIFESTATIONSNO PATHOGNOMONIC CLINICAL FINDINGNO PATHOGNOMONIC CLINICAL FINDING

Typical symptoms: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 MANIFESTATIONSCLINICAL MANIFESTATIONSNO PATHOGNOMONIC CLINICAL FINDINGNO PATHOGNOMONIC CLINICAL FINDING

Typical finding on P/E: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 DIAGNOSISDIFFERENTIAL DIAGNOSIS

Brain abscessBrain abscess

Epidural & Subdural abscessEpidural & Subdural abscess

Neoplasms, BrainNeoplasms, Brain

Pediatric febrile seizuresPediatric febrile seizures

Stroke & Hemorrhagic or IschemicStroke & Hemorrhagic or Ischemic

WORK-UPWORK-UPLab Studies:Lab Studies:

CSFCSF Mononuclear pleocytosisMononuclear pleocytosis Elevated proteinElevated protein Nl or reduce glucoseNl or reduce glucose Initial may be NlInitial may be Nl Hemorrhagic natureHemorrhagic natureElevated RBCElevated RBC HSV is rarely culturedHSV is rarely cultured

CSF/PCRCSF/PCRSensitive Sensitive & & SpecificSpecific

WORK-UPWORK-UPImaging Studies:Imaging Studies:MRI MRI ( Preferred mainly imaging ) ( Preferred mainly imaging ) Bilateral Temporal & Inferior Frontal ChangesBilateral Temporal & Inferior Frontal ChangesCT-ScanCT-Scan ( much less sensitive than MRI ) ( much less sensitive than MRI )

Other tests:Other tests:EEGEEG Focal abnormalities Focal abnormalities Slow-wave or periodic sharp-waveSlow-wave or periodic sharp-wave Over temporal lobeOver temporal lobe Sensitive Not SpecificSensitive Not Specific

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TREATMENTTREATMENTGoals of therapy:Goals of therapy:1.1.Shorten the clinical courseShorten the clinical course

2.To prevent complications2.To prevent complications

1.1.To prevent subsequent recurrenceTo prevent subsequent recurrence

TREATMENTTREATMENTASYCLOVIR ASYCLOVIR

The drug of choiceThe drug of choice

1010mg/kg (or 500mg/m2 ) IV q8hmg/kg (or 500mg/m2 ) IV q8hEach dose infused over 1 hourEach dose infused over 1 hour

Duration: 10 to 14 daysDuration: 10 to 14 days