Herpes simplex encephalitis: Difference between revisions
From IDWiki
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
| − | == |
+ | ==Background== |
*Infection of the brain parenchyma by [[Herpes simplex virus|HSV]], with a predilection for temporal lobes |
*Infection of the brain parenchyma by [[Herpes simplex virus|HSV]], with a predilection for temporal lobes |
||
| − | === |
+ | ===Microbiology=== |
| − | * |
+ | *More commonly caused by [[HSV-1]] than [[HSV-2]] (which more commonly causes [[aseptic meningitis]]) |
| − | === |
+ | ===Pathophysiology=== |
| − | * |
+ | *About one-third are from primary infection while two-thirds are from reactivation of latent infection |
| − | === |
+ | ===Epidemiology=== |
| − | * |
+ | *Causes about 10% of [[encephalitis]] cases |
==Clinical Manifestations== |
==Clinical Manifestations== |
||
| Line 25: | Line 25: | ||
*Rapidly progressing and can lead to coma |
*Rapidly progressing and can lead to coma |
||
| − | == |
+ | ==Differential Diagnosis== |
| − | * |
+ | *Other causes of [[encephalitis]] |
==Investigations== |
==Investigations== |
||
| Line 49: | Line 49: | ||
*[[Acyclovir]] 10mg/kg q8h IV for 14 days |
*[[Acyclovir]] 10mg/kg q8h IV for 14 days |
||
**Ensure adequate hydration and adjust for renal function |
**Ensure adequate hydration and adjust for renal function |
||
| + | |||
| + | == Prognosis == |
||
| + | |||
| + | * 15% recover completely |
||
| + | * 20% have severe neurologic sequelae |
||
| + | ** Primarily dysnomia and impaired new learning |
||
| + | ** Also seizures, neuropsychiatric illnesses |
||
| + | * 28% mortality even with treatment |
||
| + | * Prognosis is worse with those who are older, are sicker at presentation, or have delayed treatment |
||
[[Category:Herpesviridae]] |
[[Category:Herpesviridae]] |
||
Revision as of 18:11, 12 August 2020
Background
- Infection of the brain parenchyma by HSV, with a predilection for temporal lobes
Microbiology
- More commonly caused by HSV-1 than HSV-2 (which more commonly causes aseptic meningitis)
Pathophysiology
- About one-third are from primary infection while two-thirds are from reactivation of latent infection
Epidemiology
- Causes about 10% of encephalitis cases
Clinical Manifestations
- Fever
- Headache
- Altered level of consciousness
- Personality and behavioural changes
- Focal neuro deficits
- Seizures
- Rapidly progressing and can lead to coma
Differential Diagnosis
- Other causes of encephalitis
Investigations
- Imaging
- CT head usually normal
- MRI head can show T2 signal change in temporal lobes
- Lumbar puncture
- Elevated protein
- Lymphocytosis (10-1000 WBCs)
- Erythrocytes in 80% of cases ("hemorrhagic necrotizing meningoencephalitis")
- Normal or slightly low glucose
- HSV PCR is confirmatory
- EEG
- Spikes and slow waves over involved areas
- Periodic lateralized epiieptiform discharges (PLEDs)
- Usually predominately over involved termporal lobe
Management
- Acyclovir 10mg/kg q8h IV for 14 days
- Ensure adequate hydration and adjust for renal function
Prognosis
- 15% recover completely
- 20% have severe neurologic sequelae
- Primarily dysnomia and impaired new learning
- Also seizures, neuropsychiatric illnesses
- 28% mortality even with treatment
- Prognosis is worse with those who are older, are sicker at presentation, or have delayed treatment
