Herpes simplex encephalitis: Difference between revisions

Revision as of 22:08, 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

@@ 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
-== Clinical Manifestations ==
+=== Microbiology ===
-* Fever
-* Headache
-* Altered level of consciousness
-** Personality and behavioural changes
-* Focal neuro deficits
-* Seizures
-* Rapidly progressing and can lead to coma
+* More commonly caused by [[HSV-1]] than [[HSV-2]] (which more commonly causes [[aseptic meningitis]])
-== Investigations ==
+=== Pathophysiology ===
-* 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 (&quot;hemorrhagic necrotizing meningoencephalitis&quot;)
-** 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
+* About one-third are from primary infection while two-thirds are from reactivation of latent infection
-== Management ==
+=== Epidemiology ===
-* [[Acyclovir]] 10mg/kg q8h IV for 14 days
-** Ensure adequate hydration and adjust for renal function
+* 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 (&quot;hemorrhagic necrotizing meningoencephalitis&quot;)
+**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
 [[Category:Herpesviridae]]