| Element | Comment |
|---|---|
| Clinical features | Acute onset (symptoms usually <1 week) Fever Headache Personality change/abnormal behaviour Alteration in conscious level Seizures Focal neurological abnormalities (cranial nerve palsies, dysphasia, hemiparesis, ataxia) |
| CT brain | May be normal May show generalized brain swelling with loss of cortical sulci and small ventricles May show areas of low attenuation in the temporal and/or frontal lobes |
| CSF findings | High lymphocyte count (50–500/mm3), with predominance of polymorphs in early phase, and red cells often present Protein concentration increased, up to 2.5 g/L Glucose is usually normal but may be low Herpes simplex DNA may be detected in CSF by PCR |
| Electroencephalography | Abnormal in two-thirds of cases, with a spike and slow wave pattern localized to the area of brain involved. |
| Management | Aciclovir 10 mg/kg 8-hourly IV Seek expert advice from an infectious diseases physician and neurologist |