Herpes Simplex Encephalitis

Clinical Description

Rare neurological disorder characterized by inflammation of the brain due to herpes simplex virus infection

Signs and Symptoms

• Fever, change in behaviour and seizures, which may be either focal or generalized.

Evidence of mucocutaneous involvement is usually not present. lumbar puncture shows the above features of viral meningoencephalitis, but in this condition may be additionally hemorrhagic in nature.

Investigations

• Lumbar puncture shows features of a viral meningoencephalitis, but in this condition may be additionally hemorrhagic in nature.
• A positive HSV PCR test on CSF is diagnostic.
• A temporal focus on EEG or neuro-imaging is strongly supportive of the diagnosis.
• A positive HSV PCR test on CSF is diagnostic.

Treatment

• Acyclovir, IV, 10 mg/kg 8 hourly for 21 days. Start therapy as early as possible, before results are available. If PCR is negative, stop treatment.
• Treat seizures appropriately with available Antiepileptic drugs, Phenytoin or Carbamazepine.
• It is important to initiate therapy and then refer to Centre where neuro- imaging is available.

Complications and Referral Criteria

• For neuroimaging: patients whose condition deteriorate not responding or worsening in condition, i.e., decrease in level of consciousness or develop and cranial nerve palsies, despite being initiated on appropriate therapy.
• This is especially urgent in patients with tuberculous meningitis, who may develop hydrocephalus and require an urgent shunting procedure.
• Patients with shunts.