Encephalitis

Question 1

Clinical features of encephalitis?

Answer 1

fever, headache, psychiatric symptoms, seizures, vomiting

focal features e.g. aphasia

peripheral lesions (e.g. cold sores) have no relation to the presence of HSV encephalitis

Question 2

Pathophysiology of encephalitis?

Answer 2

HSV-1 is responsible for 95% of cases in adults
typically affects temporal and inferior frontal lobes

Question 3

Investigations for encephalitis?

Answer 3

Cerebrospinal fluid
- lymphocytosis
- elevated protein
- PCR for HSV, VZV and enteroviruses

Neuroimaging
- medial temporal and inferior frontal changes (e.g. petechial haemorrhages)
- normal in one-third of patients
- MRI is better

EEG
- lateralised periodic discharges at 2 Hz

Question 4

Management of encephalitis?

Answer 4

intravenous aciclovir should be started in all cases of suspected encephalitis