Seizures in encephalitis: predictors and outcome

Seizures are common in encephalitis but there is paucity of comprehensive studies evaluating predictors of seizures.

To evaluate the frequency and predictors of seizures in encephalitis patients and its effect on outcome.

In a prospective hospital based study, the patients with encephalitis were evaluated clinically and presence of seizure, its type and duration were noted. Patients' consciousness was assessed by Glasgow coma scale (GCS) score and neurological findings were recorded. Blood count, serum chemistry, electroencephalography (EEG), cranial MRI and CSF examination were done. The diagnosis of encephalitis was based on ELISA and PCR and grouped into herpes, Japanese, dengue and nonspecific encephalitis. Hospital mortality and 3-month outcome were noted.

148 patients with encephalitis whose median age was 26 (range 1-75) years were included. Seizures occurred in 63 (42.6%) patients; 18 of whom had status epilepticus. Seizures were more common in herpes (75%) followed by Japanese (54%) encephalitis. The predictors of seizure in encephalitis were age, GCS score and cortical involvement on MRI. 61% children had seizures compared to 36.6% adults and 53.3% with cortical involvement on MRI had seizure compared to 14.3% without. Seizures were not related to mortality but associated with poor outcome.

In encephalitis, seizures occur in 42.6% patients especially in children with low GCS score and having cortical involvement on MRI.