Spectrum of movement disorders in encephalitis

To study the frequency and type of movement disorders and correlate these with MRI findings and outcome. Consecutive patients having encephalitis with movement disorders were included. The encephalitides were categorized into Japanese encephalitis (JE), herpes simplex, dengue, mumps, measles and nonspecific, depending on respective ELISA or CSF PCR. The movement disorders were recorded and severity was graded into mild, moderate, severe and markedly severe. Cranial MRI was done on a 1.5 T scanner acquiring T1, T2 and FLAIR sequence, and the location of MRI changes was noted. Outcome was defined at 6 months on the basis of functional status into complete, partial or poor. The type and severity of movement disorders and their relation to outcome was evaluated. Seventy-four out of 209 encephalitis patients had movement disorders; 67.6% of the patients had JE, 51.2% nonspecific and 11.3% dengue encephalitis. Their median age was 19 years and 16 were females. Parkinsonian features were present in 36, dystonia in six and both in 32 patients. The severity of movement disorders ranged between 2 and 4 (scale: none = 0, mild = 1, moderate = 2, severe = 3, markedly severe = 4). Movement disorders were common in males (P = 0.0001), and more frequent in JE (P = 0.03) and those having substantia nigra involvement on MRI (P = 0.03). Dystonia was associated with worse outcome than parkinsonian features only (P = 0.01). Movement disorders are common and severe in JE and are related to typical anatomical involvement.