Adult-onset Rasmussen’s encephalitis.

Rasmussen’s encephalitis (RE) is characterised by refractory focal seizures, unilateral cortical deficits, and progressive unihemispheric focal cortical atrophy of undetermined aetiology. A majority of these cases present in childhood, and three disease stages have been recognised: a ‘prodromal stage’, an ‘acute stage’ and a ‘residual stage’. Adult-onset and variant forms have also been described but are rare, and we report one such case with frequent refractory focal seizures, right-sided hemiparesis, aphasia, and marked atrophy of the left perisylvian cortex with a slow disease progression over 17 years. Immunotherapy with corticosteroids, IVIG, plasma exchange, and tacrolimus has been tried in RE with variable results. Hemispherectomy and disconnective techniques like functional hemispherectomy and hemispherotomy are effective in achieving seizure freedom in 62.5% to 85% cases, but carry a risk of motor and language deficits.