Autoimmune Encephalitis

A 12-year-old girl presented with behavioural disturbances (decreased interaction, decline in scholastic performance, abusive behaviour and abnormal involuntary movements of the right hand with generalised seizures for 6 weeks). After 1–2 weeks, she progressively developed involuntary perioral movements, refractory status epilepticus and mutism. There was no fever, headache, myoclonic jerks, visual complaints, weight loss or any systemic complaints. At the time of admission, she had intermittent respiratory disturbances, was in altered sensorium with status epilepticus, and had perioral dyskinesias and right upper limb dystonic posturing with the presence of pyramidal signs. She was then intubated and kept in mechanical ventilation. Routine lab investigations including anti-TPO antibody level were within normal limits. MRI brain and CSF studies showed no abnormalities. Electroencephalography showed generalised theta-delta range slowing with “delta brush” and focal epileptiform discharges as well (Fig. 23.1). CSF anti-NMDA receptor antibody was positive. She was treated with a course of intravenous methylprednisolone followed by intravenous immunoglobulins (IVIg) but showed no signs of improvement. She was then started on large-volume plasmapheresis along with oral steroids. She made mild-to-moderate improvement. She was extubated, weaned off the ventilator, and shifted to the ward where she continued to have mutism and mild Parkinsonism with stereotypy movements of the hand. She improved significantly, and presently she is on low dosage of steroids.