Anti NMDAr antibody mediated encephalitis typically presents as neuropsychiatric syndrome, seizures and focal deficits (aphasia). However initial presentation with focal motor deficits has only been recently described.

Case 1:

A girl presented first at 2 years of age with 3 left focal motor seizures. EEG: right posterior slow. Mild left upper limb dystonia noted. Oxcarbamazepine/valproate controlled seizures.

Lost to follow up, year on she re-presented with left sided weakness (MRC 3/5). PET brain: hypometabolism right high parietal cortex. Anti NMDAr antibodies were negative in a lab but positive in another! High dose methyl prednisolone resulted in complete recovery.

After 2 years (clinically asymptomatic), she presented with aphasia- initially receptive then expressive. Anti NMDAr antibodies (sent to Oxford this instance) were positive. She is receiving immunomodulation.

Case 2:

A 13-year-old girl presented with left focal motor seizures- shoulder and hand (nil face). EEG: right hemispheric slow waves. Soon she developed dyspraxia of left hand with worsening seizures- anti epileptic medications escalated. Then she developed typical phenotype: confusion, irrelevant speech, altered sleep wake cycle and worsening of left hand use. Anti NMDAr antibodies tested positive. She responded dramatically to IV methyl prednisolone. Parents refused IVIG / immunomodulation.

At 2 years follow-up she is seizure free/ no focal deficits. Antibodies are weakly positive.

Both cases: MRI brain/ relevant tests were normal. No underlying neoplasm detected.

Conclusion: Clinical phenotype of anti NMDAr antibody mediated encephalitis is expanding- focal motor deficits at presentation is an additional aspect to be considered.