Objective:

To describe 3 patients with unique presentations of anti-NMDAR encephalitis.

Case 1: A 4 yr. old boy presented with history of blank stares, whole body jerking like episodes of sudden onset and progressively worsening in nature. At presentation, the child was slow, unable to walk and mute. Clinical examination revealed an encephalopathic child with poor eye contact   with spontaneous multifocal small to moderate amplitude myoclonus, with hypotonia and hyperreflexia. Electroencephalography revealed multiple generalized bursts of spike and polyspike wave discharges time locked with the myoclonic jerks.

Case 2: A 10 yr. old boy presented with history of inability to walk, shaking movements of the hands and trunk with double vision; which was of sudden onset and preceded by a viral prodromal. Clinical examination revealed a boy with opthalmoplegia, bilateral action and positional limb tremor, with normotonia and hyperreflexia. MRI revealed T2 hyperintensity over the entire brainstem and cerebellum.

Case 3: An 8 yr. old Malay girl who presented with recurrent blurring of vision for three episodes, diagnosed as optic neuritis and responded well to steroids. The fourth episode of optic neuritis was associated with encephalopathy, hypersomnolence and selective mutism. Clinical examination showed hyperreflexia with MRI changes of white matter signal abnormality over the right occipital region.

All the case tested positive for anti NMDAR antibody and responded well to immunotherapy.

Conclusion: Our observations suggests that anti-NMDAR encephalitis may present with unexpected phenotype which may cause confusion of the minds of the managing neurologists.