encephalitis

A 73 year old male, who is a known diabetic, hypertensive with a past history of CVA was brought with complaints of acute onset difficulty in doing day to day activities as well as some bizarre behavioral episodes. His family noted that the patient was not able to do his routine activities like bathing and praying unless prompted to do so. The patient also reportedly had way finding difficulty. He was also reported as having memory problems recently, forgetting to take his medicines on time and forgetting where the kitchen utensils were usually kept. The patient had difficulty in cooking for himself, using the wrong ingredients in the wrong order, while he was quite proficient in cooking till recent past. His wife also noted he had some visual hallucinations of a man standing and talking in the doorway. There was aimless night time wandering and urination at inappropriate places, which continued while he was admitted in our center. The bizarre behavioral episodes were found to be facio brachial dystonic seizures during which he would turn his head to the left and laugh and talk by himself, with a rhythmic movement of left hand. The pupils were unreactive with a nystagmus with the fast component towards left was noted. These episodes were frequent, happening every 3-6 hours. Vital signs were within normal limits. Neurological exam was significant for constructional apraxia, dressing apraxia, perseveration with no language disturbance or disorientation. MMSE score was calculated to be 20. Brain imaging revealed small vessel ischemic changes. EEG revealed a normal study. An rapid onset dementia with faciobrachiodystonic seizure we done autoimmune encephailitis work up in a serum sample was negative for all autoantibodies. Suspecting the faciobrachiodystonic seizures to be a presentation of LG1 autoimmune encephalitis, the patient was started on antiepileptics and pulse steroid therapy therafter which all his symptoms resolved over a period of days. Although the relevant antibodies were negative, given the rapid progression of dementia including the facio brachio dystonic seizures which are pathognomic of LGI1 encephalitis and the prompt response to steroid therapy, Seronegative autoimmune encephalitis was the final diagnosis.