Epilepsia partialis continua as the presenting feature of anti-NMDA receptor encephalitis in a young male

Abstract

Dear editor, The autoimmune encephalitis syndromes have a wide clinical spectrum ranging from typical limbic encephalitis to complex neuropsychiatric manifestations such as deficits of memory, cognition, psychosis, seizures, abnormal movements, or coma. Anti-NMDA receptor encephalitis is increasingly recognised as an important cause of encephalitis, and its presentation in children is different from that in adults. Children as young as 8 months have been reported with this syndrome [1]. Features like dysautonomia and hypoventilation are less frequently seen in children. Here, we report a case of a 13-year-old male child who presented with epilepsia partialis continua as the presenting manifestation of anti-NMDA receptor encephalitis. This has been rarely described in literature. A 13-year-old previously healthy child presented with sudden onset involuntary abnormal twitching movements of right side of the face with eyelid myoclonias along with lesser involvement of the left side (Video 1) 3 days prior to admission. These movements were present even during sleep. There was no impaired awareness, tongue bite or incontinence. He gave a history of low-grade fever 7 days back that lasted for 3 days and resolved spontaneously. There was no history of behaviour disturbances, dysautonomia, memory deficits or change in sensorium. There was no family history of seizures. Initial investigations such as complete blood count along with kidney function tests and liver function tests were normal. A lumbar puncture was done, and it showed 3 cells, all lymphocytes with normal sugar and protein concentration and no oligoclonal bands. CSF neuro-viral panel was sent, and it was negative. Neuroimaging showed asymmetrical T2 flair hyperintensities involving bilateral temporal lobes (left more than right) without any diffusion restriction and contrast enhancement (Fig. 1). EEG showed generalised slowing with spike waves and myoclonia artefact waves (Fig. 2). He was given intravenous levetiracetam (1.5 g/day) and lacosamide (100 mg/day) with intravenous acyclovir with no improvement over 24 h. So he was started on midazolam infusion. He achieved control of seizures with midazolam infusion, but seizures recurred on tapering of midazolam. Dosages of levetiracetam and lacosamide were increased to 2 g/day and 200 mg/day respectively. In view of refractory focal motor status epilepticus and no improvement with acyclovir along with these neuroimaging findings. CSF NMDA was sent which turned out to be positive. Other antibodies in the autoimmune panel were negative. A CT thorax and CT abdomen were negative for any tumour. The patient was given intravenous methylprednisolone (1 g/day for 5 days) that led to control of his refractory seizures. He was discharged with oral steroids and is seizure-free for 6 months on follow-up. Children with anti-NMDAR encephalitis have more frequent neurological symptoms like seizures and orofacial dyskinesias or choreoathetoid movement of limbs. They usually lack the psychiatric symptoms at the onset of disease. In some cohorts, most young patients presented with focal motor seizures, whereas generalised tonic–clonic seizures or status epilepticus at the time of presentation are rare findings [2]. Cases of epilepsia partialis continua (EPC) in paediatric anti-NMDAR encephalitis have been rarely reported [3, 4]. In one such report, a child with EPC was evaluated for anti-NMDA receptor encephalitis only after he developed orofacial dyskinesia * Vaibhav Seth [email protected]