Acute Encephalopathy in a Patient with Dravet Syndrome

Abstract

Dravet syndrome (severe myoclonic epilepsy in infancy) is an epileptic syndrome with various types of seizures that begin in the first year of life and may result in intellectual impairment. Mutations of the SCN1A gene are the most prevalent genetic cause of Dravet syndrome. In this study, we report a 12-year-old girl with Dravet syndrome carrying an SCN1A mutation, c.2785Cdel (L929del fsX934). She had an episode of status epilepticus and persistent lethargy after 48 h of acute febrile illness that was preceded by an annual flu vaccination. Low voltage activities detected by electroencephalogram and elevated neuron-specific enolase/interleukin-6 concentrations in the cerebrospinal fluid suggested acute encephalopathy. MRI showed abnormalities in the bilateral thalami, cerebellum and brainstem. These abnormalities were protracted over a month. The biochemical and MRI characteristics of this case are different from any known type of encephalopathy, and may suggest a vulnerability of neurons expressing mutant SCN1A in the brain.

Key words

Dravet syndrome - acute encephalopathy - SCN1A - voltage-dependent sodium channel - vaccination

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