Abstract
Rasmussen encephalitis (RE) is a severe epileptic and inflammatory encephalopathy
of unknown etiology, responsible for focal neurological signs and cognitive decline.
The current leading hypothesis suggests a sequence of immune reactions induced by
an indeterminate factor. This sequence is thought to be responsible for the production
of autoantibody-mediated central nervous system degeneration. However, these autoantibodies
are not specific to the disease and not all patients present with them. We report
the case of a 4-year-old girl suffering from RE displaying some atypical features
such as fast evolution and seizures of left parietal onset refractory to several antiepileptics,
intravenous immunoglobulins, and corticosteroids. Serum autoantibodies directed against
voltage-gated potassium channels (VGKC) were evidenced at 739 pM, a finding never
previously reported in children. This screening was performed because of an increased
signal in the temporolimbic areas on brain magnetic resonance imaging, which was similar
to what is observed during limbic encephalitis. The patient experienced epilepsia
partialis continua with progressive right hemiplegia and aphasia. She underwent left
hemispherotomy at the age of 5.5 years after which she became seizure free with great
cognitive improvement. First described in adults, VGKC autoantibodies have been recently
described in children with various neurological manifestations. The implication of
VGKC autoantibodies in RE is a new observation and opens up new physiopathological
and therapeutic avenues of investigation.
Keywords
autoimmunity - child - epilepsia partialis continua - immunosuppressive therapy -
Rasmussen encephalitis
