[Faciobrachial dystonic seizures. Semiologic diagnosis in limbic encephalitis]

Limbic encephalitis (LE) associated with positive potassium channel complex antibodies often manifests with faciobrachial dystonic seizures (FBDS). We retrospectively analyze two cases, admitted to our video-EEG unit between 2006 and 2014. Both patients were males, aged 66 and 76 years respectively, presenting with brief, but very frequent uni/bilateral dystonic brachial movements, hand posturing and ipsilateral facial grimacing. Severe hyponatremia was found in both patients who went on to develop cognitive impairment. Immunosuppressive therapy improved both seizures and cognitive dysfunction. Serology testing confirmed anti VGKC antibody presence. FBDS are often the first manifestation of LE associated to positive anti VGKC antibodies, and are refractory to treatment with antiepileptic drugs. Early diagnosis and treatment of FBDS with immunosuppressive therapy is important, not only because of seizure suppression, but also because it may help limit the extent of the cognitive damage.