At the age of 11, a female patient presented a motor status epilepticus with continuous jerks of the right leg, clinically corresponding to epilepsia partialis continua (EPC) associated to myoclonic dystonia. The patient had no history of epilepsy, early-life trauma, or central nervous system infection. A consecutive work-up showed left fronto-centro-parietal epileptic activity. The rest of the work-up (MRI, cerebrospinal fluid analysis, neuropsychological assessment and antineuronal antibody screening) was unremarkable. Epileptic activity was refractory to levetiracetam, carbamazepine, lamotrigine, valproic acid, and phenobarbital. Six years later, the patient developed tonico-clonic focal and gereralized seizures. Follow-up MRI showed a discrete atrophy of the sylvian valley. These features suggested the diagnosis of Rasmussen encephalitis. The patient is currently under corticoisteroid therapy, levetiracetam associated to carbamazepine and clonazepam  and botulinum toxin injections with no further clinical progression so far.

Rasmussen's syndrome is a rare, inflammatory encephalitis, typically presenting in childhood. Cases of late-onset Rasmussen have also been described, but the clinical picture is less defined, rendering final diagnosis difficult. While late-onset Rasmussen’s syndrome may mimic the early-onset form, symptoms often progress more slowly, the neurological defect and the cognitive impairment are more variable. Some atypical features may be noted such as the presence of movement disorders at the beginning of the disease, found in our patient, or bilateral hemispheric involvement or a picture of temporal lobe epilepsy. Surgical hemispheric disconnection that appears the most effective treatment in children to improve seizure control is not indicated in this form for evident functional reasons. Based on recent pathogenic concepts, different medical treatments may be proposed.