Rasmussen syndrome: an atypical presentation in ten patients

The aim of this study was to analyse the electroclinical and imaging findings and outcome of patients with Rasmussen syndrome (RS) with atypical manifestations. We conducted a retrospective, descriptive study of 10 of 44 consecutive patients with RS with atypical features, followed between 1999 and 2017. Six patients were boys and four were girls. The mean and median ages at onset of the seizures were 8.8 and 6.5 years, respectively (range: 4.6-13 years). All of the patients except one had seizures. Eight patients (80%) had epilepsia partialis continua that started at a mean age of 7.5 years (range: 7-15 years). In our series, hemiparesis without seizures was the first manifestation in three patients, one of whom had dual pathology. In two patients, the first manifestation was dyskinetic movements, followed by delayed-onset seizures associated with unilateral caudate atrophy. Two patients had a focal lesion mimicking focal cortical dysplasia as the first MRI abnormality; one of these two patients had epileptic spasms in clusters. Bilateral cerebral hemisphere involvement was observed in three patients during the course of the disease. Six of eight patients responded well to surgical treatment. Progressive hemiparesis alone or with delayed-onset seizures, dyskinetic movements associated with seizures, a focal lesion mimicking focal cortical dysplasia, and bilateral brain involvement were the atypical features recognized. Our series of patients responded well to surgery. Clinical, video-EEG, and neuroradiological follow-up is important for early confirmation of RS in order to initiate adequate management of the condition.