[Late onset Rasmussen's syndrome: clinical and therapeutic characteristics].

Rasmussen's syndrome is a rare inflammatory brain disease characterized by severe intractable epilepsy, and unilateral progressive motor defect associated with controlateral hemispheric atrophy. The disorder usually affects children, although occasional reports of adult-onset Rasmussen's syndrome have been reported. We report her four patients in whom seizures began in adolescence or adulthood with clinical and radiological symptoms suggesting the diagnosis of Rasmussen's syndrome. We compared them with thirty-three cases described in the literature between 1987 and 2004. While adult-onset Rasmussen's syndrome may mimic the early-onset form, symptoms often progress more slowly and the neurological defect is more variable. Occipital lobe involvement appears to be more common than in the childhood form, and some atypical features may be noted such as bilateral hemispheric involvement or a picture of temporal lobe epilepsy or the présence of movement disorders at the beginning of the disease. Surgical hemispheric disconnection that appears the most effective treatment in children to improve seizure control is not indicated in adults for evident functional reasons. Based on recent pathogenic concepts, different medical treatments may be proposed. Large multicentric controlled studies are mandatory to define a clear medical therapeutic strategy in these cases of adult-onset.