Unusual presentation and MRI findings in Rasmussen's syndrome.

Rasmussen's syndrome is a chronic disorder characterized by uncontrollable focal seizures and eventually epilepsia partialis continua, ipsilateral hemiparesis, developmental arrest, and cerebral inflammation. Viral and autoimmune etiologies have been postulated. A patient is presented who illustrates the wide variability of clinical and radiographic presentations in this disorder. The patient is an 8-year-old female who developed intermittent facial twitching at 2 years of age that eventually progressed to epilepsia partialis continua. Electroencephalography demonstrated clinical seizures that emanated from the right parasagittal area. Cranial magnetic resonance imaging revealed pronounced atrophy of the right caudate nucleus, globus pallidus, and putamen, with mild increased T2-weighted signal in the right striatum, without accompanying cortical atrophy. Ictal single-photon emission computed tomography revealed markedly reduced uptake in the right hemisphere that was maximum in the right basal ganglia. Cerebrospinal fluid, blood, and urine collected for metabolic and immunologic screening and DNA testing for a wide variety of disorders were all unremarkable. Neuropsychologic testing demonstrated difficulties in memory, attention, and calculation. Brain biopsy revealed mild microglial activation, rare glial nodules, and collections of lymphocytes and histiocytes, consistent with the clinical diagnosis of Rasmussen's syndrome. After a modified hemispherectomy, she demonstrated marked clinical improvement.