Abstracts

RATIONALE: In the context of a collaborative study we collected 13 patients in whom Rasmussen's Encephalitis (RE) had been diagnosed on the basis of the following criteria: presence of drug resistant focal epilepsy (with or without epilepsia partialis continua), evidence of progressive neurological deficits and progressive hemispheric atrophy on CT and/or MRI. Ten patients had undergone surgery, and diagnosis was confirmed on a neuropathologic basis. METHODS: Clinical histories, EEG and imaging were reviewed with particular attention on the clinical and instrumental findings that characterized the onset of disease. RESULTS: Age at onset ranged between 14 months and 11 years (mean 5.2 ? 2.9 years) The first symptoms was an isolated partial seizure in 12 cases and subacute onset of motor deficit in one case, followed within a few days by partial motor status. In most cases, seizures relapsed within few days. Frequence of seizures increased progressively and intractability was established within six months after onset. Persistent focal slow or epileptic EEG activity appeared in all cases between 1 day and four months after the onset on seizures. Focal MRI abnormalities suggestive of RE were evident from the first examination, even in the 7 patients who had their first scan within one month of onset. The earliest MRI abnormalities included focal areas of white matter signal hyperintensity, enlargement of sylvian scissure and lateral ventricle, atrophy of the frontal and parietal lobe, and in some cases atrophy of caudate head. CONCLUSIONS: The electroclinical and MRI features are diagnostic for RE from the first months of disease. In particular early signs include stereotyped focal seizures associated to contralateral EEG focal slow activity and to contralateral MRI focal abnromalities.