Abstracts

We report on the outcome of 13 patients who underwent hemispherotomy, for the relief of drug resistant seizures, at the Neurological Institute of Milan, between 2000 and 2005., The 13 patients were affected by static or progressive encephalopathies, involving the right hemisphere in 7 cases, and the left in 6. Diagnosis was made by MRI and confirmed by pathological study. Motor, mental, and language evaluation have been performed before surgery and at least yearly during a follow-up lasting 6-72 months (median 35.5 months). All the patient underwent peri-insular hemispherotomy., Four patients had malformation of cortical development (2 hemimegalencepahly, 2 cortical dysplasia), 3 patients suffered of acquired perinatal brain damage and 6 patients were affected by Rasmussen encephalitis (RE). Age at the first seizure was 1 month - 11 years (median 4.4 years), age at surgery was 6 months-18 years (median 7.3 years), the mean delay between the onset of seizures and surgery being 3.3 years (range 4 months-9 years). In all the patients motor deficit contralateral to the affected hemisphere, mental retardation or cognitive decline, of different severity, were present at the time of treatment. Post-op course was complicated in 2 cases (chemical meningitis, subdural hematoma). There were no life-threatening complications. Among the 10 patients followed-up for at least 12 months, surgery was judged as successful in 8 cases. Six patients became seizure-free (3/4 cases with RE, 2/2 cases with acquired brain damage, 1 / 2 cases with diffuse cortical dysplasia), whereas 2 children (1 with RE, 1 with cortical dysplasia) showed [gt]50% reduction of seizures. Antiepileptic treatment was withdrawn in 3 patients, and simplified in 4. In all the 8 patients neurological condition improved: motor deficits remained unchanged in 3 patients and improved in 5; a significant cognitive and behavioural improvement was observed in 5 patients, no patient with left hemispherotomy experienced worsening in language. No improvement in seizure frequency, nor in motor and cognitive skills was, by contrast, obtained in the 2 children affected by hemimegalencephaly., Our data support the efficacy of peri-insular hemispherotomy in unilateral encephalopathies. As already reported, the seizure outcome is related to the underlying pathology, with the best results in acquired brain damage and in RE, and the worst in hemimegalencephaly. Our data also confirm that control of seizures is often associated with improvement of motor and mental abilities when surgery is performed in childhood.,