Abstracts

RATIONALE: Hamartomas of the hypothalamus (HH) are well known to produce a refractory epilepsy syndrome which may be associated with precocious puberty, cognitive difficulties and behaviour problems. The pathogenesis of the latter two is not clearly understood. Fratelli et al reported on 8 children with HH and gelastic seizures and noted the severity of cognitive impairment was related to the severity of complex partial and gelastic seizures. However, the neuropsychological profile in adult patients with HH, whose epilepsy is only of mild or moderate severity, and who are functioning well in activities of daily living, is not understood.
Objective: To characterize the neuropsychological deficits in adult patients with hypothalamic hamartoma and mild to moderate severity of epilepsy.
METHODS: 6 adult patients with hypothalamic hamartoma underwent comprehensive neuropsychological assessment with the WAIS III, the Doors and People Memory test battery and tests of executive functioning including verbal fluency, Trail making and the Hayling and Brixton tests. Two patients were tested before and after stereotactic thermocoagulation of the hypothalamic hamartoma.
RESULTS: Three patients were in the average or low average range of IQ. These three patients showed impairment of memory function relative to intellectual function and these ranged across verbal and visuospatial memory. In contrast, there were no impairments in executive functioning. These patients all had mild simple and complex partial seizures
Three other patients were in the borderline range of IQ, or slightly below this. They were overall lower functioning and showed relative impairments in working memory and mild executive impairment. However, relative to intellectual abilities, they did not show memory impairment. These three patients had more frequent and more severe seizures.
Two patients underwent sterotactic thermocoagulation of the hamartoma with reduction in seizures . They reported improvement in memory postoperatively, although this was still abnormal.
CONCLUSIONS: Memory impairment is an important finding in patients with hypothalamic hamartoma, epilepsy and average or low average IQ. Cognitive impairment is greater in patients with more frequent and more severe seizures. Improvement in memory following treatment directed at the hamartoma suggests a causative relationship between the epileptiform activity produced by the hamartoma and the cognitive difficulties.
Reference:
Cognitive deficits in children with gelastic seizures and hypothalamic hamartoma.
Frattali CM, Liow K, Craig GH, Korenman LM, Makhlouf F, Sato S, Biesecker LG, Theodore WH. Neurology 2001 Jul 10;57(1):43-6