Cognitive functions in juvenile and adult patients with gelastic epilepsy due to hypothalamic hamartoma

To describe extend and severity of cognitive deficits in juvenile and adult patients with gelastic seizures and hypothalamic hamartoma (HH) and to analyze the impact of epilepsy-related variables on cognitive performance.

Thirteen juvenile and adult patients (mean age, 25 years; seven men) underwent comprehensive neuropsychological testing assessing intellectual performance, attention and executive functions, verbal and visual memory, and visuospatial abilities.

Intellectual abilities ranged from moderate mental retardation to good average performance; 54% of the patients displayed below-average global intellectual abilities. Attentional and executive functions were impaired in 23% to 46% of the patients. Below-average visuospatial capabilities were observed in 39% of the cases. Memory functions were impaired regarding both visual (77%) and verbal learning (62%). Nonparametric correlation analysis revealed a significant relation between monthly partial seizure frequency and reduced cognitive flexibility and reduced performance in mental rotation. In addition, HH volume was significantly negatively correlated with cognitive flexibility, whereas age at onset and duration of epilepsy did not show significant correlation to cognitive performance.

More than half of the adult patients with gelastic seizures and HH displayed deficits in a broad range of cognitive functions, expressed mostly in visual and verbal learning and memory. Some of the deficits could be shown to correlate with disease-related characteristics representing the severity of the epilepsy or the size of the underlying lesion. These findings prompt for a longitudinal investigation of the development of these cognitive deficits to analyze further the relevant factors contributing to this wide spectrum of cognitive impairments.