Cognitive functioning before and after surgical resection for hypothalamic hamartoma and epilepsy

Objective: To determine whether patients with hypothalamic hamartoma (HH) improve in their cognitive functioning after neurosurgical resection of their HH and explore what variables correlate with cognitive outcome. Methods: Thirty-two patients underwent preoperative and postoperative neuropsychological testing. The age range of patients was between 3.3 and 39.3 years (mean 12.2 years, SD 7.0). The average time interval between surgery and postoperative neuropsychological testing was 23.4 months (range 5.1-47.2 months). Tests administered varied on the basis of the patient's age and clinical condition. Results: As a group, measures of overall intelligence showed improvement postsurgery, with associated improvement in processing speed. Memory scores did not demonstrate consistent improvement or decline. Duration of epilepsy, age at surgery, and level of neurocognitive functioning prior to surgery were correlated with postsurgical cognitive status. Patients who had mental retardation but were testable generally showed the greatest gains. Conclusions: Despite the great variability in level of cognitive impairment in patients with HH and refractory epilepsy, level of intelligence may show mild to moderate improvements postsurgery if no surgical complications occur. The variables that predict cognitive outcome are not fully delineated, but testable individuals with the greatest presurgical cognitive impairment and those with the shortest duration of epilepsy appear to make the greatest gains in intellectual functioning. Classification of evidence: This study provides Class IV evidence that single surgical resection for HH was associated with improvement in some subset measures of intellectual functioning, but not memory. Factors that predict better outcomes cannot be determined.