Long‐term cognitive outcome after radiosurgery in epileptic hypothalamic hamartomas and review of the literature

Abstract

Objective Epileptic patients with hypothalamic hamartoma (HH) frequently present cognitive impairments. Surgical techniques aiming at HH can be very efficient for epilepsy relief and cognitive improvement but are also demonstrated to carry a significant risk of additional reduction in memory function in these already disabled patients. Gamma knife radiosurgery (GKS) offers an efficient minimally invasive procedure. We evaluated the effect of stereotactic radiosurgery on cognitive outcome. Methods We designed a prospective single‐center case series study. Thirty‐nine epileptic patients (median age = 17 years, range = 4–50) with HH underwent preoperative and postoperative testing of intelligence quotient (IQ; all patients), including a working memory component, and other memory function testing (for patients ≥16 years old). All patients were prospectively evaluated and underwent complete presurgical and postsurgical clinical, electrophysiological, endocrinal, and visual assessments. In all patients, the postoperative assessment was performed at least 3 years after radiosurgery. We explored what variables correlate with cognitive outcome. Literature review was done for other surgical techniques and their risks for cognitive complications after surgery. Results No decline was observed in intellectual ability (including working memory) after GKS, and no memory decline was seen in adults. We observed significant improvement (>1 SD in z‐score) in working memory index (46%) and processing speed index (35%), as well as improvement in full‐scale IQ (24%), verbal comprehension index (11%), perceptual organization index (21%), verbal learning (20%), and visual learning (33%). Before GKS, the probability of seizure cessation was higher in patients with higher cognitive performance. After GKS, the cognitive improvement was significantly higher in the seizure‐free patients compared to the non‐seizure‐free patients. Significance We found clear cognitive improvement in a high percentage of patients but importantly no significant decline in intellectual ability (including working memory) and no decline in memory in adult patients 3 years after GKS. GKS compares favorably to the other surgical techniques in terms of cognitive outcome, with similar seizure freedom.

Minimally invasive procedures for hypothalamic hamartoma–related epilepsy: a systematic review and meta-analysis

“…Articles from the same institution as Curry et al 17 that included patients in a similar period were also excluded. 18,19 Studies by Sonoda et al 20 and Hamdi et al 21 were also excluded since they reported cognitive results rather than epilepsy outcomes after HH treatment. Four articles [22][23][24][25] were excluded because of duplicated data with the study by Shirozu et al 26 Only 7 patients from Abla et al 27 and 6 from Mathieu et al 28 were included because other procedures were performed during the follow-up period.…”

Leveraging expertise and optimizing clinical research: Initial success of a pediatric epilepsy surgery collaborative

“…Although functional decline in pediatric epilepsy patients after surgery occurs in a minority of patients, some evidence suggests that outcomes beyond a year postoperatively are needed to appreciate the positive impact on cognitive functioning. [28][29][30] Establishing infrastructure for a prospective longitudinal database across centers is essential to rigorously achieving epilepsy benchmarks set forth by the epilepsy field to transform pediatric epilepsy care.…”

“…Ultimately, longitudinal outcomes of the cohort will be most informative in predicting and guiding the optimal timing of surgical treatment in the context of the developmental trajectory of neuropsychological functioning. Although functional decline in pediatric epilepsy patients after surgery occurs in a minority of patients, some evidence suggests that outcomes beyond a year post‐operatively are needed to appreciate the positive impact on cognitive functioning 28–30 . Establishing infrastructure for a prospective longitudinal database across centers is essential to rigorously achieving epilepsy benchmarks set forth by the epilepsy field to transform pediatric epilepsy care.…”

A Review of the Surgical Procedures for the Treatment of Drug-Resistant Epilepsy and Their Seizure Control Outcomes

“…The risks and adverse events might outweigh the clinical benefits in many cases since it is associated with severe memory disorders especially when used to treat MTLE. However, a literature review published in the Epilepsia Journal showed promising long-term cognitive outcome after the treatment of epileptic hypothalamic hamartomas using this method [55].…”