Parents' view of the cognitive outcome one year after pediatric epilepsy surgery.

OBJECTIVES: The cognitive outcome of pediatric epilepsy surgery has mainly been examined on the basis of standardized tests. Here, we analyzed the outcome in six cognitive domains from the parents' view. METHODS: Included were consecutive surgical pediatric patients whose parents filled-in a comprehensive questionnaire on cognitive problems in children and adolescents (Kognitive Probleme bei Kindern und Jugendlichen (KOPKIJ); Gleissner et al. 2006) at the preoperative baseline (T1) as well as twelve months thereafter (T2). All children also underwent standard neuropsychological assessments at T1 and T2. RESULTS: Parents of 96 patients provided pre- and postoperative KOPKIJ data. Overall, 80% of the children became seizure-free at the follow-up. Group means indicated a strong positive effect of time on KOPKIJ and neuropsychological performance. We found postoperative improvements in five out of six cognitive domains (language, memory, executive functions, attention, school; unchanged: visuospatial abilities). Individually, improvements were twice as likely as declines. However, 33 patients (35%) experienced significant decline in at least one cognitive domain. Later onset of epilepsy resulted in better performance but had no effect on change scores. Seizure-free status, lower antiseizure drug load, and stronger drug reduction after surgery contributed to postoperative cognitive improvements as perceived by the parents; no other effects of clinical factors were obtained (e.g., localization/lateralization). Despite their similar outcome patterns, change scores as derived from parental ratings and neuropsychological assessment were not correlated. CONCLUSIONS: Parents acknowledged the overall positive neurocognitive development after pediatric epilepsy surgery as previously shown by standardized tests. Seizure freedom and lower antiseizure drug load contributed to the beneficial cognitive outcome. Even if cognitive improvements outweighed declines, a risk for cognitive decline with impact on everyday functioning does exist.

Long-term outcome of hemispheric surgery at different ages in 61 epilepsy patients.

OBJECTIVE: Hemispheric neurosurgery is an established treatment for severe epilepsy caused by extended unilateral brain pathology. However, it is still an unresolved question at which age surgery should best be performed. In light of decreasing plasticity and the cumulative impact of seizures and anticonvulsants on neurodevelopment, early surgery appears preferable. METHODS: We retrospectively investigated the medical, cognitive-behavioural and psychosocial long-term outcome (follow-up: 9.4 years (1.1-19.4)) of hemispherectomy as a function of age at surgery (early: <7 years/intermediate: 7-16 years/late: >16 years) based on a structured postal survey in a large patient sample (N=61/81, return rate: 75%). RESULTS: At follow-up, 45 (74%) patients were seizure free. Presurgical levels of intelligence were below average in most patients (79%) and postsurgical cognition largely resembled the presurgical capacities. Best seizure outcome was obtained for early surgery patients (90% seizure free). Patients with late surgery, however, exhibited higher presurgical and postsurgical intelligence and better psychosocial achievements. Binary logistic regression identified better presurgical intelligence and higher age at surgery as positive predictors of postsurgical intelligence. Lower presurgical intelligence and postsurgical seizure freedom predicted intellectual pre-post improvements. CONCLUSIONS: Our data confirm the efficacy and cognitive safety of hemispheric surgeries performed at different ages. Eligible older and high functioning patients can be perfect candidates. Presurgical intelligence serves as indicator of the functional integrity of the contralateral hemisphere, which mainly determines postsurgical cognition and psychosocial outcome. Seizure freedom promotes cognitive improvement. As many unknown factors determined age at surgery, our retrospective data neither question early surgeries nor suggest postponing surgery.

Neuropsychological results in pediatric patients with epilepsy surgery in the parietal cortex.

This study evaluated pre- and postoperatively cognitive functions in 15 pediatric patients with surgically treated parietal lobe epilepsy (PLE). Seizure outcome was very satisfying with 87% seizure-free patients 1 year after surgery, and 82% in the long-term follow-up. Preoperative intelligence was in the subaverage range. Impairments in specific cognitive functions (memory, attention, executive functions) were evident preoperatively for 39-66% of patients. Behavioral disorders were rare. No side differences (left versus right PLE) were indicated pre- or postoperatively. Postoperative improvements were found in behavior and attention; other cognitive functions were unchanged. All in all, this preliminary study indicated a satisfactory neuropsychological outcome in pediatric patients with PLE.

Postsurgical outcome in pediatric patients with epilepsy: a comparison of patients with intellectual disabilities, subaverage intelligence, and average-range intelligence.

PURPOSE: Intellectual disabilities are often associated with bilateral or diffuse morphologic brain damage. The chances of becoming seizure free after focal surgery are therefore considered to be worse in patients with intellectual disabilities. The risk of postoperative cognitive deficits could increase because diffuse brain damage lowers the patient's ability to compensate for surgically induced deficits. Several studies in adult patients have indicated that IQ alone is not a good predictor of postoperative cognitive and seizure outcome. Our study evaluated this subject in children and adolescents. METHODS: Pediatric patients with intellectual disabilities (IQ < or = 70), subaverage intelligence (IQ between 71 and 85), or average-range intelligence (IQ > 85) were matched according to several clinical and etiologic criteria to determine the influence of IQ (N = 66). RESULTS: No dependency of seizure outcome, postoperative cognitive development, and behavioral outcome on the IQ level was found. All groups slightly improved in attention while memory functions tended to decrease and executive functions were stable. School placement remained unchanged for the majority of patients. Between 67 and 78% were seizure free 1 year after surgery (Engel outcome class I). CONCLUSIONS: IQ alone is not a good predictor of postoperative outcome in pediatric patients with epilepsy. As with patients of average-range intelligence, the decision to operate on patients with a low level of intelligence should depend on the results of the presurgical diagnostics. If the results of the neuropsychological examination indicate diffuse functional impairment, this should not hinder further steps, if all other findings are consistent.

Memory outcome after selective amygdalohippocampectomy in patients with temporal lobe epilepsy: one-year follow-up.

PURPOSE: In a previous study we reported clinically significant memory declines 3 months after selective amygdalohippocampectomy (SAH) in 140 patients with mesial temporal lobe epilepsy, particularly if the resection was left-sided. We supposed that the observed postoperative impairments might have reflected acute effects of surgery. Therefore we evaluated in the present study whether a recovery can be found 1 year after surgery. METHODS: Verbal and nonverbal memory functions were assessed in 115 patients before and 3 and 12 months after unilateral SAH. RESULTS: No recovery of postoperative verbal memory declines was found in the left-SAH group. Clinically meaningful losses were still evident in 33 to 50% of patients. In right-SAH patients, a recovery of verbal memory was indicated, and effects of surgical complications were no longer evident. One year after surgery, the corresponding preoperative performance was the only significant predictor of a postoperative change in the left-SAH group. CONCLUSIONS: Verbal memory decline observed 3 months after left SAH is persistent 1 year after surgery. Declines in verbal memory, which were observed in some right-SAH patients at the short-term follow-up, seem to be temporary.

Analysis of different types of resection for pediatric patients with temporal lobe epilepsy.

OBJECTIVE: Resection strategies for the treatment of temporal lobe epilepsy (TLE) are a matter of discussion. Few data on the significance of resection type are available for pediatric patients with TLE. METHODS: Data for a series of 89 children who were surgically treated for TLE were analyzed. A first cohort of patients were mainly surgically treated with anterior temporal lobectomies. For a second cohort, resections were preoperatively "tailored" to the lesion and presumed epileptogenic area. RESULTS: The follow-up period was 46 months (range, 14-118 mo). Seventy-seven patients (87%) attained satisfactory seizure control (82% Engel Class I and 5% Class II). For 12 patients (13%), seizure control was unsatisfactory (8% Class III and 5% Class IV). Anterior temporal lobectomies resulted in 94% satisfactory seizure control (33 patients), whereas the success rates were only 74% (20 patients) for amygdalohippocampectomy (AH) (P = 0.023) and 77% (13 patients) for lesionectomy plus hippocampectomy (not significant). All patients who underwent purely lateral temporal lesionectomies became seizure-free (14 patients). Logistic regression revealed the factors of AH (P = 0.021) and left-side surgery (P = 0.017) as significant predictors of unsatisfactory seizure control. Satisfactory seizure control was not dependent on the histopathological diagnoses. There was a low rate of verbal memory deterioration after left-side operations. Neuropsychological deterioration was rare after right temporal resections. Attentional and contralateral functions improved after surgery. CONCLUSION: Surgery for the treatment of juvenile TLE is successful and safe, but the resection type may influence outcomes. Results after AHs were disappointing, probably because of difficulties in precise localization of the epileptogenic focus among children. Neuropsychological results demonstrated minimal rates of deterioration and significant improvements in contralateral functions. Surgical treatment of juvenile TLE should be encouraged, but the use of especially left AH should possibly be restricted.

Memory outcome after selective amygdalohippocampectomy: a study in 140 patients with temporal lobe epilepsy.

PURPOSE: The technique of selective amygdalohippocampectomy (SAH) was originally developed in epilepsy surgery to spare unaffected brain tissue from surgery, thus minimizing the cognitive consequences of temporal lobe surgery. The results of previous studies, however, are equivocal in this regard. This study evaluated memory after SAH in a large sample of patients with mesial temporal lobe epilepsy. METHODS: The 140 patients received material-specific memory tests before and 3 months after unilateral SAH. RESULTS: Significant declines in all aspects of verbal learning and memory were found particularly for the left resected group. With reliability-of-change indices, a high number of patients showed postoperative verbal memory declines, < or = 51% in left SAH and < or = 32% in right SAH. For left SAH, a higher preoperative verbal memory performance, a lower preoperative nonverbal memory score, an older age at surgery, and a later onset of epilepsy predicted a stronger decline in verbal memory. After right SAH, the risk for a verbal memory decline was slightly increased when patients had surgical complications or a presurgical evaluation with bilateral intrahippocampal depth electrodes. Results concerning nonverbal memory were less clear. CONCLUSIONS: The results clearly indicate, that particularly left SAH can lead to a significant decline in memory functions. Predictors of postoperative verbal memory were similar to those reported for temporal lobectomy. Postoperative deteriorations were broader and stronger in our study than in previous studies. We discuss methodologic differences (sample size, retest interval, extent of resection) and other factors as possible reasons.

Memory reorganization in adult brain: observations in three patients with temporal lobe epilepsy.

We present three patients with left-sided temporal lobe epilepsy who exhibited preoperatively a neuropsychological pattern characteristic for interhemispheric language transfer (marked nonverbal memory deficits, relatively preserved verbal memory and language performance). The Wada test indicated atypical language dominance in two patients, but one patient was clearly left hemispheric language dominant. All patients showed a marked recovery of nonverbal memory after left-sided surgery. Results are discussed with respect to memory transfer and plasticity for memory functions in the adult brain.