Cognitive outcome of surgery

Neuropsychological assessment in pediatric epilepsy surgery: A French procedure consensus

Neuropsychological assessment is a mandatory part of the pre- and post-operative evaluation in pediatric epilepsy surgery. The neuropsychology task force of the ILAE - French Chapter aims to define a neuropsychological procedure consensus based on literature review and adapted for French practice. They performed a systematic review of the literature published between 1950 and 2023 on cognitive evaluation of individuals undergoing presurgical work-up and post-surgery follow-up and focused on the pediatric population aged 6-16. They classified publications listed in the PubMed database according to their level of scientific evidence. The systematic literature review revealed no study with high statistical power and only four studies using neuropsychological scales in their French version. Afterwards, the experts defined a neuropsychological consensus strategy in pediatric epilepsy surgery according to the psychometric determinants of cognitive tests, specificity of epilepsy, surgery context, French culture and literature reports. A common French neuropsychological procedure dedicated to pediatric epilepsy surgery is now available. This procedure could serve as a guide for the pre- and post-surgical work-up in French centers with pediatric epilepsy surgery programs. The main goal is to anticipate the functional risks of surgery, to support the postoperative outcome beyond the seizure-related one, while taking into consideration the plasticity and vulnerability of the immature brain and allowing the possibility of collaborative studies.

Is There a Cognitive Decline in Pediatric Patients Following Epilepsy Surgery?

BACKGROUND

Epilepsy surgery is currently the only way to cure drug-resistant epilepsy (DRE). The loss of epileptic activity or its propagation in the developing brain may not only result in seizure freedom but also be associated with further positive effects. Here, we analyzed the cognitive development of children and adolescents with DRE after epilepsy surgery.

METHODS

We evaluated retrospectively the cognitive development of children and adolescents before and after epilepsy surgery.

RESULTS

Fifty-three children and adolescents underwent epilepsy surgery at a median age of 7.62 years. Overall seizure freedom was 86.8% at a current median observation period of 20 months. Presurgically, 81.1% had the clinical diagnosis of cognitive impairment, which was confirmed by standardized tests in 43 of 53 patients (76.7%). Further 10 patients had severe cognitive impairment rendering a standardized test impossible. The median intelligence quotient (IQ)/development quotient value was 74. After surgery, caretakers reported developmental progress in all patients, whereas the median IQ decreased slightly (P = 0.404). In eight patients the IQ points decreased after surgery; however, their individual raw scores increased in line with their reported increase in cognitive abilities.

CONCLUSIONS

We did not detect any cognitive deterioration in children following epilepsy surgery. A loss of IQ points did not correspond to a real loss of cognitive abilities. These patients developed more slowly than age-matched peers with an average development speed but profited individually as seen in their raw scores. Therefore, an individual analysis of raw scores is relevant to assess the cognitive development after surgery.

Results of a 2-week novel robotic rehabilitation program in 18 children with prior hemispherectomy

BACKGROUND

Partial preservation of sensory and motor functions in the contralateral extremities after hemispherectomy is likely secondary to cortical reorganization of the remaining hemisphere and can be improved by rehabilitation. This study aims to investigate behavioral changes that may occur after a 2-week novel robotic rehabilitation program in 18 children with prior anatomic hemispherectomy. Other conventional rehabilitation methods were also reviewed and compared.

METHODS

This study examined the impact of a novel robotic rehabilitation 2-week program on 18 hemispherectomy patients (average age 14.3 ± 3.9 years; age at hemispherectomy 5.6 ± 4.5 years).

RESULTS

Statistically significant improvements were seen in the six-minute walk test (29 m, p < 0.001), Canadian Occupational Performance Measure performance (1.64 points, p = 0.002) and satisfaction (2.49 points, p = 0.001), and individual perceived performance on survey (1.72 points, p = 0.042). Fifteen patients showed improvement in the upper extremity Fugl-Meyer scores with an average increase of 3 points (p = 0.006).

CONCLUSION

This study demonstrates clinically meaningful and statistically significant improvements in motor function and behavior following a novel robotic rehabilitation two-week program.

Intelligence quotient (IQ) as a predictor of epilepsy surgery outcome

INTRODUCTION

About one-third of patients with epilepsy have a refractory form which is associated with important economic and psychosocial burden. Most of these patients also suffer from comorbidities. One of the most frequent is cognitive impairment. Resective surgery or neuromodulation techniques may improve seizure control. Several factors have been proposed as potential predictors of the success of surgery regarding seizure frequency. We aimed to study preoperative cognitive performance as a predictor of the epilepsy surgery outcome.

METHODS

In this ambispective study we studied total intelligence quotients (IQ) measured before surgery with the Wechsler Adult Intelligence Scale (WAIS) as a potential predictor of Engel Class at 1 year after surgery. Then we included IQ in a multivariate model and tested its performance.

RESULTS

Preoperative IQ was a significant and independent predictor of the Engel Class at 1 year after surgery (OR 0.94; CI 0.90-0.98; p = 0.007). The multivariate model including the age at epilepsy onset, education level, sex, and the type of surgery (resective versus palliative surgery) showed an area under the ROC curve of 0.85.

CONCLUSIONS

A low intelligence level may constitute a marker of worse prognosis after epilepsy surgery. However, other predictors should also be considered when evaluating surgical candidates.

A methodological perspective on the cognitive outcome of epilepsy surgery in children and adolescents

PURPOSE

The purpose of the study was to explore the impact of timing and test specificity of cognitive outcome measures after pediatric epilepsy surgery.

METHODS

A consecutive national cohort of 114 children with medically resistant epilepsy having had resective epilepsy surgery were screened for children tested with a complete age-appropriate Wechsler Intelligence test at two or three time-points. This provided 43 children for analyses. Composite subscale scores were assessed in comparison to index and intelligence quotient (IQ) scores.

RESULTS

We found a main effect of time in seizure-free children for full-scale IQ (FSIQ); F(2, 42) = 6.49 with higher T2 measures compared with T1 (M_Diff = 5.46, p = .006). There was a difference in FSIQ scores between seizure-free and nonseizure-free children at T2; M = 7.31, 95% confidence interval (CI) [0.05 to 14.57], t(38) = 2.04, p = .049, favoring seizure-free children. A statistical difference between composite scale scores and index scores was found with medium to large effect. The correlation of medical treatment (anti-epileptic drug (AED)) change and score differences in FSIQ outcome was significant (p = .041), with less AED correlated with a higher FSIQ. All children with left-temporal surgery had a stable or improved verbal comprehension composite subscale score outcome at T2 regardless of seizure status.

CONCLUSION

Our results correspond to some longitudinal studies with outcome measures >2 years, in contrast to short-term studies ≤2 years with a stable outcome. Our study supports the fact that the specificity of the used tests and the timing of assessments after pediatric epilepsy surgery are essential factors for the clinical validity of outcome measures. However, there are further needs of extensive longitudinal studies to provide a better understanding of life-long cognitive development and impact after childhood epilepsy surgery.

Increase in cognitive function is seen in many single-operated pediatric patients after epilepsy surgery

PURPOSE

The recurrent seizures of pediatric drug-resistant epilepsy (DRE) are known to impair brain development and can lead to a loss in cognitive functioning. Surgery is increasingly being used to treat children with DRE. This study investigates the pre- and postoperative cognitive function in a pediatric epilepsy surgery cohort as well as predictive determinants of change in intelligence quotient (IQ) following surgery.

METHODS

A consecutive series of 91 Danish children who underwent focal resective epilepsy surgery between January 1996 and December 2016 were included. All underwent preoperative cognitive evaluation and were reevaluated at 1-year and/or 2-year follow-up. Single-operated and multi-operated patients were examined separately.

RESULTS

79 of 91 patients were single-operated. Single-operated patients received less anti-epileptic drugs (AED) and experienced a decrease in seizure frequency postoperatively, p < 0.001. IQ increased postoperatively (IQ change ± standard deviation: 3.3 ± 14.0), p < 0.05. High preoperative seizure frequency was a significant predictor for decreased IQ, p < 0.01. Multi-operated patients did not experience a reduction in AED treatment. Surgery and continued AED treatment did, however, result in significantly better seizure control, p < 0.01. IQ remained unchanged in multi-operated patients.

CONCLUSION

Epilepsy surgery allowed for IQ gains in single-operated patients. Preoperative seizure frequency was a significant predictor of IQ change following surgery. Interactions between other, not included, possible predictors remain to be examined. Single-operated patients had the best cognitive outcome. The inclusion of a non-surgical control group is needed to assess the extent of the beneficial effects of surgery on cognitive ability.

Improvement of intellectual outcomes in 20 children with refractory epilepsy after individualized surgery

Background:

Refractory epilepsy is a common and troublesome neurosurgical disease. This study is designed to compare seizure control and degrees in intellectual outcome in children with refractory epilepsy after surgical treatment.

Methods:

20 children with refractory epilepsy were treated with tailored epilepsy surgery or vagus nerve stimulation (VNS). We used the Engel Epilepsy Surgery Outcome Scale to evaluate seizure control and the Wechsler Intelligence Scale for Children, fourth edition (WISC-IV), to test the children's intellectual outcomes 7-day preoperative and 3-, 6-, and 12-month postoperative.

Results:

In total, 14 cases were seizure free (Engel I) and 2 cases to have suffered few attacks since surgery (Engel II). In two cases, the frequency of seizures decreased by >90% (Engel III). In the remaining two cases, the effects of surgery on seizure control were not obvious (Engel IV). All children completed the WISC-IV test. On average, postoperative intelligence quotient (IQ) increased by 6.35 points 12-month postsurgery compared with the results of the preoperative tests (P < 0.01). Second, intellectual outcomes after surgery in the Engel I and II groups increased by >3.88 points compared with in the Engel III and IV groups (P < 0.05). Finally, there were no fatal complications over the long-term follow-up except for intracranial infection of two cases; postoperative subcutaneous hematoma occurred in one case and hoarseness in one case.

Conclusion:

Individualized epilepsy surgery is safe and effective for children with refractory epilepsy. It can control or reduce the frequency of postoperative attacks as well as improve postoperative intellectual outcomes to different degrees.

Temporal lobe epilepsy in infants and children

Clinical expression of temporal lobe seizures is different with a more diverse and more extensive etiology in infants and children than it is in adults. It is dominated by cortical dysplasia, low-grade tumors and perinatal damage. Hippocampal sclerosis, although less frequent, exists in children usually as a dual pathology associated with ipsilateral neocortical lesions. The clinical semiology of temporal seizures is more varied, and sometimes misleading. Motor features including tonic, clonic or myoclonic behaviors, and infantile spasms predominate in infants. Classical complex partial seizures with behavioral arrest and automatisms, as well as lateralizing signs are rare and occur mostly with onset after the age of two years. Interestingly, aura, emotional, and autonomic signs seem to be independent on the brain maturation process. Moreover, the neuropsychological profile varies according to age of onset and duration, lateralization of the focus and etiology. Quality of care benefits from individual cognitive assessment for memory and emotional processes.