Predictors of language skills in the long term after pediatric epilepsy 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.

Neurophysiology, Neuropsychology, Epilepsy, 2022: Hills We Have Climbed and the Hills Ahead. Cognition and Sensory Systems in Healthy and Diseased Subjects

This article summarizes selected presentations from a session titled "Cognition and Sensory Systems in Healthy and Diseased Subjects", held to highlight and honor the work of Dr. Marilyn Jones-Gotman. The session was part of a two-day symposium, "Neurophysiology, Neuropsychology, Epilepsy, 2022: Hills We Have Climbed and the Hills Ahead". The session presented research on epilepsy and sensory systems by colleagues and former trainees of Dr. Jones-Gotman. The extended summaries provide an overview of historical and current work in the neuropsychology of epilepsy, neuropsychological and neuroimaging approaches to understanding brain organization, sex differences in brain mechanisms underlying neurological disorders, dietary influences on brain function and cognition, and expertise in olfactory training and language experiences and their implications for brain organization and structure.

Quality of life of children with residual seizures after epileptic resection surgery

Objective

Epilepsy dramatically affects the quality of life (QoL) of children, and resection surgery can improve their QoL by reducing seizures or completely controlling them. Children who have postoperative seizures tend to show a poorer QoL. The aim of the present study was to investigate the QoL of children with seizures after resection surgery and its influencing factors.

Methods

In the present study, we retrospectively reviewed 151 consecutive children who underwent resection surgery. We then divided them into two groups, seizure and seizure-free groups, according to the seizure outcomes 1 year after surgery. Variables were categorized into a number of factor types such as preoperative factors, surgery-related factors, postoperative factors, and family factors. QoL and seizure outcomes more than 3 years after surgery were assessed according to the ILAE seizure outcome classification and the CHEQOL-25 scale.

Results

Forty-three (28.5%) of the 151 children had seizures 1 year after surgery, and two children died during the follow-up period. The mean CHEQOL-25 scale for children with seizures was 63.5 ± 18.2, and 20 (48.8%) patients had poor QoL. Surgery-related factors, such as surgical complications and surgical sequelae, were not statistically associated with QoL. Preoperative language development retardation or language dysfunction [odds ratio (OR) = 29.3, P = 0.012) and postoperative ILAE seizure outcome classification (OR = 1.9, P = 0.045)] were significantly associated with QoL.

Significance

Children with seizures after resection surgery had a relatively poor QoL. Surgery-related factors, such as surgical complications and surgical sequelae, cannot predict the QoL. Preoperative language development retardation or language dysfunction and postoperative ILAE seizure outcome classification were independent predictors of the quality of life (QoL). For children who could not achieve the expected freedom from seizure after surgery, a lower ILAE grade (ILAE 1-3) is also an acceptable outcome since it predicts a higher QoL.

Long-term outcomes of children with drug-resistant epilepsy across multiple cognitive domains

AIM

To simultaneously evaluate long-term outcomes of children with drug-resistant epilepsy (DRE) across multiple cognitive domains and compare the characteristics of participants sharing a similar cognitive profile.

METHOD

Participants were adolescents and young adults (AYAs) diagnosed with DRE in childhood, who completed a comprehensive neuropsychological battery evaluating intelligence, memory, academic, and language skills at the time of surgical candidacy evaluation and at long-term follow-up (4-11y later). Hierarchical k-means clustering identified subgroups of AYAs showing a unique pattern of cognitive functioning in the long-term.

RESULTS

Participants (n=93; mean age 20y 1mo [standard deviation {SD} 4y 6mo]; 36% male) were followed for 7 years (SD 2y 4mo), of whom 65% had undergone resective epilepsy surgery. Two subgroups with unique patterns of cognitive functioning were identified, which could be broadly categorized as 'impaired cognition' (45% of the sample) and 'average cognition' (55% of the sample); the mean z-score across cognitive measures at follow-up was -1.86 (SD 0.62) and -0.23 (SD 0.54) respectively. Surgical and non-surgical patients were similar with respect to seizure control and their long-term cognitive profile. AYAs in the average cognition cluster were more likely to have better cognition at baseline, an older age at epilepsy onset, and better seizure control at follow-up.

INTERPRETATION

The underlying abnormal neural substrate and seizure control were largely associated with long-term outcomes across cognitive domains.

Cognitive Outcome After Epilepsy Surgery in Children

Cognitive dysfunction in children with epilepsy is primarily contributed by etiology, seizures, frequency of interictal epileptiform discharges, and adverse effects of antiepileptic drugs. The direct effect of epilepsy surgery on cognitive outcome depends on two key factors: the function that is present in the epileptogenic zone to be removed, and the dysfunction outside the epileptogenic zone caused by epilepsy. Studies on cognitive outcome in children after various types of epilepsy surgery estimate "no significant change" in about 70% of children, improvement in cognition in 10%-15%, and decline in 10%-15%. In young children with epileptic encephalopathy, the reversible dysfunction outside the epileptogenic zone is larger and hence carry better chances of improved outcome after successful surgery. If the epileptogenic zone harbors significant cognitive function (memory, language, or other function), then a decline in function may occur with its resection. Understanding the pathophysiological basis for the cognitive changes after epilepsy surgery assists in counseling patients and families before surgery.

Does education play a role in language reorganization after surgery in drug refractory temporal lobe epilepsy: An fMRI based study?

OBJECTIVES

Patients with drug refractory epilepsy (DRE) and a high level of education may differ in their language recovery after surgery. Our aim was to determine whether there were differences in the extent of improvement and pattern of reorganization of language functions on functional magnetic resonance imaging (fMRI) after surgery to treat refractory temporal lobe epilepsy (TLE) between patients with more than 12 years of formal education versus those with a shorter period of regular schooling.

METHODS

After approval by an institutional ethics committee, 60 right-handed, adult patients of left TLE and 20 right-handed, healthy controls were recruited to the study. Multiple aspects of language (Repetition, Naming, Word fluency, Visual word and Comprehension reading) were tested using the Indian Aphasia Battery (IAB) in the Hindi language; fMRI was performed using a standardized Hindi language paradigm (lexical, semantic, syntactic and comprehension components) in both cases and controls, before and after an anterior temporal lobectomy (in cases) with a 1.5T MR Scanner. An array of performance tests of intelligence and the verbal adult intelligence scale (VAIS) were used to measure the Intelligence Quotient (IQ) in Left TLE (LTLE) patients before and after surgery. Language laterality was estimated using the laterality index (LI-toolbox-spm8). Cohen's d test was performed to determine the effect sizes of the differences in the IAB scores, and Pearson's correlation was applied between regional (IFG and STG) activation in controls and TLE patients with more than 12 years of schooling [higher educational status (HES subgroup)] and those with less than 12 years of schooling [lower educational status (LES subgroup)].

RESULTS

At the baseline, clinical testing with IAB showed better scores in controls than in cases. Better scores were observed in subjects with higher levels of education than in those with lower levels of education. An improvement was observed in IQ scores in both the HES and LES groups after ATLR; significant worsening in the abstract ability subtest was noted in the LES group, whereas in the HES group there was an improvement. Blood-oxygen-level dependent (BOLD) activation during language tasks was observed in both cerebral hemispheres in the TLE cases, while it was observed in the traditional left hemispheric language areas in controls. Postoperatively, greater BOLD activation was observed in the left inferior frontal gyri (IFG, r=0.65^*; p<0.05), middle frontal gyrus (MFG, r=0.77^**; p<0.01) superior temporal gyri (STG, r=0.88^* p<0.02) and angular gyrus (AG, r=0.73^*; p<0.04) in HES compared to LES subjects. Similarly, LI showed left lateralization of the frontal (LIw=0.77 & 0.71) and temporal (LIw=0.74 & 0.5) regions in controls and the TLE group (post-surgery) compared to the pre-surgery group during language tasks.

CONCLUSIONS

Greater improvement in language skills and BOLD activation in the left hemisphere in TLE-patients (after epilepsy surgery) with a high level of education was similar to that of healthy controls, implying that education has an effect on the functional reorganization/recovery of language areas.