Epilepsy surgery for people with a low IQ

Low IQ predicts worse long-term seizure outcome after resective epilepsy surgery - A propensity score matched analysis

OBJECTIVE

To describe long-term seizure outcomes in patients with IQ < 70 undergoing resective epilepsy surgery and to analyse whether baseline IQ predicts seizure outcome.

METHODS

Patients undergoing focal resective epilepsy surgery 1995-2017 at age ≥ 4 years were identified in the population-based Swedish National Epilepsy Surgery Register. Two-year, five-year and long-term (10-20-year follow-up) outcomes were analysed. Seizure outcomes of patients with IQ ≥ 70 and IQ < 70 at baseline were compared in the full cohort and between propensity score matched groups.

RESULTS

Follow-up data were available for 884 patients, 79 of whom had IQ < 70. Matched controls were found for 74 of the IQ < 70 patients. Preoperative MRI pathology was unifocal in 54 % and 79 % of IQ < 70 and IQ ≥ 70 patients before matching compared to 58 % and 62 % after matching, respectively. Patients with IQ < 70 achieved significantly worse seizure outcomes at all time points both when analysing the full cohort and the matched groups. After matching, the proportions of seizure-free patients in the IQ < 70 group were 28 %, 32 % and 32 % at the 2-year, 5-year and long-term follow-ups, respectively. Corresponding figures in the IQ ≥ 70 group were 54 %, 62 % and 60 % (p for difference between IQ groups 0.004, 0.002 and 0.049). In the IQ < 70 group, 36 %, 29 % and 45 % had a ≥ 75 % reduction in seizure frequency at the respective three follow-ups.

CONCLUSION

Low preoperative IQ predicts lower chances of seizure freedom after resective epilepsy surgery and few patients with IQ < 70 remain completely seizure-free in the long term. Nevertheless, a significant proportion had a reduction in seizure frequency of at least 75 % at long-term follow-up, indicating an important palliative potential of resective surgery for epilepsy patients with intellectual disability.

Treatment of psychiatric comorbidities in patients with epilepsy and intellectual disabilities: Is there a role for the neurologist?

This paper will explore the nature of psychiatric co-morbidities in people with an intellectual disability (ID) who have epilepsy. The complexity of clinical presentations and associated co-morbidities require thorough assessment utilising both neurological and psychiatric skills. The neurologist plays a central role in the management of epilepsy in people with ID and therefore requires basic competencies in the assessment of neuropsychiatric co-morbidities. This is key to liaison with other specialist services to ensure individuals receive holistic person-centred care. This article is part of the Special Issue "Obstacles of Treatment of Psychiatric Comorbidities in Epilepsy".

Factors affecting seizure outcome after epilepsy surgery: an observational series

IMPORTANCE

Surgical treatment can bring seizure remission in people with focal epilepsy but requires careful selection of candidates.

OBJECTIVES

To determine which preoperative factors are associated with postoperative seizure outcome.

DESIGN

We audited seizure outcome of 693 adults who had resective epilepsy surgery between 1990 and 2010 and used survival analysis to detect preoperatively identifiable risk factors of poor seizure outcome.

RESULTS

Seven factors were significantly associated with increased probability of recurrence of seizures with impaired awareness postsurgery: MRI findings (eg, HR adjusted for other variables in the model 2.5; 95% CI 1.6 to 3.8 for normal MRI compared with hippocampal sclerosis), a history of secondarily generalised convulsive seizures (2.3; 95% CI 1.7 to 3.0 for these seizures in the previous year vs never), psychiatric history (1.3; 95% CI 1.1 to 1.7), learning disability (1.8; 95% CI 1.2 to 2.6) and extratemporal (vs temporal) surgery (1.4; 95% CI 1.02, 2.04). People with an older onset of epilepsy had a higher probability of seizure recurrence (1.01; 95% CI 1.00, 1.02) as did those who had used more antiepileptic drugs (1.05; 95% CI 1.01 to 1.09). Combinations of variables associated with seizure recurrence gave overall low probabilities of 5-year seizure freedom (eg, a normal MRI and convulsive seizures in the previous year has a probability of seizure freedom at 5 years of approximately 0.19).

CONCLUSIONS AND RELEVANCE

Readily identified clinical features and investigations are associated with reduced probability of good outcome and need consideration when planning presurgical evaluation.

Behavioral disorder in people with an intellectual disability and epilepsy: A report of the Intellectual Disability Task Force of the Neuropsychiatric Commission of ILAE

The management and needs of people with intellectual disability (ID) and epilepsy are well evidenced; less so, the comorbidity of behavioral disorder in this population. "Behavioral disorder" is defined as behaviors that are difficult or disruptive, including stereotypes, difficult or disruptive behavior, aggressive behavior toward other people, behaviors that lead to injury to self or others, and destruction of property. These have an important link to emotional disturbance. This report, produced by the Intellectual Disability Task Force of the Neuropsychiatric Commission of the ILAE, aims to provide a brief review of some key areas of concern regarding behavioral disorder among this population and proposes a range of research and clinical practice recommendations generated by task force members. The areas covered in this report were identified by experts in the field as being of specific relevance to the broad epilepsy community when considering behavioral disorder in persons with epilepsy and ID; they are not intended to be exhaustive. The practice recommendations are based on the authors' review of the limited research in this field combined with their experience supporting this population. These points are not graded but can be seen as expert opinion guiding future research and clinical practice.

Epilepsy & IQ: the clinical utility of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) indices in the neuropsychological assessment of people with epilepsy

We examined Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) General Ability Index (GAI) and Full Scale Intelligence Quotient (FSIQ) discrepancies in 100 epilepsy patients; 44% had a significant GAI > FSIQ discrepancy. GAI-FSIQ discrepancies were correlated with the number of antiepileptic drugs taken and duration of epilepsy. Individual antiepileptic drugs differentially interfere with the expression of underlying intellectual ability in this group. FSIQ may significantly underestimate levels of general intellectual ability in people with epilepsy. Inaccurate representations of FSIQ due to selective impairments in working memory and reduced processing speed obscure the contextual interpretation of performance on other neuropsychological tests, and subtle localizing and lateralizing signs may be missed as a result.

Ethical considerations in paediatric neurology: neuromuscular disease and epilepsy

The pace of developing technology with respect to many diagnostic tests, as well as available treatments including artificial ventilation, may have progressed at a faster rate than our ethical, humane ability to decide on the optimal choices for our patients. In fact, who should make these choices; physicians or patients and families? Certain ethical aspects of neuromuscular disorders and epilepsy are reviewed. For neuromuscular disease, the example of Duchenne muscular dystrophy (DMD) with regards to genetic testing, relatively early wheelchair placement and individualised invasive ventilation is discussed. In epilepsy, performing neurosurgery in severely impaired children is probably appropriate in some cases if desired by the family. Financial and human costs restrict therapies and testing for epilepsy as well as other neurological and medical diseases. Whether it is ethical to consider costs in medical treatment or not, it is certainly a reality.

Presurgical epilepsy localization with interictal cerebral dysfunction

Localization of interictal cerebral dysfunction with 2-[(18)F]fluoro-2-D-deoxyglucose (FDG) positron emission tomography (PET) and neuropsychological examination usefully supplements electroencephalography (EEG) and brain magnetic resonance imaging (MRI) in planning epilepsy surgery. In MRI-negative mesial temporal lobe epilepsy, correlation of temporal lobe hypometabolism with extracranial ictal EEG can support resection without prior intracranial EEG monitoring. In refractory localization-related epilepsies, hypometabolic sites may supplement other data in hypothesizing likely ictal onset zones in order to intracranial electrodes for ictal recording. Prognostication of postoperative seizure freedom with FDG PET appears to have greater positive than negative predictive value. Neuropsychological evaluation is critical to evaluating the potential benefit of epilepsy surgery. Cortical deficits measured with neuropsychometry are limited in lateralizing and localizing value for determination of ictal onset sites, however. Left temporal resection risks iatrogenic verbal memory deficits and dysnomia, and neuropsychological findings are useful in predicting those at greatest risk. Prognostication of cognitive risks with resection at other sites is less satisfactory.

The clinical utility of the Warrington Recognition Memory Test in people with a low IQ

The sensitivity of the Warrington Recognition Memory for Faces (RMF) to reliably localize temporal lobe dysfunction in surgical epilepsy candidates is not as strong as that of the Recognition Memory for Words (RMW). Previous research has indicated that its diagnostic utility is improved in patients with lower IQs. Data from 114 patients with unilateral hippocampal sclerosis was retrospectively examined to explore the accuracy of both subtests in patients with IQs within the low average/borderline impaired and intellectual disability ranges. In our group, the RMF did not discriminate between right and left hippocampal sclerosis, whilst the RMW did. However, many patients functioning within the intellectual disability range are unable to complete the RMW. There is a need to develop neuropsychological protocols appropriate for this group.