The Prevalence of Seizure Types among Individuals Referred for Phase I Neuropsychological Assessment: Demographic and Neuropsychological Characteristics

The prevalence of seizure types among the subpopulation of patients referred for phase I neuropsychological assessment likely differs from the prevalence of specific seizure types within the general seizure population. Understanding the prevalence of clinical diagnoses is critical to maximizing the predictive value of any assessment or diagnostic technique, clinical neuropsychological assessment of patients with seizures being no exception. Data from a series of 835 patients referred for phase I neuropsychological evaluation are used to report the prevalence of specific seizure types, as well as neuropsychological and demographic characteristics. Considerations for clinical neuropsychological research and practice are briefly discussed.     

Multivariate neuropsychological prediction of seizure lateralization in temporal epilepsy surgical cases

PURPOSE: Neuropsychological assessment can be of assistance in determining seizure lateralization in cases where EEG and MRI findings do not provide clear lateralizing data. While several studies have examined the lateralizing value of individual neuropsychological measures, clinicians are still in need of a statistically sound method that permits the incorporation of multiple neuropsychological variables to predict seizure lateralization in the individual patient. METHOD: The present study investigated the lateralizing value of several commonly used neuropsychological measures in a large sample of patients (n = 217) who eventually underwent surgical resection to treat their epilepsy. Side of surgery was used to operationally define seizure lateralization. A comparison of the relative utility of a multivariate versus univariate approach to predict seizure lateralization was conducted in temporal epilepsy cases. RESULTS: The results provide evidence for the incremental validity of neuropsychological measures, other than memory and IQ tests, in the prediction of seizure lateralization in patients with medically intractable epilepsy. These data indicate that a multivariate approach increases the accuracy of prediction of seizure lateralization for temporal lobe epilepsy cases. CONCLUSION: This study supports the use of a multivariate approach using neuropsychological measures to predict seizure lateralization in temporal epilepsy surgical candidates. Regression formulas are provided to enhance the clinical utility of these findings.     

Luria's approach to neuropsychological assessment.

A. R. Luria's approach to neuropsychological assessment was examined. Three basic points of departure from Luria are presented: his interpretation of cognitive activity as functional systems, his emphasis on the individualized approach, and the importance of the analysis of the errors. A distinction was introduced between Luria's neuropsychological testing, and Luria's neuropsychological approach; the former refers to the specific set of neuropsychological tests Luria used and developed and the latter, to the specific clinical use of these tests. It is emphasized that Luria's basic contribution to assessment in neuropsychology, refers to the clinical approach he proposed and developed. Problems related to the normalization and validity of neuropsychological tests are analyzed. It is concluded that different approaches in neuropsychological assessment are related to the specific goals for which neuropsychological assessment is performed.     

Lateralising value of neuropsychological protocols for presurgical assessment of temporal lobe epilepsy

PURPOSE: To estimate the value of neuropsychological measurements in determining the side of seizure onset for presurgical assessment in patients with temporal lobe epilepsy. The lateralising value of neuropsychological protocols was evaluated for all patients and in subpopulations depending on surgical outcome with regard to seizure control, speech dominance, neuropathology, and need for intracranial EEG recordings. METHODS: A battery of neuropsychological procedures was carried out preoperatively in 125 patients who underwent left (n = 66) or right (n = 59) temporal lobectomies. Binary logistic regression analysis was performed to find sets of variables that allowed the best prediction of the side of seizure onset (assumed to be the operated-on side). RESULTS: Combinations of noninvasive neuropsychological tests and Wada subscores showed the highest lateralising values: 80.8% for all patients, 79.4% in seizure-free patients, 86.0% in patients not rendered seizure free, 85.7% in left speech patients, 77.8% in non-left speech patients, 89.3% in patients with mesial temporal sclerosis (MTS), 78.1% in non-MTS patients, 80.3% in patients who underwent intracranial EEG recordings, and 77.3% in those who did not. CONCLUSIONS: The lateralising value (80-90%) of neuropsychological protocols appears similar to that of other tests widely accepted for lateralisation (ictal and interictal scalp EEG and neuroimaging). Attention should be paid to neuropsychological results, particularly from the Wada test, during presurgical assessment of temporal lobe epilepsy, as they can provide strong support for findings from other lateralising tests, particularly in patients with presumed MTS or in left-speech patients.     

Accuracy of clinical neuropsychological versus statistical prediction in the classification of seizure types

Many studies have reported on the pattern of neuropsychological test performance across varied seizure diagnosis populations. Far fewer studies have evaluated the accuracy of the clinical neuropsychologist in formulating an impression of the seizure diagnosis based on results of neuropsychological assessment, or compared the accuracy of clinical neuropsychological judgment to results of statistical prediction. Accuracy of clinical neuropsychological versus statistical prediction was investigated in four seizure classification scenarios. While both methods outperformed chance, accuracy of clinical neuropsychological classification was either equivalent or superior to statistical prediction. Results support the utility and validity of clinical neuropsychological judgment in epilepsy treatment settings.     

Indications and expectations for neuropsychological assessment in routine epilepsy care: Report of the ILAE Neuropsychology Task Force,Diagnostic Methods Commission, 2013–2017

The International League Against Epilepsy (ILAE) Diagnostic Methods Commission charged the Neuropsychology Task Force with the job of developing a set of recommendations to address the following questions: (1) What is the role of a neuropsychological assessment? (2) Who should do a neuropsychological assessment? (3) When should people with epilepsy be referred for a neuropsychological assessment? and (4) What should be expected from a neuropsychological assessment? The recommendations have been broadly written for health care clinicians in established epilepsy settings as well as those setting up new services. They are based on a detailed survey of neuropsychological assessment practices across international epilepsy centers, and formal ranking of specific recommendations for advancing clinical epilepsy care generated by specialist epilepsy neuropsychologists from around the world. They also incorporate the latest research findings to establish minimum standards for training and practice, reflecting the many roles of neuropsychological assessment in the routine care of children and adults with epilepsy. The recommendations endorse routine screening of cognition, mood, and behavior in new‐onset epilepsy, and describe the range of situations when more detailed, formal neuropsychological assessment is indicated. They identify a core set of cognitive and psychological domains that should be assessed to provide an objective account of an individual's cognitive, emotional, and psychosocial functioning, including factors likely contributing to deficits identified on qualitative and quantitative examination. The recommendations also endorse routine provision of feedback to patients, families, and clinicians about the implications of the assessment results, including specific clinical recommendations of what can be done to improve a patient's cognitive or psychosocial functioning and alleviate the distress of any difficulties identified. By canvassing the breadth and depth of scope of neuropsychological assessment, this report demonstrates the pivotal role played by this noninvasive and minimally resource intensive investigation in the care of people with epilepsy.     

Age of seizure onset, functional reorganization, and neuropsychological outcome in temporal lobectomy

Patients with early onset seizure disorder tend to have less cognitive decline following surgical resection than patients with late onset seizure disorder. Differential opportunity for presurgical cerebral functional reorganization has been proposed to account for this "age of onset" effect. However, the relationships between age of seizure onset, functional organization, and neuropsychological outcome remain incompletely understood. To shed additional light on these issues, we investigated 66 patients with anterior temporal lobectomies (37 left; 29 right), all of whom completed comprehensive neuropsychological assessment prior to and following surgical resection. The sample was divided into two groups: 34 patients with early onset (EO) epilepsy and 32 patients with late onset (LO) epilepsy. We found the typical age of onset effect: post-surgically, EO patients demonstrated relatively better outcome in multiple neuropsychological domains, especially verbal memory, compared to LO patients. Based on presurgical Wada testing, 23 patients were classified as having traditional cerebral functional organization (TFO) and 35 were classified as having nontraditional cerebral functional organization (NTFO). The NTFO group had an earlier age of seizure onset than the TFO group, and NTFO was more frequent in EO patients (70%) than LO patients (50%). NTFO patients demonstrated relatively better post-surgical outcome in several neuropsychological domains, compared to TFO patients. Our findings are consistent with the notion that functional reorganization may be an explanatory factor for the better neuropsychological outcome of EO epilepsy patients following anterior temporal lobectomy.     

Panayiotopoulos syndrome: A clinical,EEG, and neuropsychological study of 93 consecutive patients

Purpose: To explore the clinical, electroencephalography (EEG), neuropsychological features, and prognosis of Panayiotopoulos syndrome (PS). Methods: Of 1,794 children aged between 1 and 14 years referred for the first afebrile focal seizure, between January 1992 and December 2004, 93 (5.2%) had PS according to clinical criteria. Results: Age at onset ranged from 1.1 to 8.6 years, and was earlier in children with more than one seizure. Autonomic seizures followed a stereotypical onset and progression. Emesis, pallor, or flushing was almost always among the first symptoms that usually culminated in vomiting (77.4% of patients). More than half (55%) of seizures were longer than 30 min but these did not appear to affect remission and number of seizures. Interictal EEG showed great variability, with 79.5% of patients showing spikes of variable localizations and evolution over time; 16.1% had background abnormalities only, and 5.4% had consistently normal EEG studies. Onsets in five ictal EEGs were posterior or anterior—left or right. On neuropsychological testing, IQ and subtests of Wechsler Intelligence Scale for Children–Revised (WISC‐R) were within normal limits, although some minor statistically significant differences were found in arithmetic, comprehension, and picture arrangement in comparison with controls. Cumulative probability of recurrence was 57.6%, 45.6%, 35.1%, and 11.7% at 6, 12, 24, and 36 months, respectively, after the first seizure. Thirty‐four (58.6%) of 59 patients treated with antiepileptic drugs continued having seizures before ultimate remission. Discussion: PS is a uniform childhood susceptibility to autonomic seizures that is related to early age of development and with excellent prognosis with regard to seizure remission and neuropsychological development.     

Qualitative neuropsychological performance characteristics in frontotemporal dementia and Alzheimer's disease

BACKGROUND: Frontotemporal dementia (FTD) and Alzheimer's disease are clinically distinct disorders, yet neuropsychological studies have had variable success in distinguishing them. A possible reason is that studies typically rely on overall accuracy scores, which may obscure differences in reasons for failure. OBJECTIVES: To explore the hypothesis that analysis of qualitative performance characteristics and error types, in addition to overall numerical scores, would enhance the neuropsychological distinction between FTD and Alzheimer's disease. METHODS: 38 patients with FTD and 73 with Alzheimer's disease underwent assessment of language, visuospatial abilities, memory, and executive function, using a neuropsychological screening instrument and standard neuropsychological tests. In each of these cognitive domains, performance characteristics and error types were documented, in addition to numerical scores on tests. RESULTS: Whereas comparison of neuropsychological test scores revealed some group differences, these did not occur consistently across tests within cognitive domains. However, analysis of performance characteristics and error types revealed qualitative differences between the two groups. In particular, FTD patients displayed features associated with frontal lobe dysfunction, such as concrete thought, perseveration, confabulation, and poor organisation, which disrupted performance across the range of neuropsychological tests. CONCLUSIONS: Numerical scores on neuropsychological tests alone are of limited value in differentiating FTD and Alzheimer's disease, but performance characteristics and error types enhance the distinction between the two disorders. FTD is associated with a profound behavioural syndrome that affects performance on cognitive assessment, obscuring group differences. Qualitative information should be included in neuropsychological research and clinical assessments.     

The relationship between sleep problems and neuropsychological functioning in children with first recognized seizures

Epilepsy is associated with sleep disturbance, but little is known about how early this relationship develops and how it affects neuropsychological functioning. This study documented the frequency and types of sleep problems and examined how sleep problems are associated with seizures and neuropsychological functioning in 332 children following their first recognized seizure (ages 6–14) and in 225 sibling controls. Formal neuropsychological batteries were administered to all subjects. Sleep was measured using the Sleep Behavior Questionnaire and the Child Behavior Checklist. Sleep problems were more frequent in the seizure sample relative to siblings and previously published norms; bedtime difficulties, daytime somnolence, and parasomnias were the most frequently occurring sleep problems. In the seizure group, sleep problems were related to seizure parameters and to neuropsychological functioning. Seizure patients with significant sleep problems had worse neuropsychological functioning on all measures. Findings demonstrate the significant impact of sleep disturbance on children with newly recognized seizures.     

The relationship between sleep problems and neuropsychological functioning in children with first recognized seizures

Epilepsy is associated with sleep disturbance, but little is known about how early this relationship develops and how it affects neuropsychological functioning. This study documented the frequency and types of sleep problems and examined how sleep problems are associated with seizures and neuropsychological functioning in 332 children following their first recognized seizure (ages 6–14) and in 225 sibling controls. Formal neuropsychological batteries were administered to all subjects. Sleep was measured using the Sleep Behavior Questionnaire and the Child Behavior Checklist. Sleep problems were more frequent in the seizure sample relative to siblings and previously published norms; bedtime difficulties, daytime somnolence, and parasomnias were the most frequently occurring sleep problems. In the seizure group, sleep problems were related to seizure parameters and to neuropsychological functioning. Seizure patients with significant sleep problems had worse neuropsychological functioning on all measures. Findings demonstrate the significant impact of sleep disturbance on children with newly recognized seizures.     

Predictors of neuropsychological impairment in seizure-free epilepsy patients

Persons with epilepsy are at increased risk of cognitive deficits as a result of various factors like etiology, structural brain lesions, seizure frequency, seizure type, age at onset of epilepsy, hereditary factors, psychosocial factors, and possible adverse effects of antiepileptic drugs (AEDs). Despite the fact that the majority of epilepsy patients are seizure-free, previous studies on the relationship between epilepsy-related variables and cognitive function have mainly been conducted on patients with persisting seizures. In this study 158 adults with epilepsy on AED monotherapy and without epileptic seizures for at least 2 years were investigated with a neuropsychological test battery in addition to a neurological examination, MRI and EEG. The major findings were that the group had education and employment status similar to the population mean and neuropsychological function in the normal range. In the patient group without idiopathic generalized epilepsy known cerebral etiology was found to be a highly significant predictor of neuropsychological deficit. For patients with idiopathic generalized epilepsy, early seizure debut at < or =18 years was a powerful predictor of neuropsychological impairment.     

Base rates of negative response bias and malingered neurocognitive dysfunction among criminal defendants referred for neuropsychological evaluation

Several studies reveal the prevalence of negative response bias (NRB) in civil forensic settings, but little NRB base rate information is available for criminal forensic neuropsychological settings. We reviewed the published literature on neuropsychological NRB in the civil setting. We then present data from 105 criminal defendants serially referred for neuropsychological assessment to determine the prevalence of NRB. The rate of NRB using one positive indicator was 89.5%. The rate was 70.5% when using two or more positive indicators and 53.3% for three or more indicators. Based on the Slick, Sherman, and Iverson (1999) classification for malingered neurocognitive dysfunction (MND), 19% were Valid, 26.7% were Possible MND, 32.4% were Probable MND, and 21.9% were Definite MND. The combined rate of probable and definite MND was 54.3%. Results suggest rates of neuropsychological NRB and malingering in criminal forensic settings are higher than in civil forensic settings.     

Brain atrophy: neuropsychological and electroencephalographic tests

Neuropsychological and electroencephalographic investigations of 200 patients with tomographically confirmed brain atrophy failed to demonstrate significant differences in relation to control group of patients without this atrophy in whom CT was done for the same clinical indications as in the studied group. In both groups the results of neuropsychological investigations were correlated with age. In the EEG the only statistically significant difference was a greater frequency of seizure activity in the patients with brain atrophy.     

Beyond localization: the role of traditional neuropsychological tests in an age of imaging

Rapid advances in structural and functional magnetic resonance imaging (MRI) present two significant challenges to the rationale and role of the traditional neuropsychological assessment in the presurgical evaluation of epilepsy surgery candidates today. The first is a direct challenge to the model of material-specific memory that has underpinned much clinical practice over the last 50 years. The second, more fundamental, challenge goes to the very heart of the lateralizing/localizing approach that has been the cornerstone of clinical neuropsychology practice in epilepsy surgery centers to date. This review examines these challenges and suggests some ways in which the profession might respond and adapt. We conclude that noninvasive neuropsychological assessment remains a critical investigation in the presurgical evaluation of epilepsy surgery patients. Its value stretches beyond the localization of a surgically remediable seizure focus. Once a vital test, other investigations are now superior in this respect in many cases. However, new technologies have enhanced the role of the traditional neuropsychological assessment, which is now able to provide unparalleled insights and predictions into the way in which the underlying pathology, seizures, and proposed surgery shape an individual's profile of cognitive abilities. Detailed neuropsychological feedback enables the patient to make an informed decision, and forms the basis of the tailor made preemptive rehabilitation programs that can be implemented preoperatively, minimizing the most significant morbidity associated with epilepsy surgery today.     

The assessment of neuropsychological functioning in schizophrenia

Overwhelming evidence suggests that compromised neuropsychological function is frequently observed in schizophrenia. The neuropsychological profile is typically characterized by prominent specific deficits in memory and learning, working memory, executive functions, attention, and processing speed, which are evident on a background of a generalized cognitive deficit. This paper provides a review of studies of neuropsychological functioning in schizophrenia. The main cognitive ability areas affected in schizophrenia are described, and the degree of impairment in each ability area as found in studies of schizophrenia patients is summarized, based on meta-analytic findings. Recent studies that have compared neuropsychological functioning across psychotic disorders are presented, and finally, neuropsychological assessment batteries specifically developed for schizophrenia are introduced.     

Impact of depressed mood on neuropsychological status in temporal lobe epilepsy

OBJECTIVES: Depression is a common psychiatric complication of temporal lobe epilepsy. This study examined the effect of depressed mood on neuropsychological performance among patients with chronic temporal lobe epilepsy. METHODS: Seventy consecutive surgery candidates for medication resistant complex partial seizures of unilateral temporal lobe origin were assessed for psychiatric symptoms and underwent comprehensive neuropsychological assessment. RESULTS: Standardised psychiatric interview disclosed that 34% of the patient sample exhibited significant depression. Controlling for seizure frequency, patients with comorbid depression at the time of neuropsychological assessment exhibited significantly poorer performance on measures of intelligence, language, visuoperceptual ability, memory, and executive function. Within lateralised temporal lobe epilepsy groups, the adverse effects of depression on cognitive function were greater in patients with left temporal lobe compared with those with right temporal lobe epilepsy. In addition, depression seemed to be underrecognised and undertreated as none of the patients with epilepsy and comorbid depression were treated for their psychiatric condition at the time of admission for monitoring. CONCLUSIONS: Depression, a common psychiatric comorbidity among patients with chronic temporal lobe epilepsy, seems to be undertreated and to have adverse effects on cognitive functioning.     

A novel inherited SCN1A mutation associated with different neuropsychological phenotypes: Is there a common core deficit?

We report a three-generation, clinically heterogeneous family in which we identify a novel inherited splicing mutation of the SCN1A gene. Thirteen subjects were submitted to genetic analysis, clinical and instrumental examination, and neuropsychological assessment.In eight subjects, a heterozygous c.2946+5G>A donor splice site alteration in the SCN1A gene was found. Half of them had never had a seizure and showed normal EEG and cognitive profile, whereas the other half had a history of seizures and variable neuropsychological impairments ranging from moderate cognitive disabilities to mild visual–motor impairments. Different clinical phenotypes were identified, including generalized epilepsy with febrile seizure plus (GEFS +), Dravet syndrome, and partial epilepsy with febrile seizure plus (PEFS +).Remarkable clinical heterogeneity can be found among family members carrying the same SCN1A gene mutation. Variable involvement of visual–motor abilities might represent a neuropsychological feature which needs to be further explored in other familial cases.     

Rasmussen's encephalitis: the relevance of neuropsychological assessment in patient's treatment and follow up

Rasmussen's encephalitis is characterized by refractory epilepsy, neurological deterioration and progressive atrophy of one cerebral hemisphere. The objective of this study is to describe the importance of neuropsychological evaluation in the treatment decision and follow-up of patients with Rasmusseńs encephalitis. Neuropsychological assessment was performed in two steps. Firstly, the clinical history was obtained and the Vineland adaptative behavior scale (VABS) was applied. After this first step, the patients with social maturity level equal or higher than the inferior limit underwent a battery of neuropsychological assessment. We evaluated three patients before any specific treatment was started, and six months after the intervention (surgery or plasmapheresis). Patient 1 underwent left hemispherectomy and had global improvement on second neuropsychological assessment. This suggests that the decision of performing surgery was adequate. Patients 2 and 3 underwent plasmapheresis. They did not present cognitive decline between both evaluations which suggest that our decision of postponing surgery was adequate as well. We conclude that neuropsychological assessment is important when evaluating patients with Rasmusseńs encephalitis. That is especially true for patients in whom disease progression is slow, and surgery timing has to be carefully planned.     

Indications and expectations for neuropsychological assessment in epilepsy surgery in children and adults

In our first paper in this series (Epilepsia 2015; 56(5): 674–681), we published recommendations for the indications and expectations for neuropsychological assessment in routine epilepsy care. This partner paper provides a comprehensive overview of the more specialist role of neuropsychological assessment in the pre and postoperative evaluation of epilepsy surgery patients. The paper is in two parts. The first part presents the framework for the mandatory role of neuropsychologists in the presurgical evaluation of epilepsy surgery candidates. A preoperative neuropsychological assessment should be comprised of standardised measures of cognitive function in addition to wider measures of behavioural and psychosocial function. The results from the presurgical assessment are used to: (1) establish a baseline against which change can be measured following surgery; (2) provide a collaborative contribution to seizure characterization, lateralization and localization; (3) provide evidence‐based predictions of cognitive risk associated with the proposed surgery; and (4) provide the evidence base for comprehensive preoperative counselling, including exploration of patient expectations of surgical treatment. The second part examines the critical role of the neuropsychologist in the evaluation of postoperative outcomes. Neuropsychological changes following surgery are dynamic and a comprehensive, long‐term assessment of these changes following surgery should form an integral part of the postoperative follow‐up. The special considerations with respect to pre and postoperative assessment when working with paediatric populations and those with an intellectual disability are also discussed. The paper provides a summary checklist for neuropsychological involvement throughout the epilepsy surgery process, based on the recommendations discussed.