Faculty Bibliography

OBJECTIVE:To identify cognitive phenotypes in temporal lobe epilepsy (TLE) and test their reproducibility in a large, multi-site cohort of patients using both data-driven and clinically driven approaches. METHOD/METHODS:Four-hundred seven patients with TLE who underwent a comprehensive neuropsychological evaluation at one of four epilepsy centers were included. Scores on tests of verbal memory, naming, fluency, executive function, and psychomotor speed were converted into z-scores based on 151 healthy controls (HCs). For the data-driven method, cluster analysis (k-means) was used to determine the optimal number of clusters. For the clinically driven method, impairment was defined as >1.5 standard deviations below the mean of the HC, and patients were classified into groups based on the pattern of impairment. RESULTS:Cluster analysis revealed a three-cluster solution characterized by (a) generalized impairment (29%), (b) language and memory impairment (28%), and (c) no impairment (43%). Based on the clinical criteria, the same broad categories were identified, but with a different distribution: (a) generalized impairment (37%), (b) language and memory impairment (30%), and (c) no impairment (33%). There was a 82.6% concordance rate with good agreement (κ = .716) between the methods. Forty-eight patients classified as having a normal profile based on cluster analysis were classified as having generalized impairment (n = 16) or an isolated language/memory impairment (n = 32) based on the clinical criteria. Patients with generalized impairment had a longer disease duration and patients with no impairment had more years of education. However, patients demonstrating the classic TLE profile (ie, language and memory impairment) were not more likely to have an earlier age at onset or mesial temporal sclerosis. SIGNIFICANCE/CONCLUSIONS:We validate previous findings from single-site studies that have identified three unique cognitive phenotypes in TLE and offer a means of translating the patterns into a clinical diagnostic criteria, representing a novel taxonomy of neuropsychological status in TLE.

There has been considerable public interest in the topic of traumatic brain injury (TBI) as a risk factor for development of late-life dementia. A review was performed on empirical studies examining the relationship between these two conditions. Although results from a number of studies clearly demonstrate that TBI is a positive risk factor for developing dementia, there are an equivalent number of studies that obtain inconclusive or negative findings. Inconsistencies across studies are often the result of methodological findings including the nature of the investigational design, choice of comparison groups, and criteria used to define cases. In many studies, the diagnosis of TBI is obtained retrospectively in a manner that is subject to bias. Accurate identification of dementia cases is often compromised by the use of inappropriately brief follow-up periods and variations in diagnostic methods. There remains no universally accepted neurobiological mechanism to explain the transition from acute TBI to the chronic effects of dementia. Studies of specialty populations, including athletes and military personnel are beset by secular and cohort effects, raising questions about the applicability of findings to the general population. No existing studies have been able to exclude the possible effects of confounding medical or lifestyle factors in facilitating the onset of dementia following TBI. Although the research findings suggest a general association between TBI and dementia, the specifics of the relationship remain poorly defined.

This paper describes ten core features of a neuropsychological assessment with the aim of helping neurologists understand the unique contribution the evaluation can make within the wider context of diagnostic methods in epilepsy. The possibilities, limitations and cautions associated with the investigation are discussed under the headings below: 1. A neuropsychological assessment is a collaborative investigation. 2. Assessment prior to treatment allows for the accurate assessment of treatment effects. 3. The nature of an underlying lesion and its neurodevelopmental context play an important role in shaping the associated neuropsychological deficit. 4. Cognitive and behavioural impairments result from the essential comorbidities of epilepsy which can be considered as much a disorder of cognition and behaviour as of seizures. 5. Patient's subjective complaints can help us understand objective cognitive impairments and their underlying neuroanatomy, resulting in improved patient care. At other times, patient complaints reflect other factors and require careful interpretation. 6. The results from a neuropsychological assessment can be used to maximise the educational and occupational potentials of people with epilepsy. 7. Not all patients are able to engage with a neuropsychological assessment. 8. There are limitations in assessments conducted in a second language with tests that have been standardized on different populations to that of the patient. 9. Adequate intervals between assessments maximise sensitivity to meaningful change. 10. Patients should be fully informed about the purpose of the assessment and have realistic expectations of the outcome prior to referral.

Unprecedented media coverage of concussion in sport has led to increased fears regarding the potential negative effects of participation in contact sports including North American football and ice hockey. Initial responses of professional sports leagues to implementation of acute concussion management practices and reports of a neurodegenerative condition known as chronic traumatic encephalopathy (CTE) developing in retired players caused an atmosphere of distrust whereby the leagues were accused of maintaining cover-ups analogous to what had been seen in association with studies of tobacco and smoking. This article reviews the important role that psychology has played in the study of sports concussion and in the establishment of methods currently used to diagnose and track concussion symptoms. Results of existing studies have shown that the neurobiological effects of concussion are rather short-lived with development of persisting symptoms in some individuals associated more with psychosocial factors than underlying physiological effects. With regard to CTE, the status of the science remains preliminary with little definitive information known about its epidemiology or cause. In the midst of the ongoing controversy, a polarized climate has developed in association with concussion and CTE, divided by believers in the dangers of long-term consequences and deniers who question the status of the existing science. The conclusion is that it is important for psychology to extend its scope of study to provide increased understanding of the social factors underlying the current polarized climate while continuing to provide the public with an accurate and reliable account of the existing science. (PsycInfo Database Record (c) 2020 APA, all rights reserved)Public Significance Statement"”Continued media reporting of the sports concussion and its potential long-term effects has been accompanied by public concerns about the safety of contact sports and potential development of chronic traumatic encephalopathy (CTE). Controversies have emerged about the status of the science, creating polarization on the topic. Psychology has provided significant contributions to our scientific knowledge on sports concussion and has the potential to provide a key to understanding the factors underlying division on these topics. (PsycInfo Database Record (c) 2020 APA, all rights reserved)Une couverture médiatique sans précédent des commotions cérébrales dans le sport a entraîné une augmentation des craintes quant aux effets négatifs potentiels de la participation aux sports de contact, notamment au football et au hockey sur glace en Amérique du Nord. Les premières réponses des ligues sportives professionnelles à la mise en Å“uvre de pratiques de gestion des commotions aiguës et les déclarations de maladie neurodégénérative connue sous le nom d"™encéphalopathie traumatique chronique (CTE) en développement chez les joueurs retraités ont provoqué une atmosphère de méfiance où les ligues ont été accusées de dissimulations de manière similaire à ce qui avait été observé avec les études sur le tabac et le tabagisme. Le présent article examine le rôle important que la psychologie a joué dans l"™Ã©tude des commotions liées au sport et dans l"™Ã©tablissement de méthodes actuellement utilisées pour diagnostiquer et surveiller les symptômes de commotion cérébrale. Les résultats des études existantes ont montré que les effets neurobiologiques de commotion cérébrale sont plutôt de courte durée avec l"™apparition de symptômes persistants, chez certaines personnes, plutôt associés à des facteurs psychosociaux qu"™aux effets physiologiques sous-jacents. En ce qui concerne la CTE, le statut de la science reste préliminaire, avec peu de renseignements définitifs connus sur son épidémiologie ou sa cause. Au cÅ“ur de la controverse actuelle, un climat polarisé s"™est développé en lien avec la commotion cérébrale et la CTE, divisé par les croyants aux dangers des conséquences à long terme et les négateurs qui remettent en question le statut de la science existante. En conclusion, il est important pour la psychologie d"™Ã©tendre sa portée d"™Ã©tude afin de mieux comprendre les facteurs sociaux sous-jacents au climat polarisé actuel tout en continuant à fournir au public un compte rendu exact et fiable de la science existante. (PsycInfo Database Record (c) 2020 APA, all rights reserved)

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Magnetic resonance imaging (MRI)-negative temporal lobe epilepsy (TLE) may be a distinct syndrome from TLE with mesial temporal sclerosis (TLE-MTS). Imaging and neuropsychological features of TLE-MTS are well-known; yet, these features are only beginning to be described in MRI-negative TLE. This study examined whether a quantitative measure of cortical gray and white matter blurring (GWB) was elevated in the temporal lobes ipsilateral to the seizure onset zone of individuals with MRI-negative TLE relative to TLE-MTS and healthy controls (HCs) and whether GWB elevations were associated with neuropsychological comorbidity. Gray-white matter blurring from 34 cortical regions and hippocampal volumes were quantified and compared across 28 people with MRI-negative TLE, 15 people with TLE-MTS, and 51 HCs. Declarative memory was assessed with standard neuropsychological tests and the intracarotid amobarbital procedure (IAP). In the group with MRI-negative TLE (left and right onsets combined), hippocampal volumes were within normal range but GWB was elevated, relative to HCs, across several mesial and lateral temporal lobe regions ipsilateral to the seizure onset zone. Gray-white matter blurring did not differ between the groups with TLE-MTS and HC or between the groups with TLE-MTS and MRI-negative TLE. The group with MRI-negative TLE could not be distinguished from the group with TLE-MTS on any of the standard neuropsychological tests; however, ipsilateral hippocampal volumes and IAP memory scores were lower in the group with TLE-MTS than in the group with MRI-negative TLE. The group with left MRI-negative TLE had lower general cognitive abilities and verbal fluency relative to the HC group, which adds to the characterization of neuropsychological comorbidities in left MRI-negative TLE. In addition, ipsilateral IAP memory performance was reduced relative to contralateral memory performance in MRI-negative TLE, indicating some degree of ipsilateral memory dysfunction. There was no relationship between hippocampal volume and IAP memory scores in MRI-negative TLE; however, decreased ipsilateral IAP memory scores were correlated with elevated GWB in the ipsilateral superior temporal sulcus of people with left MRI-negative TLE. In sum, GWB elevations in the ipsilateral temporal lobe of people with MRI-negative TLE suggest that GWB may serve as a marker for reduced structural integrity in regions in or near the seizure onset zone. Although mesial temporal abnormalities might be the major driver of memory dysfunction in TLE-MTS, a loss of structural integrity in lateral temporal lobe regions may contribute to IAP memory dysfunction in MRI-negative TLE.