The hemispheric lateralization of memory has largely been informed through the study of patients with temporal lobe epilepsy originating from medial temporal sources (mTLE). The material-specific model of memory relies on the basic framework that the left temporal lobe mediates verbal memories, while the right temporal lobe mediates non-verbal memories. Over the years, this model has been refined, and even challenged, as our understanding of the material-specific memory deficits in mTLE has been further elaborated in the neuropsychological and neuroimaging literature. The first goal of this mini-review is to highlight the major findings in the mTLE literature that have advanced and expanded our understanding of material-specific memory deficits in mTLE. Second, we will review how functional neuroimaging patterns of material-specific hemispheric lateralization in mTLE are being translated into the innovative clinical application of preoperative fMRI memory mapping.
Neuropsychological studies comparing patients with psychogenic nonepileptic seizures (PNES) to those with epilepsy have been largely equivocal. The variability in the neuropsychological literature highlights the heterogeneity of the PNES population across a number of psychiatric and neurologic factors. Phenotypic presentations in PNES arise from complex interactions between vulnerable cognitive and emotional systems. We propose that variability in neuropsychological findings in PNES emerge in the context of diverse psychiatric, neurologic, and clinical factors. Traditional assessments that fail to integrate cognitive and emotional/behavioral profiles sufficiently would fall short in characterizing the complexity of brain-behavior relationships in this population. To advance the neuropsychology of PNES, we propose a systematic approach to measure a number of factors that influence cognitive impairment in this population. We begin by reviewing the current neuropsychological literature in PNES and discussing a number of factors that influence cognitive deficits. We then present a comprehensive neuropsychological battery designed to capture elements (cognitive dysfunction, psychopathology, emotion processing deficits) underlying the proposed vulnerable cognitive-emotional system in PNES. It is our hope that the proposed battery will facilitate the aggregation of data across neuropsychological investigations, to allow more advanced statistical analyses, and ultimately enhance our understanding of PNES and the development of effective management and treatment options.
We aimed to investigate the cognitive and psychosocial outcomes of patients older than 50 with drug-resistant temporal lobe epilepsy as compared to a younger cohort. One hundred and thirty-one patients with temporal lobe epilepsy (47% age ≥ 50) who underwent comprehensive neuropsychological testing were retrospectively identified. A comparison of percentage of Z scores < - 1.5 between the older and younger cohort on Trail Making Tests A and B, Boston Naming Test, Rey Auditory Verbal Learning Test (RAVLT) delayed recall, and Rey-Osterrieth complex figure test delayed recall was performed as well as the presence of disability due to epilepsy and depression scores. Grading of white matter hyperintensities on MRI was also performed. Older patients with epilepsy were more likely to score Z < - 1.5 on the RAVLT (54.1 vs 32.8%) and were more likely to be on disability due to their seizures (23.0 vs 5.7%). A higher grade of white matter hyperintensities correlated with worse performance on Trail Making Test A, while a higher number of anti-epileptic drugs (AEDs) correlated with worse performance on Trail Making Test B regardless of age. The results of this study reveal that older patients with drug-resistant epilepsy are a vulnerable population with an impaired cognitive profile. In addition, limiting the number of AEDs and addressing markers of small vessel disease should also be prioritized by clinicians.
Background
Brain regions critical to episodic memory are altered during the preclinical stages of Alzheimer’s disease (AD). However, reliable means of identifying cognitively-normal individuals at higher risk to develop AD have not been established.
Objective
To examine whether fMRI can detect early functional changes associated with scene encoding in a group of presymptomatic Presenilin-1 (PSEN1) E280A mutation carriers.
Methods
Participants were 39 young, cognitively-normal individuals from an autosomal dominant early-onset AD kindred, located in Antioquia, Colombia. Participants performed an fMRI scene encoding task and a post-scan subsequent memory test.
Results
PSEN1 mutation carriers exhibited hyperactivation within medial temporal lobe regions during successful scene encoding (hippocampal formation, parahippocampal gyrus) compared to age-matched non-carriers.
Conclusion
Hyperactivation in medial temporal lobe regions during scene encoding is seen in individuals genetically-determined to develop AD years before their clinical onset. Our findings will guide future research with the ultimate goal of using functional neuroimaging in the early detection of preclinical AD.
Practical experience is central to the education and training of neuropsychologists, beginning in graduate school and extending through postdoctoral fellowship. However, historically, little attention has been given to the structure and requirements of practicum training in clinical neuropsychology. A working group of senior-level neuropsychologists, as well as a current postdoctoral fellow, all from a diverse range of settings (The AACN Practicum Guidelines Workgroup), was formed to propose guidelines for practicum training in clinical neuropsychology. The Workgroup reviewed relevant literature and sought input from professional organizations involved in education and training in neuropsychology. The proposed guidelines provide a definition of practicum training in clinical neuropsychology, detail entry and exit criteria across competencies relevant to practicum training in clinical neuropsychology, and discuss the relationship between doctoral training programs and practicum training sites. The proposed guidelines also provide a methodology for competency-based evaluation of clinical neuropsychology practicum trainees and outline characteristics and features that are integral to an effective training environment. Although the guidelines discussed below may not be implemented in their entirety across all clinical neuropsychology practicum training sites, they are consistent with the latest developments in competency-based education.
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