Neuropsychology: traditional and new methods of investigation

Association between the Cognitive-Related Behavioral Assessment Severity Stage and Activities of Daily Living Required for Discharge to Home in Patients with Stroke: A Cross-Sectional Study

This study aimed to characterize cognitive function examined using Cognitive-related Behavioral Assessment (CBA) in activities of daily living (ADLs). According to CBA severity at discharge, 791 patients were assigned to five groups (most severe, severe, moderate, mild, and normal). The total scores for Functional Independence Measure (FIM) motor items were compared for each group. Multiple logistic regression analysis was performed to clarify the association between CBA severity and independence in ADL items. Independence in each ADL according to CBA severity was 0-4.8%, 26.8-45.0%, 84.3-91.0%, and 97.2-100% for all ADLs in the most severe to severe, moderate, mild, and normal groups, respectively. Significant differences were found in the FIM motor score according to CBA severity between the groups (p < 0.01). A mild or normal CBA was associated with a higher odds ratio (OR) for dressing the upper body (OR = 21.90; 95% confidence interval (CI), 13.50-35.70), bladder management (OR = 11.60; 95% CI, 7.21-18.60), transfers to the bed/chair/wheelchair (OR = 18.30; 95% CI, 11.40-29.40), transfers to the toilet (OR = 18.30; 95% CI, 11.40-29.30), and walking (OR = 6.60; 95% CI, 10.60-26.10). A CBA severity greater than mild (23 points) was associated with independence in ADLs that are important for discharge to home.

Feasibility, Contrast Sensitivity and Network Specificity of Language fMRI in Presurgical Evaluation for Epilepsy and Brain Tumor Surgery

Language fMRI has become an integral part of the planning process in brain surgery. However, fMRI may suffer from confounding factors both on the patient side, as well as on the provider side. In this study, we investigate how patient-related confounds affect the ability of the patient to perform language fMRI tasks (feasibility), the task sensitivity from an image contrast point of view, and the anatomical specificity of expressive and receptive language fMRI protocols. 104 patients were referred for language fMRI in the context of presurgical procedures for epilepsy and brain tumor surgery. Four tasks were used: (1) a verbal fluency (VF) task to map vocabulary use, (2) a semantic description (SD) task to map sentence formation/semantic integration skills, (3) a reading comprehension (RC) task and (4) a listening comprehension (LC) task. Feasibility was excellent in the LC task (100%), but in the acceptable to mediocre range for the rest of the tasks (SD: 87.50%, RC: 85.57%, VF: 67.30%). Feasibility was significantly confounded by age (p = 0.020) and education level (p = 0.003) in VF, by education level (p = 0.004) and lesion laterality (p = 0.019) in SD and by age (p = 0.001), lesion laterality (p = 0.007) and lesion severity (p = 0.048) in RC. All tasks were comparable regarding sensitivity in generating statistically significant image contrast (VF: 90.00%, SD: 92.30%, RC: 93.25%, LC: 88.46%). The lobe of the lesion (p = 0.005) and the age (p = 0.009) confounded contrast sensitivity in the VF and SD tasks respectively. Both VF and LC tasks demonstrated unilateral lateralization of posterior language areas; only the LC task showed unilateral lateralization of anterior language areas. Our study highlights the effects of patient-related confounding factors on language fMRI and proposes LC as the most feasible, less confounded, and efficiently lateralizing task in the clinical presurgical context.

O crescimento da avaliação neuropsicológica no Brasil: uma revisão sistemática

Resumo Pesquisas científicas relacionadas à avaliação neuropsicológica têm despertado interesse crescente nos últimos anos. Este estudo objetivou realizar uma revisão sistemática sobre avaliação neuropsicológica no Brasil e foi efetuado nas bases de dados SciELO, PePSIC, LILACS e BDTD, no período de setembro/2012 a novembro/2012, utilizando as palavras-chave avaliação neuropsicológica. A amostra final resultou em 241 trabalhos empíricos originais formados por artigos científicos (n=131), dissertações de mestrado (n=68) e teses de doutorado (n=42), abrangendo o período de 1993 a 2012. Os resultados evidenciaram que: a) mais de 60% da produção científica concentra-se no período de 2007 a 2012, com média de produção de 12,7% por ano; b) o número de artigos científicos soma pouco mais de 50% se comparado com o número de teses e dissertações; c) a publicação de pesquisas sobre a temática se dá majoritariamente em periódicos médicos (47,7%); d) o principal eixo temático que emprega Avaliação Neuropsicológica são distúrbios neuropsiquiátricos (49,7%); e) a Região Sudeste concentra mais de 50% da produção científica nacional. Conclui-se que esta pesquisa revela um panorama atualizado da produção científica sobre o tema, enfatizando a necessidade de mais pesquisas psicométricas e de outras revisões sistemáticas envolvendo temas de interesse da neuropsicologia, como reabilitação neuropsicológica.

The mismatch negativity (MMN) potential as a tool for the functional mapping of temporal lobe epilepsies

Temporal lobe epilepsies are associated with cognitive dysfunctions in memory which are important clues currently used clinically for the lateralization of the epileptic focus in evaluations for epilepsy surgery. Because these lobes also contain the primary auditory cortex, the study of auditory evoked potentials (AEPs) is a candidate, not yet established, complementary method to characterize epilepsy-induced dysfunction. We aimed to establish the clinical usefulness of auditory evoked potentials for the study of pediatric symptomatic temporal lobe epilepsies. A group of 17 patients (ages 4-16) with symptomatic epilepsies undergoing evaluation for epilepsy surgery epilepsy was submitted to auditory evoked potentials using 35-channel scalp EEG recordings. A control group of 10 healthy volunteers was studied with the same protocol. The P100 and mismatch negativity (MMN) potential latencies and normalized amplitudes were studied. We also performed a voxel-based lesion-symptom mapping (VLSM) to determine the anatomical areas associated with changes in the AEPs. Eleven patients had temporal lobe epilepsy, three had frontal lobe epilepsy, and three had occipital lobe epilepsy. Latencies for the P100 were normal in 15/17 and in 11/17 for the MMN, with no consistent correlation with the epilepsy type. The MMN amplitude was abnormal in 7/17 patients, all with temporal lobe epilepsies (sensitivity of 64%). Of these patients, four had a decreased MMN associated with a Heschl's gyrus lesion in the VLSM, and three had an increased MMN associated with hippocampal lesion. No extratemporal epilepsy showed MMN amplitude abnormalities (specificity of 100%). The P100 amplitude was abnormal in 3/17, two with temporal and one with frontal lobe epilepsies. The auditory MMN has a high specificity but a low sensitivity for temporal lobe epilepsy in symptomatic pediatric epilepsies. Amplitude decreases of the MMN are associated with homolateral Heschl's gyrus lesions, and MMN increases with hippocampal lesions.

CE hospital service utilization is reduced following neuropsychological evaluation in a sample of U.S. veterans

The aim of this study was to evaluate the objective value of neuropsychological evaluation (NPE) through reduction in Emergency Room (ER) visits and hospitalizations. Retrospective analysis examined trends in ER visits and hospitalizations in 440 U.S. veterans who completed NPE between the years of 2003 and 2010. Within-subjects comparisons showed significant decreases in incidence of hospitalization and length of hospitalization in the year after evaluation compared to the year prior. Mean number of hospitalizations declined from 0.31 (SD = 0.64) pre-NPE to 0.22 (SD = 0.59) post-NPE; there were a total of 41 fewer hospitalizations in the year following NPE. Mean length of hospitalization decreased from 1.9 days (SD = 5.6) pre-NPE to 1.06 days (SD = 3.9) post-NPE; there were a total of 368 fewer days of hospitalization post-NPE. This reduction was not attributable to age or time. Incidence of ER visits also decreased from pre-NPE (M = 0.74, SD = 1.3) to post-evaluation (M = 0.69, SD = 1.3), though this was not significant. These findings provide preliminary evidence of the clinical and potential economic value of neuropsychological services within a medical setting. Follow-up studies should examine individual and exam-specific factors that may contribute to reduced utilization.

The use and importance of liposomes in positron emission tomography

Among different imaging modalities, Positron Emission Tomography (PET) gained importance in routine hospital practice depending on ability to diagnose diseases in early stages and tracing of therapy by obtaining metabolic information. The combination of PET with Computed Tomography (CT) forms hybrid imaging modality that gives chance to obtain better images having higher resolution by fusing both functional and anatomical images in the same imaging modality at the same time. Therefore, better contrast agents are essentially needed. The advance in research about developing drug delivery systems as specific nanosized targeted systems gained an additional importance for obtaining better diagnosis and therapy of different diseases. Liposomes appear to be more attractive drug delivery systems in delivering either drugs or imaging ligands to target tissue or organ of diseases with higher accumulation by producing in nano-scale, long circulating by stealth effect and specific targeting by modifying with specific ligands or markers. The combination of positron emitting radionuclides with liposomes are commonly in research level nowadays and there is no commercially available liposome formulation for PET imaging. However by conjugating positron emitter radionuclide with liposomes can form promising diagnostic agents for improved diagnosis and following up treatments by increasing image signal/contrast in the target tissue in lower concentrations by specific targeting as the most important advantage of liposomes. More accurate and earlier diagnosis of several diseases can be obtained even in molecular level with the use of stable and effectively radiolabeled molecular target specific nano sized liposomes with longer half-lived positron emitting radionuclides.

Neuropsychological outcome after extra-temporal epilepsy surgery

BACKGROUND

The neuropsychological results of temporal lobe epilepsy surgery are well reported in the literature. The aim of this study was to analyse the neuropsychological outcome in a consecutive series of patients with extra-temporal epilepsy.

METHODS

We retrospectively analysed the data of patients operated between 1996 and 2008 for extra-temporal epilepsy. Standard neuropsychological tests were applied. We assessed the neuropsychological outcome after surgery and the correlation of the neuropsychological outcome with (1) side and localisation of surgery, (2) Engel scale for seizure outcome and (3) timing of surgery.

FINDINGS

Patients had a better neuropsychological outcome when undergoing non-frontal resection [χ2 (2) =6.66, p = 0.036]. Subjects who had undergone left or right resection showed no difference in outcome [χ2 (2) =0.533, p = 0.766]. The correlation between the Engel scale for seizure re-occurence and the neuropsychological scores showed only a tendency for better outcome (Spearman ρ = -0.437; p = 0.069). The global measure of change did not correlate significantly with delay of surgery (Spearman ρ = -0.163; p = 0.518).

CONCLUSIONS

Resective epilepsy surgery improves neuropsychological status outcome in patients with extra-temporal epilepsy even if the patient did not become seizure free. The outcome is better for non-frontal localisation.

Impaired social cognition 30 years after hemispherectomy for intractable epilepsy: the importance of the right hemisphere in complex social functioning

Clinical research with individuals following hemispherectomy typically quantifies the success of surgical outcomes by focusing primarily on the achievement of seizure control and the preservation of general brain functions, such as movement, sensation, language, and memory. In addition to these outcomes, careful study of individuals following hemispherectomy also has the potential to contribute to our understanding of functional brain asymmetries involving other complex cognitive behaviors. In this study, we report preliminary evidence for the lateralization of social perception. We administered a series of neuropsychological tests that were developed to assess emotional recognition and the formation of social inferences and advanced social cognitive judgments, as they occur in everyday situations, to two adult participants who underwent complete anatomic left- or right-sided hemispherectomy. Our results show that despite a 30-year postsurgical period of recovery and consistent and high levels of family support and social engagement, distinct cognitive profiles are still evident between our right- and left-sided participants. In particular, participant S.M., who underwent an anatomic right hemispherectomy, showed the most severe impairments in identifying negative emotional expressions and conversational exchanges involving lies and sarcasm and in "mentalizing" the intent of others. In contrast, participant J.H., who underwent an anatomic left hemispherectomy was highly skilled interpersonally, despite evident language-related limitations, and showed only mild difficulties when asked to identify emotional expressions involving disgust and anger. These results suggest that the right hemisphere plays a particularly important role in social cognitive functioning and reasoning. Further examination of the extent of social perceptual difficulties prior to and following surgical intervention for epilepsy may guide the development of effective social skills training programs that can improve quality of life beyond seizure control.

[Neuropsychology, plasticity and childhood epilepsy]

Epilepsy is one of the most frequent childhood disorders. While most cases are well controlled, approximately 30-50% are resistant to medical treatment. In these cases, neurosurgery may be an option. Since 1979, our team at the Sainte-Justine Hospital in Montreal has studied the impact of epilepsy on the psycho-motor and cognitive development of the affected children. The aim of a first series of studies was to explore the extent and limits of cerebral plasticity by investigating the neuropsychological sequelae of early versus late callosotomy and hemispherectomy. In keeping with the plasticity hypothesis, the results revealed that the children who were operated before puberty showed fewer deficits than those operated during adolescence or adulthood. However, the compensatory mechanisms available to them appeared to be limited with respect to the nature and complexity of the information they can process. For instance, young children having undergone section of the corpus callosum resembled individuals born without a corpus callosum (callosal agenesis) in that there did not show the typical disconnection deficits seen in adult ''split-brain'' patients. However, they exhibited deficits on tasks requiring interhemispheric integration of motor and visuo-motor information. By the same token, hemispherectomy patients were still able to make visual judgements in their ''blind'' visual field but they were found to be impaired on a variety of visual and auditory tasks (localization of a sound sources in space) requiring the participation of both hemispheres. In a second series of studies, carried out in collaboration with a Parisian team, we intended to describe the neuropsychological profile of focal epilepsies, specifically frontal and temporal epilepsy. Contrary to the common belief that childhood epilepsy would result in diffuse impairments, we were able to demonstrate that children manifest the same localized deficits as adult patients. In studies presently underway in our laboratories, we make use of functional neuroimaging techniques such as high density electrophysiology, optical imaging and magnetoencephalography to investigate pre-and postoperative language and memory functions and to study the impact of epilepsy on brain maturation.

Cognitive impairment in juvenile myoclonic epilepsy

BACKGROUND AND PURPOSE

Cognitive impairments are frequent consequences of epilepsy, with intellectual ability reportedly being lower in patients with idiopathic generalized epilepsies than in the general population. However, neuropsychological investigations have been rarely performed in patients with juvenile myoclonic epilepsy (JME). We aimed to quantify the cognitive function in JME patients using various neuropsychological tests.

METHODS

We compared cognitive function in 27 JME patients with that in 27 healthy volunteers using tests examining cognitive performance, such as the verbal and visual memory, frontal function, attention, IQ score, and mood. In the JME group, we examined risk factors for cognitive function such as age, sex, family history, education level, age at seizure onset, seizure frequency, EEG abnormality, disease duration, and previous intake of antiepileptic drugs.

RESULTS

Verbal learning was significantly lower in JME patients than in controls, and attention and verbal fluency were impaired in JME patients compared with controls. However, general intellectual ability and mood did not differ between the groups. Early onset of seizure and long duration of disease were closely related to impaired cognitive function.

CONCLUSIONS

JME patients may exhibit impaired cognitive function, in terms of memory and execution, despite having normal intelligence and mood.