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Neuropsychological Function (neuropsychological + function)

Distribution by Scientific Domains

Medical Sciences	77%
Psychology	22%

Selected Abstracts

Temporal lobe epilepsy surgery and the quest for optimal extent of resection: A review

EPILEPSIA, Issue 8 2008
Johannes Schramm
Summary The efficacy of surgery to treat drug-resistant temporal lobe epilepsy (TLE) has been demonstrated in a prospective randomized trial. It remains controversial which resection method gives best results for seizure freedom and neuropsychological function. This review of 53 studies addressing extent of resection in surgery for TLE identified seven prospective studies of which four were randomized. There is considerable variability between the intended resection and the volumetrically assessed end result. Even leaving hippocampus or amygdalum behind can result in seizure freedom rates around 50%. Most authors found seizure outcome in selective amygdalohippocampectomy (SAH) to be similar to that of lobectomy and there is considerable evidence for better neuropsychological outcome in SAH. Studies varied in the relationship between extent of mesial resection and seizure freedom, most authors finding no positive correlation to larger mesial resection. Electrophysiological tailoring saw no benefit from larger resection in 6 of 10 studies. It must be concluded that class I evidence concerning seizure outcome related to type and extent of resection of mesial temporal lobe structures is rare. Many studies are only retrospective and do not use MRI volumetry. SAH appears to have similar seizure outcome and a better cognitive outcome than TLR. It remains unclear whether a larger mesial resection extent leads to better seizure outcome. [source]

VIQ-PIQ Discrepancies in Partial Epilepsy: On the Relation to Lat- eralities of Focal MRI Lesions, P3 Peaks, and Focal Spikes.

EPILEPSIA, Issue 2000
Osamu Kanazawa
Purpose: A number of previous ncurophysiological studies have indicated that the glutamatergic system is important in the induction of epileptiform activity and the dcvelopment of epileptogenesis. Clutamate transport is the primary mechanism of inactivation of syiiaptically released glutamate. GLAST is classified BS an astrocytic transporter and occurs in high concentrations in the ccrebcllum. The pathophysiologic rolc of GLAST in epilepsy is not known in detail. To investigate the role of thc astroglial glutamatc transporter GLAST in epileptogenesis, we compared amygdalu-kindling and pentylenctetrazolc (PTZ) induced seizures in GLAST-deficient mice (GLAST(-/-)) wild-type mice (GLAST(+/+)), and maternal C57Black6/J mice (C57). Purpose: Subtest IQ such as verbal IQ (VIQ) and performance IQ (PIQ) in WAIS or WISC are thought to represent neuropsychological functions of the left and right hemispheres, respectively. The P300 (P3) event-related potential reflects cognitive processes. We do not ye1 know the brain site of P3 origin or how epileptogenic foci (EF) influ- ence P3 potentials. To examine neuropsychological influence by partial epilepsy (PE), we studied VIQ-PIQ discrepancies in PE in relation to lateralities of focal MRI lesions, P3 peaks, and EF. Methods: Thirteen patients showed VIQ-PIQ discrepancies significant at the p7lt;O.O5 level, represented by a>l2-point spread for the WAIS in adults, and a 15-point spread in the WISC in children. We evoked P3 potentials in the individuals with discrepant IQ differences by asking them to keep a mental count of rare tones, including introduction of oddbail tones. EEGs were recorded by the international 10,20 system and P3 peaks were shown in a topographical view by offline analysis. Patients were divided into normal and abnormal groups according to MRI findings, and were examined for the laterali- ties of the dominant side in subtest IQ (conventionally, we regarded higher VIQ as left hemisphere dominant and higher PIQ as right hemisphere dominant), P3 peaks, and EF. We did not correlate results with lert or right handedness. Results: Five patients (38.5%) were in the normal group and 8 patients (61.5%) were in the abnormal group. Concordance of the lateralities in P3 peaks and dominant side in subtest IQ was shown in 1 patient (20%) in the normal group and 5 patients (62.5%) in the abnormal group. In the normal group, all patients showed contralateral P3 peak shift to EF, and all except I patient showed contralateral P3 peak shift to the dominant side in subtest IQ. The other 3 patients in the abnormal group showed unilateral focal cortical dysplasias (FCD), ipsilateral P3 shift, and contralateral dominant side in subtest IQ to the focal MRI lesions. Conclusion: In our partial epilepsy series with VIQ-PIQ discrepancies, concordance of the lateralities in P3 peaks and dominant side in subtest IQ was shown in < half of the patients. Epileptogenic foci seem to have 3 different grades of influence on P3 peak shift and dominant side in subtest IQ according to the severities of accompanying focal MRI lesions: 1. Without MRI lesions, EF can make P3 peak shift contralaterally, but the dominant side in the subtest IQ shift ipsilaterally; 2. With less severe focal MRI lesions such as hippocampal atrophy etc., EF can make not only P3 peaks but also the dominant side in the subtest IQ shift contralaterally; 3. With severe focal MRI lesions such as FCD, EF can make the dominant side in the subtest IQ shift contralaterally, but the P3 peak may shift ipsilaterally. Epileptogenic foci without MRI lesions seem to control ipsilateral P3 potentials. MRI lesions render a hemisphere unlikely to become dominant, but epileptogenic foci can coexist with apparently normal neuropsychological function. [source]

Motor laterality asymmetry and nonmotor symptoms in Parkinson's disease,

MOVEMENT DISORDERS, Issue 1 2010
Esther Cubo
Abstract Background: In patients with Parkinson's disease (PD), asymmetric motor signs provide an interesting model to evaluate whether asymmetric nigrostriatal degeneration can affect neuropsychological function and other nonmotor symptoms (NMS). This study was designed to evaluate the predominant laterality of motor symptoms and its relationship with cognition and other NMS in idiopathic PD. Methods: Nationwide, longitudinal, and multicenter study (ELEP Registry) using outpatients with PD. Left PD (LPD) and right PD (RPD) was defined based on the motor signs on the SCOPA-motor scale. To include the clinical spectrum of asymmetric PD patients, we considered two groups of patients with mild-moderate and extreme asymmetry. Predominant LPD or RPD with mild-moderate versus extreme asymmetry were compared using the following scales: cognition, psychosis (Parkinson Psychosis Rating Scale), anxiety/depression, sleep (and autonomic dysfunction at baseline and 1 year later. Nonparametric tests were used for comparison. Results: One hundred forty-nine PD patients (74 RPD and 75 LPD) with mild-moderate asymmetry and 90 (47 RPD and 43 LPD) with extreme asymmetry and a mean age of 64.5 (10.4) years were included. Extreme RPD had higher Parkinson Psychosis Rating Scale scores over time (P = 0.005) compared with LPD, but no significant differences were observed between LPD and RPD in terms of other NMS. Conclusions: These findings suggest that damage to left-hemisphere plays a disproportionately greater role in PD-related psychosis over time. In contrast, motor laterality does not consistently affect other NMS, suggesting that NMS are related to a more widespread brain disorder. © 2009 Movement Disorder Society [source]

Practitioner Review: Computerized assessment of neuropsychological function in children: clinical and research applications of the Cambridge Neuropsychological Testing Automated Battery (CANTAB)

THE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 5 2003
Monica Luciana
Background: Computers have been used for a number of years in neuropsychological assessment to facilitate the scoring, interpretation, and administration of a variety of commonly used tests. There has been recent interest in applying computerized technology to pediatric neuropsychological assessment, which poses unique demands based on the need to interpret performance relative to the child's developmental level. Findings: However, pediatric neuropsychologists have tended to implement computers in the scoring, but not administration, of tests. This trend is changing based on the work of experimental neuropsychologists who frequently combine data obtained from test batteries with lesion or neuroimaging data allowing descriptions of brain,behavior relations to be made with increasing confidence. One such battery is the Cambridge Neuropsychological Testing Automated Battery (CANTAB), and current studies in which the CANTAB has been used to measure executive functions in children are reviewed. Conclusions: Computerized batteries of this type can record aspects of performance that are difficult for psychometrists to achieve, and these may reflect activity in developing neural networks with more sensitivity than can be achieved with traditional tests. However, before computerized test administration becomes a routine part of pediatric neuropsychological assessment, several obstacles must be overcome. Despite these limitations, it is concluded that computerized assessment can improve the field by facilitating the collection of normative and clinical data. [source]

Declined neural efficiency in cognitively stable human immunodeficiency virus patients,

ANNALS OF NEUROLOGY, Issue 3 2009
Thomas Ernst PhD
Objective To determine whether brain activation changes in clinically and neurocognitively normal human immunodeficiency virus (HIV),infected and in HIV-seronegative control (SN) participants over a 1-year period. Methods Functional magnetic resonance imaging (fMRI) was performed in 32 SN and 31 HIV patients (all with stable combination antiretroviral treatment) at baseline and after 1 year. Each participant performed a set of visual attention tasks with increasing attentional load (from tracking two, three, or four balls). All HIV and SN participants had normal neuropsychological function at both examinations. Results Over 1 year, HIV patients showed no change in their neurocognitive status or in task performance during fMRI. However, HIV patients showed significant 1-year increases in fMRI signals in the prefrontal and posterior parietal cortices for the more difficult tasks, whereas SN control participants showed only decreases in brain activation in these regions. This resulted in significant interactions between HIV status and time of study in left insula, left parietal, left temporal, and several frontal regions (left and right middle frontal gyrus, and anterior cingulate). Interpretation Because fMRI task performance remained unchanged in both groups, the HIV patients appeared to maintain performance by increasing usage of the attention network, whereas the control participants reduced usage of the attention network after 1 year. These findings suggest improved efficiency or a practice effect in the SN participants but declined efficiency of the neural substrate in HIV patients, possibly because of ongoing brain injury associated with the HIV infection, despite their apparent stable clinical course. Ann Neurol 2009;65:316,325 [source]

Interactive effect of central obesity and hypertension on cognitive function in older out-patients with Type 2 diabetes

DIABETIC MEDICINE, Issue 12 2008
E. Kim
Abstract Aim Central obesity, hypertension and diabetes mellitus have been related individually to cognitive dysfunction. We aimed to study the interactive effects of these co-occurring risk factors on cognitive decline, which remain unclear in older patients with diabetes. Methods We assessed metabolic profiles and neuropsychological functions in 60 older out-patients with Type 2 diabetes to examine the associations of central obesity with cognitive functions, while controlling for other confounding factors in these subjects. Results Waist circumference was associated with poor performance in digits forward (r2 = 0.11, P = 0.02), choice reaction time (r2 = 0.08, P = 0.04) and cognitive reaction time (r2 = 0.07, P < 0.05) even after adjustment for potential confounders including age, gender, education and HbA1c. There were also significant interactions between central obesity and hypertension with respect to performance of digits forward (P = 0.04) and delayed verbal cued recall (P = 0.03). Conclusion Our findings suggest that, in addition to glycaemic control, central obesity and hypertension influence cognitive functions, such as attention and psychomotor speed in older patients with Type 2 diabetes. [source]

VIQ-PIQ Discrepancies in Partial Epilepsy: On the Relation to Lat- eralities of Focal MRI Lesions, P3 Peaks, and Focal Spikes.

Neuropsychological studies in anorexia nervosa

INTERNATIONAL JOURNAL OF EATING DISORDERS, Issue S1 2005
Kate Tchanturia PhD
Abstract Neuropsychological findings in eating disorders are somewhat inconsistent. This may be because individual studies have used a broad range of tests on relatively small, heterogeneous clinical groups, thus limiting the detection of subtle neuropsychological differences in these patients. Therefore, rather than using broad assessments of a variety of neuropsychological functions, adoption of a more focused, hypothesis-driven approach based on clinical practice is proposed. This will allow more in-depth investigations of targeted functions and will improve the chances of detecting a problem, of exploring its ecologic validity, and of tailoring a treatment. We have demonstrated this approach using our neuropsychological studies of cognitive flexibility in anorexia nervosa (AN). © 2005 by Wiley Periodicals, Inc. [source]

Timing of Thyroid Hormone Action in the Developing Brain: Clinical Observations and Experimental Findings

JOURNAL OF NEUROENDOCRINOLOGY, Issue 10 2004
R. T. Zoeller
Abstract The original concept of the critical period of thyroid hormone (TH) action on brain development was proposed to identify the postnatal period during which TH supplement must be provided to a child with congenital hypothyroidism to prevent mental retardation. As neuropsychological tools have become more sensitive, it has become apparent that even mild TH insufficiency in humans can produce measurable deficits in very specific neuropsychological functions, and that the specific consequences of TH deficiency depends on the precise developmental timing of the deficiency. Models of maternal hypothyroidism, hypothyroxinaemia and congential hyperthyroidism have provided these insights. If the TH deficiency occurs early in pregnancy, the offspring display problems in visual attention, visual processing (i.e. acuity and strabismus) and gross motor skills. If it occurs later in pregnancy, children are at additional risk of subnormal visual (i.e. contrast sensitivity) and visuospatial skills, as well as slower response speeds and fine motor deficits. Finally, if TH insufficiency occurs after birth, language and memory skills are most predominantly affected. Although the experimental literature lags behind clinical studies in providing a mechanistic explanation for each of these observations, recent studies confirm that the specific action of TH on brain development depends upon developmental timing, and studies informing us about molecular mechanisms of TH action are generating hypotheses concerning possible mechanisms to account for these pleiotropic actions. [source]