PubMed Health⌕ Search

Biomedical subjects

Samuel T Gontkovsky

Publications and source records attributed to Samuel T Gontkovsky.

14 recordsLinked to original sources
PubMed2006

Wechsler Adult Intelligence Scale-III inter-subtest scatter: a comparison of brain-damaged patients and normal controls.

This study assessed the validity of Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) inter-subtest scatter (as measured by the scaled score range) as an indication of cognitive impairment due to brain dysfunction. Participants were 174 individuals with documented brain damage. Means for age, education, and WAIS-III full-scale IQ were 49.19 years (SD = 15.33), 12.57 years, (SD = 2.78), and 88.45 (SD = 17.78). The scatter ranges for brain-damaged participants were compared with those of the WAIS-III standardization sample. Results indicated that the full-scale IQ is significantly correlated with amount of scatter, r(172) = .42, p < .0001, so that a definitive answer to the question requires control of full-scale IQ. In the present analyses, inter-subtest scatter among the individuals for the sample as a whole was no greater than that for persons in the standardization sample, but subtest scatter was significantly greater for participants with IQs > or = 90. This finding suggests that there may be small differences in scatter between brain-damaged persons and normal controls, but that scatter is relatively insensitive to the presence of brain damage or dysfunction. Therefore, interpretation of marked inter-subtest variability as a sign of brain damage appears unwarranted.

Aged, 80 and over↗
PubMed2006

Practical methods for the clinical assessment of information processing speed.

The rate at which individuals are capable of processing information is considered a sensitive indicator of brain dysfunction, particularly among clinical populations whose neurocognitive impairments generally are considered relatively mild in nature. Assessment of information processing speed often is confounded, however, by comorbid impairments in other constructs of neurocognition, including attentional capacity, visuospatial perception, language, immediate memory, and motor speed/coordination. This investigation examined the effect of controlling for various potential confounders on the strength of associations among several potential measures of information processing speed. Participants were 64 patients diagnosed with clinically definite multiple sclerosis. Analysis indicated consistent significant and positive associations among measures of processing speed, which generally persisted despite simultaneous statistical control of potential confounding factors. Results imply that examined confounding variables are similarly related to the measures of processing speed. Therefore, any of the measures of information processing speed considered in this study may be used as a proxy for the more direct measure of this construct derived from the Sternberg Memory Scanning Test.

Cognition↗
PubMed2006

Effect of urbanicity of residence on TBI outcome at one year post-injury.

OBJECTIVE: To determine the impact of urbanicity of residence and occurrence of medical complications on outcome after traumatic brain injury (TBI). STUDY DESIGN: A consecutive series of persons admitted for inpatient TBI rehabilitation followed for 1 year post-injury. SETTING: Inpatient brain injury rehabilitation programme in the southeastern US. PARTICIPANTS: One hundred and eleven persons with severe (67%), moderate (18%) or mild (15%) TBI. OUTCOME MEASURE: Functional status at 2 year post-injury as measured by the Disability Rating Scale (DRS). RESULTS: Functional status at follow-up was predicted by age, DRS at admission for rehabilitation, injury severity, alcohol use, continued need for medications and medical complications (validated R2 = 0.57; p < 0.0001). Urbanicity of residence was not predictive of functional status. CONCLUSIONS: As expected, participants who experienced more medical complications and required continued use of medications had poorer functional outcomes. Contrary to expectation, more rural residents did not have poorer outcomes than persons residing in more urban areas.

Adult↗
PubMed2005

Multidimensional assessment of acute confusion after traumatic brain injury.

OBJECTIVES: To describe the phenomenology of posttraumatic confusional state (PTCS) and to provide preliminary validation of a new procedure, the Confusion Assessment Protocol (CAP), for assessing PTCS. DESIGN: Criterion standard investigation. SETTING: Inpatient traumatic brain injury (TBI) rehabilitation program. PARTICIPANTS: Two consecutive series of patients (n=62, n=93) with TBI admitted for inpatient rehabilitation. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Clinical diagnosis of delirium based on Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) criteria, classification of posttraumatic amnesia (PTA) based on the Galveston Orientation and Amnesia Test (GOAT), and Disability Rating Scale score at time of rehabilitation hospital discharge. Results Agreement between the diagnosis of PTCS with the CAP and DSM-IV classification of delirium was 87%, and agreement between PTCS and PTA using GOAT criteria was 90%. Patients classified as in PTCS sustained more severe injuries and required longer rehabilitation stays. Confusion status was associated with poorer functional status at rehabilitation discharge. CONCLUSIONS: The CAP is a brief, structured, repeatable measure of multiple neurobehavioral aspects of PTCS. Confusion status as determined by CAP assessment contributed to prediction of outcome at rehabilitation discharge after adjustment for other potential predictors.

Adult↗
PubMed2005

The WASI matrix reasoning subtest: performance in traumatic brain injury, stroke, and dementia.

Previous research reported that the WAIS-III Matrix Reasoning (MR) subtest was insensitive to the effects of traumatic brain injury (TBI), learning disability, and attention deficit hyperactivity disorder. This study was conducted to determine whether these findings generalize to the Wechsler Abbreviated Scale of Intelligence (WASI) MR subtest and to explore the subtest's sensitivity to other brain disorders. When 81 brain-damaged patients completed the WASI, the MR subtest was the highest score in the profile. For subgroups of TBI and Dementia, MR yielded the highest mean T-score. For patients with stroke, MR was the second highest mean. Subtest comparisons with estimated premorbid IQ suggested MR might show selective sensitivity. Results indicated no predictive validity for TBI, whereas MR was sensitive to the cognitive sequelae of stroke and dementia.

Aged↗
PubMed2004

Construct validity of the 7/24 spatial recall test.

This investigation was conducted to examine the construct validity of the 7/24 Spatial Recall Test (7/24). Participants were 64 outpatients who met criteria for clinically definite multiple sclerosis (MS). Data obtained from administration of a fixed neuropsychological assessment battery were analyzed to evaluate the relation between demographic, physical, and emotional factors and performance on the 7/24, to examine the measure's convergent/discriminant validity, to determine which variables account for the greatest proportion of variance in 7/24 scores, and to assess further the test's sensitivity to the cognitive sequelae of MS. Findings suggest that 7/24 scores are significantly explained by the constructs of visual-spatial perception/analysis, memory, reasoning, and/or processing speed. The proportion of variance in 7/24 performances accounted for by cognitive and demographic variables, however, was quite low. Relative to the measure's normative sample, participants in this investigation performed significantly poorer on number of responses recalled across Set A learning trials but not on Set A long-delay recall. Results of this investigation indicate some level of sensitivity of the 7/24 to the cognitive impairments associated with MS but offer only weak support for the 7/24 as a valid measure of visuospatial learning/memory.

Adult↗
PubMed2003

RBANS performance: influences of sex and education.

A sample of 278 men and 353 elderly women who resided in the community received the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) as part of a study of health in mature adult Oklahomans. Females attained significantly higher scores on the Immediate and Delayed Memory and the Language Indexes. Males performed better on the Visuospatial/Construction Index, but there was no sex difference on the Attention or Total Indexes. Differences related to sex were modest (2-6 Index points), but combined with the larger effects of education could lead to an adjustment of up to 11 Index points.

Aged↗
PubMed2003

Exploratory factor analysis of the Wechsler Abbreviated Scale of Intelligence (WASI) in adult standardization and clinical samples.

Exploratory factor analyses were conducted separately on the Wechsler Abbreviated Scale of Intelligence (WASI; The Psychological Corporation, 1999) adult standardization sample (n = 1,145) and a diagnostically heterogeneous adult clinical sample (n = 201). In the latter group, means for age, education, and WASI Full Scale IQ were 59.25 years (SD = 17.52), 12.39 years (SD = 2.88), and 89.91 (SD = 16.00). For each sample, the four WASI subtests were subjected to a principal-axis factor analysis followed by varimax and promax rotations. Two factors were specified to be retained. Verbal Comprehension and Perceptual Organization factors were identified in both analyses. Coefficients of congruence were 0.98 for Factor I and 0.99 for Factor II, suggesting factorial equivalence across the standardization and clinical samples.

Adolescent↗
PubMed2003

Analyzing the subcortical dementia syndrome of Parkinson's disease using the RBANS.

On mental status examinations, groups of equally impaired patients with subcortical (Huntington's disease, HD; Parkinson's disease, PD) or cortical (Alzheimer's disease, AD) dementias exhibit different patterns of neuropsychological deficits. Using the Repeatable Battery for Assessment of Neuropsychological Status (RBANS), classification accuracies of 90% or greater have been reported for individual patients with AD or HD. To test the generality of the RBANS classification algorithm, we studied patients with dementia (AD and PDD) and without dementia (PDND). Classification accuracies were AD: 87%, PDD: 78%, and PDND: 39%. Comparisons of performance on subtests of the RBANS showed that all groups performed more poorly on tests that require motor skill or rapid information processing and that memory performance by the PD groups was not improved by procedures that enhance encoding and facilitate retrieval. The RBANS is useful for discriminating patterns of cognitive impairment in PD and AD, but only if the diagnosis of dementia is established independent of the RBANS test results. Cognitive slowing is not specific to subcortical dementia and current concepts of memory dysfunction in PD may require re-examination.

Aged↗
PubMed2002

Age and educational influences on RBANS index scores in a nondemented geriatric sample.

Research has indicated the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS; Randolph, 1998) to be sensitive to the effects of brain dysfunction and capable of accurately discriminating cortical from subcortical dementias (Randolph, Tierney, Mohr, & Chase, 1998). It recently has been demonstrated, however, that certain indices of the measure are susceptible to educational influences (Lineweaver, Zone, Chelune, Hermann, & Dow, 2001). The present investigation examined the effects of age and education on the six RBANS indices in a sample of nondemented older adults. Education accounted for a statistically significant proportion of the variance across all RBANS indices for this group (range=1.9-7.6%), while age increased the variance accounted for on four of six indices (range=0.5-2.2%). Regression-based educational corrections for index scores were derived to allow for appropriate adjustment. Effects of age, although statistically significant, were too small to make clinical adjustment on three of the four index scores worthwhile. On the Delayed Memory Index, however, correction for age for persons 80 years old and higher should be considered.

Aged↗
PubMed2002

T-score and raw-score comparisons in detecting brain dysfunction using the booklet category test and the short category test.

Often considered one of the more discriminating tests between normal and brain-damaged individuals, the Category Test has been described as a complex measure of new problem solving, logical analysis, concept formation, abstract reasoning, and mental efficiency. Since publication of a booklet format by DeFilippis and McCampbell in 1979, researchers have attempted to develop other versions to reduce time required for administration. The present study compared the sensitivity of the Short Category Test, Booklet Format with the Booklet Category Test. Subjects were 22 male veterans seen for comprehensive neuropsychological evaluation and were classified into a brain-damaged or a control group (ns =11) according to independent neurological or neuroradiological evidence. Comparison of performances based on T scores yielded no significant differences between the groups on either format. Analyses of performance based upon suggested raw score cut-offs for the tests, however, yielded a statistically meaningful difference, but caution is in order when using T scores derived from age- or education-based normative data to suggest the presence of brain dysfunction. Raw score cut-offs yielded valid differentiation of individual patients in both groups.

Adult↗
PubMed2002

Sensitivity of the semantic fluency subtest of the repeatable battery for the assessment of neuropsychological status.

This study examined the concurrent validity of the Semantic Fluency subtest of the Repeatable Battery for the Assessment of Neuropsychological Status. Performance by cognitively impaired vs nonimpaired neurological patients was examined in relation to the performance of these groups on the Controlled Oral Word Association Test. Analyses indicated these tests are largely equivalent with respect to both sensitivity to neurocognitive dysfunction and discrimination of cognitively impaired from nonimpaired neurological patients. Findings support the psychometric validity of the Semantic Fluency subtest in the evaluation of brain dysfunction.

Aged↗
PubMed2002

Current directions in computer-assisted cognitive rehabilitation.

Technological advances over the past decade have given rise to the development of multiple computer-assisted cognitive rehabilitation programs. While results of investigations examining the efficacy of such techniques have been mixed, a positive trend for utilization of these procedures has been demonstrated. This review provides a discussion of the progression of research in this area, from anecdotal studies to controlled empirical investigations. Methodological shortcomings are examined and directions for future research in computer-assisted cognitive rehabilitation suggested.

Brain Injuries↗