Generalized cognitive function after stroke

Response time and response time variability as indicators of response quality during static automated perimetry

PURPOSE

Perimetry is a both demanding and strenuous examination method that is often accompanied by signs of fatigue, leading to false responses and thus incorrect results. Therefore, it is essential to monitor the response quality. The purpose of this study was to evaluate the response time (RT) and its variability (RTV) as quality indicators during static automated perimetry.

METHODS

Size III Goldmann stimuli (25.7') were shown with the OCTOPUS 900 perimeter in four visual field locations with 13 different stimulus luminance levels (0.04-160 cd/m2). An increased rate of false-positive and false-negative catch trials (25% each) served to monitor the response quality simultaneously together with response time recording. Data evaluation was divided into global and individual analysis. For global analysis, the agreement indices (AI, agreement between time periods with an increased number of false responses to catch trials and time periods with pathological response to time-based values set into relation to time periods in which only one of the two criteria was considered pathological) and for individual analysis, the Spearman correlation coefficients were calculated. Ophthalmologically normal subjects with a visual acuity ≥ 0.8, and a maximum spherical/cylindrical ametropia of ± 8.00/2.50 dpt were included.

RESULTS

Forty-eight subjects (18 males, 30 females, age 22-78 years) were examined. The total number of false responses to catch trials was (median/maximum): 6/82. RT and RTV were compared to the occurrence of incorrect responses to catch trials. The resulting individual Spearman correlation coefficients (median/maximum) were for RT: ρRT = 0.05/0.35 and for RTV: ρRTV = 0.27/0.61. The global analysis of the RTV showed agreement indices (median/maximum) of AIRTV = 0.14/0.47.

CONCLUSIONS

According to this study, an increased portion of catch trials is suitable as a verification tool for possible response quality indicators. The RTV is a promising parameter for indicating the response quality.

Demographically adjusted normative data for the Halstead category test in a Spanish-speaking adult population: Results from the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS)

OBJECTIVE

The present study aimed to develop norms applicable to Spanish-speakers living in the United States (U.S.)- Mexico border region for the Halstead Category Test (HCT), a test of executive function.

METHODS

Healthy native Spanish-speakers (N = 252; Age: range 19-60 years, M = 37.28, SD = 10.24; Education: range 0-20 years; M = 10.65, SD = 4.33; 58.33% women) living in the U.S.-Mexico border region of California and Arizona completed the HCT as part of a comprehensive neuropsychological test battery. The univariable and interactive effects of demographic variables on HCT raw scores were examined. Total scores were normed using fractional polynomial equations, controlling for age, education, and gender. T-scores were also computed for HCT scores of the current Spanish-speaking normative sample using published, demographically-adjusted norms for English-speaking non-Hispanic Whites and Blacks. Impairment rates (T-Scores < 40) were calculated using published and current norms.

RESULTS

Age was significantly associated with increased number of errors, and education and male gender were associated with decreased number of HCT errors (total raw scores). Applying norms developed for English-speaking non-Hispanic Whites and Blacks resulted in overestimation of impairment rates in the current sample (impairment: 48% with White norms and 27% with Black norms). This pattern was evident across levels of education except in participants with 13+ years of education, where rates of impairment using non-Hispanic Black norms were comparable to those based on newly developed norms.

CONCLUSION

The present study presents norms for the HCT in a sample of U.S. Spanish-speakers, providing an important tool for identifying executive dysfunction in this population.

Neuropsychological function in type 2 diabetes mellitus

Type 2 diabetes mellitus (DM) is a major and growing health problem. Brain-related effects of type 2 DM have been studied in several ways over the past few decades. Results have shown effects on brain structure, incidence of dementia, and impairment of various cognitive functions. The present study examined a sample of clinically-referred patients with type 2 DM and compared them with a sample of control patients who were matched on a pairwise basis on age, education, and gender. Each patient was tested using a comprehensive, integrated neuropsychological test battery. Results showed a pattern of generalized and specific neuropsychological dysfunction affecting a broad range of neurocognitive and sensorimotor abilities. However, no differences were found on measures of attention/concentration, memory, or abstract reasoning. Nevertheless, the DM group consistently performed worse on all measures. The DM group's score on a summary measure of neuropsychological function (GNDS) reflected moderate brain-related impairment. A neurocognitive profile is identified that may help clinicians understand their DM patients.

The test accuracy of the Montreal Cognitive Assessment (MoCA) by stroke lateralisation

BACKGROUND

The Montreal Cognitive Assessment (MoCA) is an increasingly popular screening tool for detecting cognitive impairment post-stroke. However its' test accuracy by stroke lateralisation is as yet unknown.

AIM

Our aim was to investigate whether the test accuracy of the MoCA differs by stroke lateralisation across different cognitive domains.

METHODS

We retrospectively examined the cognitive profiles of 228 subacute stroke patients (86 Left, 142 Right), comparing MoCA-total and domain-specific scores with performance on detailed neuropsychological assessment.

RESULTS

The prevalence of cognitive impairment detected on neuropsychological assessment was high and relatively comparable between the right and left hemisphere stroke groups (91% and 93% respectively). Notably however, 29% of the right stroke group and 6% of the left stroke group achieved a "cognitively-intact" MoCA score (≥25). A high proportion of right stroke patients who had an overall MoCA-intact score were found to be impaired in intellectual functioning, processing speed, executive functions and non-verbal memory on neuropsychological assessment. Furthermore, a high proportion of patients who scored full-marks within a MoCA-specified domain, irrespective of their overall score, were found to have impairment on corresponding neuropsychological assessment for both stroke groups.

CONCLUSIONS

Particular care needs to be taken in interpreting MoCA-intact performance for right hemisphere patients due to its poor sensitivity to right hemisphere deficits. Scoring maximum points within a MoCA-specified domain also does not necessarily indicate intact cognitive functioning in that domain. Clinicians should consider supplementing their MoCA assessment with additional tools to increase the test accuracy of detecting relevant cognitive impairments post-stroke.

WAIS-IV Profiles in First-Ever Unilateral Ischemic Stroke Patients

This study aims to identify WAIS-IV profiles in unilateral ischemic stroke patients in rehabilitation (n = 107) compared to matched controls, to determine if patients demonstrate lateralized cognitive impairment, and to investigate whether aphasia has an additional effect on language and working memory subtests. Analyses revealed impairment in performance of stroke patients relative to controls, while effect of left-hemisphere stroke were large on subtests with language and processing speed demands, and of right-hemisphere stroke on subtests with visuo-spatial and processing speed demands. Aphasia had an additional effect on language, working memory and processing speed subtests. Findings confirm the pattern of cognitive deficits found with older versions of the WAIS and suggest that the WAIS-IV detects cognitive deficits in stroke patients.

A brief neuropsychological battery for use in the chronic heart failure population

BACKGROUND

Cognitive impairment is a recognized consequence of heart failure; however, there are no neuropsychological batteries with documented psychometric data in the chronic heart failure population.

AIMS

To document the psychometric properties of a brief neuropsychological battery in a chronic heart failure sample.

METHODS

The Repeatable Battery for the Assessment of Neuropsychological Status, Trail Making Test Part A and Part B, and letter fluency was administered to a sample of individuals with chronic heart failure.

RESULTS

Eighty individuals with stable heart failure participated in this study. Individuals with chronic heart failure scored significantly lower than expected age and education adjusted norms in the domains of attention (p < 0.001), memory (p < 0.001), language (p < 0.001), executive function (p < 0.001), and psychomotor speed (p = 0.02). Scores on the tests of memory and executive function correlated to functional status (r = 0.28, p = 0.02 and r = 0.29, p = 0.03, respectively). Acceptable convergent validity and test-retest reliability were documented for this battery.

CONCLUSION

The neuropsychological battery had adequate reliability and validity in individuals with chronic heart failure.

Regression equations for predicting scores of persons over 65 on the Rey Auditory Verbal Learning Test, the mini-mental state examination, the trail making test and semantic fluency measures

OBJECTIVES

Scores on neuropsychological tests are often used to detect abnormal changes in cognition in older persons. Accordingly, it is important to have normative data that allow the abnormality of a test score to be determined precisely and accurately. Regression equations that estimate an expected score based on demographic or premorbid factors can be an efficient method of making normative comparisons. Our aim was to compute regression equations with age, gender and estimated premorbid IQ as predictors of scores on the Rey Auditory Verbal Learning Test (AVLT), the Trail Making Test (TMT), Mini-mental State Examination (MMSE) and measures of semantic fluency.

DESIGN

All measures were administered to a group of 272 healthy older persons aged between 65 and 90 during the pre-treatment phase of a study evaluating the effect of nutritional supplements on cognition. Premorbid IQ was estimated using the National Ault Reading Test (NART). Stepwise multiple regression procedures were used to determine the weights to be applied to the predictor variables.

RESULTS

Age and premorbid IQ were found to be significantly correlated with all test variables; gender correlated significantly with most scores. Regression equations based on the 3 predictor variables explained between 10% and 30% of the variance of the range of test scores. The use of these equations in clinical practice was illustrated.

CONCLUSION

The significant correlations between the predictor variables and test scores justified computing a set of equations for use in interpreting data from older persons. The abnormality of the difference between predicted and obtained scores provides a convenient index of an individual's current level of neuropsychological functioning.

Utility of the Neuropsychological Assessment Battery in detecting cognitive impairment after unilateral stroke

This study evaluated the clinical utility of the Neuropsychological Assessment Battery (NAB) in a stroke sample by examining the NAB's ability to differentiate a chronic stroke group with radiologically confirmed unilateral damage (n = 42) and a demographically matched healthy control (HC) group (n = 36). The stroke group performed more poorly than the control group across NAB Total score and all five Domain scores. Receiver operator curves (ROC) were derived and area under the curve (AUC) showed moderate diagnostic effectiveness (AUC .70 to .90) for NAB Total score, all five Domain scores, a motor composite, and a Global Deficit Score (GDS) that has been shown to closely approximate clinical ratings of neuropsychological impairment. The NAB Total, GDS, and motor composite had comparable clinical utility, whereas the Attention and Executive domain scores demonstrated better classification utility compared with the Memory domain. Because 90.5% of our stroke sample had middle cerebral artery territory strokes, the comparison of motor and cognitive classification utility may be biased. However, follow-up analyses showed that the NAB accounted for additional variance even when motor composite was included in the model. Sensitivity, specificity, and odds ratios at various clinical cutoffs are provided. These results suggest that the NAB is a useful clinical tool for detection of cognitive deficits in individuals with chronic unilateral stroke, although lenient clinical cutoffs appear warranted to maximize sensitivity.

Exploring cognitive effects of self reported mild stroke in older adults: selective but robust effects on story memory

Relatively little systematic information is available regarding patterns of cognitive effects of mild stroke in older adults. We explored this problem with a series of two independent samples from the Victoria Longitudinal Study data archives. In Study 1, self-reported mild stroke and neurologically intact matched controls were (a) confirmed as similar on a set of neurocognitive speed, basic cognition, and awareness indicators, and (b) compared for differences on a set of episodic, semantic, and working memory tasks. The mild stroke group was selectively worse on the language intensive story memory task. This effect was partially attributable to a deficit in remembering the most thematic information. Study 2 closely replicated these procedures and results. In addition, Study 2 follow-up analyses, comparing provisional right-hemisphere damaged and left-hemisphere damaged (LHD) participants, revealed that the thematic story memory deficit for mild stroke participants could be due to the selective impairment of LHD participants.

Therapeutic issues in vascular dementia: studies, designs and approaches

Vascular dementia (VaD) is a heterogeneous disorder resulting from various cerebrovascular diseases (CVD) causing cognitive impairment that reflects severity and location of damage. Epidemiological studies suggest VaD is the second commonest cause of dementia, but autopsy series report that pure VaD is infrequent, while combined CVD and Alzheimer's Disease(AD) is likely the commonest pathological-dementia correlate. Both diseases share vascular risk factors and benefit from their treatment. The most widely used diagnostic criteria for VaD are highly specific but not sensitive. Vascular Cognitive Impairment (VCI) is a dynamic, evolving concept that embraces VaD, Vascular Cognitive Impairment No Dementia (VCIND) and mixed AD and CVD. Clinical trials to date have focused on probable and possible VaD with beneficial effects evident for different drug classes, including cholinergic agents and NMDA agonists. Limitations have included use of cognitive tools suitable for AD that are insensitive to executive dysfunction. Disease heterogeneity has not been adequately controlled and subtypes require further study. Diagnostic VaD criteria now 13 years old need updating. More homogeneous subgroups need to be defined and therapeutically targeted to improve cognitive-behavioural outcomes including optimal control of vascular risk factors. More sensitive testing of executive function outlined in recent VCI Harmonization criteria and longer trial duration are needed to discern meaningful effects. Imaging criteria must be well-defined, with centralized review and standardized protocols. Serial scanning with quantification of tissue atrophy and lesion burden is becoming feasible, and cognitive interventions, including rehabilitation pharmacotherapy, with drugs strategically coupled to cognitive -behavioural treatments, hold promise and need further development.

Poststroke memory function in nondemented patients: a systematic review on frequency and neuroimaging correlates

BACKGROUND AND PURPOSE

Poststroke memory dysfunction is a prerequisite for the diagnosis of poststroke dementia. This diagnosis is made within months after a stroke, apparently assuming a relatively stable course of the poststroke memory function. Clinical experience added to anecdotal evidence from the literature suggests that poststroke memory function may be reversible. The aim of the present study was to systematically review the available data on the time course of poststroke memory function in nondemented stroke survivors. In addition, we wanted to investigate the role of (pre-)stroke characteristics on poststroke memory function.

METHODS

We performed systematic literature search of PubMed with the following medical subject heading terms: memory and stroke. The search strategy yielded 798 articles of which 65 fulfilled our inclusion criteria and went on to the data extraction stage.

RESULTS

Five studies reported the prevalence of poststroke memory dysfunction at different poststroke intervals. The prevalence of poststroke memory dysfunction varied from 23% to 55% 3 months poststroke, which declined from 11% to 31% 1 year poststroke. Larger stroke volume, prestroke medial temporal lobe atrophy, and white matter lesions were related with decreased poststroke memory function.

CONCLUSIONS

Not all patients with poststroke memory dysfunction 3 months after a stroke had memory dysfunction 1 year poststroke. Consequently, not all criteria for the dementia diagnosis were fulfilled any more. This may indicate that poststroke dementia may be reversible in a substantial proportion of patients with stroke. Preferably, standardized reassessment of cognitive function should be performed in each patient diagnosed with poststroke dementia.

The WAIS-R factors: usefulness and construct validity in neuropsychological assessments

One-hundred and twelve patients were administered the Wechsler Adult Intelligence Scale-Revised (WAIS-R), an abbreviated Wechsler Memory Scale-Revised, and the Halstead-Reitan Neuropsychological Test Battery. In order to replicate an earlier study (Sherman, Strauss, Spellacy, & Hunter, 1995), correlations were generated between the WAIS-R factor scores and neuropsychological and memory tests. The Verbal Comprehension factor (Factor 1) correlated with Speech Sounds Perception Test (SSPT), the Seashore Rhythm Test (SSRT), the Category Test, and memory indices. The Perceptual Organizational factor (Factor 2) correlated with the time, memory, and location scores of the Tactual Performance Test, the SSPT, SSRT, the Category Test, Trails A, Trails B, memory indices, and finger tapping. The Freedom From Distractibility factor (Factor 3) was correlated with the Category Test, the SSPT, the SSRT, Trails A, Trails B, immediate Logical Memory, and Visual Reproduction. Modest correlations suggest that the WAIS-R factors may be useful for understanding underlying cognitive performance and can be functional for generating hypotheses, but should not be utilized exclusively to make clinical inferences.

Cognitive recovery after stroke: a 2-year follow-up

OBJECTIVES

To determine (1) whether long-term improvement of cognitive function takes place after stroke and (2) which clinical factors influence cognitive recovery.

DESIGN

Cohort study with patients who were assessed at 2.3 and 27.7 months after stroke.

SETTING

Home-based stroke patients.

PARTICIPANTS

From a group of 229 stroke patients, 92 were approached to participate. Sixty-five (43 men, 22 women; mean age, 56.4y) agreed, and they were neuropsychologically assessed at 72.2 days after stroke. A group of 33 controls (12 men, 21 women; mean age, 52.4y) was used as a reference sample.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Orientation, memory, attention, visuospatial, visuoconstructive, language, and arithmetic abilities were assessed with an extensive neuropsychologic test battery.

RESULTS

Significant improvements across time were noted for all cognitive domains. The biggest improvement was found in the attentional domain; the least, in the memory domain. In addition, a small subset of patients accounted for the significant improvement in all cognitive domains; most patients showed no improvement or declined. Factors influencing recovery were side of the stroke and incidence of lowered consciousness on admission. Patients with right-side brain damage performed better than those with left-side brain damage and showed more improvement over time. Patients with lowered consciousness on admission performed worse than patients without lowered consciousness. No significant effect was found for gender, type of stroke, cortical versus subcortical lesions, having 1 stroke or multiple strokes, or the interval between the stroke and the neuropsychologic assessment.

CONCLUSION

There was room for improvement in all cognitive domains, although this improvement was gained by only a small number of patients. Hence, most patients must cope with serious permanent cognitive decline after stroke.

Increased risk of cognitive impairment 3 months after mild to moderate first-ever stroke: a Community-Based Prospective Study of Nonaphasic English-Speaking Survivors

BACKGROUND AND PURPOSE

Results of hospital-based studies indicate a high risk of cognitive impairment 3 months after stroke. There are no comprehensive data on this issue from prospective community-based studies comparing first-ever stroke patients with stroke-free subjects.

METHODS

We administered a comprehensive neuropsychological battery to 99 community-based nonaphasic survivors of first-ever stroke at 3 months and 99 age- and sex-matched (1:1) stroke-free individuals. Domain-specific cognitive deficits were identified by blinded neuropsychological consensus.

METHODS

Stroke patients were more likely to suffer any cognitive impairment (relative risk [RR], 1.5; 95% CI, 1.1 to 2.1) attributable mainly to a greater risk of single-domain cognitive impairment (RR, 2.8; 95% CI, 1.5 to 5.3) but not multiple-domain cognitive impairment (RR, 1.2; 95% CI, 0.8 to 1.9).

CONCLUSIONS

In this community-based study, a first-ever stroke of mild to moderate severity was associated with a significant risk of cognitive impairment at 3 months, even in the absence of clinical aphasia. This was due primarily to an increased risk of solitary deficits rather than generalized deficits.

Dementia and cognitive impairment three months after stroke

To investigate the cognitive capacities of a cohort of ischaemic or haemorrhagic stroke survivors and to identify the clinical determinants of post-stroke cognitive impairment, we evaluated 237 patients admitted to a Stroke Unit (mean age 59; SD=12.7). Three months after stroke, patients were submitted to a neuropsychological evaluation that included the Mini-Mental State Examination (MMSE), a complementary battery to assess specific cognitive domains, the Hamilton Depression Rating Scale (HDRS) and the Blessed Dementia Scale (BDS). Disturbed performance on at least one domain was detected on 131 (55%) patients: 27% had cognitive deficits other than memory, 7% had focal memory deficit, 9% had memory and other cognitive deficits and 6% had dementia. Dementia was associated with female gender (P=0.01), older age (P=0.01) and lower education level (P=0.04). Patients with memory deficits were older (P=0.01) with lower educational level (P=0.08) and more left sided lesions (P=0.02) than patients without memory deficits. In this middle aged stroke survivors cognitive impairment was common 3 months after stroke, while dementia was infrequent.

Executive functions and speed of mental processing in elderly patients with frontal or nonfrontal ischemic stroke

Impairments in executive functions have been related to aging and frontal lobe lesions. Aging also causes slowing of mental processing. We examined whether ischemic stroke in the frontal brain area results in dysexecutive syndrome, or whether the frontal stroke causes increased slowing of mental processing. Neurological, radiological and neuropsychological examinations were carried out 3 months post-stroke on 250 ischemic stroke patients (55-85 years) and on 39 healthy control subjects. Of the patients, 62 had frontal and 188 had nonfrontal lesions. The neuropsychological examination comprised several cognitive domains, including tests considered to measure executive functions. The frontal group was slower than the nonfrontal group in tasks measuring speed of mental processing which were time-limited (Trail Making A, Stroop dots and fluency). They were also inferior in the Digit Span backwards task. There were no differences between the groups in other cognitive domains, nor in some tests which are considered to be measures of executive functions (e.g. WCST). Impairments in executive functions were evident in both the frontal and the nonfrontal groups compared with the controls, but no dysexecutive syndrome specifically related to frontal lesions was found. Frontal stroke related mainly to the slowing of mental processing.

Differential diagnosis of the major progressive dementias and depression in middle and late adulthood: a summary of the literature of the early 1990s

There is a preponderance of research on the neuropsychology of the various dementias. There are also direct comparisons between two or more dementias available in the literature. This paper sought to summarize the most recent literature, primarily from 1990 through mid-1996, including recent reviews of the literature from previous decades. The purpose was to provide, in one location, a summary of neuropsychological (i.e., cognitive, motor, and psychiatric) characteristics of major noninfectious, progressive dementias and depression of middle and late adulthood. It is hoped that this review, particularly a summary table provided, will serve as a guide in the differential diagnosis of the dementias by clinicians. In addition to Alzheimer's disease, vascular dementias, Parkinson's disease, Lewy body dementia, Huntington's disease, and frontal lobe dementia, the impact of depression on cognitive functioning is covered given the frequency with which neuropsychologists are asked to differentiate depression from primary dementia.

Interpretation of VIQ-PIQ and intersubtest differences on the Spanish version of the WAIS

Although the Spanish version of the Wechsler Adult Intelligence Scale (WAIS; Escala de Inteligencia Wechsler para Adultos [EIWA]) is the most frequently used intellectual assessment for Spanish speaking clients in the United States, there is little information available on score differences necessary to establish reliable and abnormal differences between Performance IQ (PIQ) and Verbal IQ (VIQ), and between the various subtests of the EIWA. The present study, based on EIWA standardization data (N = 616 Puerto Ricans), reports reliability data and base rates to assist in evaluating the clinical significance of PIQ-VIQ differences. The results demonstrated substantial similarity between the EIWA and the English versions of the Wechsler tests. The interpretation of these differences is discussed, and tables are presented of statistically and clinically significant differences.

Attention deficits in stroke patients with aphasia

Attentional capacity and sustained attention were investigated in 21 aphasic stroke patients and 21 non-brain-damaged patients. Attentional capacity was assessed using a series of reaction time (RT) tasks. The aphasic patients demonstrated impaired attentional capacity as shown by slower processing speed than the non-brain-damaged group (p < .01) and greater increases in RT with increased processing load (p < .05). Similar patterns were found for both verbal and spatial material. There was no significant relationship between severity of auditory comprehension deficits and attentional capacity. Sustained attention was assessed using a cognitive vigilance task requiring identification of a target letter presented infrequently over 32 minutes. Both the aphasic and the non-brain-damaged group demonstrated a decline in performance with time on task as shown by a steady increase in RTs (p < .0001), but the decline was equivalent across the groups. Thus, the aphasic group did not show a specific deficit in the ability to sustain attention.

Differential visuospatial dysfunction following striatal, frontal white matter, or posterior thalamic infarction

The present study investigated visuospatial functioning in 35 right-hand dominant patients with striatal, frontal white matter, or posterior thalamic infarction, in the right cerebral hemisphere. On tasks of visual detection and discrimination, the groups performed within normal limits and comparable to one another. On tasks of visual synthesis and spatial analysis, each group was significantly impaired, with greatest impairment following infarction of deep grey structures. Correlational analyses indicated that in the striatal and frontal white matter groups, visual synthesis and spatial analysis task performance were strongly correlated with performance on neuropsychological tests of executive control. This relationship was not observed in the posterior thalamic group. The results support the hypothesis of differential patterns of visuospatial performance depending on the anatomical locus of subcortical lesions. The findings are explained in terms of differing subcortical circuitry and suggest that multiple substrates mediate the sequelae of subcortical lesions.

Frontal lobe lesions, diffuse damage, and neuropsychological functioning in traumatic brain-injured patients

This study quantified lesion volume in relation to damage location and executive functioning in traumatic brain-injured (TBI) patients. Magnetic resonance (MR) scans of 68 TBI patients were analyzed by taking volumetric measures of lesion sites. Patients were grouped according to the presence/absence of frontal lobe lesions. Measures of frontal lesion volume were studied as predictors for outcome on designated tests of executive functioning (Halstead Category Test and Wisconsin Card Sorting Test). Results showed no significant differences in level of deficit between groups. In addition, no significant differences were found between groups on other tests of neuropsychological functioning (Trail Making Test, Parts A and B, and Wechsler Adult Intelligence Scale-Revised). These results suggest that tests that are traditionally used to detect "frontal lobe" damage may not be adequate for distinguishing specific frontal lobe dysfunction, and do not add anything unique about frontal lobe integrity and neuropsychological functioning in TBI patients.

Visuoperceptual-spatial ability and visual memory in vascular dementia and dementia of the Alzheimer type

This study investigated the relationship between visuoperceptual ability and visual memory in dementia. Twenty individuals with probable dementia of the Alzheimer type, 24 individuals with probable vascular dementia, and 20 healthy, elderly adults underwent neuropsychological evaluation. Hierarchical multiple regression analyses suggested that perceptual organization skills contributed to a significant amount of the variance in novel, but not famous, face recognition. This finding was most robust in the clinical groups. Causality cannot be attributed from this regression model. Results suggest, however, that visual processing deficits are more strongly related to the memory process at the time of encoding rather than during recognition of remote information.

Neuropsychological impairment in children with sickle cell anemia and cerebrovascular accidents

Neuropsychological functioning of children with sickle cell anemia (HbSS) who have experienced a single stroke has not been extensively investigated. In this study, the neuropsychological functioning of 10 children with HbSS who were receiving transfusion therapy following stroke with no identifiable recurrence was examined. The patients were subgrouped into children with only left hemisphere stroke (LCI), N = 4, and those with only right hemisphere stroke (RCI), N = 6. Results indicated that these youngsters experienced significant impairments of cognitive functioning following stroke. It was found that the LCI and RCI children tended to perform more like adult stroke patients than what has been typically reported in children with infantile hemiplegia. These findings support the need for periodic neuropsychological evaluation following stroke in order to identify patterns of higher cortical dysfunction and assist in the development of appropriate rehabilitation and special education programs. Further, pediatricians, child neurologists, and psychologists who care for these children must act as strong advocates on their behalf in order to ensure that they receive appropriate rehabilitation and the special education services necessary for maximal recovery and future educational success.

Cognitive deficits in asymptomatic first-degree relatives of Alzheimer's disease patients

The present study was designed to determine whether neuropsychological deficits exist in asymptomatic first-degree relatives of Alzheimer's disease (AD) patients. The neuropsychological performances of 20 first-degree asymptomatic relatives of NINCDS-ADRDA diagnosed AD patients were compared to 20 normal controls without family history of AD. Cognitive functions assessed included intelligence, memory, overall brain function, verbal learning, and language and constructional abilities. Significant statistical differences were found between the groups across several cognitive areas indicating lower functioning in the first-degree relatives of AD patients. Fifty percent of the first-degree subjects but only 20% of controls showed a pattern of significant neuropsychological deficit. The results demonstrate neuropsychological deficits in asymptomatic first-degree relatives of AD patients, suggesting that preclinical markers for AD may be present long before the clinical manifestation of the disease.

Cognitive impairment after stroke: frequency, patterns, and relationship to functional abilities

Cognitive function was examined in 227 patients three months after admission to hospital for ischaemic stroke, and in 240 stroke-free controls, using 17 scored items that assessed memory, orientation, verbal skills, visuospatial ability, abstract reasoning, and attentional skills. After adjusting for demographic factors with standardised residual scores in all subjects, the fifth percentile was used for controls as the criterion for failure on each item. The mean (SD) number of failed items was 3.4 (3.6) for patients with stroke and 0.8 (1.3) for controls (p < 0.001). Cognitive impairment, defined as failure on any four or more items, occurred in 35.2% of patients with stroke and 3.8% of controls (p < 0.001). Cognitive domains most likely to be defective in stroke compared with control subjects were memory, orientation, language, and attention. Among patients with stroke, cognitive impairment was most frequently associated with major cortical syndromes and with infarctions in the left anterior and posterior cerebral artery territories. Functional impairment was greater with cognitive impairment, and dependent living after discharge either at home or nursing home was more likely (55.0% with, v 32.7% without cognitive impairment, p = 0.001). In a logistic model examining the risks related to dependent living after stroke, cognitive impairment was a significant independent correlate (odds ratio, OR = 2.4), after adjusting for age (OR = 5.2, 80 + v 60-70 years) and physical impairment (OR = 3.7, Barthel index < or = 40 v > 40). It is concluded that cognitive impairment occurs frequently after stroke, commonly involving memory, orientation, language, and attention. The presence of cognitive impairment in patients with strike has important functional consequences, independent of the effects of physical impairment. Studies of stroke outcome and intervention should take into account both cognitive and physical impairments.

A meta-analysis of the relative sensitivity of neuropsychological screening tests

The National Institute of Mental Health recently formed a committee of experts which published a proposal for a lengthy neuropsychological test battery judged most apt to detect diffuse brain damage while covering a wide range of cognitive abilities. The purposes of the present study were (1) to assemble empirical evidence of the existence of statistically significantly sensitive screening tests across an equivalently wide range of functional domains, and (2) to present this evidence systematically, in such a manner as to help clinicians select subsets of screening tests manifesting greatest sensitivity to diffuse brain damage. It was found that in certain functional domains (speed of processing, problem solving, executive functions), marked differences in sensitivity occurred. Brief tests just as sensitive as time-consuming tests were also identified. The reader is cautioned about possible extraneous sources of the differences obtained (test and group selection bias, test reliability, test difficulty, procedural effects, Type I error). Nevertheless, it was concluded that a brief highly sensitive and functionally wide-ranging neuropsychological test battery for screening cases of putative diffuse brain dysfunction can be assembled.

Neuropsychological sequelae of stroke as a function of handedness

The preservation of visuospatial ability relative to verbal ability following right middle cerebral artery stroke was assessed in 19 left- and 19 right-handed male patients who were group-matched on the basis of age, education, and time elapsed since stroke. Analysis of covariance (covarying education) indicated that the left- and right-handed groups were significantly different with regard to the discrepancy between Verbal IQ and Performance IQ, with the left-handed patients showing a smaller difference than the right-handers. These results provide further evidence that sinistrality may be associated with less hemispheric specialization.