An Examination of the Wechsler Adult Intelligence Scales,Fourth Edition (WAIS-IV) in Individuals with Complicated Mild,Moderate and Severe Traumatic Brain Injury (TBI)

This study examined the clinical utility of the Wechsler Adult Intelligence Scales-Fourth Edition (WAIS-IV) in individuals with complicated mild, moderate or severe TBI. One hundred individuals with TBI (n = 35 complicated mild or moderate TBI; n = 65 severe TBI) and 100 control participants matched on key demographic variables from the WAIS-IV normative dataset completed the WAIS-IV. Univariate analyses indicated that participants with severe TBI had poorer performance than matched controls on all index scores and subtests (except Matrix Reasoning). Individuals with complicated mild/moderate TBI performed more poorly than controls on the Working Memory Index (WMI), Processing Speed Index (PSI), and Full Scale IQ (FSIQ), and on four subtests: the two processing speed subtests (SS, CD), two working memory subtests (AR, LN), and a perceptual reasoning subtest (BD). Participants with severe TBI had significantly lower scores than the complicated mild/moderate TBI on PSI, and on three subtests: the two processing speed subtests (SS and CD), and the new visual puzzles test. Effect sizes for index and subtest scores were generally small-to-moderate for the group with complicated mild/moderate and moderate-to-large for the group with severe TBI. PSI also showed good sensitivity and specificity for classifying individuals with severe TBI versus controls. Findings provide support for the clinical utility of the WAIS-IV in individuals with complicated mild, moderate, and severe TBI.     

Etiological heterogeneity and intelligence test scores in patients with schizophrenia

Previous research has indicated that patients with a family history of schizophrenia show a greater degree of cognitive and neuropsychological impairment than patients without a family history. We examined the neurocognitive performance, using the WAIS-R, of 51 patients with a family history (familial) and 103 patients without a family history (sporadic) to determine if differences exist that may help to explain the heterogeneous neuropsychological profile of the illness. The family history groups did not differ with respect to gender, diagnosis, ethnicity, age, age of onset, education or duration of illness. Multivariate analyses, covarying for age of onset and education, showed the sporadic group performed significantly better than the familial group on the digit symbol and object assembly subtests, with a trend level difference in overall performance IQ score. Additionally, we identified significant gender differences in favor of males for full scale and verbal IQ, the information, digit span, block design, and arithmetic subtests, and at a trend level, the picture assembly subtest. The family history group differences reflect relative dysfunction in visual attention and scanning, visuomotor control, and spatial processing and reasoning. Overall, the results suggest that sporadic patients have better perceptual-organizational skills and faster speed of processing.     

Wechsler Adult Intelligence Scale performance. Cortical localization by fluorodeoxyglucose F 18-positron emission tomography

We compared local cerebral glucose metabolism, as determined by positron emission tomography following administration of fluorodeoxyglucose F 18, with Wechsler Adult Intelligence Scale (WAIS) scores in 22 right-handed persons. Five study subjects were normal volunteers and the remainder had Alzheimer's disease. Subtest scores within the verbal IQ group or the performance IQ group were generally highly interrelated; there was usually no correlation between the verbal and performance subtests. The cortical distribution of regions in which glucose metabolism was most closely associated with verbal subtest scores generally centered in the left parasylvian area. In contrast, scores on the performance subtests mainly localized to the right posterior parietal region. Most WAIS subtests thus appeared to evaluate primarily either verbal or visuospatial cognitive functions and either left parasylvian or right posteroparietal cortical activity.     

Mild cognitive impairment and Alzheimer's disease: an investigation of the CERAD-NP test battery

To investigate the psychometric properties of the German version of the CERAD-NP, neuropsychological deficits were compared between 49 patients with mild cognitive impairment (MCI), 80 patients with Alzheimer's disease (AD), 36 with major depression (MD), and 26 elderly controls. All participants were outpatients of the memory clinic of the Section of Geriatric Psychiatry, Heidelberg University. Diagnoses were established based on clinical examination, laboratory testing, neuroimaging, and routine neuropsychological testing according to the criteria of aging-associated cognitive decline (AACD) for MCI, NINCDS-ADRDA for AD, and DSM-IV for MD, respectively. All CERAD-NP subtests discriminated between controls and AD patients with the latter showing significantly (p< or = 0.05) lower test scores. The subtests verbal fluency and constructive apraxia differed significantly between mildly and moderately AD, while the subtests assessing declarative (epsisodic) memory performance showed only minor, non-significant differences between the respective groups. The LKB patients took an intermediate position between controls and AD patients with significantly lower scores in verbal fluency and declarative memory performance than the controls. When compared with the AD patients, MCI patients were significantly impaired in all subtests except constructive apraxia. Relative to the controls, the patients with MD showed a decreased episodic memory performance but no evidence suggesting an impairment in other neuropsychological domains. Our results indicate that the CERAD-NP is a psychometric instrument which allows a sensitive discrimination between mild and moderate AD, MCI, MD and healthy controls. However, sensitivity of discrimination between different stages of dementia varies with respect to the different subtest. While the subtest for episodic memory showed floor effects already for mild dementia, subtests for verbal fluency and constructive apraxia were able to discriminate even between more advanced stages of the disease.     

Short form of the WAIS-III for use with patients with schizophrenia

The recent publication of the Wechsler Adult Intelligence Scale (WAIS-III), the most widely used standard test of intelligence, requires the development of a new short form for use with patients with schizophrenia for many clinical and research purposes. We used regression analyses of complete WAIS-III data on 41 outpatients with schizophrenia and 41 education-, and age-matched healthy subjects to determine the best combination of subtests to use as a short form. Excluding three subtests that are time-consuming to administer, and requiring that the solution includes one subtest from each of the four WAIS index scores, the combination that most fully accounted for the variance in full-scale IQ (FSIQ) for both participants with schizophrenia (R(2)=0.90) and healthy controls (R(2)=0.86) included the information, block design, arithmetic, and digit symbol subtests. When the restrictions regarding which subtests could enter were relaxed, the best four-subtest solution included information, block design, comprehension, and similarities. Although the latter explained 95% of the variance in FSIQ for schizophrenia participants and 90% of the variance for healthy controls, it consistently overestimated FSIQ for the schizophrenia group. We recommend the four-factor short form for use in future research and clinical practice in which a quick, accurate IQ estimate is desired.     

A gender difference in the association between APOE genotype and age-related cognitive decline.

OBJECTIVE: To determine whether the APOE epsilon4 allele is associated with age-related intellectual decline in a community-dwelling sample of Danes. METHODS: A sample of 189 subjects who did not have dementia was tested with the Wechsler Adult Intelligence Scale (WAIS) at the ages of 50 and 80 years. Of these subjects, 163 (84 women and 79 men) completed all WAIS subtests at both assessments and 139 completed the digit symbol and block design subtests at the ages of 50, 60, 70, and 80 years. RESULTS: Cognitive decline from the age of 50 to the age of 80 years was substantial and larger for the performance subtests than for the verbal subtests (the declines were 18.40 for the performance IQ and 8.39 for the verbal IQ). APOE genotype was unrelated to the observed WAIS results of the 80-year assessment, but there was a significant interaction between APOE genotype and sex for decline scores in the performance IQ and three performance subtests (digit symbol, block design, and object assembly). In women, 26 epsilon4 carriers showed larger decline than 58 noncarriers, whereas there was no significant relation between APOE genotype and cognitive decline in men. The association in women between APOE genotype and cognitive decline was significant only for decline in the decade from age 70 to age 80 years. The interaction between sex and APOE genotype remained significant when education was included as a covariate. CONCLUSION: The APOE epsilon4 allele is associated with normal age-related decline in cognitive functions in women only. This finding may be supportive of recent evidence suggesting sex differences in APOE-associated risk for AD. Thus, the sex difference in the risk of sporadic AD may partly be explained by a sex-specific impact of the APOE epsilon4 allele on age-related cognitive decline.     

无痴呆型血管性认知障碍患者执行功能损害特征分析

目的探讨无痴呆型血管性认知障碍（VCIND）患者执行功能损害的特征。方法采用语义与语音流畅试验、数字符号编码测验、连线测验、画钟测验和Stroop色词测验对43例VCIND患者和35名性别、年龄和文化程度相匹配的正常对照进行测试。结果与正常对照组相比,VCIND组患者计时类测验明显低于正常对照组（P＜0.01）,计分类测验中数字符号编码测验、语义与语音流畅试验低于正常对照组（P＜0.01）,其中Stroop色词测验计分（P＜0.05）。与正常对照组比较,VCIND组画钟测验评分无统计学意义（P〉0.05）。结论VCIND患者执行功能损害主要表现为转换障碍、工作记忆损害、知觉运动与信息处理速度减慢。     

Cognitive impairment in patients with idiopathic normal pressure hydrocephalus

Cognitive impairment in patients with idiopathic normal pressure hydrocephalous (iNPH) has not been clearly documented. We performed standardized neuropsychological assessments of 21 patients with iNPH and of 42 patients with Alzheimer's disease (AD) matched to the patients with iNPH 2:1 by age, sex, and Mini-Mental State Examination score. Compared with the AD group, the iNPH group scored significantly higher on the orientation subtest of the Alzheimer's Disease Assessment Scale and on the general memory and delayed recall subtests of the Wechsler Memory Scale-Revised (WMS-R), and significantly lower on the attention/concentration subtest of the WMS-R and on the digit span, arithmetic, block design and digit symbol substitution subtests of the Wechsler Adult Intelligence Scale-Revised. The impairment of frontal lobe functions is disproportionately severe and memory impairment is disproportionately mild in patients with iNPH compared with AD. Recognition of these features contributes to an early diagnosis, which can lead to a better prognosis.     

A comparison of the WAIS and WAIS-R using T-score conversions that correct for age, education, and sex

A newly developed T score conversion system that corrects Wechsler Adult Intelligence Scale (WAIS) and Wechsler Adult Intelligence Scale-Revised (WAIS-R) subtest and IQ scores for appropriate demographic variables was used to compare subjects' performance on the two versions of the instrument. Using 428 pairs of subjects matched on age, education, and sex, with one person in each pair having taken the WAIS and the other the WAIS-R, we found no significant differences in level or pattern of performance when analyses were performed on the T scores. This was in contrast to highly significant differences when uncorrected scaled scores and IQ values were compared. Therefore, the T score system appears to provide a tool which may help clinicians make more direct comparisons between the results obtained on the WAIS and WAIS-R.     

Analysis of functional hemispheric asymmetry in children with partial epilepsy and normal IQ by performance in WISC subtests]

We studied 87 normal IQ children, 26 partial epileptic (epileptic group) and 61 non-epileptic children (control group) with mean age of 9 years in relation to cognitive performance in Wechsler Infant Scale for Children (WISC) battery. The epileptic group showed lower score in IQ performance and in three verbal subtests (Information, Digit span, Arithmetic) and three performance subtests (Block Design, Object Assembly and Coding). Patients with right hemisphere EEG focus showed low score in subtests related to spatial ability and non-verbal attention, whereas patients with left hemisphere EEG focus showed low score only in Digit span subtest (related to immediate memory and verbal attention). The authors suggest that cognitive deficits in partial non-lesional epileptic children is related to the side of EEG interictal abnormalities, even in children with normal IQ.     

Trajectories of change in self-reported psychotic-like experiences in childhood and adolescence

Estimates of pre-morbid IQ are widely used to measure the trajectory of cognitive function and decline in people with schizophrenia. This study examined the usefulness of two indices of decline to identify cognitive subtypes in first episode psychosis, and to determine the specificity of non-IQ neuropsychological impairments in this population. Neuropsychological data were collected from 118 first episode psychosis patients and compared to 118 epidemiologically matched controls. The National Adult Reading Test (NART) and the Information subtest of the WAIS-III were compared as indicators of crystallised intelligence or 'pre-morbid IQ'. Measurement of NART minus current full scale IQ (FSIQ) (where 10 points discrepancy is the decline criterion) did not reveal a large group of individuals with 'deteriorating' IQ patterns. Using the Information subtest and the same decline criteria, a 'deteriorating' patient group emerged (36%) but was matched by a larger 'deteriorating' control group (45%). The 'deteriorating' patient group performed at a low IQ level for tasks that loaded highly on performance ability but a relatively high level for tasks measuring verbal skills. Verbal memory discriminated patients from controls better than IQ. Compared to controls, patients showed large selective impairments of verbal episodic memory (effect size, d=1.4) These data suggest that in first episode populations, caution should be exercised in inferring deterioration of IQ from discrepancies between reading-based and other IQ tests. Rather, sub-groups of patients and controls do show greater verbal aptitude in comparison to performance skills. Memory is generally impaired in first episode patients regardless of IQ.     

Cognitive features in euthymic bipolar patients in old age

Objectives:  Studies of cognition in bipolar disorder (BD) have reported impairments in processing speed, working memory, episodic memory, and executive function, but they have primarily focused on young and middle-aged adults. In such studies, the severity of cognitive deficits increases with the duration of illness. Therefore, one would expect more pronounced deficits in patients with longstanding BD. The first aim of the present study was to determine the pattern and the magnitude of cognitive impairment in older euthymic BD patients. The second aim was to explore the interrelationship between these cognitive deficits and determine whether they reflect a single core impairment or the co-occurrence of independent cognitive deficits.
Methods:  Twenty-two euthymic elderly BD patients and 22 controls, matched for gender, age, and education, underwent a comprehensive neuropsychological assessment.
Results:  Compared to controls, BD patients had significantly reduced performance in processing speed, working memory, verbal fluency, and episodic memory, but not in executive function. Hierarchical regression analyses showed that verbal fluency and working memory impairments were fully mediated by changes in processing speed. This was not the case for the episodic memory dysfunction.
Conclusion:  The cognitive profile in older euthymic BD cases is similar to the one described in younger BD cohorts. Our results further suggest that impaired processing speed plays a major role in the cognitive changes observed in BD patients except for deficits in episodic memory, thus providing strong evidence that processing speed and episodic memory are two core deficits in elderly BD patients.     

Subtest profiles of the WISC-R and WAIS in mentally retarded patients with epilepsy

In this study, WISC-R and WAIS subtest profiles of mentally retarded patients with epilepsy are analysed with respect to the Verbal-Performance IQ Discrepancy scores and rank order of mean subtest scores. The relative strengths and weaknesses in cognitive patterns of this sample are compared with subtest profiles mentioned in the literature on mentally retarded populations and samples of normal intelligent patients with epilepsy in order to determine the impact of epilepsy factors on cognition. The results indicate that people with mental retardation have problems with the verbal subtests Arithmetic, Vocabulary and Information, while patients with epilepsy have problems with Coding (Digit Symbol), Digit Span and Information. For this sample of mentally retarded patients with epilepsy, the most difficult subtests are Digit Span and Coding. The results concerning subtest profiles in different populations are discussed in light of the deleterious impact of epilepsy on cognition, which may superimpose the general effect of brain damage in mentally retarded patients. It is suggested that especially attentional processes, as measured with the subtest Coding, are vulnerable for epilepsy factors.     

A comparison of the wais and wais-r using t-score conversions that correct for age,education, and sex

Abstract

A newly developed T score conversion system that corrects Wechsler Adult Intelligence Scale (WAIS) and Wechsler Adult Intelligence Scale-Revised (WAIS-R) subtest and IQ scores for appropriate demographic variables was used to compare subjects' performance on the two versions of the instrument. Using 428 pairs of subjects matched on age, education, and sex, with one person in each pair having taken the WAIS and the other the WAIS-R, we found no significant differences in level or pattern of performance when analyses were performed on the T scores. This was in contrast to highly significant differences when uncorrected scaled scores and IQ values were compared. Therefore, the T score system appears to provide a tool which may help clinicians make more direct comparisons between the results obtained on the WAIS and WAIS-R.     

Discrepancy of performance among working memory-related tasks in autism spectrum disorders was caused by task characteristics, apart from working memory, which could interfere with task execution

Working memory performance has been inconsistently reported in autism spectrum disorders (ASD). Several studies in ASD have found normal performance in digit span and poor performance in digit symbol task although these are closely related with working memory. It is assumed that poor performance in digit symbol could be explained by confirmatory behavior, which is induced due to the vague memory representation of number-symbol association. Therefore it was hypothesized that the performance of working memory task, in which vagueness did not cause confirmatory behavior, would be normal in ASD. For this purpose, the Advanced Trail Making Test (ATMT) was used. The performance of digit span, digit symbol and ATMT was compared between ASD and normal control. The digit span, digit symbol and ATMT was given to 16 ASD subjects and 28 IQ-, age- and sex-matched control subjects. The scores of these tasks were compared. A significantly lower score for ASD was found only in digit symbol compared with control subjects. There were no significant difference in digit span and working memory estimated by ATMT. Discrepancy of scores among working memory-related tasks was demonstrated in ASD. Poor digit symbol performance, normal digit span and normal working memory in ATMT implied that ASD subjects would be intact in working memory itself, and that superficial working memory dysfunction might be observed due to confirmatory behavior in digit symbol. Therefore, to evaluate working memory in ASD, tasks that could stimulate psychopathology specific to ASD should be avoided.     

Fuld's formula and WAIS subtests in differential diagnosis of dementia

The Fuld formula and the linear discriminant function applied to WAIS subtest scores were tested for their ability to identify Alzheimer's disease and senile dementia of the Alzheimer type in a group of 101 demented subjects. The sensitivity and specificity of Fuld's formula for Alzheimer dementia against other dementias were 44.2% and 73.8% respectively; when compared with an age-matched normal control group specificity was 91.4%. When the linear discriminant function was applied only WAIS subtest scores in "similarities and digit span" and "object assembly" significantly differentiated Alzheimer from other dementias (sensitivity 61.5% and specificity 63.3%). Specificity increased to 97.1% when the function was applied to discriminate Alzheimer from normal controls. Discriminant analysis applied to other WAIS subtests for the two demented groups revealed "picture completion" as significantly differentiating the groups but it did not contribute to diagnostic accuracy. WAIS scores are of limited value in the differential diagnosis of dementias.     

Wechsler intelligence scale profiles in Alzheimer type dementia and healthy ageing

Meta-analytic techniques were used to integrate the Wechsler Adult Intelligence (WAIS) scores of healthy elderly subjects and Alzheimer type dementia patients from 21 studies. Although age-scaled scores for demented subjects were lower than those of healthy elderly subjects for all subtests, the profiles for both groups were essentially parallel, with no subtest having significantly poorer scores than the others for the dementia patients. The pattern confirms other findings that verbal tests do not ‘hold’ to a greater degree than performance tests in dementia.     

Assessment of nondeclarative learning in severe Alzheimer dementia: the Implicit Memory Test (IMT)

Although patients with Alzheimer dementia (AD) have impaired explicit memory, more automatic, implicit aspects of learning and memory may be relatively preserved. However, neuropsychological tests for the assessment of implicit memory are lacking. This study examines a newly developed test, the Implicit Memory Test, in 28 patients with severe AD (mini-mental state examination 5 to 12) and 22 cognitively unimpaired matched controls (mini-mental state examination 25 to 29). The Implicit Memory Test consists of visually presented word (stem-completion) and picture (fragmented picture identification) subtests, each comprising 3 learning trials and a delayed test. Explicit memory was also assessed, using the verbal paired-associate learning subtest from the Wechsler Memory Scale and the Visual Association Test. Patients with AD obtained a floor performance on both explicit memory tests, whereas a significant learning curve was found for both the stem-completion and the fragmented pictures subtests of the Implicit Memory Test. Delayed testing on the fragmented pictures subtest showed a preserved performance that may have been mediated by implicit learning. Delayed performance on the stem-completion subtest, however, showed clear memory decay that suggests contamination by explicit memory function, at least in the controls. These findings extend the earlier results on word-stem completion and fragmented picture identification in patients with mild-to-moderate AD and indicate that residual learning capacity can be assessed in severe AD.     

Factor analysis of the wechsler memory scale-revised and the halstead-reitan neuropsychological battery

A principal components factor analysis of the 12 subtests of the WMS-R, WAIS Verbal and Performance IQ scores, and measures of a modified Halstead-Reitan Neuropsychological Battery was performed on a sample of 135 patients. The Visual Reproduction subtests I and II factored with other spatial measures and Performance IQ while Logical Memory I and II and Verbal Paired Associates I and II emerged as separate verbal memory factors. Additionally, two attention/concentration factors were found, one primarily verbal and one primarily visual. Further study in the interpretation of the Verbal and Visual Memory Indexes was advised.     

Learning and memory impairment in PTSD: relationship to depression

Memory function was studied in combat veterans with posttraumatic stress disorder (PTSD), combat veterans without PTSD, and noncombat veterans. The Vocabulary and Digit Span subtests of the WAIS and Logical Memory (LMS) and Verbal Paired Associates (VPAS) subtests of the Wechsler Memory Scale III were administered. Combat veterans with PTSD showed impaired memory on the LMS and VPAS compared to combat veterans without PTSD or noncombat veterans. Veterans with PTSD also showed lower WAIS Vocabulary subtest scores--but not digit span subtest scores--than combat veterans without PTSD or noncombat veterans. Medication status, co-morbid diagnosis, and age all failed to account for these memory differences, but when self-assessed depression--as measured by the Zung Self-Rating Depression Scale--or anxiety--as measured by the Spielberger State-Trait Anxiety Scale--was statistically removed, group differences on these memory measures were no longer significant. However, using a stepwise regression procedure, in which both anxiety and depression were employed to predict the LMS and VPAS scores, only the Zung scale reliably predicated performance. The present results, showing that PTSD is associated with general learning and memory impairments, is an important finding, but the specific effects of depression as a mediator of these deficits should be further studied.