General intellectual impairment in chronic right hemisphere damaged patients with anosognosia: a group study

The study evaluates the possible relations between cognitive impairment, persisting anosognosia for hemiplegia and peripersonal neglect. Thirty eight chronic right hemisphere stroke patients were divided in three age- and education-matched groups: A (n = 13) patients with left hemiparesis, peripersonal neglect, and anosognosia for hemiplegia; B (n = 12) patients with left hemiparesis and peripersonal neglect, and C (n = 13) patients with left hemiparesis only. We used MMSE and WAIS Verbal IQ and verbal subtests to assess cognitive impairment in patients, in order to avoid a bias due to visuospatial deficit, which is common in patients with neglect. VIQ, Information, Digit Span and Vocabulary WAIS subtests as well as MMSE were found to be significantly lower in group A versus group B. No difference was found in any test between groups B and C, indicating a general worse cognition in patients compared to those without anosognosia for hemiplegia. Patients with anosognosia for hemiplegia also showed larger brain lesions and, more frequently, frontal, parietal, temporal and basal ganglia involvement, particularly if they had low verbal IQ, indicating a relationship between cognitive impairment, persisting anosognosia for hemiplegia and large right hemisphere lesions.     

General intellectual impairment in chronic right hemisphere damaged patients with anosognosia: A group study

The study evaluates the possible relations between cognitive impairment, persisting anosognosia for hemiplegia and peripersonal neglect. Thirty eight chronic right hemisphere stroke patients were divided in three age- and education-matched groups: A (n?=?13) patients with left hemiparesis, peripersonal neglect, and anosognosia for hemiplegia; B (n = 12) patients with left hemiparesis and peripersonal neglect, and C (n?=?13) patients with left hemiparesis only. We used MMSE and WAIS Verbal IQ and verbal subtests to assess cognitive impairment in patients, in order to avoid a bias due to visuospatial deficit, which is common in patients with neglect. VIQ, Information, Digit Span and Vocabulary WAIS subtests as well as MMSE were found to be significantly lower in group A versus group B. No difference was found in any test between groups B and C, indicating a general worse cognition in patients compared to those without anosognosia for hemiplegia. Patients with anosognosia for hemiplegia also showed larger brain lesions and, more frequently, frontal, parietal, temporal and basal ganglia involvement, particularly if they had low verbal IQ, indicating a relationship between cognitive impairment, persisting anosognosia for hemiplegia and large right hemisphere lesions.     

The relationship between IQ, memory, executive function, and processing speed in recent-onset psychosis: 1-year stability and clinical outcome

Studies commonly report poor performance in psychotic patients compared with controls on tasks testing a range of cognitive functions, but, because current IQ is often not matched between these groups, it is difficult to determine whether this represents a generalized deficit or specific abnormalities. Fifty-three first-episode psychosis patients and 53 healthy controls, one-to-one matched for sex, age, and full-scale current IQ, were compared on Wechsler Adult Intelligence Scale (WAIS) subtests representing indices of perceptual organization, verbal comprehension, processing speed, and working memory as well as other tests of executive function and episodic memory. The groups showed an equivalent pattern of performance on all WAIS subtests except digit symbol processing speed, on which the patients were significantly worse. Patients were also worse on measures where performance correlated with digit symbol score, namely working and verbal memory tasks. Standardized residual scores for each subtest were calculated for each patient using the difference between their actual subtest score and a predicted subtest score based on their full-scale IQ and the performance of controls. Scaled scores and residual scores were examined for relationships with clinical measures. Digit symbol-scaled score was significantly correlated with concurrent negative syndrome score at baseline, and digit symbol residual score significantly predicted residual negative symptoms at 1-year follow-up. In summary, our comparison of patients and controls precisely matched for IQ revealed that processing speed was attenuated in recent-onset schizophrenia, contributed significantly to working and episodic memory deficits, and was a prognostic factor for poor outcome at 1 year.     

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.     

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.     

Language Function After Temporal Lobectomy Without Stimulation Mapping of Cortical Function

Summary We studied 95 patients who underwent standard anterior temporal lobectomy (ATL) without stimulation mapping of language areas, using neuropsychological parameters of language function preoperatively and 1 year postoperatively [Boston Naming Test and Verbal Fluency, and the Information, Comprehension, Arithmetic, Similarities, Digit Span, and Vocabulary subtests of the Wechsler Adult Intelligence Scale (WAIS)]. Verbal IQ (VIQ), Performance IQ (PIQ), Full-scale IQ (FSIQ), and Verbal Deviation Quotient were also evaluated, as were parameters of memory function. All patients had hemisphere dominance for language assessed by an intracarotid amytal test. Fifty-three patients had a left dominant (LHDL) ATL with a mean extent of lateral resection of 4.8 cm, and 10 had a left ATL with right or mixed hemisphere dominance (RHDL, MDL). Thirty-two patients had a right nondominant ATL. Seizure outcome was 57 and 59% seizure-free for LHDH and right nondominant group, respectively, 1 year after operation. Comparison of preoperative scores showed the LHDL group to have significantly lower scores than the right nondominant group for several parameters of language function and memory. The group undergoing left dominant ATL showed no significant loss of language function postoperatively and actually showed gains in many parameters. Standard ATL without stimulation mapping of language areas and with conservative lateral resection is safe for long-term language function. In addition, evidence shows preexisting language dysfunction in patients undergoing left dominant ATL.     

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.     

Arithmetic skills in patients with unilateral cerebral lesions

In this paper we describe the construction of a Graded Difficulty Arithmetic test (GDA) consisting of 12 additions and 12 subtractions which are orally presented. The test was administered to a control group of 100 volunteer subjects with extra-cerebral neurological disorders and to two experimental groups of patients with unilateral cerebral lesions of the left and right hemisphere. In the control group performance on the GDA was found to correlate highly with other measures of verbal intelligence, namely the National Adult Reading Test, the WAIS Arithmetic subtest and the WAIS Digit Span subtest. Between group analysis showed a significant groups effect on the GDA, the left hemisphere lesion group showing greater impairment compared to the right hemisphere lesion group and the controls. Using "cut-off" scores the left hemisphere lesion group's performance was shown to be significantly worse than that of the right hemisphere lesion group, who in turn were not significantly worse than the control group.     

Metabolic correlates of cognitive function in children with unilateral Sturge–Weber syndrome: Evidence for regional functional reorganization and crowding

To evaluate metabolic changes in the ipsi‐ and contralateral hemisphere in children showing a cognitive profile consistent with early reorganization of cognitive function, we evaluated the regional glucose uptake, interhemispheric metabolic connectivity, and cognitive function in children with unilateral SWS. Interictal 2‐deoxy‐2[¹⁸F]fluoro‐D‐glucose (FDG)‐PET scans of 27 children with unilateral SWS and mild epilepsy and 27 age‐matched control (non‐SWS children with epilepsy and normal FDG‐PET) were compared using statistical parametric mapping (SPM). Regional FDG‐PET abnormalities calculated as SPM(t) scores in the SWS group were correlated with cognitive function (IQ) in left‐ and right‐hemispheric subgroups. Interhemispheric metabolic connectivity between homotopic cortical regions was also calculated. Verbal IQ was substantially (≥10 points difference) higher than non‐verbal IQ in 61% of the right‐ and 71% of the left‐hemispheric SWS group. FDG SPM(t) scores in the affected hemisphere showed strong positive correlations with IQ in the left‐hemispheric, but not in right‐hemispheric SWS group in several frontal, parietal, and temporal cortical regions. Significant positive interhemispheric metabolic connectivity, present in controls, was diminished in the SWS group. In addition, the left‐hemispheric SWS group showed inverse metabolic interhemispheric correlations in specific parietal, temporal, and occipital regions. FDG SPM(t) scores in the same regions of the right (unaffected) hemisphere showed inverse correlations with IQ. These findings suggest that left‐hemispheric lesions in SWS often result in early reorganization of verbal functions while interfering with (“crowding”) their non‐verbal cognitive abilities. These cognitive changes are associated with specific metabolic abnormalities in the contralateral hemisphere not directly affected by SWS.     

Wais Performance IQ in Aphasia as a Function of Auditory Comprehension and Constructional Apraxia

This study investigated differences in nonverbal intelligence between diagnostic subgroups of aphasics using the Performance Tests of the Wechsler Adult Intelligence Scale (WAIS). Subjects were 98 right-handed hospitalized males with unilateral left-hemisphere damage who had unambiguous clinical diagnoses of Broca's, Anomic, Conduction, Mixed Non-Fluent, Wernicke's, or Global aphasia. Group differences were examined using the WAIS Performance IQ (PIQ), subscores for spatial organization (Block Design and Object Assembly) and for verbalizability (Picture Completion and Picture Arrangement).There were significant group differences for each WAIS score, determined by the impaired performance of the Global aphasics. With covariance correction for level of auditory comprehension, group differences were eliminated on the verbalizable subtests, but not on the spatial organization subtests. Covarying for level of constructional apraxia (assessed with drawings, sticks, blocks), however, eliminated group differences for both subscores. Using demographic, neurological, linguistic variables, multiple regression analyses confirmed the covariate analysis findings; constructional apraxia was the most predictive variable for both spatial and verbalizability subscores, while auditory comprehension and education level predicted performance on the verbalizable subtests.     

Does operational diagnosis of schizophrenia significantly impact intellectual deficits in psychotic disorders?

Background Evidence suggests that, as a group, patients with schizophrenia have intellectual deficits that may precede the manifestation of psychotic symptoms; however, how successfully intelligence tests are able to discriminate schizophrenia from other psychotic disorders has yet to be investigated in detail. Methods Using Wechsler Adult Intelligence Scale – Revised (WAIS‐R) data for 55 inpatients with schizophrenia and 28 inpatients with non‐schizophrenic psychotic disorders (NSPD) (schizophreniform disorder, brief psychotic disorder, delusional disorder, psychotic disorder due to a general medical condition, and psychotic disorders not otherwise specified), intelligence performance was compared between schizophrenia and NSPD and among different subtypes of schizophrenia. Results There were no significant differences in intelligence quotient (IQ), verbal IQ (VIQ) and performance IQ (PIQ) discrepancy, and subtest scores of WAIS‐R between the patients with schizophrenia and those with NSPD. These diagnostic groups were not discriminated well by any WAIS‐R variables. Schizophrenia patients with prominent negative symptoms, on the other hand, had a significantly larger IQ discrepancy (VIQ > PIQ) than those without prominent negative symptoms and NSPD patients. Intelligence performance in schizophrenia did not differ with respect to diagnostic subtypes and longitudinal courses. Conclusions The current study failed to show diagnostic usefulness of WAIS‐R in discriminating schizophrenia and other psychoses. A diagnosis of schizophrenia does not significantly impact intellectual deficits in psychotic disorders.     

Sex Differences in the Cognitive Effects of Unilateral Brain Damage

One hundred subjects (50 men, 50 women), of whom 80 had suffered a unilateral cerebrovascular accident (40 left, 40 right), were tested on the WAIS. In the case of left hemisphere damage the male patients showed lower Verbal than Performance Scale IQ scores; for the right brain damaged men Performance Scale scores were Lower than their scores on the Verbal Scale. Women with unilateral brain damage showed no such reliable discrepancies between their Verbal and Performance Scale scores. This difference in the patterning of WAIS IQs in male and female stroke patients persisted even after the scores of those few patients with any significant degree of expressive aphasia had been excluded from consideration.     

Cognitive recovery after severe head injury. 1. Serial testing on the Wechsler Adult Intelligence Scale.

The Wechsler Adult Intelligence Scale was administered serially to 40 severely head-injured adults, and the results compared with a matched group of 40 non-injured men. The scores on the verbal subtests showed less initial impairment and were faster to recover to the level of the comparison group than were the non-verbal subtest scores. Verbal IQ of the head-injury group approached that of the comparison group within about one year of injury, while recovery of Performance IQ continued over about three years.     

Alzheimer's disease: focal cortical changes shown by positron emission tomography

Local rates of cortical glucose metabolism were estimated by positron emission tomography in 13 right-handed patients with Alzheimer's disease. Individuals with disproportionate failure of language function had markedly diminished metabolism in the left frontal, temporal, and parietal regions. Patients with predominant visuo-constructive dysfunction evidenced a hypometabolic focus in the right parietal cortex. Patients with memory failure as the most apparent feature had no significant metabolic asymmetry in cortical regions. In all subjects, verbal competency generally correlated with metabolic activity in the left frontal and temporal areas, while visuo-constructive test performance was linked to glucose utilization in the right parietal lobe.     

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.     

Lateralisation of striatal function: evidence from 18F-dopa PET in Parkinson's disease

OBJECTIVES: The aetiology of the cognitive changes seen in Parkinson's disease (PD) is multifactorial but it is likely that a significant contribution arises from the disruption of dopaminergic pathways. This study aimed to investigate the contribution of the dopaminergic system to performance on two executive tasks using (18)F-6-fluorodopa positron emission tomography ((18)F-dopa PET) in PD subjects with early cognitive changes. METHODS: 16 non-demented, non-depressed PD subjects were evaluated with the Tower of London (TOL) spatial planning task, a verbal working memory task (VWMT) and (18)F-dopa PET, all known to be affected in early PD. Statistical parametric mapping (SPM) localised brain regions in which (18)F-dopa uptake covaried with performance scores. Frontal cortical resting glucose metabolism was assessed with (18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG) PET. RESULTS: SPM localised significant covariation between right caudate (18)F-dopa uptake (Ki) and TOL scores and between left anterior putamen Ki and VWMT performance. No significant covariation was found between task scores and (18)F-dopa Ki values in either limbic or cortical regions. Frontal cortical glucose metabolism was preserved in all cases. CONCLUSIONS: These findings support a causative role of striatal dopaminergic depletion in the early impairment of executive functions seen in PD. They suggest that spatial and verbal executive tasks require integrity of the right and left striatum, respectively, and imply that the pattern of cognitive changes manifest by a patient with PD may reflect differential dopamine loss in the two striatal complexes.     

Gender,Memory, and Hippocampal Volumes: Relationships in Temporal Lobe Epilepsy

Previous research has suggested bilateral hippocampal support for verbal memory in women with early left-hemisphere injury and that women experience better verbal memory outcome following anterior temporal lobectomy (ATL). The present study investigated two issues: (1) Do women have better verbal memory outcome following ATL compared with men? (2) Are verbal memory abilities differentially supported by the right and left hippocampus in males and females? Verbal memory performance [Wechsler Memory Scale: Logical Memory (LM) savings score] was assessed in 70 patients who underwent ATL. MRI volumetric measurements of the left and right hippocampus were performed. No LM savings score difference was found between groups preoperatively although a statistically significant gender effect (P < 0.04) was found for postoperative LM savings scores. Females displayed better postoperative memory performance, regardless of side of surgery. Preoperative verbal memory performance was not associated with right or left hippocampal volumes in either left or right ATL females, although the right hippocampus was positively associated with memory performance for left ATL males. Hippocampal volumes were not associated with postoperative LM savings scores for any group. Results suggest that prose recall was only modestly influenced by gender and that bilateral hippocampal support for prose recall was not present in our female patients.     

Are Verbal Intelligence Subtests and Reading Measures Immune to Non-Credible Effort?

The validity of neuropsychological testing is reliant on examinees putting forth adequate effort, yet it has been asserted that verbal subtests from the Wechsler Adult Intelligence Scales (WAIS) are insensitive to suboptimal effort in comparison to other commonly used neuropsychological measures. The current study examined performance differences on the entire WAIS-IV and WRAT-4 Reading, as well as the CVLT-II and several WMS-IV subtests, in 207 Veterans classified into Credible Effort (n = 146) and Non-credible Effort (n = 61) groups. Analyses revealed that the Non-credible Effort group performed significantly lower on all examined measures including verbal tests, with moderate to large effect sizes observed for most tests. Current findings thus indicate that WAIS-IV verbal subtests and reading ability measures, such as on the WRAT-4, are not insensitive to effects of non-credible effort. Consequently it is recommended that these tests not generally be used to estimate baseline intellectual functioning when found in the presence of non-credible effort. While there was broad performance suppression across all measures examined, results also showed a distinct continuum of test susceptibility with some measures being more or less sensitive to inadequate effort. Recommendations for future performance validity test development are presented.     

Neuropsychological disturbances in hemiparkinson's disease

Nine parkinsonian patients with main unilateral symptoms on the right side (RHP) and nine with symptoms on the left side (LHP) were assessed through a comprehensive neuropsychological battery. RHP performed at a lower level than LHP on the WAIS verbal subtests. Although both groups scored poorly on a test of frontal lobe functions, RHP performed significantly lower than LHP. On a line bisection task, LHP showed a mild left hemispatial neglect. In conclusion, mild but significant intergroup differences were observed, tending to correlate with predominantly hemispheric functional deficits.     

Development and Validation of the Design Organization Test (DOT): a rapid screening instrument for assessing visuospatial ability

A brief paper-and-pencil instrument was developed to rapidly assess visuospatial ability and serve as an alterative to the WAIS Block Design subtests during screening or when assessment time is limited. The Design Organization Test (DOT) consists of square black-and-white grids with visual patterns similar to those of the Block Design subtests. Administration is straightforward and requires examinees to reproduce as many designs as possible in 2 minutes using a numerical code key. For 411 college students, alternate forms of the DOT yielded reliability estimates comparable to that of the test-retest reliability of WAIS-III Block Design subtest. In a clinical sample, the DOT was significantly correlated (r = .92) with WAIS-III Block Design scores and was successfully substituted in place of Block Design raw scores without significant change in Performance IQ or Full Scale IQ. The results suggest that the DOT provides a useful and rapid screening measure of visuospatial ability.