Test-retest variability in children with epilepsy--a comparison of WISC-R profiles

Reports of test-retest variability appear recurrently in relation to epilepsy. To date, the amount of information available on the stability of cognitive profiles over a number of years is limited. In this study, 45 children were assessed, using the Wechsler Intelligence Test for Children - Revised (WISC-R). The children were retested after a period of at least 2 years. A group of 20 children was tested 3 times. The average follow-up period was 4.2 years. Although most subjects in our sample had a high seizure frequency and continued to have their seizures during the period of follow-up, a marked stability of cognitive profiles is found over a period of time. These profiles show low scores for the subtests Information, Coding, Digit Span, Vocabulary and resemble profiles reported in other studies on subjects with intractable epilepsies.     

Classification Accuracy of the Portland Digit Recognition Test in Traumatic Brain Injury

Test-order effect on the WAIS-III and WMS-III scores was evaluated using the WMS-III standardization sample. Participants completed the standardization editions of the WAIS-III and WMS-III in one session, with the tests administered in roughly counterbalanced order. Repeated measure MANOVA analyses were conducted to determine if there was an overall test-order effect for subtest, index, or IQ scores. No significant test-order effects were found for either the WAIS-III index or IQ scores or for the WMS-III index scores. At the subtest level, the majority of the WAIS-III and WMS-III subtests did not show a significant test-order effect. The exceptions were Digit Span and Digit Symbol-Coding on the WAIS-III and Faces II and Logical Memory II on the WMS-III. Although statistically significant test-order effects were found on these subtests, the effect sizes were small. This study indicates that the test-order effect is not a potential threat to the internal validity of the WAIS-III and WMS-III normative data. The practical implications of the current study are discussed.     

Co-norming the WAIS-III and WMS-III: Is there a test-order effect on IQ and memory scores?

Test-order effect on the WAIS-III and WMS-III scores was evaluated using the WMS-III standardization sample. Participants completed the standardization editions of the WAIS-III and WMS-III in one session, with the tests administered in roughly counterbalanced order. Repeated measure MANOVA analyses were conducted to determine if there was an overall test-order effect for subtest, index, or IQ scores. No significant test-order effects were found for either the WAIS-III index or IQ scores or for the WMS-III index scores. At the subtest level, the majority of the WAIS-III and WMS-III subtests did not show a significant test-order effect. The exceptions were Digit Span and Digit Symbol-Coding on the WAIS-III and Faces II and Logical Memory II on the WMS-III. Although statistically significant test-order effects were found on these subtests, the effect sizes were small. This study indicates that the test-order effect is not a potential threat to the internal validity of the WAIS-III and WMS-III normative data. The practical implications of the current study are discussed.     

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.     

Detecting incomplete effort with Digit Span from the Wechsler Adult Intelligence Scale-Third Edition

The current study evaluated the utility of the Digit Span subtest in discriminating patients with mild head trauma from individuals referred for independent neuropsychological evaluation with objective evidence of poor effort. Various indices from the Digit Span subtest were evaluated to determine the best discriminator of brain injury from poor motivation patient groups: Digit Span Forward, Digit Span Backwards, Reliable Digit Span, Digit Span Age-Corrected Scaled Score, and the difference score between the Vocabulary and Digit Span scaled scores. The Digit Span scaled score was found to be the best discriminating index. A cutoff score of less than or equal to 7 accurately classified 75% of persons in the incomplete effort group and 69% of persons in the TBI group. Application of this cutoff score to a non-litigating mild brain injury group yielded a 77% correct classification rate. However, Digit Span scaled score accounted for a modest amount of variation and it is not recommended as a stand-alone validity measure.     

Detecting Incomplete Effort with Digit Span from the Wechsler Adult Intelligence Scale—Third Edition

The current study evaluated the utility of the Digit Span subtest in discriminating patients with mild head trauma from individuals referred for independent neuropsychological evaluation with objective evidence of poor effort. Various indices from the Digit Span subtest were evaluated to determine the best discriminator of brain injury from poor motivation patient groups: Digit Span Forward, Digit Span Backwards, Reliable Digit Span, Digit Span Age-Corrected Scaled Score, and the difference score between the Vocabulary and Digit Span scaled scores. The Digit Span scaled score was found to be the best discriminating index. A cutoff score of less than or equal to 7 accurately classified 75% of persons in the incomplete effort group and 69% of persons in the TBI group. Application of this cutoff score to a non-litigating mild brain injury group yielded a 77% correct classification rate. However, Digit Span scaled score accounted for a modest amount of variation and it is not recommended as a stand-alone validity measure.     

Functional Equivalence of WAIS-III/WMS-III Digit and Spatial Span under Forward and Backward Recall Conditions

The purpose of the current study was to examine the performance characteristics of the Wechsler Spatial Span subtest in a mixed clinical sample. Contrary to expectation, differential patterns of performance were obtained on the Digit and Spatial Span tasks. Forward Digit Span scores were significantly higher than backward recall scores, but this was not the case for Spatial Span. There were no differences between forward and backward raw Spatial Span scores at the mean level. Further, about one third of the sample showed better performance on backward compared to forward Spatial Span. In addition, performance on the Spatial Span backward task correlated unexpectedly with that of the WMS-III Immediate and Delayed Auditory Index scores. Overall, the findings suggest that clinicians should be hesitant when interpreting the Spatial Span task, and the backward condition in particular, as a measure of working memory. Finally, methodological concerns with the Spatial Span task are noted, raising additional concerns regarding the meaning of this task.     

Validation of the Wechsler Memory Scale-Revised in a Sample of People with Intractable Temporal Lobe Epilepsy

Summary: Purpose: The Wechsler Memory Scale-Revised (WMS-R) is used routinely for presurgical assessment of memory for patients considering elective resection of the temporal lobe and/or hippocampus for the relief of intractable temporal lobe epilepsy (TLE). We investigated the validity of the WMS-R in a population of people with TLE.
Methods: The sample consisted of 138 patients with a diagnosis of TLE in which the epileptogenic focus was clearly and exclusively lateralized to either the right or left hemisphere. They underwent a complete neuropsychological examination as a routine part of their investigation for epilepsy surgery. Psychometric scores included in this study were: Wechsler Adult Intelligence Scale-Revised (WAIS-R) I.Q. scores, National Adult Reading Test Revised (NART-R) predicted-I.Q. scores, and WMS-R Memory Index and subtest scores.
Results: Multiple univariate analyses were performed. The group with left temporal focus had significantly lower Verbal Memory Index, Logical memory (both immediate and delayed), and Digit Span scores. Visual/Verbal discrepancy scores incorrectly identified most patients with right temporal focus. Analyses of a total group of people with epilepsy (i.e., mixed temporal, frontal, occipital and unknown foci) as compared with the normative sample indicated that the patient group scored significantly lower across all memory index scores and most memory subtests.
Conclusions: Our results confirm that the WMS-R is capable of lateralizing to left hemispheric impairment but is more problematic in the assessment of right hemispheric impairment. The Visual/Verbal Memory Index discrepancy has questionable validity. People with epilepsy performed less well on the WMS-R than did the normative sample. The need for reliable and valid nonverbal tests of memory is therefore warranted.     

Functional equivalence of WAIS-III/WMS-III digit and spatial span under forward and backward recall conditions

The purpose of the current study was to examine the performance characteristics of the Wechsler Spatial Span subtest in a mixed clinical sample. Contrary to expectation, differential patterns of performance were obtained on the Digit and Spatial Span tasks. Forward Digit Span scores were significantly higher than backward recall scores, but this was not the case for Spatial Span. There were no differences between forward and backward raw Spatial Span scores at the mean level. Further, about one third of the sample showed better performance on backward compared to forward Spatial Span. In addition, performance on the Spatial Span backward task correlated unexpectedly with that of the WMS-III Immediate and Delayed Auditory Index scores. Overall, the findings suggest that clinicians should be hesitant when interpreting the Spatial Span task, and the backward condition in particular, as a measure of working memory. Finally, methodological concerns with the Spatial Span task are noted, raising additional concerns regarding the meaning of this task.     

Cognitive impairment profile differences in patients with psychogenic non-epileptic seizures and epilepsy patients with generalized seizures

ABSTRACT

Objective: This study aimed to compare cognitive skills in epilepsy patients and psychogenic non-epileptic seizures (PNES) patients who have no history of frequent seizures to those of a healthy control group.

Methods: This prospective cross-sectional study was conducted between January 2017 and June 2019 and included 103 epilepsy patients, 100 PNES patients, and 101 healthy controls, aged 18 to 60 years. Patients with fewer than 12 annual seizure episodes and no history of seizures during the last 30 days were added to the study. A sociodemographic data form, the Beck Anxiety and Depression Scales, Montreal Cognitive Assessment, Digit Span test, and Stroop Color-Word Interference Test were used.

Results: Compared to the control group, sub-component scores were significantly lower in naming, attention, abstract thinking, and delayed recall for the epilepsy and PNES groups. Sub-component scores in orientation, executive functioning, and delayed recall were significantly lower in the epilepsy group compared to the PNES group. Digits Backward subtest scores and total Digit Span test scores were significantly lower in the epilepsy and PNES groups. Patients in the epilepsy and PNES groups took longer to complete the Stroop test and made more errors and corrections compared to the healthy controls. There was a negative correlation between the duration of the disease and the total Digit Span score in the epilepsy group.

Conclusion: These findings suggest that the epilepsy group showed reduced cognitive scores even though they did not suffer from frequent seizures and were not drug-resistant.     

Asymmetry in auditory and spatial attention span in normal elderly genetically at risk for Alzheimer's disease

Some studies of elderly individuals with the ApoE-e4 genotype noted subtle deficits on tests of attention such as the WAIS-R Digit Span subtest, but these findings have not been consistently reported. One possible explanation for the inconsistent results could be the presence of subgroups of e4+ individuals with asymmetric cognitive profiles (i.e., significant discrepancies between verbal and visuospatial skills). Comparing genotype groups with individual, modality-specific tests might obscure subtle differences between verbal and visuospatial attention in these asymmetric subgroups. In this study, we administered the WAIS-R Digit Span and WMS-R Visual Memory Span subtests to 21 nondemented elderly e4+ individuals and 21 elderly e4- individuals matched on age, education, and overall cognitive ability. We hypothesized that a) the e4+ group would show a higher incidence of asymmetric cognitive profiles when comparing Digit Span/Visual Memory Span performance relative to the e4- group; and (b) an analysis of individual test performance would fail to reveal differences between the two subject groups. Although the groups' performances were comparable on the individual attention span tests, the e4+ group showed a significantly larger discrepancy between digit span and spatial span scores compared to the e4- group. These findings suggest that contrast measures of modality-specific attentional skills may be more sensitive to subtle group differences in at-risk groups, even when the groups do not differ on individual comparisons of standardized test means. The increased discrepancy between verbal and visuospatial attention may reflect the presence of "subgroups" within the ApoE-e4 group that are qualitatively similar to asymmetric subgroups commonly associated with the earliest stages of AD.     

The impact of the native language of Alzheimer's disease and normal elderly individuals on their ability to recall digits

Recent studies have indicated that Spanish-speaking Alzheimer's disease (AD) patients perform more poorly than English-speaking patients on the Digit Span subtests of the Wechsler Adult Intelligence Scale-Revised (WAIS-R). In the current investigation, the performance of English-speaking and Spanish-speaking Alzheimer's disease patients (N = 119) and normal elderly controls (N = 91) were compared with regards to their capacity to remember digit strings of different lengths. Subjects were administered the standard version of the Digit Span subtest of the WAIS-R as well as a modification of the test (chunking task) in which the numbers were presented in pairs (e.g. 27, 41, 46, 12, etc.). Results indicated that both English-speaking groups, AD patients as well as normal controls, had significantly higher scores on all aspects of the standard Digit Span tasks relative to their Spanish-speaking counterparts (forward, backward, and total scores). In contrast, English-speaking and Spanish-speaking AD groups did not differ with regards to their performance on the two digit chunking task forward score. Similar performance on all aspects of the chunking task was evidenced in the English-speaking and Spanish-speaking normal elderly control groups. These findings have important implications for the development of more culture and language appropriate cognitive test batteries for AD patients and the normal elderly.     

Estimation of WAIS-III intelligence from combined performance and demographic variables: development of the OPIE-3

Data from the WAIS-III standardization sample (The Psychological Corporation, 1997) was used to generate several FSIQ estimation formulas that used demographic variables and current WAIS-III subtest performance. The standardization sample (N=2,450) was randomly divided into two groups, the first was used to develop the formulas and the second group was used to validate the prediction equations. Age, education, ethnicity, gender, region of the country as well as Vocabulary, Information, Matrix Reasoning, and Picture Completion subtests raw scores were used as predictor variables. Regression formulas were generated using four subtest, two subtest, single verbal, two performance subtest, and single performance algorithms. The four-subtest model combined Information, Vocabulary, Matrix Reasoning, and Picture Completion raw scores with demographic variables. The two-subtest algorithm used Vocabulary and Matrix Reasoning raw scores with demographic variables. Formulas to estimate FSIQ using only verbal or performance subtests were developed for use with lateralized populations. The formulas for estimating premorbid FSIQ were highly significant and accurate in predicting FSIQ scores of participants in the WAIS-III normative sample.     

Brief Report: The Use of WAIS-III in Adults with HFA and Asperger Syndrome

The WAIS III was administered to 16 adults with high functioning autism (HFA) and 27 adults with Asperger syndrome. Differences between Verbal Intelligence (VIQ) and Performance Intelligence (PIQ) were not found. Processing Speed problems in people with HFA appeared. At the subtest level, the Asperger syndrome group performed weak on Digit Span. Comprehension and Block Design were relative strengths. In the HFA group, performance on Digit-Symbol Coding and Symbol Search was relatively poor. Strengths were found on Information and Matrix Reasoning. The results suggest that the VIQ-PIQ difference cannot distinguish between HFA and Asperger syndrome. WAIS III Factor Scale and Subtest patterning provides a more valid indicator.     

Estimation of WAIS-III Intelligence from Combined Performance and Demographic Variables: Development of the OPIE-3

Data from the WAIS-III standardization sample (The Psychological Corporation, 1997) was used to generate several FSIQ estimation formulas that used demographic variables and current WAIS-III subtest performance. The standardization sample (N =2,450) was randomly divided into two groups, the first was used to develop the formulas and the second group was used to validate the prediction equations. Age, education, ethnicity, gender, region of the country as well as Vocabulary, Information, Matrix Reasoning, and Picture Completion subtests raw scores were used as predictor variables. Regression formulas were generated using four subtest, two subtest, single verbal, two performance subtest, and single performance algorithms. The four-subtest model combined Information, Vocabulary, Matrix Reasoning, and Picture Completion raw scores with demographic variables. The two-subtest algorithm used Vocabulary and Matrix Reasoning raw scores with demographic variables. Formulas to estimate FSIQ using only verbal or performance subtests were developed for use with lateralized populations. The formulas for estimating premorbid FSIQ were highly significant and accurate in predicting FSIQ scores of participants in the WAISIII normative sample.     

Hemispheric specialization in partial epilepsy. Role of dichotic listening CV task and central audiological evaluation in the neuropsychological assessment.

We studied 49 patients with partial epilepsy divided into lesional cases (i.e. with lesions on CT scan) and non-lesional cases (i.e. without CT scan lesions), in relation to the Wechsler Intelligence Scale subtests (Coding, Digit span), dichotic listening CV task and Central Auditory Test (SSI, PSI). The aim of this paper was to study the hemispheric prevalence in dichotic listening task with regard to cognitive performance, as well as the presence or absence of central auditory dysfunction. Lesional cases presented a hemisphere prevalence in dichotic listening task with regard to cognitive performance, as well as the non-lesional cases tend to report the stimuli in the same side of EEG focus. Significant differences were found among the lesional and non lesional cases in relation to the digit span score and Coding subtest in right lesional cases versus right non-lesional cases. Both lesional and non-lesional group showed signs of central auditory dysfunction. We suggest that the dichotic listening and SSI and PSI test can be useful for a best comprehension of asymmetric neuropsychological performance in partial epilepsy.     

Construct validity of the Denman Memory for Human Faces test

Assessed the validity of the Denman Memory for Human Faces (MHF) subtest employing a clinical sample. Factor analysis with marker variables was employed to establish the nature of the extracted factors. The MHF subtest, WAIS-R Verbal (i.e., Information, Vocabulary, and Digit Span) and Performance (i.e., Block Design and Object Assembly) subtests, the Wechsler Memory Scale Mental Control, Paired Associate Learning, 30-min Logical Memory, and 30-min Visual Reproduction, and Benton's Facial Recognition Test were subjected to a maximum likelihood factoring procedure with Varimax rotation. Four factors were extracted which accounted for 72.7% of the variance. Factor I was perceptual-organization, Factor II was verbal comprehension, Factor III was general memory, and Factor IV was attention-concentration. The MHF subtest achieved a substantial loading (i.e., 0.56) on the general memory factor along with Logical Memory (0.54), Visual Reproduction (0.51), and Paired Associate Learning (0.71). Clinical applications of the MHF were discussed.     

Wechsler Adult Intelligence Scale-Third Edition findings in relation to severity of brain injury in litigants

WAIS-III findings were reported for 150 litigants, classified into three groups according to severity of traumatic brain injury (TBI), and a general population control group. There was a significant "dose response" relationship between TBI severity and all Index/IQ scores. Effect size was greatest for the Processing Speed Index (PSI). Between group differences were significant on all subtests except Information and Digit Span. Effect sizes were greatest for Digit Symbol, Symbol Search, Similarities, and Picture Arrangement. Relative to the control group, there was a significant difference for the Severe and Extremely Severe TBI groups on all IQ/Index scores and most subtests. The Moderate TBI group differed significantly on one Index (the PSI) and none of the subtests. Clinical implications of the findings are discussed in relation to the utility of the WAIS-III in assessing the cognitive sequelae of TBI, the use of current WAIS-III IQ scores to assess intelligence-memory discrepancies, WAIS-III short forms, and estimation of premorbid intelligence.     

血管性认知功能障碍的评估：中华成人智力量表的临床应用与建议

目的 考查中华成人智力量表（ISCA）在血管性认知功能障碍评估中的应用价值.方法 使用ISCA测验64例脑梗死患者,并将成绩与64名健康配对者进行比较.结果 脑梗死组的数字符号、积木构图等6项分测验量表分低于配对者,3项智商低于配对者,差异有统计学意义（P＜0.01）.常识测验、图形推理等6项分测验量表分低于配对组,差异无统计学意义（P＞0.05）.脑梗死组可疑损伤（低于一个标准差）的人数多于配对者,其中,与相似概括、数字符号、积木构图3项测验量表分和操作智商对应的可疑损伤人数（脑梗死组/配对组）分别为16/5、26/7、21/5和24/11,差异有统计学意义（P＜0.01）.ISCA核心分测验和三个量表在脑梗死中应用的Cronbach＇s α系数均＞0.80.结论 ISCA能为血管性认知障碍的评估提供有用的、可信的资料.     

Wechsler Adult Intelligence Scale – Third Edition Findings in Relation to Severity of Brain Injury in Litigants

WAIS-III findings were reported for 150 litigants, classified into three groups according to severity of traumatic brain injury (TBI), and a general population control group. There was a significant “dose response” relationship between TBI severity and all Index/IQ scores. Effect size was greatest for the Processing Speed Index (PSI). Between group differences were significant on all subtests except Information and Digit Span. Effect sizes were greatest for Digit Symbol, Symbol Search, Similarities, and Picture Arrangement. Relative to the control group, there was a significant difference for the Severe and Extremely Severe TBI groups on all IQ/Index scores and most subtests. The Moderate TBI group differed significantly on one Index (the PSI) and none of the subtests. Clinical implications of the findings are discussed in relation to the utility of the WAIS-III in assessing the cognitive sequelae of TBI, the use of current WAIS-III IQ scores to assess intelligence – memory discrepancies, WAIS-III short forms, and estimation of premorbid intelligence.