The Wechsler memory scale-revised, or the Wechsler memory scale-revisited?

The grasp reflex in patients with idiopathic normal pressure hydrocephalus

OBJECTIVE

To investigate the prevalence and intensity of grasp reflexes and to examine changes in these reflexes after shunt surgery in patients with idiopathic normal pressure hydrocephalus (iNPH).

METHODS

We enrolled 147 patients with probable iNPH. A standard procedure was used to determine the presence of grasp reflexes, and the intensity of these reflexes was assessed using a four-category classification. Clinical rating scales and their correlation with grasp reflexes were also evaluated. Grasp reflexes were reassessed in 72 patients 1 year after surgery.

RESULTS

We found that approximately 50.3% of patients with iNPH exhibited a positive grasp reflex. Among these patients, 69% exhibited bilateral positivity, while the remaining patients showed unilateral positivity. Furthermore, the intensity of the grasp reflex was significantly correlated with the severity of gait and with cognitive, urinary, motor, and behavioural symptoms. Surgical interventions led to a reduction (41.7%) or maintenance (30.6%) of the reflex intensity in 72.3% of iNPH patients. The changes in reflex intensity showed significant positive correlations with changes in the number of steps of the Timed Up and Go test and Trail Making Test-A scores but not with changes in total scores on the iNPH Grading Scale.

CONCLUSION

This retrospective study identified grasp reflexes as a highly prevalent phenomenon in patients with iNPH. These reflexes can assist in evaluating the severity of various symptoms, including cognitive, gait, urinary, motor and emotional symptoms.

The challenge of neuropsychological assessment of visual/visuo-spatial memory: A critical, historical review, and lessons for the present and future

A proliferation of tests exists for the assessment of auditory-verbal memory processes. However, from a clinical practice perspective, the situation is less clear when it comes to the ready availability of reliable and valid tests for the evaluation of visual/visuo-spatial memory processes. While, at face value, there appear to be a wide range of available tests of visual/visuo-spatial memory, utilizing different types of materials and assessment strategies, a number of criticisms have been, and arguably should be, leveled at the majority of these tests. The criticisms that have been directed toward what are typically considered to be visual/visuo-spatial memory tests, such as (1) the potential for verbal mediation, (2) over-abstraction of stimuli, (3) the requirement of a drawing response, and (4) the lack of sensitivity to unilateral brain lesions, mean that, in reality, the number of readily available valid tests of visual/visuo-spatial memory is, at best, limited. This article offers a critical, historical review on the existing measures and resources for the neuropsychological assessment of visual/visuo-spatial memory, and it showcases some examples of newer tests that have aimed to overcome the challenges of assessing these important aspects of memory. The article also identifies new trends and examples of how technological advances such as virtual reality may add value to overcome previous obstacles to assessment, thereby offering professionals more reliable, accurate means to evaluate visual/visuo-spatial memory in clinical practice.

Differential Effects of the Factor Structure of the Wechsler Memory Scale-Revised on the Cortical Thickness and Complexity of Patients Aged Over 75 Years in a Memory Clinic Setting

The Wechsler Memory Scale-Revised (WMS-R) is one of the internationally well-known batteries for memory assessment in a general memory clinic setting. Several factor structures of the WMS-R for patients aged under 74 have been proposed. However, little is known about the factor structure of the WMS-R for patients aged over 75 years and its neurological significance. Thus, we conducted exploratory factor analysis to determine the factor structure of the WMS-R for patients aged over 75 years in a memory clinic setting. Regional cerebral blood flow (rCBF) was calculated from single-photon emission computed tomography data. Cortical thickness and cortical fractal dimension, as the marker of cortical complexity, were calculated from high resolution magnetic resonance imaging data. We found that the four factors appeared to be the most appropriate solution to the model, including recognition memory, paired associate memory, visual-and-working memory, and attention as factors. Patients with mild cognitive impairments showed significantly higher factor scores for paired associate memory, visual-and-working memory, and attention than patients with Alzheimer's disease. Regarding the neuroimaging data, the factor scores for paired associate memory positively correlated with rCBF in the left pericallosal and hippocampal regions. Moreover, the factor score for paired associate memory showed most robust correlations with the cortical thickness in the limbic system, whereas the factor score for attention correlated with the cortical thickness in the bilateral precuneus. Furthermore, each factor score correlated with the cortical fractal dimension in the bilateral frontotemporal regions. Interestingly, the factor scores for the visual-and-working memory and attention selectively correlated with the cortical fractal dimension in the right posterior cingulate cortex and right precuneus cortex, respectively. These findings demonstrate that recognition memory, paired associate memory, visual-and-working memory, and attention can be crucial factors for interpreting the WMS-R results of elderly patients aged over 75 years in a memory clinic setting. Considering these findings, the results of WMS-R in elderly patients aged over 75 years in a memory clinic setting should be cautiously interpreted.

An Empirical Comparison of the Wechsler Memory Scale-Revised and the Memory Assessment Scales in Measuring Four Memory Constructs

Thirty participants were administered both the Wechsler Memory Scale-Revised (WMS-R) and the Memory Assessment Scales (MAS). Participants' standard (index) scores from each battery were compared across the same four memory constructs: Verbal Memory; Visual Memory; General/Global Memory; and WMS-R Attention and concentration and MAS Short-term Memory. The MAS yielded significantly lower mean standard scores across all four memory constructs. The largest difference between mean standard scores was found on Visual Memory in which the MAS mean was over one standard deviation lower than the WMS-R mean. Correlations between the MAS and the WMS-R mean standard scores were not significant on the Visual Memory and the General/Global Memory construct. Although the WMS-R and the MAS purport to measure the same memory constructs, these results suggest that they are measuring different abilities and are not comparable tests.

The Rivermead Behavioural Memory Test and Wechsler Memory Scale-Revised: Relationship to Everyday Memory Impairment

Investigations questioning the ecological validity of standardized neuropsychological instruments have led to the development of tests that are purported to be relevant to everyday functioning. The present investigation examined the relationships of the Rivermead Behavioural Memory Test (RBMT) and the Wechsler Memory Scale-Revised (WMS-R) to estimates of everyday memory functioning, as measured by patient and relative ratings on the Everyday Memory Questionnaire (EMQ). The research participants consisted of a group allegedly exposed to neurotoxicants (n = 29), and a demographically similar comparison group ( n = 20). Results indicated that the two objective memory tests did not significantly differ in their relationships to estimates of everyday memory functioning, and that use of the tests together did not improve prediction of memory complaints over the use of one test alone. In addition, patient and relative ratings were highly correlated. These results are discussed within the context of the validity of patient and relative rating scales as estimates of everyday memory impairment.

A critical evaluation of the lateralizing significance of material-specific memory deficits in patients with mesial temporal lobe epilepsy with hippocampal sclerosis

To critically assess the value of material-specific memory deficits in lateralizing temporal lobe dysfunction preoperatively, we compared the neuropsychological data of 50 consecutive patients with unilateral mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS; right: 31, left: 19) with those of 50 age- and education-matched healthy control subjects. On case-control comparison, both the subcohorts with left and right MTLE-HS performed poorly on intelligence tests, in addition to individual memory tests. However, comparison of the verbal and visual memory functions between subcohorts with right and left MTLE-HS revealed that learning trials and delayed word list recall were the only tests that hypothesized left temporal lobe dysfunction. We conclude that material-specific memory deficits are largely test driven, but there is a lateralizing role for task-specific deficits in left MTLE-HS. Although neuropsychological data help to define baseline neuropsychological impairment, caution should be exercised in interpreting the lateralizing value of material-specific memory deficits prior to surgery.

The NAB shape learning subtest as a predictor of lateralized seizure onset

This study presents the first empirical evaluation of the predictive value of the Neuropsychological Assessment Battery Shape Learning (NAB-SL) subtest in a sample of patients with unilateral temporal lobe epilepsy. Stimulus characteristics of the NAB-SL may improve predictive ability over other commonly used visual memory tests. Forty-nine patients with unilateral temporal lobe epilepsy were compared on measures of non-verbal and verbal memory (NAB-SL and Wechsler Memory Scale-III subtests). Univariate and forward conditional logistic regressions identified predictive values for each memory test individually and in combination. The NAB-SL delayed memory demonstrated consistently stronger predictive power over visual reproduction at the univariate and multivariate levels. The NAB-SL was a good predictor (80% range) of lateralized seizure onset when combined with a verbal memory measure. These preliminary results provide support for the use of the NAB-SL in preoperative epilepsy evaluations as a predictor of non-dominant temporal lobe dysfunction. Potential benefits of this test are discussed.

History of neuropsychology through epilepsy eyes

In the 19th century, Hughlings Jackson relied on clinical history, seizure semiology, and the neurologic examination as methods for seizure localization to inform the first epilepsy surgeries. In the 20th century, psychological and neuropsychological tests were first employed as both diagnostic and prognostic measures. The contemporary practice of epilepsy evaluation and management includes neuropsychology as a critical component of epilepsy care and research, and epilepsy and neuropsychology have enjoyed a very special and synergistic relationship. This paper reviews how epilepsy has shaped the practice of neuropsychology as a clinical service by asking critical questions that only neuropsychologists were in a position to answer, and how clinical care of epilepsy patients has been significantly improved based on neuropsychology's unique contributions.

Mayo's Older African Americans Normative Studies: WMS-R Norms for African American Elders

Norms for African American elders on the Wechsler Memory Scale-Revised (WMS-R) were derived from a sample of 309 community-dwelling individuals participating in Mayo's Older African Americans Normative Studies (MOAANS). Normative estimates are provided for traditional WMS-R subtest scores and for supplemental procedures to evaluate forgetting rates and recognition memory. Tables are provided to convert raw WMS-R subtest and supplemental scores to age-corrected scaled scores. These may be further adjusted for years of education, if desired, by applying regression-based corrections. We anticipate that these data will enhance the diagnostic utility and clinical interpretation of WMS-R performance in older African Americans.

WMS-III performance in epilepsy patients following temporal lobectomy

We examined performances on the Wechsler Memory Scale-3rd Edition (WMS-III) among patients who underwent temporal lobectomy for the control of medically intractable epilepsy. There were 51 right (RTL) and 56 left (LTL) temporal lobectomy patients. All patients were left hemisphere speech-dominant. The LTL and RTL patients were comparable in terms of general demographic, epilepsy, and intellectual/attention factors. Multivariate analyses revealed a significant crossover interaction (p <.001), with the RTL group scoring significantly lower on the visual than auditory indexes while the LTL group scored significantly lower on the auditory than visual memory indexes. Within-group pairwise analyses revealed statistically significant auditory versus visual index score comparisons (all p <.001) for both surgical groups. Discriminant analysis (p <.001) identified Verbal Paired Associates I, Faces I, and Family Pictures II to significantly discriminate RTL and LTL patients, with an overall correct classification rate of 81.3%. Our findings suggest that the WMS-III is sensitive to modality-specific memory performance associated with unilateral temporal lobectomy.

Confirmatory factor analysis of the WMS-III in patients with temporal lobe epilepsy

Five competing models specifying the factor structure underlying the Wechsler Memory Scale-Third Edition (D. Wechsler, 1997b) primary subtest scores were evaluated in a sample of patients with intractable temporal lobe epilepsy (N = 254). Models specifying separate immediate and delayed constructs resulted in inadmissible parameter estimates and model specification error. There were negligible goodness-of-fit differences between a 3-factor model of working memory, auditory memory, and visual memory and a nested--more parsimonious--2-factor model of working memory and general memory. The results suggest that specifying a separate visual memory factor provides little advantage for this sample--an unexpected finding in a population with lateralized dysfunction, for which one might have predicted separate auditory and visual memory dimensions.

Reliability and clinical usefulness of the short-forms of the Wechsler memory scale (revised) in patients with epilepsy

PURPOSE

The Wechsler Memory Scale-R (WMS-R) is often used for the evaluation of patients with epilepsy, but is time consuming. Two shortened forms of the WMS-R have been published in an effort to reduce the time involved in the test. The purpose of this study is to cross-validate these abbreviated forms in patients with epilepsy.

METHODS

We assessed 103 consecutive patients with drug-resistant partial epilepsy being treated in our epilepsy unit. The WMS-R was administered to all patients. The reliability of two shortened versions of the WMS-R were evaluated. The appraisal was performed taking into account the side of the epileptogenic region. The statistical analyses were carried out with the Pearson's correlation and with the intraclass correlation coefficient.

RESULTS

Both shortened formulas showed good reliability coefficients for predicting the General Memory and Delayed Recall Indices. In the overall accuracy of the predictions by both short forms no significant differences were found among the three study. groups (right, left or bilateral). However, when considering the predictive error only the three-subtest formulas comprising logical memory, verbal paired associates and visual reproduction efficiently predicted performance, regardless of the side of the epileptogenic region. Of the predicted scores in the overall sample, 92 and 97% fell below the standard error of measurement for general and delayed memory index, respectively. Both short forms correctly classified 89-94% of the performances at the average or impaired level.

CONCLUSIONS

The short form of the M-MS-R using three subtests (logical memory, verbal paired associates and visual reproduction) is reliable and time-efficient for estimating the General and Delayed Recall Memory indexes in patients with drug-resistant partial epilepsy.

Cross-validation of the two- and three-subtest short forms of the Wechsler Memory Scale-Revised

Researchers have noted the usefulness of an abbreviated form of the Wechsler Memory Scale-Revised. A number of studies have suggested that estimating General Memory and Delayed Recall scores using 3-subtest or 2-subtest equations decreases testing time without sacrificing reliability or clinical accuracy. The purpose of this study was to cross-validate previous results in a mixed clinical sample, as well as to examine the validity of the 2-subtest equations. Results of this study provide support for the use of the 3-subtest short form to estimate memory ability in normal and cognitively impaired patients. However, using only 2 subtests to estimate index scores resulted in a decline in predictive accuracy.

An analysis of neuropsychological change scores following selective temporal resection of the non-dominant temporal lobe

Reliable change in neuropsychological test scores was examined in patients undergoing right-sided, selective temporal resections for the relief of intractable epilepsy. Measures were taken prior to surgery, 1-month post-operatively and 1-year post-operatively. Non-verbal memory performance was more robustly measured than in previous studies. Results failed to replicate previous studies which report verbal memory deficits even following right-sided surgery. No strong evidence of a material-specific, non-verbal memory deficit was found on commonly used tests of non-verbal memory. The majority of patients failed to show reliable decline in performance following surgery indicating that fears of post-operative memory decline may be unfounded.

Psychometric properties and factor structure of the Wechsler Memory Scale-Revised in a sample of persons with intractable epilepsy

The Wechsler Memory Scale-Revised (WMS-R) is used routinely as a presurgical assessment of memory for clients considering elective resection of the temporal lobe and/or hippocampus for the relief of intractable temporal lobe epilepsy. This research investigated the psychometric properties of the WMS-R in a population of people with epilepsy. The sample consisted of 181 patients with a diagnosis of epilepsy who underwent a complete neuropsychological examination as a routine part of their investigation. The results confirm that the WMS-R has acceptable levels of reliability as measured by internal consistency. A factor analysis revealed a consistent three-factor structure: Visual Memory, Verbal Memory, and Attention/ Concentration factors. Multiple regression analysis, however, indicated that the Visual Memory index was susceptible to a number of influences, throwing into question whether it is a pure measure of nonverbal memory functioning.

Confirmatory factor analysis of the Wechsler Memory Scale-Revised in a sample of clients with alcohol dependency

Previous analyses of the Wechsler Memory Scale-Revised (WMS-R; Wechsler, 1987) have reported one-, two-, and three-factor solutions and raised questions about the validity of the visual memory subtests. These various findings may stem in part from different methods of analysis, and from the study of different participant samples. To address these issues, we analysed data from the WMS-R and a spatial maze test administered to 154 participants with a history of alcohol dependence. Results from confirmatory factor analysis supported the interpretation of three factors underlying the WMS-R subtests and the spatial maze score in this sample, namely, attention-concentration, immediate memory, and delayed recall. This result held despite the inclusion of the maze score which is a well-validated measure of visuo-spatial memory.

Performance on the Wechsler Memory Scale-Revised for patients with mild traumatic brain injury and mild dementia

The purpose of this study was to delineate significant differences among mild traumatic brain-injured and early onset mild dementia patients examined using the Wechsler Memory Scale-Revised subtests. In comparison to 12 mild traumatic brain-injured patients, 11 mild dementia patients scored significantly lower on Verbal Paired Associates I and II, Visual Reproduction I and II, and Visual Paired Associates I. Raw score summaries for the Wechsler Memory Scale-Revised indicated significantly lower scores on Verbal Memory, Visual Memory, and the over-all composite. General Memory for mild dementia patients in comparison to individuals who sustained a mild traumatic brain injury. Despite equivalent scores on Attention/Concentration, the dementia group did not show significantly lowered delay in memory recall by comparison with mild closed-head injured patients. The study recommends replication with much larger sample sizes to validate the results.

Validation of the Wechsler Memory Scale-Revised in a sample of people with intractable temporal lobe epilepsy

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.

Predicting cognitive impairment in epilepsy: findings from the Bozeman epilepsy consortium

We examined the contribution of age of seizure onset, seizure duration, seizure laterality, seizure location, gender, handedness, and cerebral speech representation to cognitive attainment in 1,141 patients with medically refractory seizures. The combined influence of the predictor variables was modest. Age of seizure onset was the best single indicator of Full Scale IQ (partial r = .23) and General Memory (partial r = .20). Laterality and location of dysfunction, and cerebral speech dominance were also relevant and independent indicators of aspects of cognition. Except for age of onset of seizures (early onset was associated with poorer cognitive attainment), however, the magnitude of the effects was limited.

Verbal vs. visual categories on the Wechsler Memory Scale-revised: how meaningful a distinction?

This study investigated whether the a priori classification of Wechsler Memory Scale-Revised (WMS-R) subtests into separate Verbal and Visual categories is warranted. Correlational and hierarchical clustering analyses found that (a) memory test performance correlated significantly with performance on subtests of Form II of the Luria-Nebraska Neuropsychological Battery (LNNB-II) that measure substrates of particular memory processes; and (b) subtests that appeared a priori to involve verbal skills clustered separately from those that appeared to involve nonverbal (visual) skills. However, the WMS-R Visual Paired Associates subtest did not cluster with the nonverbal scales as expected, and the LNNB-II Memory Scale appeared to be predominantly a test of verbal memory. Practical consequences of these findings were discussed.

The diagnostic utility of savings scores: differentiating Alzheimer's and Huntington's diseases with the logical memory and visual reproduction tests

Recent research has demonstrated that patients with dementia of the Alzheimer type (DAT) evidence more rapid forgetting than do patients with Huntington's disease (HD). The present study focused on whether such group differences translated into measures with adequate sensitivity and specificity at different stages of these disorders. It was found that measures of forgetting (i.e., savings scores) based upon the Logical Memory and Visual Reproduction tests of the Wechsler Memory Scale--Revised had satisfactory to excellent sensitivity and specificity in differentiating DAT and HD patients from healthy control subjects. Savings scores also had good sensitivity and specificity in differentiating DAT from HD in the early stages of the diseases. However, unsatisfactory specificity may limit the utility of savings scores in differentiating among patients with moderate DAT and HD.

Malingering on neuropsychological memory tests: potential objective indicators

We evaluated five potential indicators of malingering on the Rey Memory Test (RMT), Hebb's Recurring Digits (HRD), the Wechsler Memory Scale-Revised (WMS-R), the Complex Figure Test (CFT), and the Auditory Verbal Learning Test (AVLT). Fifty-seven subjects were assigned randomly to either a control group or a simulated malingering group. Two indicators-discriminant functions derived from the WMS-R and from the CFT/AVLT-achieved classification accuracy of 88% and 86%, respectively, without misidentifying controls as malingerers. Among the remaining indicators, there were problems with the recommended RMT cut-off, but it and the HRD show some promise. Subjects who simulated malingering did so by suppressing performance on tasks that involve recall as well as recognition memory and are relatively easy, but not obviously so.

Standardized and flexible batteries in neuropsychology: an assessment update

This article summarizes current literature relevant to commonly used tests and test batteries in clinical neuropsychology. The first section contains a discussion of the philosophy and relative advantages of standardized and flexible battery approaches in neuropsychology. The second contains historical background and a literature review of the two major standardized test batteries: the Halstead-Reitan and Luria-Nebraska. The third section includes reviews of tests that are frequently used in the flexible battery approach. Various tests of intellectual functioning, attention, memory, language, and spatial analyses are critiqued in this section. Contributions of the process approach are noted. The article ends by underscoring the need for continued research into the nature of neuropsychological measures and the abilities they assess.

The Wechsler Memory Scale-Revised: psychometric characteristics and clinical application

The psychometric characteristics of the Wechsler Memory Scale-Revised (WMS-R) are evaluated and related to its clinical utility. The accuracy of the scale scores is shown to be limited by their high standard error, low reliabilities, and consequent large standard errors of measurement. Specific procedures are discussed for establishing confidence intervals and for testing the significance of differences between scores. It is concluded that the WMS-R, like the original Wechsler Memory Scale, provides only a rough estimate of overall memory functioning. The multidimensional index scores have not been shown effective in describing the nature or the pattern of memory deficits. Recommendations for the clinical use of the WMS-R are provided.

Prospects for faking believable memory deficits on neuropsychological tests and the use of incentives in simulation research

The vulnerability of several neuropsychological memory tests--the Wechsler Memory Scale--Revised, Complex Figure Test, Auditory Verbal Learning Test, and Rey Memory Test--to faked deficits was evaluated. Subjects were randomly assigned to one of three conditions: Control (n = 28), Malingering with a financial incentive (n = 30), and Malingering without a financial incentive (n = 28). Overall, the performance of the Malingering Groups was not significantly different from one another, but both groups were significantly poorer than Controls. Discriminant functions with a reduced set of predictors correctly classified about 75% of cases in both the Control and the combined Malingering Groups on cross-validation. The results suggest that neuropsychological memory tests are vulnerable to faked deficits, and that recognition tasks are disproportionately affected. The use of incentives in simulation research is also discussed.

Instruments for the functional assessment of older patients

Structured assessment instruments are particularly useful in screening for problems that often go undetected in older patients. In addition, such instruments can provide information about conditions and abilities or limitations that are not regularly assessed in standard clinical practice. Often, their administration is delegated to other health professionals, but these tools still provide useful information to the physician. Clinicians should view assessment instruments as they would any other clinical test. They should be familiar with the strengths, weaknesses, and precision of any test used and understand how best to use the test as an adjunct to clinical practice. In addition, clinicians must learn to focus on functional status, in terms of both assessment and outcome, in their care of older patients.