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

Effects of Antiparkinson Medication on Cognition in Parkinson's Disease: A Systematic Review

OBJECTIVE

This study aimed to systematically review the effects of currently prescribed antiparkinson medication on cognition in patients with mild-to-moderate Parkinson's disease (PD) who were either cognitively intact or mildly impaired.

METHODS

English- and French-language studies published between 1969 and 2017 were accessed via MedLine, PsychNET, EMBASE and EBSCO databases. Methodological quality (MQ) was evaluated with the quality assessment instrument of the Cochrane Collaboration Depression, Anxiety and Neurosis Review (scores from 0% to 44% indicate very low quality; scores from 45% to 64% indicate low quality; scores from 65% to 84% indicate medium quality; and scores from 85% to 100% indicate high quality). Hedges' g and Student's t-test were performed on all cognitive outcome measures reported.

RESULTS

In total, 14 studies assessed the cognitive effects of levodopa (L-D), pramipexole (PRX), selegiline (SEL) and rasagiline (RAS) in mild-to-moderate non-demented PD patients. The MQ was overall low, with an average score of 49.1%. Results for L-D showed deleterious effects on a test of cognitive inhibition, as well as benefits on tests of attention/processing speed/working memory, executive functions and episodic memory. Pramipexole was associated with a worsening of episodic memory and impulse control. Results on SEL indicated a deterioration of global cognition over time and of concept formation. Rasagiline had some benefits on working memory and verbal fluency.

CONCLUSION

Antiparkinson medications can have deleterious (L-D; PRX; SEL) and beneficial (L-D; RAS) effects on cognition. However, randomized double-blind placebo-controlled trials with larger sample sizes are required to better elucidate this issue.

Spreading activation in nonverbal memory networks

Theories of spreading activation primarily involve semantic memory networks. However, the existence of separate verbal and visuospatial memory networks suggests that spreading activation may also occur in visuospatial memory networks. The purpose of the present investigation was to explore this possibility. Specifically, this study sought to create and describe the design frequency corpus and to determine whether this measure of visuospatial spreading activation was related to right hemisphere functioning and spreading activation in verbal memory networks. We used word frequencies taken from the Controlled Oral Word Association Test and design frequencies taken from the Ruff Figural Fluency Test as measures of verbal and visuospatial spreading activation, respectively. Average word and design frequencies were then correlated with measures of left and right cerebral functioning. The results indicated that a significant relationship exists between performance on a test of right posterior functioning (Block Design) and design frequency. A significant negative relationship also exists between spreading activation in semantic memory networks and design frequency. Based on our findings, the hypotheses were supported. Further research will need to be conducted to examine whether spreading activation exists in visuospatial memory networks as well as the parameters that might modulate this spreading activation, such as the influence of neurotransmitters.

Spatial memory for asymmetrical dot locations predicts lateralization among patients with presurgical mesial temporal lobe epilepsy

This study examined the ability of an asymmetrical dot location memory test (Brown Location Test, BLT) and two verbal memory tests (Verbal Selective Reminding Test (VSRT) and California Verbal Learning Test, Second Edition (CVLT-II)) to correctly lateralize left (LTLE) or right (RTLE) mesial temporal lobe epilepsy that was confirmed with video-EEG. Subjects consisted of 16 patients with medically refractory RTLE and 13 patients with medically refractory LTLE who were left hemisphere language dominant. Positive predictive values for lateralizing TLE correctly were 87.5% for the BLT, 72.7% for the VSRT, and 80% for the CVLT-II. Binary logistic regression indicated that the BLT alone correctly classified 76.9% of patients with left temporal lobe epilepsy and 87.5% of patients with right temporal lobe epilepsy. Inclusion of the verbal memory tests improved this to 92.3% of patients with left temporal lobe epilepsy and 100% correct classification of patients with right temporal lobe epilepsy. Though of a limited sample size, this study suggests that the BLT alone provides strong laterality information which improves with the addition of verbal memory tests.

Cerebrovascular reactivity to carbon dioxide in Alzheimer's disease

There is growing evidence that cerebrovascular reactivity to carbon dioxide (CVRCO2) is impaired in Alzheimer's disease (AD). Preclinical and animal studies suggest chronic hypercontractility in brain vessels in AD. We review (a) preclinical studies of mechanisms for impaired CVRCO2 in AD; (b) clinical studies of cerebrovascular function in subjects with AD dementia, mild cognitive impairment (MCI), and normal cognition. Although results of clinical studies are inconclusive, an increasing number of reports reveal an impairment of vascular reactivity to carbon dioxide in subjects with AD, and possibly also in MCI. Thus, CVRCO2 may be an attractive means to detect an early vascular dysfunction in subjects at risk.

Visual memory in patients after anterior right temporal lobectomy and adult normative data for the Brown Location Test

Several large meta-analytic studies have failed to support a consistent relationship between visual or "nonverbal" memory deficits and right mesial temporal lobe changes. The Brown Location Test (BLT), a recently developed dot location learning and memory test, uses a nonsymmetrical array and provides control over many of the confounding variables (e.g., verbal influence and drawing requirements) inherent in other measures of visual memory. In the present investigation, we evaluated the clinical utility of the BLT in patients who had undergone left or right anterior mesial temporal lobectomy. We also provide normative data of 298 healthy adults for standardized scores. Results revealed significantly worse performance on the BLT in the right as compared to the left lobectomy group and the healthy adult normative sample. The present findings support a role for the right anterior mesial temporal lobe in dot location learning and memory.

A new measure of visual location learning and memory: development and psychometric properties for the Brown Location Test (BLT)

There are a variety of well-established neuropsychological tests that are helpful in identifying global and specific verbal memory deficits. In contrast, tests of visual memory have produced less consistent results likely due in part to confounding variables such as verbal encodability, administration difficulties, and insufficient differentiation of among types of visual memory. The Brown Location Test (BLT) was designed to specifically measure visual memory for location of identical objects (dots) and address limitations found in commonly employed visual memory tests. This paper describes the empirical basis for the BLT and reports the psychometric properties of the test. Results indicate good internal and alternate form reliabilities. Factor analysis of a brief test battery confirmed that BLT performance is generally independent of verbal memory and global intellectual abilities. BLT performance declined with age, but there was no association between performance and gender, education, or intellectual functioning. In view of the favorable psychometric properties observed during preliminary studies, additional normative and validation studies in healthy and patient populations are warranted.

Verbal mediation and memory for novel figural designs: a dual interference study

To the extent that all types of visual stimuli can be verbalized to some degree, verbal mediation is intrinsic in so-called "visual" memory processing. This impurity complicates the interpretation of visual memory performance, particularly in certain neurologically impaired populations (e.g., aphasia). The purpose of this study was to investigate the relative contributions of verbal mediation to recognition memory for visual stimuli that vary with respect to their amenability to being verbalized. In Experiment 1, subjects attempted to verbally describe novel figural designs during presentation and then identify them in a subsequent recognition memory test. Verbalizing these designs facilitated memory. Stimuli that were found to be easiest or most difficult to verbalize at the group level were retained for the second study. In Experiment 2, subjects evidenced superior recognition memory for the relatively easy to verbalize items. This advantage was attenuated in subjects who performed a concurrent verbal interference task during encoding, but not in those who performed an analogous visual interference task. These findings provide evidence that impoverished verbal mediation disproportionately impedes memory for visual material that is relatively easy to verbalize. Implications for the clinical assessment of visual memory are discussed.

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.

Validation of the Wechsler Memory Scale-III in a population of people with intractable temporal lobe epilepsy

The Wechsler Memory Scale-Third Edition (WMS-III) was developed to overcome the limitations of the Wechsler Memory Scale-Revised and is now routinely used for pre-surgical assessment of memory for patients considering elective surgery for the relief of temporal lobe epilepsy (TLE). We investigated the validity of this relatively new measure in a population of people with resistant TLE. The sample consisted of 99 patients with a diagnosis if TLE in which the epileptogenic focus was clearly identified and localised to either the right or left hemisphere. Patients underwent a full neuropsychological assessment as part of their pre-surgical investigation, including the WMS-III. Patients with right temporal focus had significantly lower scores on the visual immediate and delayed indices of the WMS-III than they did on the corresponding auditory indices. The left temporal focal epilepsy group, however, showed no significant disparity between auditory and visual scores. The overall scores of the WMS-III were significantly lower than the normative data from the WMS-III standardisation samples. Like its predecessor the Wechsler Memory Scale-Revised, the WMS-III has limited value in identifying particular memory deficits associated with either left and right temporal lobe focus. The results of the WMS-III show that it is capable of lateralising to right hemispheric impairment but is more problematic in the assessment of left hemispheric impairment. The visual verbal discrepancy has questionable validity. The search for reliable and valid measures to distinguish between left and right temporal epileptic focus continues.

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.

The neuropsychological and emotional consequences of living with intractable temporal lobe epilepsy: implications for clinical management

PURPOSE

To investigate and document the neuropsychological and emotional effects of epilepsy in people with intractable temporal lobe epilepsy (TLE).

METHODS

273 patients with a diagnosis of TLE underwent a complete neuropsychological and psychological examination as a routine part of their investigation for epilepsy surgery. Neuropsychological assessment included measures of intellect, memory, language functioning, higher executive functioning, emotional well-being and the psychosocial impact of epilepsy and its treatment.

RESULTS

The sample comprised 135 females and 138 males with a clearly lateralised epileptogenic focus. Patients were mildly anxious but not depressed, although many reported that epilepsy and its treatment had a marked effect on their daily lives. Current reading ability was in the average range; the mean obtained full scale IQ was 88 (low average range). Verbal memory functioning was within the borderline impaired range with visual memory functioning within the average range. Mean language performance was between the 5-10th percentile. Higher executive functioning results were in the normal range. Multiple univariate analyses were performed according to onset laterality. There were no significant differences between the groups on measures of psychological or emotional functioning. Participants with left TLE scored significantly lower than those in the right temporal group on measures of verbal intelligence, general intelligence, attention span and expressive language functioning.

CONCLUSIONS

Patients with intractable epilepsy suffer significant neuropsychological difficulties in terms of their intellect, memory and language. Higher executive functioning appears unaffected. In addition, there is also evidence of emotional distress. These all impact upon their day-to-day functioning, which can be improved by the application of various psychological therapies and interventions.

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.

[Memory disorders in epileptic patients]

The author studied the mnemonic activity from epileptic patients with complex partial seizures (CPS), with the aims: 1) to identify memory disorders; and 2) to compare the patients' with the controls' results. Fifty adult patients and 20 subjects without neuropsychiatric disorders were studied. The methods consisted in: 1) investigation of the mnemonic activity through the Wechsler Memory Test (subtests: Storage and Recall, Recent Memory, and Immediate Memory); 2) comparison among the results of both groups; association from mnemonic activity with brain SPECT. In the three subtests, the patients showed cognitive performance significantly lower than the controls (p < 0.05). It was found association from reduced blood flow, mainly in left temporal region, with memory impairment of the three subtetsts. The conclusion was that the CPS are associated to memory impairment.