Stephen C. Bowden

Neurocognitive impairment associated with alcohol use disorders: implications for treatment.

Between 50% and 80% of individuals with alcohol use disorders experience mild to severe neurocognitive impairment. There is a strong clinical rationale that neurocognitive impairment is an important source of individual difference affecting many aspects of addiction treatment, but empirical tests of the direct influence of impairment on treatment outcome have yielded weak and inconsistent results. The authors address the schism between applied-theoretical perspectives and research evidence by suggesting alternative conceptual models of the relationship between neurocognitive impairment and addiction treatment outcome. Methods to promote neurocognitive recovery and ways in which addiction treatments may be modified to improve psychosocial adaptation are suggested. Specific suggestions for future research that may help clarify the complex relations between neurocognitive impairment and addiction treatment are outlined.

Alzheimer's Disease and Driving: Prediction and Assessment of Driving Performance

OBJECTIVES: To examine driving competence in a group of drivers diagnosed with probable Alzheimers Disease (AD) in terms of a standardized open road evaluation and expert judgments. To examine the validity of a standardized medical examination, including administration of the Mini‐Mental Status Exam (MMSE), and a standardized neuropsychological assessment as predictors of open road driving performance.

Neuropsychological and Information Processing Performance and Its Relationship to White Matter Changes Following Moderate and Severe Traumatic Brain Injury: A Preliminary Study

Reductions in information processing speed have frequently been reported following moderate and severe traumatic brain injuries (TBIs), consistent with the effects of diffuse white matter damage. Although the corpus callosum (CC) is a common site for diffuse damage following TBI, the effects of this damage on information processing speed have not been adequately examined. This study assessed a TBI group and a matched control group on tests of attention, memory, fluency, and set shifting ability, together with reaction time (RT) tasks requiring the inter- and intrahemispheric processing of visual and tactile information. The RT tasks were designed to target the cognitive functions that are likely to be affected by diffuse white matter damage, including damage to the CC. The TBI group demonstrated deficits in verbal and visual fluency and verbal memory. They were also slower on the visual and tactile RT tasks, were more affected by task complexity, and slower on RT tasks requiring the interhemispheric transfer of information. In fact, one of the interhemispheric tactile RT tasks proved to be the most discriminating of all the cognitive and RT measures. MRIs completed on a subset of TBI participants indicated that the mean CC measurements were 5% to 19% smaller than a normative control group, with the most atrophied areas being the isthmus and anterior midbody. Although white matter atrophy was moderately related to visual and tactile RT performance, and total hippocampal volume related to memory performance, CC area was not related to many of the tasks that were designed to tap interhemispheric processing. None of the standard cognitive tests correlated with outcome in the TBI group, but 1 of the tactile RT measures was significantly related to 2 measures of outcome.

Differential neuropsychological test sensitivity to left temporal lobe epilepsy

We examined the sensitivity of the Rey Auditory Verbal Learning Test (AVLT), California Verbal Learning Test (CVLT), Boston Naming Test (BNT), and Multilingual Aphasia Examination Visual Naming subtest (MAE VN) to lateralized temporal lobe epilepsy (TLE) in patients who subsequently underwent anterior temporal lobectomy. For the AVLT (n = 189), left TLE patients performed more poorly than their right TLE counterparts [left TLE = 42.9 (10.6), right TLE = 47.7 (9.9); p < .002 (Cohens d = .47)]. Although statistically significant, the CVLT group difference (n = 212) was of a smaller magnitude [left LTE = 40.7 (11.1), right TLE = 43.8 (9.9); (p < .03, Cohens d = .29)] than the AVLT. Group differences were also present for both measures of confrontation naming ability [BNT: left LTE = 43.1 (8.9), right TLE = 48.1 (8.9); p < .001 (Cohens d = .56); MAE VN: left TLE = 42.2, right TLE = 45.6, p = .02 (Cohens d = .36)]. When these data were modeled in independent logistic regression analyses, the AVLT and BNT both significantly predicted side of seizure focus, although the positive likelihood ratios were modest. In the subset of 108 patients receiving both BNT and AVLT, the AVLT was the only significant predictor of seizure laterality, suggesting individual patient variability regarding whether naming or memory testing may be more sensitive to lateralized TLE.

The Reliability and Internal Validity of the Wisconsin Card Sorting Test

This study examined the internal validity of the Wisconsin Card Sorting Test in two samples. In an alcohol-dependent sample (n= 151), exploratory factor analysis of internal validity, using Lisrel 8, showed that the six principal scores derived from the test could be fitted to a model with one factor and correlated errors. In a sample of university students (n= 75), we replicated the one factor internal validity model identified in the alcohol-dependent sample, and we also examined the alternate-form reliability of the Wisconsin. The reliability data, together with a reanalysis of information from the most recent edition of the test manual, suggest that the test should not be used for clinical purposes in its present form.

Accuracy of the Wechsler Test of Adult Reading (WTAR) and National Adult Reading Test (NART) when estimating IQ in a healthy Australian sample

Abstract The recently published Wechsler Test of Adult Reading (WTAR) has been co-normed with the third editions of the Wechsler Adult Intelligence and Memory Scales (WAIS-III, WMS-III), and has been shown to reliably estimate intelligence in U.S. and U.K. samples. However, the suitability of the WTAR for use in Australia has not been established, nor is there any clear basis for determining whether to use U.S. or U.K. norms to convert WTAR raw scores to obtain estimates of IQ. This study examined the accuracy with which both the WTAR and the National Adult Reading Test (NART) estimated concurrent WAIS-III IQ performance in a sample of 93 healthy Australian adults who completed all three measures. WTAR reading, demographics, and combined (reading and demographics) estimates of WAIS-III IQ (verbal IQ, full-scale IQ) were calculated using both U.S. and U.K. norms. NART estimates of IQ were also calculated. Although the WTAR and NART IQ estimates all significantly correlated with WAIS-III IQ, there were significant discrepancies between the mean estimated and concurrent IQs. These discrepancies were smallest for the NART. Moreover, the accuracy of all IQ estimates was related to ability level, such that the WTAR and NART overestimated the IQs of persons who were below average in ability and underestimated the IQs of those who were of high average or above average ability. IQs were underestimated or overestimated by as many as 36 or 30 points, respectively. Clinicians are therefore advised to use these measures with caution.

Wernicke-Korsakoff syndrome not related to alcohol use: a systematic review

Objective Although Wernicke-Korsakoff syndrome (WKS) is a common condition, diagnosis remains difficult. WKS not associated with alcohol is rare and thought to present differently to alcohol-related WKS. We conducted a systematic review of WKS not related to alcohol to enhance understanding of WKS not related to alcohol and WKS in general. Methods A systematic review was conducted of case reports, published in English, of Wernickes encephalopathy and WKS in patients without a history of alcohol-use disorder. Main data sources: MEDLINE, Index Medicus. Eligible cases totaled 623. Publication dates ranged from 1867 to 2014. Comparisons of clinical presentation were made with published data on samples comprising, almost exclusively, alcohol-related WKS. Results A wide array of illnesses precipitated WKS. When diagnosis of WKS was performed postmortem, non-alcohol-related cases presented a similar number of signs of the classic triad as alcohol-related cases (p=0.662, Cohens w=0.12) but more signs when diagnosed antemortem (p<0.001, Cohens w=0.46). The most common sign was altered mental state. Korsakoff syndrome or ongoing memory impairment was reported in 25% of non-alcohol-related WKS, although cognitive status was not explicitly reported in many cases. When duration of memory impairment was reported, 56% had clinically obvious memory impairment lasting beyond the period of acute presentation. Non-alcohol-related WKS was more often associated with female gender, younger age, shorter duration of precipitating illness and better survival rate compared to alcohol-related WKS. Conclusions Thiamine deficiency in the absence of an alcohol-use disorder can cause the full clinical spectrum of WKS, including chronic cognitive impairment and Korsakoff syndrome.

Confirmatory factor analysis of combined Wechsler Adult Intelligence Scale-Revised and Wechsler Memory Scale-Revised scores in a healthy community sample

This study examined the joint factor structure of the Wechsler Adult Intelligence Scale-Revised (D. Wechsler, 1981) and Wechsler Memory Scale-Revised (D. Wechsler, 1987) in a sample of 399 healthy young adults (206 women and 193 men) recruited for a nonnative study in Sydney, Australia: the Macquarie University Neuropsychological Normative Study. Using confirmatory factor analysis, the authors contrasted alternative models of ability in the respective Wechsler scales, focusing in particular on hypotheses relating to memory function. The best-fitting solution comprised a model representing Verbal Comprehension, Perceptual Organization, Attention-Concentration, Verbal Memory and Visual Memory. The results are discussed in terms of the incremental validity of ability assessment, potential for improvement in model-fit, and implications for professional practice.

Is performance on the Wechsler test of adult reading affected by traumatic brain injury

OBJECTIVES The validity of the National Adult Reading Test (NART) as a predictor of premorbid IQ when used with patients who have sustained a traumatic brain injury (TBI) has been questioned in recent years. This study examined whether performance on the Wechsler Test of Adult Reading (WTAR) is similarly affected by TBI in the first year after an injury. DESIGN AND METHOD The WTAR scores of participants who had sustained a mild TBI (N=82), moderate TBI (N=73), severe TBI (N=61) or an orthopaedic injury (N=95) were compared (cross-sectional study). A subset of 21 mild TBI, 31 moderate TBI, 26 severe TBI and 21 control group participants were additionally reassessed 6 months later to assess the impact of recovery on WTAR scores (longitudinal study). RESULTS The severe TBI group had significantly lower scores on the WTAR than the mild TBI, moderate TBI and control groups in the cross-sectional study, despite being matched demographically. The findings from the longitudinal study revealed a significant group difference and a small improvement in performance over time but the interaction between group and time was not significant, suggesting that the improvements in WTAR performance over time were not restricted to more severely injured individuals whose performance was temporarily suppressed. CONCLUSIONS These findings suggest that reading performance may be affected by severe TBI and that the WTAR may underestimate premorbid IQ when used in this context, which may cause clinicians to underestimate the cognitive deficits experienced by these patients.

Cognitive functioning in idiopathic generalised epilepsies: A systematic review and meta-analysis

Cognitive function in idiopathic generalised epilepsies (IGE) is of increasing research attention. Current research seeks to understand phenotypic traits associated with this most common group of inherited epilepsies and evaluate educational and occupational trajectories. A specific deficit in executive function in a subgroup of IGE, juvenile myoclonic epilepsy (JME) has been a particular focus of recent research. This systematic review provides a quantitative synthesis of cognitive function outcomes in 26 peer-reviewed, case-control studies published since 1989. Univariate random-effects meta-analyses were conducted on seven cognitive factor-domains and separately on executive function. Patients with IGE demonstrated significantly lower scores on tests across all cognitive factor-domains except visual-spatial abilities. Effect sizes ranged from 0.42 to 0.88 pooled standard deviation units. The average reduction of scores on tests of executive function in IGE compared to controls was 0.72 standard deviation units. Contrary to current thinking, there was no specific deficit in executive function in JME samples, nor in other IGE syndromes. Of more concern, people with IGE are at risk of pervasive cognitive impairment.