Test-retest practice effects and test score changes of the WAIS-R in recovering traumatically brain-injured survivors

Test-retest reliability of spatial navigation in adults at-risk of Alzheimer's disease

The Virtual Supermarket Task (VST) and Sea Hero Quest detect high-genetic-risk Alzheimer`s disease (AD). We aimed to determine their test-retest reliability in a preclinical AD population. Over two time points, separated by an 18-month period, 59 cognitively healthy individuals underwent a neuropsychological and spatial navigation assessment. At baseline, participants were classified as low-genetic-risk of AD or high-genetic-risk of AD. We calculated two-way mixed effects intraclass correlation coefficients (ICC) for task parameters and used repeated measures ANOVAS to determine whether genetic risk or sex contributed to test-retest variability. The egocentric parameter of the VST measure showed the highest test-retest reliability (ICC = .72), followed by the SHQ distance travelled parameter (ICC = .50). Post hoc longitudinal analysis showed that boundary-based navigation predicts worsening episodic memory concerns in high-risk (F = 5.01, P = 0.03), but in not low-risk, AD candidates. The VST and the Sea Hero Quest produced parameters with acceptable test-retest reliability. Further research in larger sample sizes is desirable.

Spontaneous recovery of memory functions in an untreated case of anti NMDAR encephalitis - a reason to maintain hope

OBJECTIVE

Anti N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune disorder that was only fully discovered recently and neuropsychological outcome data remains sparse. We present the case of BA, a 19-year-old male, which illustrates the cognitive outcome in an untreated case over a time period of over 2½ years.

METHOD

We conducted three cognitive assessments, including tests of memory and executive functioning, over this time period and considered the evidence for reliable change in memory function using the Wechsler Advanced Clinical Solutions (ACS) serial assessment package.

RESULTS

Our findings revealed mild memory problems 6 months post-discharge with, at best, static and potentially declining memory functioning at follow-up assessment 12 months post-discharge. However, the results of testing at 30 months post-discharge revealed significant improvements in immediate and delayed memory index performances.

CONCLUSIONS

Our report of a case of anti-NMDAR encephalitis provides evidence for spontaneous improvements in memory functioning occurring more than 2 years after initial assessment and also demonstrates both the utility and potential limitations of the ACS serial assessment software when used in a relatively typical clinical assessment situation.

Practice Effects on Visuomotor and Problem-Solving Tests by Children

Practice effects on a visuomotor test (the Developmental Test of Visuo-Motor Integration), a timed visual discrimination test (the Underlining Test), and two problem-solving tests (the Porteus Mazes Test and the Tower of Hanoi Test) were analyzed. Children of two age groups ( Ms: 7.7 and 11.6 yr.) were chosen to study the effect of age on practice effects. The tests were repeated nine times with test-retest intervals of 2 mo. The Developmental Test of Visuo-Motor Integration showed no practice effects, while the Porteus Mazes Test, the Underlining Test, and the Tower of Hanoi Test showed significant practice effects. Practice effects were larger for the older age group on all the tests, except the Developmental Test of Visuo-Motor Integration. The Developmental Test of Visuo-Motor Integration and the Underlining Test showed good reliability, but those of the problem-solving tasks were less satisfactory. The stability of all the tests, except the Tower of Hanoi Test, was good.

Estimating Full Scale IQ While Minimizing the Effects of Practice

The present study attempted to ascertain the best estimate of true Wechsler Adult Intelligence Scale-Revised (WAIS-R) Full Scale IQ (FSIQ) when confronted with an individual who recently had been administered the WAIS-R. Sixty-five college undergraduate participants were administered the WAIS-R twice within 14 days. WAIS-R summary scores, factor scores, and short-form estimates obtained from the second assessment were compared to FSIQ at the first evaluation. The results indicated that Verbal IQ, the Verbal Comprehension factor score, and subtracting 6 points from the current FSIQ are the least affected by repeat assessment and the most accurate estimates of FSIQ at the first evaluation. Use of these estimates of FSIQ are encouraged when evaluating an individual who has been administered the WAIS-R in the recent past.

Methodological Issues in Longitudinal Research on Cognitive Recovery after Traumatic Brain Injury: Evidence from a Systematic Review

Background: Previous research addressing cognitive recovery after traumatic brain injury (TBI) in adults has predominately used cross-sectional methods. This systematic review examines longitudinal research into cognitive recovery in the first 2 years following moderate-to-severe TBI in adults and aims to identify apparent methodological issues with the existing literature.

Design: Systematic review of the first 2 years post-trauma.

Setting: Data were extracted from three electronic databases and manual searches of published articles until October 2012.

Participants: Two hundred and forty-two participants with severe TBI and 281 comparison participants were used to calculate effect sizes.

Results: Twenty papers met the selection criteria, with effect sizes computed from four studies. Moderate-to-large effect sizes were initially observed between the TBI and comparison groups on most measures (range: d = 0.2–2.8). Recovery continued in all five cognitive domains over the 2 years post-injury.

Conclusions: Results demonstrated that cognitive recovery was continuous throughout the first 2 years following moderate-to-severe TBI. Findings also indicated different rates of recovery for the specific cognitive domains, highlighting the heterogeneous nature of cognitive recovery after TBI. The review highlighted several methodological issues within the limited existing literature; recommendations were developed to improve the evidence base.

Order of item difficulty on the WAIS-R picture arrangement subtest: data from a traumatically brain-injured sample

Although the items within the WAIS-R subtests are presumed to be in ascending order of difficulty, several studies have indicated that the Picture Arrangement subtest items are out of order for clinical groups. The present study retrospectively examined item difficulty and discrimination in the test data of 74 individuals who had been referred for neuropsychological assessment following a traumatic brain injury. While results were not statistically significant, qualitative analysis of partial credit scoring for four of the items indicated some inconsistencies in the scoring rationale. Caution is recommended in the use and interpretation of the Picture Arrangement tests scores in the assessment of individuals with traumatic brain injury.

Issues associated with repeated neuropsychological assessments

Distinguishing practice effects from other factors in repeated neuropsychological assessments are discussed in the context of research studies and clinical/forensic assessments. Potential methodological procedures for reducing the impact of practice effects in research settings are outlined. In contrast, the potential clinical utility and interpretation of practice effects in clinical assessments and forensic evaluations are highlighted.