Identification of malingered head injury on the Wechsler Adult Intelligence Scale—Revised.

Nonlitigating head injured patients (N?=?67) were compared with 67 age-, IQ-, and occupation-matched participants who were instructed to malinger head trauma symptoms on the Wechsler Adult Intelligence Scale—Revised (WAIS—R). Discriminant function analysis based on the WAIS—R subtests and a Vocabulary-Digit Span difference score were able to accurately classify 79% and 71% of the cases, respectively. Decision rules cross-validated successfully in several independent groups of clinical malingerers. Head injured patients seem to show a pattern of WAIS—R subtest scores that can be discriminated from the profile produced by individuals who attempt to malinger head trauma symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of red pigment on the amyloidization of yeast proteins

The intensity of amyloid-bound thioflavine T fluorescence was studied in crude lysates of yeast strains carrying mutations in the ADE1 or ADE2 genes and accumulating the red pigment (a result of polymerization of aminoimidazoleribotide), and in white isogenic strains--either adenine prototrophs or carrying mutations at the first stages of purine biosynthesis. We found that the red pigment leads to a drop of amyloid content. This result, along with the data on separation of protein polymers of white and red strains in PAGE, suggests that the red pigment inhibits amyloid fibril formation. The differences in transmission of the thioflavine T fluorescence pattern by cytoduction and in blot-hybridization of pellet proteins of red and white [PSI(+) ] strains with Sup35p antibodies confirmed this conclusion. Purified red pigment treatment also led to a decrease of fluorescence intensity of thioflavine T bound to insulin fibrils and to yeast pellet protein aggregates from [PSI(+) ] strains. This suggests red pigment interaction with amyloid fibrils. Comparison of pellet proteins from red and white isogenic strains separated by 2D-electrophoresis followed by MALDI analysis has allowed us to identify 48 pigment-dependent proteins. These proteins mostly belong to functional classes of chaperones and proteins involved in glucose metabolism, closely corresponding to prion-dependent proteins that we characterized previously. Also present were some proteins involved in stress response and proteolysis. We suppose that the red pigment acts by blocking certain sites on amyloid fibrils that, in some cases, can lead in vivo to interfere with their contacts with chaperones and the generation of prion seeds.     

Normative data for the Wechsler Memory Scale—Revised: 25- to 34-year olds.

The normative data provided in the Wechsler Memory Scale—Revised (WMS—R) manual for individuals aged 25–34 yrs were estimated statistically by interpolation. As an empirical check of this procedure, a representative stratified sample in this age range was selected to match the 1980 US Census data on relevant demographic characteristics. Prorated Full Scale IQs for the group were normally distributed, having a mean of 101.3 (SD?=?14.58, range?=?72–231). Differences between the empirically derived and published index scores appeared to be clinically significant. Substantial intra-individual differences were common when Visual–Verbal or General–Attention/Concentration indexes were compared. Normative data for the WMS—R subtests, indexes, and distribution of differences between indexes is provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prion‐associated proteins in yeast: comparative analysis of isogenic [PSI+] and [psi−] strains

A large group of prion‐associated proteins was identified in yeast cells using a new approach, comparative analysis of pellet proteins of crude cell lysates in isogenic strains of Saccharomyces cerevisiae differing by their prion composition. Two‐dimensional (2D) electrophoresis followed by MALDI analysis of the pellet proteins of [PSI⁺] and [psi^?] strains after prion elimination by GuHCl and prion transmission by cytoduction permitted identification of ca. 40 proteins whose aggregation state correlated with the change of prion(s) content. Approximately half of these proteins belonged to chaperones and to enzymes of glucose metabolism. Chaperones are known to be involved in prion metabolism and are expected to be present in prion‐containing aggregates, but glucose metabolism enzymes are not predicted to be present. Nevertheless, several recent data suggest that their presence is not incidental. We detected six proteins involved in oxidative stress response and eight in translation. Also notable is a protease. Most of the identified proteins seem to be prion‐associated, but we cannot exclude the possibility that several proteins may propagate as prions. Copyright © 2009 John Wiley & Sons, Ltd.     

Structural equation analysis of the Wechsler Adult Intelligence Scale—Revised in a normal elderly sample.

A maximum-likelihood confirmatory factor analysis was performed by applying LISREL VII to the Wechsler Adult Intelligence Scale—Revised (D. Wechsler, 1981) results of a normal elderly sample (N?=?225). Analyses were designed to determine which of seven hypothesized factor solutions best explained the intellectual ability of older adults. Oblique and orthogonal solutions were tested for each of the factor models. The impact of age, education, and gender was examined. Results indicated that an oblique three-factor model including Verbal, Performance, and Freedom From Distractibility factors fit the best across all sample combinations. A mild gender effect was also evident. Picture Arrangement measured both Verbal and Performance characteristics in the female sample, whereas in the male sample, Picture Arrangement loaded on the Performance factor only. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Postconcussion syndrome occurs in children.

The consensus of evidence published since 1924 suggests that parents report attention deficits, hyperactivity, or conduct disorder after pediatric head injury rather than postconcussion syndrome. In this study, the symptoms reported by children after mild (n?=?38) and moderate-severe (n?=?27) head trauma were compared to those reported after orthopedic injury (n?=?47) and to adults matched for injury severity and chronicity by using a structured interview based on diagnostic criteria for postconcussion syndrome. Pediatric head trauma caused significantly more subjective symptoms after 6 weeks than orthopedic injury. These symptoms were related to head injury severity and the child's anxiety level. When assessed in a similar manner, children report postconcussion syndrome similar to that seen in adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intrasubtest scatter on the WAIS—R as a pathognomonic sign of brain injury.

Patterns of intrasubtest scatter on the Wechsler Adult Intelligence Scale—Revised were compared among patients with closed head trauma, patients with focal cerebral lesions, and neurologically normal controls. Groups were matched on relevant intelligence variables and had average mean IQs, as is the case when scatter is interpreted clinically. The head trauma group showed significantly more intratest variability than normal, but sensitivity of the scatter indices was low when decisions were made on an individual-case basis. Interpretive guidelines are suggested for future clinical cross-validation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identification of malingered head injury on the Wechsler Memory Scale—Revised.

39 head-injured outpatients were compared with 39 age-matched Ss who were instructed to malinger head trauma symptoms on the Wechsler Memory Scale—Revised (WMS—R) and Wechsler Adult Intelligence Scale—Revised (WAIS—R). Head-injured Ss were selected who were not involved in litigation or pursuing a Worker's Compensation claim. Groups did not differ significantly on IQs or memory indexes. Discriminant function analyses based on the WMS—R subtests and indexes were able to accurately classify 91% and 83% of the cases, respectively. Decision rules were cross-validated on published data from several independent studies and statistically by means of the jackknife procedure. Head-injured Ss appear to show a pattern of WMS–R scores that can be discriminated from the profile produced by individuals who attempt to malinger head trauma symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

WISC-III premorbid prediction strategies: Demographic and best performance approaches.

Wechsler Intelligence Scale for Children-Third Edition (WISC-III; D. Wechsler, 1991) standardization data were used to explore premorbid prediction strategies for use with children. First, demographic variables including parental education, occupation, and ethnicity were entered in regression analyses to determine demographic-based premorbid prediction equations. Predicted IQ scores correlated with Full Scale IQ, Verbal IQ, and Performance IQ at .53, .52, and .45, respectively. Second, demographic and current ability variables were used conjointly. The 10 standard subtests individually served as measures of present ability, and ethnicity and parental education served as demographic predictors. These equations doubled or tripled the amount of variance accounted for by demographic variables alone. Third, a WISC-III best performance approach was explored with use of the subtest/demographic equations that included either Vocabulary or Picture Completion, referred to as the BEST-2 approach. The utility of this BEST-2 approach and the pure demographic approach was investigated in a clinical sample of brain-injured children. Results support the validity of both approaches in estimating premorbid functioning in children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of patient age on neuropsychological test interpretation.

Normative test data for a 38-year-old and for a 74-year-old were obtained for the Halstead-Reitan Neuropsychological Test Battery (HRNB), the Wechsler Adult Intelligence Scale—Revised (WAIS—R), and the Wechsler Memory Scale (WMS). These test protocols were presented for blind interpretation to a random sample of psychologists specializing in neuropsychology. Test results for the "average" elderly person were interpreted as normal less frequently (42%) than results for the "average" younger adult (93%). The elderly person's test results also received higher impairment ratings and were frequently interpreted as reflecting dementia (23%). S's level of confidence with decisions made did not have an impact on accuracy rates. In addition, personal, training, and professional variables were not significantly related to judgment accuracy. The results suggest a tendency for misinterpretation of normal elderly persons' test performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)