Performance of children with traumatic brain injury on the Cognitive Assessment System

Three trail making tests for use in neuropsychological assessments with brief intertest intervals

Practice effects in serial neuropsychological assessment have led to the use of alternate forms to measure change in cognitive functioning. The construct validity of three variants of the Trail Making Test was explored over a 3-week period in a sample of 158 undergraduate students. Using confirmatory factor analysis, a two-factor (sequencing-shifting) model was identified to best represent the data. Latent means structural analysis indicated the absence of order effects, lending support for the construct validity of the three tests. The study provides evidence that the three tests can be offered as potential alternative instruments in serial assessment.

A review and empirical study of the composite scales of the Das-Naglieri cognitive assessment system

Alexander Luria’s model of the working brain consisting of three functional units was formulated through the examination of hundreds of focal brain-injury patients. Several psychometric instruments based on Luria’s syndrome analysis and accompanying qualitative tasks have been developed since the 1970s. In the mid-1970s, JP Das and colleagues defined a specific cognitive processes model based directly on Luria’s two coding units termed simultaneous and successive by studying diverse cross-cultural, ability, and socioeconomic strata. The cognitive assessment system is based on the PASS model of cognitive processes and consists of four composite scales of Planning–Attention–Simultaneous–Successive (PASS) devised by Naglieri and Das in 1997. Das and colleagues developed the two new scales of planning and attention to more closely model Luria’s theory of higher cortical functions. In this paper a theoretical review of Luria’s theory, Das and colleagues elaboration of Luria’s model, and the neural correlates of PASS composite scales based on extant studies is summarized. A brief empirical study of the neuropsychological specificity of the PASS composite scales in a sample of 33 focal cortical stroke patients using cluster analysis is then discussed. Planning and simultaneous were sensitive to right hemisphere lesions. These findings were integrated with recent functional neuroimaging studies of PASS scales. In sum it was found that simultaneous is strongly dependent on dual bilateral occipitoparietal interhemispheric coordination whereas successive demonstrated left frontotemporal specificity with some evidence of interhemispheric coordination across the prefrontal cortex. Hence, support for the validity of the PASS composite scales was found as well as for the axiom of the independence of code content from code type originally specified in 1994 by Das, Naglieri, and Kirby.

Validity of the WCST-64 After Traumatic Brain Injury in Children

The Wisconsin Card Sorting Test-64 (WCST-64) is a recently normed modification of the Wisconsin Card Sorting Test (WCST) that utilizes only one deck of cards. The present study investigated the validity of the WCST-64 in a sample of fifty-six 10- to 16-year-old children with traumatic brain injury (TBI). Standard scores for perseverative responses from the WCST-64 and from the full-length WCST shared 83% of common variance. Less than 10% of this sample had a discrepancy between the respective indexes that was greater than one standard deviation. Correlations with external criteria such as length of coma and Full Scale IQ were not significantly different between the two versions of the instrument. The findings suggest that the WCST-64 may be used interchangeably with the original WCST in older children with TBI.

Absence of adverse effects of severe hypoglycemia on cognitive function in school-aged children with diabetes over 18 months

OBJECTIVE

Some children with type 1 diabetes may be at risk of cognitive impairments, but mechanisms of this effect have not been confirmed. The objective of this study was to determine whether severe hypoglycemia (SH) in children with type 1 diabetes is associated with cognitive decline over 18 months.

RESEARCH DESIGN AND METHODS

A sample of 142 6- to 15-year-old children with type 1 diabetes (mean age 11.6 +/- 2.7 years) enrolled in a trial of intensive therapy (IT) or usual care (UC) were tested with the Das-Naglieri Cognitive Assessment System at baseline and after 9 and 18 months. Episodes of SH were recorded by parents and reported promptly for verification by study nurses. HbA(1c) was measured quarterly.

RESULTS

Over 18 months, 58 of 142 patients (41%) experienced 111 SH episodes, with a RR of SH of 1.12 for IT over UC. Neither occurrence nor frequency of SH was associated with decline in full-scale intelligence quotient (IQ), standard scores for planning, attention, simultaneous processing, or successive processing, or scaled scores on any of eight subtests. The same findings emerged when only patients who had experienced hypoglycemic seizures or coma were included in the SH group for analyses. These effects persisted when the child's age, sex, type 1 diabetes duration, and age at diagnosis were controlled statistically. HbA(1c) during the trial was not associated with cognitive changes.

CONCLUSIONS

SH did not induce adverse changes in the measures of cognitive function administered to 6- to 15-year-old children with type 1 diabetes in this study. Although SH should be avoided in all children with diabetes, these episodes did not have adverse effects on cognition in this age-group over 18 months.

Prevalence of traumatic brain injury in an ED population

The objective of this study was to determine prevalence of traumatic brain injury (TBI) in an emergency department (ED) population. Questionnaires were administered to patients in an urban, university, trauma center ED. All respondents provided demographics; patients reporting TBI were asked age at injury, if they experienced loss of consciousness (LOC), mechanism, or if medical attention was sought. Five hundred one patients completed the survey. Forty-one percent reported TBI; 23% had TBI with LOC. Mean age at injury was 21.5 years. Mechanism was evenly distributed among sports, assaults, falls, and motor vehicle crashes (MVC). Medical attention was sought for 61% of injuries. Men were more likely to report TBI (P <.001). Medical attention was more likely if MVC or LOC and less likely in sports-injured patients (all P <.01). Twenty-five percent of patients with TBI sustained repeat injury by the same mechanism. Prevalence of TBI in this population is high. Many occur by mechanisms that potentially are preventable.