Lateralized psychological impairment associated with CT lesions in head injured patients

Brief assessment of severe language impairments: Initial validation of the Mississippi aphasia screening test

PRIMARY OBJECTIVE

To validate the Mississippi Aphasia Screening Test (MAST) which includes nine sub-scales measuring expressive and receptive language abilities.

RESEARCH DESIGN

Evaluation of inpatients admitted to neurology, neurosurgery or rehabilitation units at two local hospitals and who were within 60 days of onset of a unilateral ischemic or haemorrhagic stroke (left hemisphere (LH; n=38); right hemisphere (RH; n=20)). Additional participants were recruited from the community to comprise a non-patient control sample (NP; n=36).

METHODS

Data collection included administration of the MAST and chart review.

RESULTS

The LH group showed more impairment than the RH and NP groups on summary scores. The LH group performed worse than the NP group on all sub-scales. The object recognition and verbal fluency sub-scales did not discriminate the stroke groups.

CONCLUSION

Analyses suggest good criterion validity for the MAST in differentiating communication impairments among clinical and control samples.

Wechsler Adult Intelligence Scale-Revised Block Design broken configuration errors in nonpenetrating traumatic brain injury

Final broken configuration errors on the Wechsler Adult Intelligence Scale-Revised (WAIS-R; Wechsler, 1981) Block Design subtest were examined in 50 moderate and severe nonpenetrating traumatically brain injured adults. Patients were divided into left (n = 15) and right hemisphere (n = 19) groups based on a history of unilateral craniotomy for treatment of an intracranial lesion and were compared to a group with diffuse or negative brain CT scan findings and no history of neurosurgery (n = 16). The percentage of final broken configuration errors was related to injury severity, Benton Visual Form Discrimination Test (VFD; Benton, Hamsher, Varney, & Spreen, 1983) total score and the number of VFD rotation and peripheral errors. The percentage of final broken configuration errors was higher in the patients with right craniotomies than in the left or no craniotomy groups, which did not differ. Broken configuration errors did not occur more frequently on designs without an embedded grid pattern. Right craniotomy patients did not show a greater percentage of broken configuration errors on nongrid designs as compared to grid designs.

Prediction of recovery from traumatic brain injury

This paper encompasses the prediction of early and late recovery from traumatic brain injury (TBI). Predictors of the duration of coma and the utilization of posttraumatic amnesia duration to predict residual memory function are discussed. The issues surrounding prediction of long-term neurobehavioral recovery from TBI are considered, particularly the patient and clinical variables that are related to intellectual recovery. Findings from the NIH Traumatic Coma Data are reviewed pertaining to testability as a criterion for outcome. In addition to discussing the relationship of specific neurologic indices of TBI as predictors, the results obtained using a regression model are summarized. Finally, the relationship of neuroimaging findings to neurobehavioral outcome is discussed including directions for future research.

Clinical neurological trauma parameters as predictors for neuropsychological recovery and long-term outcome in paediatric closed head injury: a review of the literature

We present a review of recent prospective studies of long-term outcome in paediatric closed head injury. Special attention is given to the relationship between the neurological trauma parameters and neuropsychological outcome. First we discuss the most important methods of assessing the severity of the injury. We review the most prominent neurobehavioural and cognitive sequelae. Subsequently we address the question of prediction of residual sequelae in view of the early trauma parameters. The main problem when comparing different studies is the lack of procedural uniformity both in assessment of the severity of the injury as well as in measurement of neuropsychological outcome. Inconsistencies and discrepancies among various studies are pointed out. We summarise those results which are supported by many studies and hence are less controversial. In addition we present some recommendations for future investigations.

Abstract thinking following severe traumatic brain injury

Abstract abilities were studied in a sample of 34 individuals with severe TBI and a control group. The results indicate that TBI interferes with performance on tests requiring individuals to process information into new categories. There appears to be a dissociation between verbal abstract abilities and visual-perceptual abstract abilities. There is evidence that Goldstein and Sheerer's [1] postulate of a general 'abstract attitude' was at least partially correct. This attitude does not appear to be related to a general verbal ideational process, as dysphasic subjects were only deficient on a purely verbal abstract task.

Intercorrelation of lesions detected by magnetic resonance imaging after closed head injury

Forty-three patients with closed head injuries were followed up 5 to 12 months post-injury. Patients had magnetic resonance imaging (MRI) and performed a variety of neuropsychological tests. There were systematic relationships between lesions in different sites: depth of lesions in orbito-frontal regions, frontal regions, and temporal poles were particularly strongly intercorrelated. Depth of lesions in specific sites also correlated with an overall measure of brain damage: the number of areas with lesions present. After correcting for premorbid differences there were significant correlations between lesions in specific sites and scores on three out of five WAIS subtests. Scores on these three subtests also correlated significantly with overall brain damage. In general, hemispheric sites which were significantly related to neuropsychological measures also showed significant intercorrelations among themselves. The findings stress the importance of patterns of lesions in head injury, and emphasize the difficulty of showing differential localization of cerebral function in this population.

How useful is the WAIS-R in closed head injury assessment?

The present study examined whether head-injury assessment findings based on the WAIS could be generalized to the WAIS-R. It also investigated whether WAIS-R findings from individuals with focal mass lesions could be generalized to closed-head-injured patients with mass lesions. Subjects were 71 CHI patients assessed with the WAIS-R an average of 1.38 years post-injury. Results were not always consistent with previous research. Patients with left or right mass lesion loci did not exhibit previously reported Verbal IQ-Performance IQ discrepancies.

Narrative and procedural discourse after closed head injury

Aspects of productivity, content, and cohesion in the narrative and procedural discourse of 11 closed head-injured (CHI) adults and 21 normal adults were examined. Two narrative tasks, one involving retelling a story heard and the other formulating a story based on a comic strip, and one procedural task of telling how to buy groceries were administered to each subject. CHI subjects consistently produced fewer words, spoke slower, used more mazes (dysfluencies), produced fewer target content units, and used fewer cohesive ties per utterance, as compared to the normal subjects. Other significant differences in discourse occurred between the two groups, but these varied from task to task. Normal subjects varied characteristics of their discourse performance according to the discourse task. Significant differences across tasks occurred on seven of the 13 discourse measures. The CHI subjects, however, showed more limited variation in that their performance varied on only three of the 13 measures. Correlations among discourse, language, and memory measures were examined and discussed. The results of this study indicate that analysis of CHI narrative and procedural discourse has important clinical and theoretical implications.

The relationship between neuropsychological function and brain damage detected by neuroimaging after closed head injury

Studies relating neuropsychology and structural neuroimaging after closed head injury are reviewed. Particular attention is given to the question of the relative contribution of focal and diffuse damage to neuropsychological impairment. The evidence currently available emphasizes the importance of diffuse damage in closed head injury. Diffuse damage is not equally distributed in the brain, and the review suggests three axes that are relevant for neuropsychological function: (1) damage may be unilateral or bilateral, (2) damage is characteristically greater in anterior regions than posterior regions, and (3) damage shows a centripetal gradient. A large gap remains between the emergent generalizations concerning head injury and reliable neuropsychological interpretation of scans from individual patients.

Neuropsychological assessment of brain damage: discriminative validity of the McCarron-Dial System

The purpose of this study was to investigate the discriminative validity of the McCarron-Dial System (MDS) in neuropsychological assessment. Multiple discriminant analysis results indicate that 92.6% of the brain-damaged and non-brain-damaged groups, and 69.6% of the right, left and diffused brain-damaged subgroups were correctly classified using the abbreviated version of the MDS. The results tentatively support the discriminative ability of the MDS for neurobehavioural diagnosis. Since the MDS has a long tradition in vocational rehabilitation and established strengths in predicting vocational and community adjustment outcomes, it may be potentially useful for both vocational and clinical neuropsychological assessment.

Influence of injury severity on quality of survival after head injury

The relationship between severity of injury [as determined by the Glasgow Coma Scale (GCS)] and the quality of survival (as determined by neuropsychological measurements and work return) were investigated in 54 conscious survivors within 16 months following head injury. While severely head injured (GCS less than or equal to 8) patients had more neuropsychological impairments in areas of intelligence, attention, memory, visuomotor speed, and motor skills than those with mild injuries (GCS greater than 8), performances after both types of injury were below normative levels in areas of learning, memory, and visuomotor speed. Unemployment increased after both severe and mild injuries, while employment status changed more frequently after severe injuries. Age had a minimal effect on neuropsychological and employment outcomes after minor head injuries (GCS greater than 13). The findings suggest that regardless of acute severity, closed head injury influences long-term quality of survival.

Relationship of acute CBF and ICP findings to neuropsychological outcome in severe head injury

Neuropsychological outcome within 1 year after severe head injury was examined in 42 conscious survivors and correlated with acute measurements of cerebral blood flow (CBF) and intracranial pressure (ICP). During acute coma, CBF was elevated in 23 patients, indicating hyperemia, and was reduced in the remaining 19 cases. Intracranial hypertension (ICP 20 mm Hg or greater) was present acutely in 15 patients and absent in 27. Occurrences of hyperemia and intracranial hypertension were significantly related. During chronic recovery, neuropsychological dysfunction was found in all cases. However, patients with hyperemia revealed greater impairment of overall intellectual and memory functions than did those with reduced flow, while patients with intracranial hypertension showed greater memory deficit than did those without ICP elevations. The results suggest that early pathophysiological events can influence subsequent neuropsychological outcome, and that chronic recovery is not homogeneous in young severely head-injured adults.

Lateralized brain damage, sex differences, and the Wechsler Intelligence Scales: a reexamination of the literature

Recent reviews have suggested that males and females show different patterns of intellectual impairment following lateralized brain injury. As the percentage of males in such studies increases, the magnitude of the difference between Verbal and Performance IQs increases. The present review reexamines this literature. Although the association between patient sex, pattern of intellectual deficit, and lateralized brain injury is reconfirmed for studies which used the Wechsler-Bellevue Intelligence Scale, there was no such relationship in those which used the more recent Wechsler Adult Intelligence Scale. In addition, it is shown that, in studies which used the former measure, the percentage of males may be highly correlated with other variables, a relationship which could have an effect on the pattern of intellectual loss following brain injury.

Late effects of hematoma on brain morphology and memory in closed head injury

In order to examine the late effects of prior hematoma on brain morphology and memory in closed head injury (CHI), 16 patients with a history of hematoma and craniotomy following injury were matched with CHI patients without prior hematoma. Volumetric estimates of cortical atrophy and ventricle size computed from CT scans were obtained in addition to Wechsler Memory scale (WMS) scores. Patients with a history of hematoma demonstrated significantly greater cortical atrophy than nonhematoma CHI patients irrespective of hematoma location. The hematoma group also was found to have greater ventricular dilation, although this difference only approached significance. In terms of memory abilities, the hematoma group was more impaired on WMS Memory Quotient (MQ) and the Associate Learning subtest in particular. Results suggest that hematoma following head injury may promote additional detrimental effects on brain morphology and memory status.

Wechsler VIQ versus PIQ differences in cerebral dysfunction: a literature review with emphasis on sex differences

For the past three decades neuropsychologists have published results which indicated that left-sided cerebral dysfunction affected the Wechsler Verbal Scale whereas right-sided dysfunction affected the Performance Scale. Recent investigations have indicated that the effects of cerebral dysfunction on performance of the Wechsler Scales may be different for males and females. In view of these reports, the present review considered 24 studies (28 samples) which have reported Wechsler IQ scores in patients with unilateral or bilateral cerebral dysfunction. Eight studies (10 samples) used the Wechsler-Bellevue I, whereas 16 studies (18 samples) employed the WAIS. In these 28 published samples, there were four exceptions to the hypothesis of lower mean VIQ in patients with left-hemisphere lesions, and lower mean PIQ in patients with right-hemisphere dysfunction. Of the four exceptions to this "rule", two samples contained only women, while a third contained only patients with missile wounds of the frontal lobe. One sample appeared to be a true exception, and could not be accounted for by lesion location or sexual composition of the sample. The studies reviewed appear to add additional support to the hypothesis of sex differences in the effects of unilateral lesions. Therefore, insofar as published mean values for the Wechsler Scales are concerned, the specific effects on Verbal versus Performance IQ appear more prominently in males.