Effect of lateralized cerebral damage upon contralateral and ipsilateral sensorimotor performances

Neuropsychological function in type 2 diabetes mellitus

Type 2 diabetes mellitus (DM) is a major and growing health problem. Brain-related effects of type 2 DM have been studied in several ways over the past few decades. Results have shown effects on brain structure, incidence of dementia, and impairment of various cognitive functions. The present study examined a sample of clinically-referred patients with type 2 DM and compared them with a sample of control patients who were matched on a pairwise basis on age, education, and gender. Each patient was tested using a comprehensive, integrated neuropsychological test battery. Results showed a pattern of generalized and specific neuropsychological dysfunction affecting a broad range of neurocognitive and sensorimotor abilities. However, no differences were found on measures of attention/concentration, memory, or abstract reasoning. Nevertheless, the DM group consistently performed worse on all measures. The DM group's score on a summary measure of neuropsychological function (GNDS) reflected moderate brain-related impairment. A neurocognitive profile is identified that may help clinicians understand their DM patients.

Descriptive Halstead-Reitan study of nonimpact mild traumatic brain injury

Patients subjected to severe acceleration forces in motor vehicle accidents that met criteria for uncomplicated mild traumatic brain injury (mTBI) in the absence of direct impact to the head were examined neuropsychologically using the Halstead-Reitan Neuropsychological Test Battery. The subjects were litigants and/or insurance claimants for whom there was psychometric evidence of acceptable test effort. The purpose of the study was to provide descriptive neuropsychological data for this particular clinical population. Individual test results were interpreted using inferential methods of level of performance, pathognomonic signs, score patterns, and right-left performance differences. These interpretive strategies yielded group data from which frequencies and percentages of atypical neuropsychological characteristics were calculated. The most salient clinical characteristics involved atypical right-left performance relationships on simple and more complex tests of motor function. Clinical data provided support for the possibility that a minority of nonimpact litigants or insurance claimants that sustain uncomplicated mTBI experience persistent diminishment in some neuropsychological abilities.

The Finger-Tip Numberwriting Test: Practice Effects versus Lateral Asymmetry

By counterbalancing hand order, both practice effects and lateral asymmetry were measured on the Finger-tip Numberwriting test together with 5 other tactile tests of finger-tip writing and finger identification administered to 32 right-handed adults averaging 41 yr. of age. Under counterbalanced hand-order conditions, the Finger-tip Numberwriting test showed no lateral asymmetry, but a significant practice effect. In contrast, the same subjects showed a left-hand advantage on nonverbal detection of tactile line direction, indicating normal right-hemispheric superiority. Normal Finger-tip Numberwriting performance likely involves integration of specialized processing capacities in both cerebral hemispheres. The results do not invalidate the standardized Finger-tip Numberwriting test as a clinical tool but demonstrate the value of manipulating independent variables when standardized clinical neuropsychological tests are applied to questions in experimental research.

Gait Characteristics and Functional Ambulation Profile in Patients with Chronic Unilateral Stroke

OBJECTIVE

Recent technical progress in gait analysis has resulted in portable walkways with embedded pressure-sensitive sensors. Often claims are made in connection with new equipment of their straightforward clinical use. The purpose of the present study was to assess whether the functional ambulation profile (FAP), calculated from walkway data, is a sensitive measure in the characterization of dissimilar patients with chronic hemiparesis due to stroke.

DESIGN

We investigated the relationships between FAP and the type of stroke, patients' functional disability, and spatial and temporal variables of gait obtained with the pressure sensor system walkway. Gait variables and FAP scores were compared in 25 patients with residual hemiparesis due to stroke and in 31 healthy subjects.

RESULTS

A prolonged swing phase in the affected side and a prolonged stance phase in the nonaffected side were found in patients. Footprint pressure data revealed reduced peak pressure of the affected-side metatarsal area in patients, probably reflecting foot paresis. Higher Barthel Index score and lower Rankin Scale score were reflected in FAP scores.

CONCLUSIONS

The FAP scores of patients reflected well their characteristic spatio-temporal gait variations; however, the FAP score seemed a reliable measure of gait normality/abnormality only in rather unhurried gait. Thus, it is useful when a single number is needed.

Lateralised motor control: hemispheric damage and the loss of deftness

OBJECTIVE

To learn if the left compared with the right hemisphere of right handed subjects exerts bilateral compared with contralateral motor control when performing precise and coordinated finger movements.

METHODS

The study investigated intertask differences of manual motor asymmetries such as speed, precision, and independent finger movements, in patients with unilateral lesions of the left (LHD) or right hemisphere (RHD) and normal controls (C).

RESULTS

Normal subjects showed the greatest right hand preference on a task that required rapid coordinated and precise independent finger movements (coin rotation). Both hemisphere damaged groups revealed contralateral motor deficits, but the magnitudes of asymmetries were found to be significantly different (RHD>C>LHD) with contralateral and ipsilateral deficits for LHD subjects. The greatest ipsilateral deficits for the LHD subjects were on those tasks that require precision (grooved pegboard and coin rotation).

CONCLUSIONS

The degree of hemispheric specialisation is, in part, dependent upon the nature of the motor task, with left hemisphere motor control necessary for tasks that require precision and coordinated independent finger movements.

Speed of finger tapping and goal attainment after unilateral cerebral vascular accident

OBJECTIVE

To determine (1) if speed of finger tapping is bilaterally slow after an acute unilateral cerebral vascular accident (CVA) and (2) if speed of finger tapping and grip strength are related to achieving rehabilitation goals during the first few weeks after stroke.

DESIGN

Prospective inception cohort study.

STUDY SETTING

Medical center and neurological institute.

PARTICIPANTS

Fifty-one patients with unilateral CVAs.

MAIN OUTCOME MEASURES

Documentation of goal attainment at discharge and bilateral measures of speed of finger tapping and grip strength.

RESULTS

Speed of finger tapping and grip strength were often bilaterally below normal limits after an acute unilateral CVA, with the contralateral hand most affected. Speed of finger tapping, but not grip strength, in the ipsilateral hand was associated with achieving rehabilitation goals. Speed of finger tapping in the contralateral hand as well as bilateral grip strength was not related to achievement of rehabilitation goals.

CONCLUSIONS

Motor findings suggest that bilateral cerebral dysfunction may be common after an acute unilateral CVA. The speed of finger movement in the hand ipsilateral to the lesion may reflect the degree to which the so-called "unaffected" cerebral hemisphere has in fact maintained its functional integrity. As such, it may be a useful behavioral marker for predicting goal attainment during early stages of neurorehabilitation.

Neuropsychological consequences of traumatic brain injury in children and adolescents

The study of the relationship between neuroscientific information and cognitive function and dysfunction is clearly a widely expanding field. In particular, there has been a growing body of research on traumatic brain injury (TBI) in children and adolescents. This article conveys recent findings concerning cognitive outcomes, with a particular focus on age differences with TBI, suggests a relationship between specific learning disorders and brain dysfunction, addresses differential hemisphere functioning with TBI, and alludes to recent developments in assessment of TBI.

A selective and critical review of neuropsychological deficits and the frontal lobes

Presumptions about the functions of the frontal lobes, and the sensitivity and specificity of certain tests to measure frontal lobe functions, are having a substantial influence on both clinical and research conclusions. In this paper the authors examine the details of the studies that have contributed to these presumptions, and find that the evidence to support these conclusions is weak. A detailed evaluation of the evidence relating to the Wisconsin Card Sorting Test and the Thurstone Word Fluency Test is also presented. Finally, the development of the belief that frontal lobe functions can be specifically measured is reviewed. The authors of this paper conclude that the "bewildering array" of deficits attributed to frontal lesions still seems to prevail.

Neuropsychological improvements following endovascular embolization of arteriovenous malformation

Two right-handed patients with large, left-hemisphere arteriovenous malformations (AVM) underwent serial endovascular embolization and neuropsychological testing procedures. One patient presented with hemorrhage, hemiplegia, and aphasia; the other patient presented with a seizure only with multiple cognitive impairments. Case 1 was assessed for motor-sensory skills in the left hand and for visual recall (nondominant hemisphere). Case 2 was administered a more global assessment of cognitive functions. Both patients demonstrated significant improvements in neuropsychological functions 1 month following endovascular embolization with >50% reduction in AVM volume. The nature and extent of these improvements are discussed with respect to intervention-related, reversed impairments.

Left cerebral dominance for bilateral simultaneous sensory stimulation?

Hom and Reitan (1982) reported findings with respect to sensorimotor deficits in groups with lateralized cerebral lesions, but evaluated the results only within a framework that related cerebral dominance to deficits that resulted from lateralized lesions. Some of the variables they studied, however, depend upon evidence of retention of functions by one hemisphere under conditions of distracting input. While the right cerebral hemisphere appears to be dominant for tactile-perceptual abilities in terms of resulting deficits, the present study suggests that the left cerebral hemisphere is dominant for certain non-language functions that reflect maintenance of sensory-perceptual abilities under conditions of distracting stimuli.

Self-report of indifference and anxiety among persons with right hemisphere stroke

A sample of persons with a single ischemic cerebral stroke was used to elucidate and quantify the indifference associated with right hemisphere stroke. Seven persons with right hemisphere stroke were compared with 10 persons with left hemisphere stroke on two aspects of indifference (social indifference and lack of anxiety). Persons with right hemisphere stroke reported themselves as being substantially less anxious (p = .025) and somewhat more socially indifferent (p = .081) than did those with left hemisphere stroke. Lack of appropriate anxiety may contribute to the clinical descriptions of indifference, failure to make expected recovery, and difficulty in relationships with others.

Generalized cognitive function after stroke

The present investigation was designed to determine the effect of cerebrovascular lesions upon general neuropsychological function. The performances of 60 patients with lateralized or diffuse cerebrovascular lesions were compared to 20 controls on cognitive and intellectual measures. Multivariate analyses indicated markedly poorer performances by the cerebrovascular groups on measures of generalized cerebral function, and no differences on such measures were found between the left- and right-damaged groups. The lateralized CVD groups demonstrated a differential tendency towards lower performances on VIQ for the left group and on PIQ for the right group. The results indicate significant neuropsychological impairment which extends beyond the expected lateralized dysfunctions, or selected deficits, associated with the damaged hemisphere. These findings indicate the importance of evaluating generalized as well as specific cognitive functions in clinical assessment of cerebrovascular lesions.

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.

Left-right comparison and children's performance on sensorimotor tests

This study compared overall performance level for both hands combined (OPL) with several lateral deviation measures calculated from scores on a composite finger localization task (FLT) and a speeded pegboard task (SPT) administered to 92 kindergarten entrants. Laterality indices were interrelated moderately or highly on each task, consistently were unrelated to OPL with respect to FLT results, and in some instances were related modestly to OPL for the SPT procedure. Significant relationships, when observed, suggested a limited tendency to diminished motor asymmetry with slowed overall performance. Results, in general, support the view that OPL and lateral deviation as measured in this study are not mutually confounded and, in large degree, comprise relatively independent sources of information to be used in a complementary manner to arrive at accurate neuropsychological inferences.

Language and visuospatial abilities in learning-disabled, brain-damaged, and nondisabled young adults

This study confirmed the construct validity of dysphasic errors but not of Block Design or dyscopia for 88 male and 22 female young adults, aged 17 to 29 yr. Right-hand sensorimotor deficits correlated with dysphasic errors but not with Block Design. Brain-damaged and learning-disabled with Halstead Impairment Index (HII) greater than or equal to 0.4 differed from nondisabled on both dysphasic errors and Block Design. Learning-disabled with HII less than 0.4 differed from nondisabled only for dysphasic errors. As a group, young learning-disabled adults had impaired language abilities. Learning-disabled with HII greater than or equal to 0.4 and brain-damaged had generalized neuropsychological deficits characterized by less adequate language and visuospatial abilities.

Neuropsychological correlates of rapidly vs. slowly growing intrinsic cerebral neoplasms

Four groups of patients with intrinsic cerebral neoplasms were compared to determine the differential effect of neoplasm (rapidly vs. slowly growing) and lateralization of damage (right vs. left hemisphere) upon neuropsychological functioning. No prior study has had enough subjects with neoplastic lesions to permit this kind of investigation. The group with rapidly growing neoplasms consistently had greater neuropsychological impairment. Lateralization of cerebral damage was found to have a differential effect on neuropsychological functions. Results indicate that neuropathological and lateralization characteristics of neoplastic lesions (and probably of cerebral lesions in general) are important variables in understanding the behavioral correlates of cerebral damage.

PPVT IQ validity in adults: a measure of vocabulary, not of intelligence

Used partial correlation and multiple regression procedures to test the hypothesis that the PPVT IQ assesses more than vocabulary in adults. Ss were 84 inpatients from psychiatry and neurology wards. The relationships between the PPVT IQ and other measures of vocabulary, intelligence, memory, visual-motor speed and education were examined in the statistical analyses. Although these variables have significant simple correlations with the PPVT IQ, the multivariate analyses show that the Vocabulary Subtest of the WAIS-R is the only important variable. No other variable or variable combinations are able to account for further PPVT IQ variance after the effect of the Vocabulary Subtest is removed. The results support the use of the PPVT as a test of adult vocabulary, but not adult intelligence, and suggest that the PPVT may be useful as part of language assessment in patients with expressive language disorders.

Are right-hemisphere lesions really larger? Lesion size and laterality in meningioma patients

Patients with pathologically confirmed diagnoses of meningioma were examined to investigate the hypothesis that left-hemisphere lesions are smaller or declared earlier than right-hemisphere lesions. 77 patients were examined with regard to age at presentation and nature of symptoms. In addition CAT scan films of 47 patients were obtained for measurement of lesion size. There were no differences between right and left lesion groups with regard to size of lesion or age at presentation. Subgroups of patients with lesions in frontal association areas also did not differ. Some relationships were discovered between lesion location and nature of symptoms.