Effect of lateralized lesions on ipsilateral and contralateral motor functioning

Impairment and recovery of left motor function in patients with right hemiplegia

OBJECTIVE

To assess the motor function of the left, supposedly unaffected, limbs of patients with an acute right vascular hemiplegia.

METHODS

Fifteen patients with an acute vascular right hemiplegia and 16 matched healthy controls were studied. Motor function of the left limbs of each patient was evaluated on days 20 and 90 after their stroke using four validated tools (hand dynamometer, isokinetic dynamometer, finger tapping, and nine hole peg test).

RESULTS

There was a significant impairment of motor function of the left limbs of patients at day 20 compared with controls. The impairment had recovered almost completely at day 90 after the stroke.

CONCLUSION

These results show the bilateral cerebral representation of the human motor system and suggest the participation of ipsilateral motor pathways in recovery after a stroke.

Gender- and age-specific changes in motor speed and eye-hand coordination in adults: normative values for the Finger Tapping and Grooved Pegboard Tests

Normative values for the Finger Tapping and Grooved Pegboard Tests were developed on a sample of 360 normal volunteers stratified according to gender, three educational groups ranging from 7 to 22 years, and four age groups subdivided between the ages of 16 to 70 years. Retest reliability was estimated for both measures. The Finger Tapping Test showed significant gender differences, since women were substantially slower, particularly in the older age groups. On the Grooved Pegboard Test, a converse gender difference was noted, since women were substantially faster than men. A smaller effect with increasing age resulted, and better educated individuals performed faster. If these motor and visuomotor tests are to be applied, then stratified normative estimates need to be implemented to provide viable clinical judgements.

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.

Relationship among CT scans, neurological exam, and neuropsychological test performance in right-brain-damaged stroke patients

Right-hemisphere stroke rehabilitation inpatients were assessed by: (1) CT scans; (2) neurological exam; and (3) cognitive and affective psychometric measures. Damage to temporal, parietal, and occipital regions was associated with visual-spatial impairments. Surprisingly, parietal damage was no more related than temporal and occipital damage to severity of visual inattention. While the neurologist's ratings of lability and depression were related to CT-scan measures, patients' self-report of depression was not so related. These findings support a less specific and probably greater interlobule organization of the right, as compared with left, hemisphere, and highlight the need for multifaceted affective assessment in such a brain-damaged group.

The relationship of limb apraxia severity to motor and language deficits

Ipsilateral motor and symbolic/linguistic skills were examined in normals and three left hemisphere damaged groups with no, mild, or moderate-severe limb apraxia. When the two apraxic groups were pooled they demonstrated poorer response inhibition and reading relative to the nonapraxic group. There were no significant group differences on motor or language tasks when the three brain damaged groups were separately compared. These results indicate there is a limited relationship between limb apraxia and some motor and linguistic skills, but the relationship was not greater for motor than linguistic skills.

Effect of lateralized cerebral damage upon contralateral and ipsilateral sensorimotor performances

Three groups of 50 adult patients with either lateralized vascular, neoplastic, or traumatic cerebral lesions were compared with respect to their contralateral and ipsilateral sensorimotor functioning. The present study investigated the extent of sensorimotor deficits associated with different types of naturally-occurring damage to the right and left hemispheres. Sensorimotor abilities were assessed using tests from the Halstead-Reitan Neuropsychological Test Battery. Intergroup comparisons showed a differential pattern of sensorimotor impairment in which the cerebrovascular group was most impaired, followed by the neoplastic group, with the trauma group demonstrating the least impairment. Interhemispheric comparisons among the lesion groups consistently demonstrated right cerebral hemisphere predominance for contralateral and ipsilateral sensorimotor functions. The findings indicate clearly that the sensorimotor functions of the two cerebral hemispheres are not merely mirror images of each other. Apparently, the functional organization of the human brain is such that the right hemisphere is predominant for both contralateral and ipsilateral sensorimotor functioning. Results are discussed in terms of these theoretical questions and in terms of several methodological considerations necessary for the appropriate study of the functional organization of sensorimotor processes.