Impaired dexterity of the ipsilateral hand after stroke and the relationship to cognitive deficit

Background and Purpose-Previous research has reported impaired hand functio n on the "unaffected" side after stroke, but its incidence, origins, and im pact on rehabilitation remain unclear. This study investigated whether impa irment of ipsilateral dexterity is common early after middle cerebral arter y stroke and explored the relationship to cognitive deficit. Methods-Thirty patients within 1 month of an infarct involving the parietal or posterior frontal lobe (15 left and 15 right hemisphere) used the ipsil ateral hand in tests that simulated everyday hand functions. Performance wa s compared with that of healthy age-matched controls using the same hand. S tandardized tests were used to assess apraxia, visuospatial ability, and ap hasia. Results-All patients were able to complete the dexterity tests, but video a nalysis showed that performance was slow and clumsy compared with that of c ontrols (P<0.001). Impairment was most severe after left hemisphere damage, and apraxia was a strong correlate of increased dexterity errors (P<0.01), whereas reduced ipsilateral grip strength correlated with slowing (P<0.05) , The pattern of performance was different for patients with right hemisphe re damage. Here there was no correlation between grip strength and slowing, while dexterity errors appeared to be due to visuospatial problems. Conclusions-Subtle impairments in dexterity of the ipsilateral hand are com mon within 1 month of stroke. Ipsilateral sensorimotor losses may contribut e to these impairments, but the major factor appears to be the presence of cognitive deficits affecting perception and control of action. The nature o f these deficits varies with side of brain damage. The effect of impaired d exterity on functional outcome is not yet known.