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.
Hanna-Pladdy
B
B
Department of Neurology, University of Florida, Gainesville 32610, USA. pladdybh@onebox.com
Mendoza
J E
JE
Apostolos
G T
GT
Heilman
K M
KM
D000328:Adult; D000368:Aged; D001927:Brain Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D005385:Fingers / Q000503:physiopathology*; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000503:physiopathology*; D010291:Paresis / Q000503:physiopathology; D014057:Tomography, X-Ray Computed