IMPAIRMENTS IN ARM CONTROL IN SUBJECTS WITH LEFT AND RIGHT-HEMISPHERESTROKE

Objectives: Our purpose was to identify impairments in movement contro l for subjects with left and right brain lesions using a kinematic ana lysis of the trajectory of a stylus during an upper limb tapping task. We hypothesized that subjects with left cerebrovascular accident (LCV A) would have bilateral deficits in programming while subjects with ri ght cerebrovascular accident (RCVA) would only have deficits in the li mb contralateral to the lesion. Study Design: Data were collected from 11 subjects with LCVA, 11 with RCVA, and 22 non-disabled subjects who were age and gender-matched to subjects with left or RCVA. Subjects w ere videotaped performing a Fitts tapping task on a single 3-inch targ et with each hand. The stylus movement was digitized at 60 Hz and data were calculated for each tap cycle and averaged across each 10-s tria l. We examined differences in the kinematic variables of cycle frequen cy, amplitude, symmetry in up and down velocity, symmetry in timing of up and down velocity, and temporal phases of acceleration and deceler ation for up and down directions of the tap cycle. Multivariate analys es were performed on four dependent kinematic variables, and univariat e ANOVAs were conducted for the differences in phases between stroke a nd non-disabled limbs. Results: Subject with LCVA showed lower frequen cies, and asymmetrical velocity and timing ratio in both 'uninvolved' and 'involved' limbs compared to non-disabled subjects, Subjects with RCVA showed similar impairments for the 'involved' limb only. Conclusi ons: Left hemisphere lesions create bilateral impairments in programmi ng movement reversals, Right hemisphere lesions produced deficits only for the limb contralateral to the lesion. Strategies used by the subj ects with LCVA may be related to the need for subjects to use feedback to perform this rapid continuous sequencing task. Suggestions for reh abilitation are presented. (C) 1997 Elsevier Science Ireland Ltd.