title: Interlimb coordination in Parkinson's disease.
abstract: This study examined the degree to which Parkinson's disease (PD) patients could "spatially link" the upper limbs to facilitate the performance of bimanual simultaneous movements. Six right-handed PD patients, and seven normal age- and sex-matched controls performed three different tasks: (a) an isotonic elbow flexion as rapidly as possible through an angle of 30 degrees; (b) an isometric contraction of the flexor muscles at the elbow joint to 40% and 60% of maximal volitional force (MVF) for a period of 5 s; (c) an isometric contraction for 2.5 s with one limb, then simultaneously performing an isotonic flexion with the contralateral limb while maintaining the isometric contraction for 2.5 s more. As expected, PD patients were significantly slower in performing the isotonic movement and produced lower peak velocities than the controls. More importantly, the two groups were differentially affected during the bimanual condition. In normals, movement time decreased and peak velocity increased in the bimanual condition. In contrast, PD patients showed increased movement times and sometimes decreased peak velocities in the bimanual condition. The results suggest that normal subjects utilize bilateral outflow to symmetrical muscle groups to synchronize the two limbs in the bimanual task, whereas PD patients dissociate the two limbs.
authors.affiliation: Motor Behavior Laboratory, University of Wisconsin-Madison 53706.
authors.forename: A
authors.initials: A
authors.lastname: Lazarus
authors.forename: G E
authors.initials: GE
authors.lastname: Stelmach
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001288:Attention / Q000502:physiology; D003342:Corpus Striatum / Q000503:physiopathology; D004298:Dopamine / Q000502:physiology; D004576:Electromyography; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009048:Motor Skills / Q000502:physiology*; D009434:Neural Pathways / Q000503:physiopathology; D009460:Neurologic Examination; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology*; D013378:Substantia Nigra / Q000503:physiopathology
chemical_list: D004298:Dopamine