title: Effects of deep brain stimulation and medication on strength, bradykinesia, and electromyographic patterns of the ankle joint in Parkinson's disease.
abstract: We investigated the control of movement in 12 patients with Parkinson's disease (PD) after they received surgically implanted high-frequency stimulating electrodes in the subthalamic nucleus (STN). The experiment studied ankle strength, movement velocity, and the associated electromyographic patterns in PD patients, six of whom had tremor at the ankle. The patients were studied off treatment, ON STN deep brain stimulation (DBS), on medication, and on medication plus STN DBS. Twelve matched control subjects were also examined. Medication alone and STN DBS alone increased patients' ankle strength, ankle velocity, agonist muscle burst amplitude, and agonist burst duration, while reducing the number of agonist bursts during movement. These findings were similar for PD patients with and without tremor. The combination of medication plus STN DBS normalized maximal strength at the ankle joint, but ankle movement velocity and electromyographic patterns were not normalized. The findings are the first to demonstrate that STN DBS and medication increase strength and movement velocity at the ankle joint.
authors.affiliation: Department of Movement Science, University of Illinois, Chicago, Illinois 60612, USA. court1@uic.edu
authors.forename: David E
authors.initials: DE
authors.lastname: Vaillancourt
authors.forename: Janey
authors.initials: J
authors.lastname: Prodoehl
authors.forename: Molly M
authors.initials: MM
authors.lastname: Sturman
authors.forename: Roy A E
authors.initials: RA
authors.lastname: Bakay
authors.forename: Leo Verhagen
authors.initials: LV
authors.lastname: Metman
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Corcos
mesh_terms: D000843:Ankle Joint / Q000294:innervation*; D000978:Antiparkinson Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001696:Biomechanical Phenomena; D002230:Carbidopa / Q000008:administration & dosage* / Q000009:adverse effects; D003131:Combined Modality Therapy; D046690:Deep Brain Stimulation / Q000379:methods*; D004567:Electrodes, Implanted; D004576:Electromyography / Q000187:drug effects*; D006801:Humans; D018476:Hypokinesia / Q000503:physiopathology / Q000628:therapy*; D007537:Isometric Contraction / Q000187:drug effects / Q000502:physiology; D007980:Levodopa / Q000008:administration & dosage* / Q000009:adverse effects; D018908:Muscle Weakness / Q000503:physiopathology / Q000628:therapy*; D018482:Muscle, Skeletal / Q000294:innervation; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D012016:Reference Values; D012815:Signal Processing, Computer-Assisted; D013223:Statistics as Topic; D019415:Torque; D016896:Treatment Outcome; D014202:Tremor / Q000503:physiopathology / Q000628:therapy
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa; D002230:Carbidopa