title: Different postural reaction patterns for expected and unexpected perturbations in patients with idiopathic Parkinson's disease and other parkinsonian syndromes.
abstract: Different postural reaction patterns after predictable and unpredictable perturbations during free stance were studied in 8 patients with idiopathic Parkinson's disease (iPD), in 4 patients with other parkinsonian syndromes (PS) and in 5 healthy controls. First, the amplitude of leaning maximally backward and forward was measured (condition I). Secondly, the body equilibrium was disturbed by self-paced, predictable, rapid arm elevations (condition II) and by sudden unpredictable toe-down and toe-up rotations of a supporting platform (condition III). Patients with PS particularly had difficulties in regaining body equilibrium after unexpected perturbations. In controls and patients with PS, unpredictable disturbances were better compensated in toe-down than in toe-up direction, whereas the opposite was true for patients with iPD. These results correspond to the fact that patients with PS had a specific leaning-backward impairment and patients with iPD, a leaning-forward impairment. The authors conclude that the differences in postural stability between patients with iPD and PS are caused by different pathophysiological mechanisms. These differences in postural stability could serve as an additional tool for differential diagnosis.
authors.affiliation: Department of Neurology, Klinikum Grosshadern, Ludwig-Maximilians University, Munich, Germany. immisch@codon.nih.gov
authors.forename: I
authors.initials: I
authors.lastname: Immisch
authors.forename: O
authors.initials: O
authors.lastname: Bandmann
authors.forename: J
authors.initials: J
authors.lastname: Quintern
authors.forename: A
authors.initials: A
authors.lastname: Straube
mesh_terms: D000368:Aged; D001132:Arm / Q000502:physiology; D005260:Female; D006615:Hip / Q000502:physiology; D006801:Humans; D007717:Knee / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology; D018482:Muscle, Skeletal / Q000503:physiopathology; D010300:Parkinson Disease / Q000503:physiopathology*; D020734:Parkinsonian Disorders / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology; D011187:Posture / Q000502:physiology*; D012782:Shoulder / Q000502:physiology