caa a22 4500 445350423 CHVBK 20180317142842.0 cr unu---uuuuu 170323e20111001xx s 000 0 eng 10.1007/s00221-011-2845-2 doi (NATIONALLICENCE)springer-10.1007/s00221-011-2845-2 Dyskinetic Parkinson's disease patients demonstrate motor abnormalities off medication [Elektronische Daten] [James Stevenson, Pouria Talebifard, Edna Ty, Meeko Oishi, Martin McKeown] The pathophysiology of l-dopa-induced dyskinesias (LIDs) in Parkinson's disease (PD) remains poorly understood. The presence of superimposed LIDs clearly differentiates motor performance of dyskinetic from non-dyskinetic PD subjects when they are on medication, but here, we investigated whether their respective motor performance differs while subjects are off l-dopa medication and LIDs are not apparent. We assessed the motor performance of nine dyskinetic and ten non-dyskinetic PD subjects off l-dopa, and of ten age-matched control subjects, during a visually guided tracking task. As previous studies have suggested that linear dynamical system (LDS) models are useful to assess motor performance in PD in addition to overall tracking error, we used LDS models to assess the damping ratio parameter of motor behavior while controlling for disease severity. While overall tracking error did not significantly differ across groups, dyskinetic PD subjects demonstrated a significantly decreased mean damping ratio compared with control and non-dyskinetic PD subjects. For both groups, greater disease severity significantly predicted a lower damping ratio, but even after controlling for disease severity, the damping ratio for dyskinetic subjects was significantly lower. Our results demonstrate, somewhat counter-intuitively, that motor performance of dyskinetic and non-dyskinetic PD subjects differ, even off l-dopa when no dyskinesias are seen. A decreased damping ratio is indicative of a tendency to overshoot a target during motor performance, similar to the dysmetria found in cerebellar patients. We discuss the possibility of motor abnormalities in dyskinetic PD patients off medication in relation to altered functional cerebellar changes described in PD. Springer-Verlag, 2011 l -Dopa-induced dyskinesias nationallicence Dynamical system models nationallicence Damping ratio nationallicence Visually guided tracking nationallicence Stevenson James Department of Neuroscience, Kinsmen Laboratory of Neurological Research, University of British Columbia, Rm. 2618, 2255 Wesbrook Mall, V6T 1Z3, Vancouver, Canada aut Talebifard Pouria Department of Electrical and Computer Engineering, University of British Columbia, 3111 Kaiser Building, 2332 Main Mall, V6T 1Z4, Vancouver, Canada aut Ty Edna Pacific Parkinson's Research Centre, University of British Columbia, M31, Purdy Pavilion, 2221 Wesbrook Mall, V6T 2B5, Vancouver, Canada aut Oishi Meeko Electrical and Computer Engineering, University of New Mexico, MSC01 1100, 1 University of New Mexico, 87131, Albuquerque, NM, USA aut McKeown Martin Department of Neuroscience, Kinsmen Laboratory of Neurological Research, University of British Columbia, Rm. 2618, 2255 Wesbrook Mall, V6T 1Z3, Vancouver, Canada aut Experimental Brain Research Springer-Verlag 214/3(2011-10-01), 471-479 0014-4819 214:3<471 2011 214 221 https://doi.org/10.1007/s00221-011-2845-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00221-011-2845-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Stevenson James Department of Neuroscience, Kinsmen Laboratory of Neurological Research, University of British Columbia, Rm. 2618, 2255 Wesbrook Mall, V6T 1Z3, Vancouver, Canada aut NATIONALLICENCE 700 1- Talebifard Pouria Department of Electrical and Computer Engineering, University of British Columbia, 3111 Kaiser Building, 2332 Main Mall, V6T 1Z4, Vancouver, Canada aut NATIONALLICENCE 700 1- Ty Edna Pacific Parkinson's Research Centre, University of British Columbia, M31, Purdy Pavilion, 2221 Wesbrook Mall, V6T 2B5, Vancouver, Canada aut NATIONALLICENCE 700 1- Oishi Meeko Electrical and Computer Engineering, University of New Mexico, MSC01 1100, 1 University of New Mexico, 87131, Albuquerque, NM, USA aut NATIONALLICENCE 700 1- McKeown Martin Department of Neuroscience, Kinsmen Laboratory of Neurological Research, University of British Columbia, Rm. 2618, 2255 Wesbrook Mall, V6T 1Z3, Vancouver, Canada aut NATIONALLICENCE 773 0- Experimental Brain Research Springer-Verlag 214/3(2011-10-01), 471-479 0014-4819 214:3<471 2011 214 221 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer