title: Plantar cutaneous function in Parkinson's disease patients ON and OFF L-dopa.
abstract: While Parkinson's disease (PD) is traditionally viewed as a motor disorder, there is mounting evidence that somatosensory function becomes affected as well. However, conflicting reports exist regarding whether plantar sensitivity is reduced in early-onset PD patients. Plantar sensitivity was assessed using monofilaments and a gold-standard, two-interval two-alternative forced choice vibrotactile detection task at both 30 and 250Hz. Lower-limb cutaneous reflexes were assessed by delivering continuous, sinusoidal vibration at 30 and 250Hz while recording muscle activity in Tibialis Anterior. We found no evidence of elevated plantar thresholds or dysfunctional lower-limb cutaneous reflexes in PD patients ON medication. We also found no acute effect of ceasing L-dopa intake on either plantar sensitivity or cutaneous reflexes. Our finding of intact cutaneous function in PD supports the further exploration of therapeutics that enhance plantar sensitivity to minimize postural instability, a source of considerable morbidity in this clinical population.
authors.affiliation: School of Kinesiology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Monica D
authors.initials: MD
authors.lastname: McKeown
authors.affiliation: School of Kinesiology, University of British Columbia, Vancouver, BC, Canada. Electronic address: ryan.peters@ubc.ca.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Peters
authors.affiliation: School of Kinesiology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Elizabeth P
authors.initials: EP
authors.lastname: Pasman
authors.affiliation: Department of Medicine, Neurology, University of British Columbia, Vancouver, BC, Canada; Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: McKeown
authors.affiliation: School of Kinesiology, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada; International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Mark G
authors.initials: MG
authors.lastname: Carpenter
authors.affiliation: School of Kinesiology, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada; International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada.
authors.forename: J Timothy
authors.initials: JT
authors.lastname: Inglis
mesh_terms: D000368:Aged; D002230:Carbidopa / Q000627:therapeutic use; D004192:Discrimination, Psychological / Q000502:physiology; D004338:Drug Combinations; D004576:Electromyography; D005260:Female; D005528:Foot / Q000503:physiopathology*; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use; D035002:Lower Extremity / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology*; D010812:Physical Stimulation; D012021:Reflex, Abnormal; D014110:Touch / Q000502:physiology*; D055698:Touch Perception / Q000502:physiology*; D014732:Vibration
chemical_list: D004338:Drug Combinations; C009265:carbidopa, levodopa drug combination; D007980:Levodopa; D002230:Carbidopa
keywords: Cutaneous; Parkinson’s disease; Perception; Psychophysics; Reflex