Sensorimotor adaptation in Parkinson’s disease: evidence for a dopamine dependent remapping disturbance

• Published in: Experimental brain research Vol. 185; no. 2; pp. 227 - 236
• Main Authors: Paquet, F., Bedard, M. A., Levesque, M., Tremblay, P. L., Lemay, M., Blanchet, P. J., Scherzer, P., Chouinard, S., Filion, J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.02.2008; Springer; Springer Nature B.V
• Subjects: Adaptation, Physiological - drug effects; Adaptation, Physiological - physiology; Aged; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Dopamine - deficiency; Dopamine - metabolism; Female; Fundamental and applied biological sciences. Psychology; Humans; Levodopa - pharmacology; Levodopa - therapeutic use; Male; Medical sciences; Middle Aged; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Neurology; Neurosciences; Parkinson Disease - drug therapy; Parkinson Disease - metabolism; Parkinson Disease - physiopathology; Photic Stimulation - methods; Psychomotor Performance - drug effects; Psychomotor Performance - physiology; Research Article; Vertebrates: nervous system and sense organs; Striatum; Dopamine; Movement; Perception; Levodopa; Neuropsychology; Procedural learning; Human; Nervous system diseases; Central nervous system; Parkinson disease; Goal directed movement; Procedural learning, Neuropsychology; Basal ganglion; Corpus striatum; Encephalon; Cerebral disorder; Pointing task; Learning; Striatum, Levodopa; Acquisition process; Depletion; Central nervous system disease; Kinematics; Degenerative disease; Extrapyramidal syndrome
• ISSN: 0014-4819; 1432-1106
• DOI: 10.1007/s00221-007-1147-1

Sensorimotor adaptation is thought to involve a remapping of the kinematic and kinetic parameters associated with movements performed within a changing environment. Patients with Parkinson’s disease (PD) are known to be affected on this type of learning process, although the specific role of dopamine depletion in these deficits has not yet been elucidated. The present study was an attempt to clarify whether dopamine depletion in PD may directly affect the capacity to internally reorganize the visuomotor remapping of a distorted environment. Fourteen PD patients were tested twice, while they were treated and while they were withdrawn from their regular levodopa treatment. Fourteen control subjects were also enrolled and tested twice. Two parallel forms of the Computed Mirror Pointing Task (CMPT), requiring making a reaching movement in a visually transformed environment (mirror inversion), were administered to each participant. Each of them had to perform 40 trials at each of the 2 testing sessions. At each trial, sensorimotor adaptation was evaluated by the initial direction angle (IDA), which reflects the direction of movement before any visually guided readjustment. Results revealed no IDA difference at baseline, between control subject and PD patients, whether they were treated or not. In all group, IDA values at that time were large, reflecting a tendency to make movements according to the real life visuomotor mapping (based on the natural direct vision). However, striking differences appeared during sensorimotor learning, in that IDA reduction along trials was poorer in patient not treated with levodopa than both control subjects and the same PD patient treated with levodopa. No difference was observed between the treated PD patients and control subjects. Given that IDA is thought to reflect the internal representation of the visuomotor mapping, it is concluded that dopamine depletion in PD would affects sensorimotor adaptation, in that it facilitates old and poorly adapted movements (real life mapping), instead of new and more adapted ones (mirror transformed mapping).