Visuomotor processing is the ability to integrate visual information into motor plans and movement correction, which is highly required in daily activities such as writing and walking. As visual impairments have been reported in people with Parkinson's disease (PD), it is likely that those impairments may affect visuomotor processing ability and subsequently impair motor performance. Furthermore, people with PD and freezing of gait (FOG) have exhibited poorer visual perception than those without FOG, yet the differences of visuomotor control have not been well investigated. Additionally, little did the studies apply neurophysiological assessment to investigate the associated neural mechanisms. This study aims to investigate behavioral and neurophysiological differences in visuomotor control among people with PD and FOG (freezers), without FOG (non-freezers), and age-matched healthy controls. Sixty-three participants, 21 freezers, 21 non-freezers, and 21 age-matched healthy controls, will be enrolled in this study. Behavioral assessments, including a manual control task and visual perception tests will be used to evaluate visuomotor and visual perceptual abilities. Neurophysiological correlates, including corticomotor excitability and corticocortical connectivity between V1-M1 and PPC-M1, will be examined using transcranial magnetic stimulation. It is hypothesized that freezers will demonstrate the greatest visuomotor impairments and disrupted corticocortical connectivity compared to non-freezers and controls. By integrating behavioral and neurophysiological outcomes, this study seeks to unravel the mechanisms linking visual and motor impairments to FOG, ultimately providing insights into targeted interventions to improve visuomotor processing and motor performance in PD.
Study Type
OBSERVATIONAL
Enrollment
63
School and Graduate Institute of Physical Therapy
Taipei, Zhongzheng Dist., Taiwan
RECRUITINGRoot-mean square-error
Overall performance accuracy relative to the target waveform, which is the mean difference between the target waveform and the participant's movement trajectory calculated over their actual movement time.
Time frame: Day 1
Directional error
The value of the instantaneous component of the hand movement vector, perpendicular to the target trajectory in every sampled time point, which will be calculated and expressed as a percentage of the total movement vector
Time frame: Day 1
Squared mean jerk
The squared mean of the jerk of the visuomotor trajectory, which a minor JSM is assumed a major smoothness by better controlling the movement.
Time frame: Day 1
Movement time
Total movement time of a trial will be recorded.
Time frame: Day 1
Tracking interruption
Frequency and duration of tracking interruptions will be recorded when the participant's cursor exits the target circle.
Time frame: Day 1
Benton Judgment of Line Orientation Test
A 30-item neuropsychological assessment of visuospatial ability. Participants are required to match 2 angled line portions on the top page to an array of 11 target lines, and the correction rate will be recorded.
Time frame: Day 2
Random dot cinematogram
A psychological assessment of visual motor perception. Participants need to distinguish the coherent motion direction, and the correction rate and minimal detectable threshold of coherence will be recorded.
Time frame: Day 2
National Eye Institute Visual Function Questionnaire-25
A 25-item self-reported questionnaire of visual-related activities, which the total score will be recorded.
Time frame: Day 2
Purdue Pegboard Test
A behavioral assessment of hand dexterity ability. Participants are instructed to use one or both hands to sequentially move as many pegs into two parallel rows of holes as possible, within a set time limit, and the movement time will be recorded.
Time frame: Day 2
Timed Up and Go Test
A behavioral assessment of dynamic balance ability. Participants will be instructed to rise from a chair, walk for 3 meters, turn around, return to the chair, and sit down, and the movement time will be recorded.
Time frame: Day 2
Movement Disorder Society Unified Parkinson's Disease Rating Scale
A comprehensive scale of Parkinson disease characteristics, including non-motor aspects of experiences of daily living, motor aspects of experiences of daily living, motor examination, and motor complications. Scores of each subscales will be recorded.
Time frame: Day 1
New Freezing of Gait Questionnaire
A self-reported questionnaire to evaluate the frequency and severity of freezing of gait in people with PD, which the total score will be recorded.
Time frame: Day 1
Cortical excitability
Transcranial magnetic stimulation (TMS) device (The Magstim Company Ltd, Whitland, UK) will be used to determine the neurophysiology of corticomotor excitability.
Time frame: Day 1 and Day 2
Corticocortical connectivity
Transcranial magnetic stimulation (TMS) device (The Magstim Company Ltd, Whitland, UK) will be used to determine the neurophysiology of corticocortical connectivity.
Time frame: Day 1 and Day 2
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