Related Experiment Videos
Impairments of movement kinematics in patients with Huntington's disease: a comparison with and without a concurrent
N Georgiou1, J G Phillips, J L Bradshaw
1Psychology Department, Monash University, Clayton, Victoria, Australia.
Insights
This study found that patients with Huntington's disease (HD) exhibit slower, less efficient voluntary movements, especially when performing a concurrent task. Their movements rely more on visual guidance, suggesting impaired internal movement control due to basal ganglia dysfunction.
Area of Science:
- Neuroscience
- Movement Science
- Clinical Neurology
Background:
- Huntington's disease (HD) is a neurodegenerative disorder affecting motor control.
- Understanding movement kinematics in HD is crucial for assessing disease progression and developing interventions.
- Voluntary movement efficiency and smoothness can be quantified using graphics tablet analysis.
Purpose of the Study:
- To quantify the efficiency and smoothness of voluntary movements in Huntington's disease (HD) patients.
- To investigate the impact of a concurrent cognitive task (digit span) on movement kinematics in HD.
- To explore differences in movement control strategies between HD patients and healthy controls.
Main Methods:
- Twelve HD patients and matched controls performed zig-zag movements using a graphics tablet.
- Movements were executed with both hands, with and without a concurrent digit span task.
- Analysis focused on movement time, peak velocity, acceleration/deceleration phases, and force efficiency across different target sizes and movement extents.
Main Results:
- Patients with HD showed slower movement times, particularly with long strokes, and less adaptation to target size compared to controls.
- A concurrent task reduced movement time and right-hand superiority but differentially affected left-hand efficiency in HD patients versus controls.
- HD patients spent more time decelerating, especially with small targets, indicating reliance on visual guidance and impaired internal movement representation.
Conclusions:
- Basal ganglia dysfunction in HD impairs the ability to generate and refine internal movement representations, leading to reliance on external visual cues.
- Concurrent tasks exacerbate motor control deficits in HD, highlighting the disease's impact on attention and automaticity.
- Movement analysis using graphics tablets provides valuable insights into the specific motor impairments in Huntington's disease.
Abstract:
This study aimed to quantify the efficiency and smoothness of voluntary movement in Huntington's disease (HD) by the use of a graphics tablet that permits analysis of movements profiles. In particular, we aimed to ascertain whether a concurrent task (digit span) would affect the kinematics of goal-directed movements. Twelve patients with HD and their matched controls performed 12 vertical zig-zag movements, with both left and right hands (with and without the concurrent task), to large or small circular targets over long or short extents. The concurrent task was associated with shorter movement times and reduced right-hand superiority. Patients with HD were overall slower, especially, with long strokes, and had similar peak velocities for both small and large targets, so that controls could better accommodate differences in target size. Patients with HD spent more time decelerating, especially with small targets, whereas controls allocated more nearly equal proportions of time to the acceleration and deceleration phases of movement, especially with large targets. Short strokes were generally less force inefficient than were long strokes, especially so for either hand in either group in the absence of the concurrent task, and for the right hand is its presence. With the concurrent task, however, the left hand's behavior changed differentially for the two groups; for patients with HD, it became more force efficient with short strokes and even less efficient with long strokes, whereas for controls, it became more efficient with long strokes. Controls may be able to divert attention away from the inferior left hand, increasing its automaticity, whereas patients with HD, because of disease, may be forced to engage even further online visual control under the demands of a concurrent task. Patients with HD may perhaps become increasingly reliant on terminal visual guidance, which indicates an impairment in constructing and refining an internal representation of the movement necessary for its effective execution. Basal ganglia dysfunction may impair the ability to use internally generated cues to guide movement.