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Differential Effects of Parietal and Cerebellar Stroke in Response to Object Location Perturbation.

Pelton TA, Wing AM, Fraser D, van Vliet P - Front Hum Neurosci (2015)

Bottom Line: To contrast impairments in reach-to-grasp coordination, in response to object location perturbation, in patients with right parietal and cerebellar lesions, in order to further elucidate the role of each area in reach-to-grasp coordination.Patients with parietal or cerebellar lesions showed some similar and some contrasting deficits.The cerebellum was more dominant in controlling temporal coupling between transport and grasp components, and the parietal area was more concerned with using sensation to relate arm and hand state to target position.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, College of Life and Environmental Sciences, University of Birmingham , Edgbaston , UK.

ABSTRACT

Background: The differential contributions of the cerebellum and parietal lobe to coordination between hand transport and hand shaping to an object have not been clearly identified.

Objective: To contrast impairments in reach-to-grasp coordination, in response to object location perturbation, in patients with right parietal and cerebellar lesions, in order to further elucidate the role of each area in reach-to-grasp coordination.

Method: A two-factor design with one between subject factor (right parietal stroke; cerebellar stroke; controls) and one within subject factor (presence or absence of object location perturbation) examined correction processes used to maintain coordination between transport-to-grasp in the presence of perturbation. Sixteen chronic stroke participants (eight with right parietal lesions and eight with cerebellar lesions) were matched in age (mean = 61 years; standard deviation = 12) and hand dominance with 16 healthy controls. Hand and arm movements were recorded during unperturbed baseline trials (10) and unpredictable trials (60) in which the target was displaced to the left (10) or right (10) or remained fixed (40).

Results: Cerebellar patients had a slowed response to perturbation with anticipatory hand opening, an increased number of aperture peaks and disruption to temporal coordination, and greater variability. Parietal participants also exhibited slowed movements, with increased number of aperture peaks, but in addition, increased the number of velocity peaks and had a longer wrist path trajectory due to difficulties planning the new transport goal and thus relying more on feedback control.

Conclusion: Patients with parietal or cerebellar lesions showed some similar and some contrasting deficits. The cerebellum was more dominant in controlling temporal coupling between transport and grasp components, and the parietal area was more concerned with using sensation to relate arm and hand state to target position.

No MeSH data available.


Related in: MedlinePlus

Experimental set-up, showing the configuration for a participant with a ride sided lesion, reaching with affected left arm to the opposing side.
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Figure 1: Experimental set-up, showing the configuration for a participant with a ride sided lesion, reaching with affected left arm to the opposing side.

Mentions: Seated close to a table edge, participants were instructed to perform fast, accurate, reach-to-grasp movements with the more affected arm using a precision grip between the thumb and index finger. Participants were instructed to lift the object 2–4 cm off the table before replacing it in the approximate same position. The start position of the hand was resting on a pressure-sensitive switch close to the body in the mid-saggital axis, with the elbow flexed to approximately 90°, the forearm in mid-pronation and the pads of the index finger and thumb touching. Reach-to-grasp movements were to perspex cylinders (10 cm height × 1.5 cm in diameter), in three locations: 10°, 30°, or 50° to the opposing side of midline, each 35 cm from the start position (Figure 1). Following 6 practice trials and 10 unperturbed control trials, two blocks of 30 experimental trials ensued with a 5 min rest period between the two blocks. Each block consisted of a randomized sequence of 20 unperturbed trials to the 30° cylinder, 5 trials perturbed to the 10° cylinder, and 5 trials perturbed to the 50° cylinder. A different randomized sequence was performed by each stroke participant. Healthy participants performed the same randomized sequence as their matched stroke participant. A visual fixation light indicated the start of each trial. Participants were instructed to move as soon as they saw the illumination of the 30° object which occurred at a random time ranging between 500 and 2000 ms after the start of each trial. In perturbed trials, the perturbation occurred at movement onset by illumination of the 10° or 50° cylinders, via release of the start switch under the hand.


Differential Effects of Parietal and Cerebellar Stroke in Response to Object Location Perturbation.

Pelton TA, Wing AM, Fraser D, van Vliet P - Front Hum Neurosci (2015)

Experimental set-up, showing the configuration for a participant with a ride sided lesion, reaching with affected left arm to the opposing side.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4499699&req=5

Figure 1: Experimental set-up, showing the configuration for a participant with a ride sided lesion, reaching with affected left arm to the opposing side.
Mentions: Seated close to a table edge, participants were instructed to perform fast, accurate, reach-to-grasp movements with the more affected arm using a precision grip between the thumb and index finger. Participants were instructed to lift the object 2–4 cm off the table before replacing it in the approximate same position. The start position of the hand was resting on a pressure-sensitive switch close to the body in the mid-saggital axis, with the elbow flexed to approximately 90°, the forearm in mid-pronation and the pads of the index finger and thumb touching. Reach-to-grasp movements were to perspex cylinders (10 cm height × 1.5 cm in diameter), in three locations: 10°, 30°, or 50° to the opposing side of midline, each 35 cm from the start position (Figure 1). Following 6 practice trials and 10 unperturbed control trials, two blocks of 30 experimental trials ensued with a 5 min rest period between the two blocks. Each block consisted of a randomized sequence of 20 unperturbed trials to the 30° cylinder, 5 trials perturbed to the 10° cylinder, and 5 trials perturbed to the 50° cylinder. A different randomized sequence was performed by each stroke participant. Healthy participants performed the same randomized sequence as their matched stroke participant. A visual fixation light indicated the start of each trial. Participants were instructed to move as soon as they saw the illumination of the 30° object which occurred at a random time ranging between 500 and 2000 ms after the start of each trial. In perturbed trials, the perturbation occurred at movement onset by illumination of the 10° or 50° cylinders, via release of the start switch under the hand.

Bottom Line: To contrast impairments in reach-to-grasp coordination, in response to object location perturbation, in patients with right parietal and cerebellar lesions, in order to further elucidate the role of each area in reach-to-grasp coordination.Patients with parietal or cerebellar lesions showed some similar and some contrasting deficits.The cerebellum was more dominant in controlling temporal coupling between transport and grasp components, and the parietal area was more concerned with using sensation to relate arm and hand state to target position.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, College of Life and Environmental Sciences, University of Birmingham , Edgbaston , UK.

ABSTRACT

Background: The differential contributions of the cerebellum and parietal lobe to coordination between hand transport and hand shaping to an object have not been clearly identified.

Objective: To contrast impairments in reach-to-grasp coordination, in response to object location perturbation, in patients with right parietal and cerebellar lesions, in order to further elucidate the role of each area in reach-to-grasp coordination.

Method: A two-factor design with one between subject factor (right parietal stroke; cerebellar stroke; controls) and one within subject factor (presence or absence of object location perturbation) examined correction processes used to maintain coordination between transport-to-grasp in the presence of perturbation. Sixteen chronic stroke participants (eight with right parietal lesions and eight with cerebellar lesions) were matched in age (mean = 61 years; standard deviation = 12) and hand dominance with 16 healthy controls. Hand and arm movements were recorded during unperturbed baseline trials (10) and unpredictable trials (60) in which the target was displaced to the left (10) or right (10) or remained fixed (40).

Results: Cerebellar patients had a slowed response to perturbation with anticipatory hand opening, an increased number of aperture peaks and disruption to temporal coordination, and greater variability. Parietal participants also exhibited slowed movements, with increased number of aperture peaks, but in addition, increased the number of velocity peaks and had a longer wrist path trajectory due to difficulties planning the new transport goal and thus relying more on feedback control.

Conclusion: Patients with parietal or cerebellar lesions showed some similar and some contrasting deficits. The cerebellum was more dominant in controlling temporal coupling between transport and grasp components, and the parietal area was more concerned with using sensation to relate arm and hand state to target position.

No MeSH data available.


Related in: MedlinePlus