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

Trudy A Pelton,Dagmar Fraser,Paulette Van Vliet,Alan M Wing

doi:10.3389/fnhum.2015.00293

Abstract

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. 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. 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). 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. 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.

Highlights

Successful control of reach-to-grasp requires coordination, “an ability to maintain a context-dependent and phase-dependent cyclical relationship between different body segments or joints in both spatial and temporal domains” (Krasovsky and Levin, 2010) of various body segments including the arm with the trunk, the shoulder with the elbow, and the hand with the arm
Studies in healthy adults have suggested hand and arm function are controlled as a single coordinated unit (Jeannerod, 1984; Wallace et al, 1990) demonstrated by significant correlations between reach and grasp components, including between the start time of the opening of the hand and the start time of hand movement toward the object (Jeannerod and Biguer, 1982; Jeannerod, 1984), between the time of maximum hand aperture and the time of peak deceleration (PD) of the hand (Jeannerod, 1984; Castiello et al, 1993), and between time of maximum aperture (TMA) and the time of peak velocity (TPV) of the hand (Wallace et al, 1990)
The prolonged movement durations (MDs) with lower PV likely reflects a greater reliance on feedback for spatial aspects of the movement, due to an impaired ability to localize visual target position, and process sensory information to maintain an estimate of arm state

Summary

Introduction

Successful control of reach-to-grasp requires coordination, “an ability to maintain a context-dependent and phase-dependent cyclical relationship between different body segments or joints in both spatial and temporal domains” (Krasovsky and Levin, 2010) of various body segments including the arm with the trunk, the shoulder with the elbow, and the hand with the arm. Studies in healthy adults have suggested hand and arm function are controlled as a single coordinated unit (Jeannerod, 1984; Wallace et al, 1990) demonstrated by significant correlations between reach and grasp components, including between the start time of the opening of the hand and the start time of hand movement toward the object (Jeannerod and Biguer, 1982; Jeannerod, 1984), between the time of maximum hand aperture and the time of peak deceleration (PD) of the hand (Jeannerod, 1984; Castiello et al, 1993), and between time of maximum aperture (TMA) and the time of peak velocity (TPV) of the hand (Wallace et al, 1990). Spatiotemporal relationships between transport and grasp in a heterogenous group of stroke patients with mild to moderate impairments, were investigated in a study where movements were performed at both fast and preferred speeds and to small and larger objects (vanVliet and Sheridan, 2007). 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

Results

Discussion

Conclusion