Voluntary control of arm movement in athetotic patients

AbstractBackgroundFunctional recovery of independent arm movement typically plateaus within six months following a stroke, leaving chronic motor deficits. This feasibility study tested whether a wearable, powered exoskeletal orthosis, driven by a percutaneous, implanted brain–computer interface (BCI), using the activity of neurons in the precentral gyrus in the affected cortical hemisphere, could restore voluntary upper extremity function in a person with chronic hemiparetic subsequent to a cerebral hemispheric stroke of subcortical gray and white matter and cortical gray matter.MethodsOne person with chronic hemiparetic stroke with upper-limb motor impairment used a powered elbow-wrist-hand orthosis that opened and closed the affected hand using cortical activity, recorded from four 64-channel microelectrode arrays implanted in the ipsilesional precentral gyrus, based on decoding of spiking patterns and high frequency field potentials generated by imagined hand movements using technology and decoding methods used for people with other causes of paralysis. The system was evaluated in a home setting daily for 12 weeks.ResultsRobust single unit activity, modulating with attempted or imagined movement, was present throughout the precentral gyrus areas. The participant was able to acquire voluntary control over a hand-orthosis BCI, with a score of 10 points on the Action Research Arm Test (out of 53) using the BCI, compared to 0 without any device, and 5 using myoelectric control. Orthosis-powered hand-opening was faster with BCI control compared to myoelectric control, on a standardized object-movement task.ConclusionsThe findings demonstrate the therapeutic potential of an implantable BCI system coupled to a brace to “electrically bypass” the stroke and promote neurally driven limb function. The participant’s ability to rapidly acquire voluntary control over otherwise paralyzed hand opening, more than 18 months after a subcortical stroke, lays the foundation for a fully implanted movement restoration system.

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Voluntary Control of Human Jaw Stiffness

Journal of Neurophysiology ◽

10.1152/jn.00164.2005 ◽

2005 ◽

Vol 94 (3) ◽

pp. 2207-2217 ◽

Cited By ~ 18

Author(s):

Douglas M. Shiller ◽

Guillaume Houle ◽

David J. Ostry

Keyword(s):

Nervous System ◽

Arm Movement ◽

Vertical Axis ◽

Voluntary Control ◽

Robotic Device ◽

Movement Accuracy ◽

Human Arm ◽

Applied Forces ◽

Stiffness Control

Recent studies of human arm movement have suggested that the control of stiffness may be important both for maintaining stability and for achieving differences in movement accuracy. In the present study, we have examined the voluntary control of postural stiffness in 3D in the human jaw. The goal is to address the possible role of stiffness control in both stabilizing the jaw and in achieving the differential precision requirements of speech sounds. We previously showed that patterns of kinematic variability in speech are systematically related to the stiffness of the jaw. If the nervous system uses stiffness control as a means to regulate kinematic variation in speech, it should also be possible to show that subjects can voluntarily modify jaw stiffness. Using a robotic device, a series of force pulses was applied to the jaw to elicit changes in stiffness to resist displacement. Three orthogonal directions and three magnitudes of forces were tested. In all conditions, subjects increased the magnitude of jaw stiffness to resist the effects of the applied forces. Apart from the horizontal direction, greater increases in stiffness were observed when larger forces were applied. Moreover, subjects differentially increased jaw stiffness along a vertical axis to counteract disturbances in this direction. The observed changes in the magnitude of stiffness in different directions suggest an ability to control the pattern of stiffness of the jaw. The results are interpreted as evidence that jaw stiffness can be adjusted voluntarily, and thus may play a role in stabilizing the jaw and in controlling movement variation in the orofacial system.

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Neuromotor Prosthetic to Treat Stroke-Related Paresis

10.21203/rs.3.rs-267501/v1 ◽

2021 ◽

Author(s):

Mijail Serruya ◽

Alessandro Napoli ◽

Nicholas Satterthwaite ◽

John Kardine ◽

Joseph McCoy ◽

...

Keyword(s):

Therapeutic Potential ◽

Motor Impairment ◽

Arm Movement ◽

Myoelectric Control ◽

Voluntary Control ◽

Motor Deficits ◽

Precentral Gyrus ◽

Home Setting ◽

Hemiparetic Stroke ◽

Hand Opening

Abstract Background Functional recovery of independent arm movement typically plateaus within six months following a stroke, leaving chronic motor deficits. This feasibility study tested whether a wearable, powered exoskeletal orthosis, driven by a percutaneous, implanted brain–computer interface (BCI), using the activity of neurons in the precentral gyrus in the affected cortical hemisphere, could restore voluntary upper extremity function in a person with chronic hemiparetic subsequent to a cerebral hemispheric stroke of subcortical gray and white matter and cortical gray matter.Methods One person with chronic hemiparetic stroke with upper-limb motor impairment used a powered elbow-wrist-hand orthosis that opened and closed the affected hand using cortical activity, recorded from four 64-channel microelectrode arrays implanted in the ipsilesional precentral gyrus, based on decoding of spiking patterns and high frequency field potentials generated by imagined hand movements using technology and decoding methods used for people with other causes of paralysis. The system was evaluated in a home setting daily for 12 weeks. Results Robust single unit activity, modulating with attempted or imagined movement, was present throughout the precentral gyrus areas. The participant was able to acquire voluntary control over a hand-orthosis BCI, with a score of 10 points on the Action Research Arm Test (out of 53) using the BCI, compared to 0 without any device, and 5 using myoelectric control. Orthosis-powered hand-opening was faster with BCI control compared to myoelectric control, on a standardized object-movement task. Conclusions The findings demonstrate the therapeutic potential of an implantable BCI system coupled to a brace to “electrically bypass” the stroke and promote neurally driven limb function. The participant’s ability to rapidly acquire voluntary control over otherwise paralyzed hand opening, more than 18 months after a subcortical stroke, lays the foundation for a fully implanted movement restoration system.

Download Full-text