Dual Coded Motor Planning in Stroke:
Evidence, Impairment and Potential Intervention
John-Ross Rizzo, MD; Todd Hudson, PhD; Andrew Abdou, OMS IV; Ira Rashbaum, MD; Preeti Raghavan, MD; Michael S. Landy, PhD
Background
Results
Control: Right Hand Dominant
Stroke is a leading cause of serious, adult, long-term disability with hemiparesis being the
1
most common motor impairment.
The purpose of this study is to better understand the motor planning and coding of arm
movements within controls and stroke patients.
In a previous study, we have demonstrated 2 motor planning systems.
2
1. Common Endpoint
2. Common Vector
Encode the endpoint to which you want
the limb to move.
VR among stroke
subjects for both
vector- and endpoint-grouped data ≈
1 for both moreaffected and lessaffected arms.
Encode direction and extent to which you
want the limb to move.
Variance Ratio
Variance Ratio
(VR) among control subjects for vector-grouped data
is > 1 and for endpoint-grouped
data ≈ 1
Stroke: More Affected Arm
Stroke: Less Affected Arm
Key:
vector-grouped
endpoint-grouped
Methods
Subjects: 12 controls, 13 stroke subjects on their
less-affected arm, and 10 stroke subjects on their
more-affected arm
Task: Subjects performed many repetitions of
reaches on a tabletop as instructed on a display
monitor with alternating blocks of trials grouped by
common endpoint and common vector.
Reach Orientation
Conclusions
Vector-coded planning is not evident among stroke subjects and, surpsingly, it is not evident in both their more-affected and less-affected arms.
Our findings have implications for designing therapeutic strategies that aim to improve motor function in stroke victims .
1
Roger, V. L. et al. Heart disease and stroke statistics--2012 update: a report from the American Heart Association. Circulation 125, e2–e220 (2012).
Hudson, T. E., & Landy, M. S. (2012). Motor learning reveals the existence of multiple codes for movement planning. Journal of neurophysiology, 108(10),
2708–16. doi:10.1152/jn.00355.2012
2
3D finger position recorded by an Optrotrack at
200 Hz
Supported by Grants NIH EY08266, TR000038, AG042379