Presenting Author:

Aparna Singh, M.S.

Principal Investigator:

Marc Slutzky, M.D.

Department:

Neurology, Ken and Ruth Davee Department

Keywords:

STROKE ,REHABILITATION , FEEDBACK

Location:

Ryan Family Atrium, Robert H. Lurie Medical Research Center

C61 - Clinical

Improving arm function in chronic stroke survivors using myoelectric-computer interface

Stroke can cause impaired arm function due to weakness, impaired sensation, and abnormal patterns of muscle activation. We have designed a myoelectric-computer interface (MCI) paradigm that maps activations of a pair of abnormally coupled muscles to orthogonal components of computer cursor movement. MCI users can learn to decouple these muscles by moving the cursor to targets along the mapping directions in an interactive game. In this study, we investigated improvement in arm function of chronic stroke survivors before, during, and after MCI training of 3 different muscle pairs in the upper arm over 18 sessions. We evaluated the effects of training duration and isometric vs. movement-based training conditions. We measured clinical outcome metrics as well as the degree of co-activation and arm joint kinematics during free reaching. Our first 16 subjects demonstrated improvement from baseline to the end of training and sustained improvement 4 weeks post-MCI use. Co-activation levels declined in all subjects in the targeted muscles, and elbow extension improved substantially in all subjects. Subjects showed modest improvement (Fugl-Meyer: 3.4 for 60-minute group, 3.6 for 90-minute group). Arm function, as measured by the Wolf Motor Function Test, also improved moderately (by 4.9 s and 10.3 s for 60- and 90-min groups, respectively). Arm function also improved outside of the lab (Motor Activity Log “How Often”: 4.1 and 4.9; “How Well”, 3.1 and 4.9 for the 2 groups, respectively). Spasticity decreased consistently across groups (-5.3 for 60-minute group, -4.21 for 90-minute group on MAS). Overall, longer MCI training showed improved functional outcomes. These results suggest that MCI training can reduce abnormal co-activation and spasticity and improve upper arm function in chronic stroke survivors. If successful, this paradigm could have a broad impact, and could be made into an inexpensive and portable device that many survivors could incorporate into their daily routine.