Paretic upper extremity movement gains are retained 3 months after training with an electrical stimulation neuroprosthesis.

OBJECTIVE

To determine retention of upper extremity (UE) motor changes 3 months after participation in a regimen in which subjects with moderate UE hemiparesis engaged in repetitive task-specific training using an electrical stimulation neuroprosthesis (ESN).

DESIGN

Prospective, blinded, cohort, pre-post study.

SETTING

Outpatient rehabilitation hospital.

PARTICIPANTS

Individuals (N=24) in the chronic stage of stroke exhibiting stable UE hemiparesis (11 men; mean age, 57.9±9.5y; age range, 39-75y; mean time since stroke at time of repetitive task-specific practice [RTP] using ESN intervention start, 36.7mo; range of onset, 7-162mo).

INTERVENTION

As part of a larger trial, subjects had been randomly assigned to receive an 8-week regimen comprised of RTP on valued activities using the ESN. This observational study assessed this single group's paretic UE motor levels immediately after, and 3 months after, the intervention.

MAIN OUTCOME MEASURES

The Fugl-Meyer (FM) assessment of sensorimotor impairment, the Action Research Arm Test (ARAT), the Arm Motor Ability Test (AMAT), and the Box and Block Test (BBT).

RESULTS

None of the scores significantly changed from the period directly after intervention to the test 3-months follow-up (FM: t=1.64; ARAT: t=2.17; AMAT: t=.76, .92, and 1.01 for the functional ability, quality of movement, and time scales, respectively; BBT: t=.36; adjusted t critical value to reject the null [t(crit)]=2.90, 2-tailed α=.008 to preserve experiment-wise error rate of .05).

CONCLUSIONS

Subjects exhibited no changes in the various functional tests, indicating that changes in paretic UE movement realized through RTP using ESN appear to be retained 3 months after the intervention has concluded. This was the first study to our knowledge to examine the longer-term effects of RTP using an ESN in any population.