Improving hand function in stroke survivors: a pilot study of contralaterally controlled functional electric stimulation in chronic hemiplegia

Abstract

Objective: To assess the feasibility of a new stroke rehabilitation therapy for the hemiparetic hand.

Design: Case series. Pre- and postintervention assessment with 1- and 3-month follow-ups.

Setting: Clinical research laboratory of a large public hospital.

Participants: Three subjects with chronic (>6mo postcerebrovascular accident) upper-extremity hemiplegia.

Intervention: Subjects used an electric stimulator to cause the paretic hand extensor muscles to contract and thereby open the hand. Subjects controlled the intensity of the stimulation, and thus the degree of hand opening, by volitionally opening the unimpaired contralateral hand, which was detected by an instrumented glove. For 6 weeks, subjects used the stimulator to perform active repetitive hand-opening exercises 2 hours daily at home and functional tasks 1.5 hours twice a week in the laboratory.

Main outcome measures: Maximum voluntary finger extension, maximum voluntary isometric finger-extension moment, finger-movement control, and box and block test (BBT) score at pre- and posttreatment and at 1 month and 3 months posttreatment.

Results: Maximum voluntary finger extension increased from baseline to end of treatment and from the end of treatment to 1-month follow-up in 2 subjects. Maximum voluntary isometric finger-extension moment, finger-movement control, and BBT score increased from baseline to the end of treatment and from the end of treatment to 1-month follow-up in all 3 subjects. The improvements generally declined at 3 months.

Conclusions: The results suggest a positive effect on motor impairment, meriting further investigation of the intervention.

Fig 1

CCFES System, consisting of electrodes, a stimulator, and a command glove. By opening the unimpaired hand wearing the command glove, the stroke survivor controls the intensity of electrical stimulation delivered to the paralyzed finger and thumb extensor muscles of the paretic hand.

Fig 2

Sum of joint angles (MP° + PIP° + DIP°) of index finger during maximum voluntary finger extension (mean +/− standard deviation). EOT = end-of-treatment assessment. Stars (*) indicate statistical significance (P < .05) relative to baseline.

Fig 3

Finger movement tracking error. Sum of errors over six tracking trials normalized to the maximum error, which was recorded at baseline for each subject.

Fig 4

A single tracking trial for Subject 1 from each assessment session. Vertical axis is the sum of joint angles (MP° + PIP° + DIP°) of index finger.

Fig 5

Isometric finger extension moment during maximum voluntary index finger extension (mean + standard deviation). Stars (*) indicate statistical significance (P < .05) relative to baseline.

Fig 6

Box and Block score. Number of blocks transferred in 60 seconds.