Date Presented 03/26/20
Imperceptible vibratory stimulation of the wrist was evaluated as an adjunct to poststroke upper-extremity rehabilitation. Using stimulation during six-week task-practice therapy was feasible and safe. Promising improvement in function was retained at one-month follow-up. The improvement was greater than those reported in literature with similar therapy. This result encourages a large randomized controlled trial to examine the efficacy of using the stimulation during therapy in improving outcomes.
Primary Author and Speaker: Amanda Vatinno
Contributing Authors: Lucion Hall, Hannah Cox, Alison Fluharty, Catilyn Taylor, Alexandra Wease, Allison Davis, Shannon Cain, Michelle Woodbury, Na Jin Seo
PURPOSE: Survivors of stroke commonly present with persistent upper extremity impairment that reduces their ability to perform functional tasks, such as self-care. This study investigates application of imperceptible random-frequency vibratory stimulation to the wrist during hand tasks via a vibrator mounted in a wristband. The stimulation primes the cortical sensorimotor network of the hand (Seo et al., 2015, Seo et al., 2019), thus having a potential to facilitate neural plasticity for recovery of hand function post-stroke. The purpose of this study was to determine feasibility, safety and preliminary efficacy of using stimulation during therapy.
DESIGN: This was a pilot study involving a single-arm intervention group with four chronic stroke survivors (>6 months post-stroke) with moderate upper extremity impairment.
METHOD: Participants received stimulation to the paretic wrist during 6-week (18-session) goal-directed task-practice therapy. Three hundred upper extremity movement repetitions were completed per session. Clinical outcome measures including the Wolf Motor Function Test (WMFT) were obtained at baseline, every third therapy session, post-therapy, and one-month follow-up. Assessments were scored by raters blinded to the time of assessment (before, after how many sessions of therapy, or follow-up). Given the small sample size we could afford within this pilot study, in lieu of having a controlled group, we retrospectively compared outcomes with other large trials that used similar therapy but no stimulation.
RESULTS: All participants completed the intervention and were retained to 1-month follow-up. No serious adverse events occurred. Stimulation was feasible to use during therapy and did not interfere with the completion of therapy tasks based on self-report of the participants and therapist. All participants improved WMFT time post intervention compared to baseline. All participants retained improvements at follow-up. The mean score had a trend of continuous improvement over the 6-week intervention period. The mean improvements at both post-therapy and follow-up were greater than the minimal detectable change, as well as mean improvements resulting from similar therapy programs reported in the literature (Lo et al., 2010, Winstein et al., 2016). Blind assessor interrater reliability for WMFT time was .99 and intrarater reliability was 1.0. All participants voluntarily reported increased use of their affected hand in daily living, such as self-feeding.
CONCLUSION: Stimulation was safe and feasible to use during a standard task-practice therapy program. Preliminary efficacy is promising. Due to the small sample size and lack of a control group, a larger trial is needed to confirm these results.
IMPACT STATEMENT: Wearable vibratory stimulation is a feasible and safe adjunct for rehabilitation therapy for survivors of stroke. Occupational therapists may consider using stimulation in clinical practice to improve outcomes in upper extremity motor function following stroke, pending evidence from a large trial.
References
Seo, N. J., Lakshminarayanan, K., Bonilha, L., Lauer, A. W., Schmit, B.D. (2015). Effect of imperceptible vibratory noise applied to wrist skin on fingertip touch evoked potentials - an EEG study. Physiol Rep. 3, e12624. doi: 10.14814/phy2.12624
Seo, N. J., Lakshminarayanan, K., Lauer, A. W., Ramakrishnan, V., Schmit, B. D., Hanlon, C. A., ... & Nagy, T. (2019). Use of imperceptible wrist vibration to modulate sensorimotor cortical activity. Experimental brain research, 237(3), 805-816.
Lo, A. C., Guarino, P. D., Richards, L. G., Haselkorn, J. K., Wittenberg, G. F., Federman, D. G., ... & Bever Jr, C. T. (2010). Robot-assisted therapy for long-term upper-limb impairment after stroke. New England Journal of Medicine, 362(19), 1772-1783. doi: 10.1056/NEJMoa0911341
Winstein, C. J., Wolf, S. L., Dromerick, A. W., Lane, C. J., Nelsen, M. A., Lewthwaite, R., ... & Azen, S. P. (2016). Effect of a task-oriented rehabilitation program on upper extremity recovery following motor stroke: the ICARE randomized clinical trial. Jama, 315(6), 571-581.
