Effectiveness of Multichannel Functional Electrical Stimulation on Upper Extremity Function During Stroke Rehabilitation

I. BACKGROUND AND SIGNIFICANCE Stroke is the third leading cause of death and is a major reason for disability among survivors (Mayo 2009). 55-75% of patients with stroke have deficiency in upper extremity (UE) function contributing to the disability (Alon, 2007). Complete recovery of UE function is only reported in 11.6% of stroke survivors 6 months following ischemic middle cerebral artery stroke (Kwakkel, 2003). Neuro rehabilitation has shifted focus to task-specific, repetitive training as we understood the concept of neuroplasticity (Kleim, 2008 ). Functional electrical stimulation (FES) has been identified as a treatment modality to enhance upper extremity function in patients during early stroke rehabilitation (Alon, 2007). FES along with task-specific training has demonstrated superior performance in hand function (Yang et al 2019) Though studies have reported improvement in UE function, the duration of treatment and timing post stroke also varies tremendously. Since the majority of the improvement in upper extremity function occurs in 11 weeks since onset (Nakayama, 1994), it is important to consider the effect of FES during that time in enhancing UE function. FES can be an expensive modality to use for patients on their own and therefore the length of stay at inpatient rehabilitation post stroke also is an important factor to consider. The average reported length of stay during inpatient rehab for patients with stroke varies from 9 to 22 days (Camicia, 2015). So it is important to assess the effectiveness of FES during the patient's inpatient stay for clinicians to choose the most appropriate intervention during the limited inpatient rehabilitation time. Most of the reported studies have used FES distally (Alon, 2007; Gharib, 2015) to improve hand function however it is also important to consider the role of proximal stability to improve UE function for tasks such as reaching. Though FES of the proximal muscles has been shown to be a superior intervention in reducing shoulder subluxation, its effect on improving motor function has been inconclusive (Vafadar et al 2015).

Traditionally, FES machines are a two-channel unit used to stimulate one muscle group at a time. The Xcite system is a battery-powered stimulator with up to 12 channels of cyclical stimulation, allowing for both proximal and distal muscle group stimulation. It is a task-specific modality to enhance mass practice during neurological re-education. Each activity has the correctly sequenced stimulation pattern to perform the prescribed activity. There has been limited research regarding this type of FES in patients with stroke during early stroke rehabilitation.

II. STUDY OBJECTIVE(S); INCLUDING SPECIFIC AIMS AND/OR HYPOTHESES The purpose of this pilot study is to determine whether two weeks of multi-channel FES along with task-specific training will improve UE function when compared to traditional rehabilitation or usual care. The secondary purpose of this study is to find whether two weeks of multi-channel FES along with task-specific training will improve shoulder range of motion, grip strength, and patient reported function when compared to traditional rehabilitation or usual care in patients with unilateral stroke resulting in hemiplegia.

Null Hypotheses:

The following null hypotheses are established for this study: