Safety and Feasibility of Various Functional Electrical Stimulation Cycling Protocols in Individuals With Multiple Sclerosis Who Are Nonambulatory

Abstract

Objective: To examine the safety, feasibility, and response to functional electrical stimulation (FES) cycling protocols requiring differing levels of effort in people with multiple sclerosis (MS) who are nonambulatory.

Design: Pilot study with pre-post intervention testing.

Setting: Outpatient clinic setting of a long-term acute care hospital.

Participants: Individuals (N=10) with MS (6 men; mean age 58.6±9.86y) who use a wheelchair for community mobility. Participants' Expanded Disability Status Scale score ranged from 6.5 to 8.5 (median 7.5).

Intervention: Participants performed 3 or 4 FES cycling protocols requiring different levels of volitional effort during 6-8 testing sessions.

Main outcome measures: The primary outcome was safety, measured by adverse events and increase in MS symptoms, all assessed throughout, immediately post- and 1 day postsession. FES cycling performance for each protocol was also recorded. Exploratory outcome measures collected before and after all testing sessions included functional assessment of MS, MS Impact Scale, Exercise Self Efficacy Scale, Patient Health Questionnaire-9 item, and the Zarit Caregiver Burden Scale.

Results: All participants (4 women, 6 men) completed all testing sessions. There were no serious adverse events or differences in vitals or symptoms between protocols. Two participants had an isolated episode of mild hypotension. Changes in pain, spasticity, and fatigue were minimal. Five participants were able to cycle for 30 minutes and completed interval training protocols requiring increasing difficulty. The remainder cycled for <3 minutes and completed a rest interval protocol. There was modest improvement on the exploratory outcome measures.

Conclusions: People with MS who use a wheelchair for community mobility can safely perform FES cycling requiring more effort than previously reported research. Therefore, the individuals may experience greater benefits than previously reported. Further study is required to better understand the potential benefits for optimizing function and improving health in people with MS.

Keywords: ADLs, activities of daily living; EDSS, Expanded Disability Status Scale; ESES, Exercise Self-Efficacy Scale; Exercise; FAMS, functional assessment of multiple sclerosis; FES, functional electrical stimulation; Health; I-Resist, resistance interval; I-Rest, rest interval; I-Stim, stimulation interval; MA, motor assist; MS, multiple sclerosis; MSIS-29, 29-Item Multiple Sclerosis Impact Scale; Multiple sclerosis; PHQ-9, 9-Item Patient Health Questionnaire; QOL, quality of life; Rehabilitation; S, standard protocol; VAS-P, visual analog scale of pain; VAS-S, visual analog scale of spasticity; rpm, revolutions per minute.

Fig 1

Flow chart of study procedure.

Fig 2

Algorithm for interval protocol selection. (A) Protocol I-Stim and I-Resist for individuals able to cycle 30 minutes in protocol S. (B) Protocol I-Rest for individuals able to cycle <30 minutes in protocol A.