Cerebellar tDCS and Balance Training in PwMS

Not Applicable

Completed

Conditions: Multiple Sclerosis

Interventions: Behavioral: Balance Training
Device: Sham Transcranial Direct Current Stimulation (tDCS)
Device: 4 mA Transcranial Direct Current Stimulation
Device: 2 mA Transcranial Direct Current Stimulation

Registration Number: NCT04391023

Lead Sponsor: University of Iowa

Brief Summary: Many people with multiple sclerosis (PwMS) have decreased balance and postural control, gait deficits, and a high frequency of falls. High fall rates and mobility impairments pose a significant risk to the independence and quality of life of PwMS. Therefore, effective interventions to improve balance and postural control are urgently needed to decrease the frequency of falls in PwMS. Balance training has been demonstrated to significantly improve postural control and gait in PwMS. One possible treatment modality to amplify the effects of balance training is transcranial direct current stimulation (tDCS), a non-invasive means to increase cortical excitability and potentially prime the brain for task specific learning. The cerebellum plays a vital role in balance and posture and may be an important target structure for tDCS studies seeking to reduce fall risk. Studies have shown that anodal cerebellar tDCS is effective in improving balance control in older adults with high fall risk and patients with chronic stroke. However, the most effective tDCS intensity and the duration of the effects on balance control has not been established. Moreover, no study has combined cerebellar tDCS and balance training to reduce fall risk in PwMS. The purpose of this study is to investigate the effects of cerebellar transcranial direct current stimulation (tDCS) on fall risk in people with relapsing-remitting multiple sclerosis. We will conduct tDCS or SHAM followed by balance training on 4 consecutive days. We will evaluate fall risk with well-established functional tasks, such as the Berg Balance Scale, Timed Up and Go (TUG), the six minute walk test (6MWT), and static posturography.

Prospective participants, men and women with relapsing-remitting MS, will be recruited. To accomplish this study, 30 participants will be randomly assigned into 3 groups (2 mA tDCS, 4 mA tDCS, or SHAM). This study involves 4 daily visits at the Integrative Neurophysiology Lab at the same time of day for each subject and three follow-up visits. The duration of visit 1 will be approximately 2.5 hours and the duration of visits 2-4 will be approximately 1.5 hours. Visit 5, 6, and 7 will be approximately 24 hours, 1 week, and 3 weeks, respectively, after visit 4 and will last approximately 1.5 hours. During tDCS sessions, participants will undergo either Sham, 2 mA, and 4 mA tDCS for 20 minutes followed by balance training.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 18

Inclusion Criteria

medically diagnosed with relapsing-remitting multiple sclerosis
18-70 years of age
moderate disability (score of 2-6 on the Patient Determined Disease Scale)
self-reported differences in function between legs, have fallen within the last year
able to walk for 6 mins, and not taking any psychoactive medication.

Exclusion Criteria

relapse within the last 60 days
have changed disease modifying medications in the last 45 days
are currently pregnant
have a concurrent neurological or neuromuscular disease
have been hospitalized within the last 90 days
have any contraindications for the tDCS device (i.e., pacemakers or metal implants)
are unable to understand/sign the consent form.

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
2 mA tDCS	Balance Training	The participants in this group will receive tDCS at 2 mA while seated comfortably. The intensity will start at 0 mA and will be incrementally increased to the target intensity (2 mA) over the initial 30 seconds. Then, the tDCS will deliver stimulation at the target intensity until the 19:30 minute time point. At this point, the current will gradually decrease back to 0 mA.
4 mA tDCS	4 mA Transcranial Direct Current Stimulation	The participants in this group will receive tDCS at 4 mA while seated comfortably. The intensity will start at 0 mA and will be incrementally increased to the target intensity (4 mA) over the initial 30 seconds. Then, the tDCS will deliver stimulation at the target intensity until the 19:30 minute time point. At this point, the current will gradually decrease back to 0 mA.
Sham tDCS	Balance Training	The tDCS device will perform a 30 second ramp up to 2 mA and then an immediate 30 second ramp down to 0 mA. Until the 19:30 minute time point, the tDCS will remain at 0 mA. At this time point, the tDCS will ramp up to 2 mA and then will immediately ramp back down to 0 mA.
4 mA tDCS	Balance Training	The participants in this group will receive tDCS at 4 mA while seated comfortably. The intensity will start at 0 mA and will be incrementally increased to the target intensity (4 mA) over the initial 30 seconds. Then, the tDCS will deliver stimulation at the target intensity until the 19:30 minute time point. At this point, the current will gradually decrease back to 0 mA.
Sham tDCS	Sham Transcranial Direct Current Stimulation (tDCS)	The tDCS device will perform a 30 second ramp up to 2 mA and then an immediate 30 second ramp down to 0 mA. Until the 19:30 minute time point, the tDCS will remain at 0 mA. At this time point, the tDCS will ramp up to 2 mA and then will immediately ramp back down to 0 mA.
2 mA tDCS	2 mA Transcranial Direct Current Stimulation	The participants in this group will receive tDCS at 2 mA while seated comfortably. The intensity will start at 0 mA and will be incrementally increased to the target intensity (2 mA) over the initial 30 seconds. Then, the tDCS will deliver stimulation at the target intensity until the 19:30 minute time point. At this point, the current will gradually decrease back to 0 mA.

Primary Outcome Measures

Name	Time	Method
Score on the Berg Balance Scale	24 hours, 2 weeks, and 4 weeks post-intervention	The BBS is a valid and reliable assessment of balance during static (e.g., standing with eyes closed) and dynamic conditions (e.g., completing a 360-degree turn) conditions. BBS scores range from 0 to 56. Lower scores indicate increased impairment in balance. A cut-off score of 44 has been established as a criterion to identify PwMS with a high fall risk.
Time to Complete the Timed Up and Go Test (TUG)	24 hours, 2 weeks, and 4 weeks post-intervention	The TUG measures the time it takes for the participant to rise from a chair, walk 3 meters, turn around, walk back to the chair, and sit down. Two trials were completed and the reported score is the average time between the two trials. A higher number means it took the participant more time to complete the task (i.e., worse performance).

Secondary Outcome Measures

Name	Time	Method
Time to Complete the Six Minute Walk Test (6MWT)	24 hours, 2 weeks, and 4 weeks post-intervention	Subjects performed the 6MWT in a cordoned-off hallway with two symbols on the ground, placed 30 meters apart. Subjects were instructed to walk as far as possible between the marks for 6 minutes, walking around each symbol like a cone. Higher scores indicate more distance walked (i.e., better performance).
Score on the Fatigue Severity Scale (FSS)	24 hours, 2-weeks, and 4-weeks post-intervention	The FSS consists of nine statements used to assess perceived fatigability. Subjects are asked to rate how much they felt a statement applied to them, on a 7-point scale (low value = does not apply, high value = high agreement with the statement). The questionnaire is scored by calculating the average response to the statements. Therefore, the scores will range from 1 to 7 (1 = low fatigue, 7 = high fatigue). A score ≥ 4 indicates a clinically significant level of fatigue.