Effects of Nonconsecutive Sessions of Transcranial Direct Current Stimulation and Stationary Cycling on Walking Capacity in Individuals With Multiple Sclerosis

Abstract

Background: Exercise has been demonstrated to be safe and well-tolerated in individuals with multiple sclerosis (MS). Physical activity has been shown to enhance the therapeutic effects of transcranial direct current stimulation (tDCS). This study aimed to determine the efficacy of intermittent tDCS combined with riding a stationary bicycle to improve walking capacity in individuals with MS. Methods: This double-blind randomized controlled trial enrolled 50 eligible participants. Thirty-nine participants completed the study: 21 in the active group and 18 in the control group. Participants were assigned randomly to exercise on a stationary bike in conjunction with anodal tDCS or to exercise combined with a sham tDCS protocol. Walking capacity tests (2-Minute Walk Test, 5-Meter Walk Test, Timed Up and Go test), manual muscle testing, the Fatigue Severity Scale, and the Multiple Sclerosis Quality of Life–54 were used to determine outcomes. Results: In terms of observed changes in 2-Minute Walk Test and 5-Meter Walk Test values, the exercise + tDCS group achieved significantly higher posttreatment values than the exercise + sham tDCS group. After the intervention and 1 month later, the intervention group's mean Timed Up and Go test value decreased significantly (P = .002) compared with that of the control group. There was no difference in Fatigue Severity Scale score, Multiple Sclerosis Quality of Life–54 score, or manual muscle testing improvement between the 2 groups. Conclusions: Nonconsecutive sessions of anodal tDCS combined with stationary cycling may have a greater effect on the walking capacity of individuals with MS than exercise alone.

Effectiveness of transcranial direct current stimulation on balance and gait in patients with multiple sclerosis: systematic review and meta-analysis of randomized clinical trials

“…This systematic review included 11 RCTs with a total sample of 230 participants for qualitative analysis, of whom 156 (67.82%) were females, with a mean age of 40.3 years for the entire sample. The types of MS included in the studies were as follows: relapsing-remitting MS in 9 studies [ 30 – 33 , 35 – 38 , 40 ], primary progressive MS in 4 studies [ 30 , 32 , 33 , 36 ], and secondary progressive MS in 2 studies [ 36 , 38 ]. None of studies included recurrent progressive MS. Out of the 11 included studies, eight applied the McDonald criteria for MS diagnosis and participant inclusion in the study [ 41 ].…”

“…The remaining three studies applied stimulation over the cerebellum, with the cathode placed on the buccinator muscle [ 34 , 38 , 39 ]. Five of the studies used electrode sizes of 25 cm 2 [ 30 , 32 , 33 , 35 , 37 ], four studies [ 34 , 38 – 40 ] used 35 cm 2 electrodes, and only two studies [ 31 , 36 ] used 16 cm 2 electrodes. The current intensity varied between 1.5 mA and 2.5 mA.…”

“…The current intensity varied between 1.5 mA and 2.5 mA. The applied current density ranged from 0.04 mA/cm 2 [ 34 ], 0.05 mA/cm 2 [ 38 , 40 ], 0.08 mA/cm 2 [ 30 , 35 , 37 , 39 ], 0.09 mA/cm 2 [ 36 ], 0.1 mA/cm 2 [ 32 , 33 ], to 1.5 mA/cm 2 [ 31 ], which was the highest current intensity used.…”

“…Two articles applied 15 min of stimulation [ 38 , 39 ]. One study applied stimulation for 25 min [ 36 ], and Oveisgharan et al used the longest stimulation time of 30 min [ 31 ]. The frequency of sessions varied from two to seven per week, with a frequency of 5 sessions per week being the most common [ 32 – 34 , 37 , 38 , 40 ].…”

“…Regarding the blinding protocol, all articles implemented similar setups between the real stimulation and sham groups, also keeping the sham stimulation time equal to the real stimulation time. Six articles used a 30-second ramp-up at the beginning of sham stimulation [ 30 , 31 , 34 , 36 , 38 , 40 ] and three articles used a 60-second ramp-up [ 32 , 33 , 37 ] to simulate the initial itching that is felt with tDCS and then disconnecting the current. This type of protocol has been described as effective for conducting double-blind clinical trials in neurorehabilitation [ 43 ].…”