An article by Phillip Krause, Johann Szecsi and Andreas Straube from the University of Munich reported benefits in reducing spastic muscle tone in a patient with MS. Stimulation by means of surface electrodes applied to the thigh muscles induced cycling leg movements.
Spastic muscle tone was measured clinically using the modified Ashworth scale and semiautomatically by pendulum testing of spasticity. This was done before and directly after stimulation.

The patient was able to endure the stimulation for 30 minutes;  there was a significant reduction of spasticity after each stimulation session. The authors conclude, that this type of stimulation could be another potential treatment modality for multiple sclerosis patients, especially those with a high score in the expanded disability Status scale.

In this case study published in the Journal of NeuroRehabilitation 22 (2007) 335–337, the authors report on a patient with multiple sclerosis who was able to tolerate FES for the induction of cycling leg movements and experienced a reduction of spastic muscle tone. 

A 46-year-old man with multiple sclerosis for more than 20 years took part in these pilot experiments. His MS episodes were initially completely remitting, but they took a secondary progressive course 10 years ago.

The patient’s current clinical state was characterized by tetraparesis mainly of the lower limbs and the left side. With a score of 7.5 on the expanded disability Status scale (EDSS), he was unable to walk and used a wheelchair for most distances, including those in his home. He was able to stand up only with support.

The degrees of muscle force were 1–2/5 in the distal and 4–5/5 in the proximal muscle groups of the lower limbs. His arms showed degrees of around 4/5.

Force impairment was also mainly on the left side, and all other fine motor activity was strongly limited. At the time of the study he was taking no medication for MS or spasticity, and no MS episode had occurred.

A patient with MS who tolerated FES very well showed a visible (swing curves) and measurable (peak velocity and relaxation index) reduction of spastic muscle tone directly after FES. Since the patient came only once in two weeks for the training and then also only for the period of testing before the training, and after testing, we could not record a further course of reduction of spasticity. However, the patient reported experiencing
the reduced muscle tone for several hours after training.

With each training session the patient tolerated the uncomfortable sensations induced with increasing electricity (from 30 mA up to 90 mA) and became used to FES.

In addition to the reduction of spasticity, as described here, FES also has other benefits, as known from its use in spinal cord injured or stroke patients.

We think that this case study presents another possible use of FES also for patients with MS and a higher EDSS score. It would be a positive additional physical therapy tool and can improve the mobility of such patients.

However, a further systematic investigation in MS patients, also concerning the question
of force development with FES training would be necessary.  This would also allow speculation about the underlying mechanisms.

A patient with MS who tolerated FES very well
showed a visible (swing curves) and measurable (peak
velocity and relaxation index) reduction of spastic muscle
tone directly after FES. Since the patient came only
once in two weeks for the training and then also only
for the period of testing before the training, and after
testing, we could not record a further course of reduction
of spasticity. However, the patient reported experiencing
the reduced muscle tone for several hours after
training.
With each training session the patient tolerated the
uncomfortable sensations induced with increasing electricity
(from 30 mA up to 90 mA) and became used
to FES. In addition to the reduction of spasticity, as
described here, FES also has other benefits, as known
from its use in spinal cord injured [8] or stroke patients
[3]. We think that this case study presents another
possible use of FES also for patients with MS and
a higher EDSS score. It would be a positive additional
physical therapy tool and can improve the mobility
of such patients. However, a further systematic investigation
in MS patients, also concerning the question
of force development with FES training would be necessary.
This would also allow speculation about the
underlying mechanisms.