A version of this (DBS-deep brain stimulation) is used in Parkinsons treatment for some folks. They have an implanted stimulator that sends pulses to the specific area of the brain that needs it. It stops the tremors associated with Parkinsons for an extended period of time. I read an article about it the other day but I am unaware if it is being trialed for MS.

They actually do the surgery while you are awake! The neurosurgeon needs you to be awake so they know that they are on the correct area of the brain to have the most effective treatment. After a few weeks of recovery, the stimulator is turned on with remarkable results. It can literally stop tremors and dystonia the second it is turned on. The patient can turn it on and off at will, and it's amazing to watch what happens when they do.

Perhaps for MS, like for Parkinson's, it will be an implanted lead to the area of the brain with a stimulator box outside the body.

They are also now doing experiments with DBS in the spinal column, rather than chancing invasive surgery on the brain.

This stuff is fascinating! I love science!