His other major research goal is to improve rehabilitation for patients who are having difficulty walking. One of Clark’s projects involves physical therapy patients being provided noninvasive, mild electrical stimulation to the brain using electrodes attached to their forehead. Previous studies have shown this method could be effective in helping reinvigorate the neural circuits responsible for controlling the many different elements of walking. However, this is the first study using the intervention across multiple sessions.
In a similar study, Clark is moving the electrodes from the forehead to the lower back in an attempt to stimulate the lumbar spinal cord. “The spinal cord is where a lot of these neural circuits are—the central pattern generators that we think create the pattern of muscle coordination needed for walking,” he explained. “We’re trying to use this electrical stimulation to upregulate those circuits.”
Because of the sheer number of variables in these studies, Clark expects to be working on them for the foreseeable future, tweaking different elements to narrow in on the best protocol. “Currently patients in the study are stimulated for 20 minutes using two milliamps of current. We don’t know if those are the right parameters,” Clark explained. “In terms of where we place the electrodes, we don’t know if we have that quite right. Is 16 sessions too little or too much? Maybe 80% of improvement happens in the first 10 sessions.”
Thinking of the field as a whole, Clark said that personalized medicine will have a big impact on rehabilitation. Not all gait impairments are the same, so not all therapy can be the same.
“People spend a lot of time in physical therapy,” he said. “And if you’re not doing the right therapy, that’s a lost opportunity.”
Clark noted that, while the attention of the nation has naturally turned toward the most recent generation of veterans, the previous generations are continuing their path to old age and the ailments that come with it. That makes research into age-related impairment more important than ever for VA.
“About half of veterans are 65 and older,” he said. “Loss of mobility function and loss of independence is a huge cost and a huge issue that the VA healthcare system is going to be dealing with for decades to come.”