Collaborative Effort Identifies A Potential Environmental Trigger for Multiple Sclerosis

Timothy Vartanian, MD, PhD

Multiple sclerosis (MS), a chronic, debilitating disorder of the central nervous system (CNS), is known to require an environmental trigger for lesion formation, but the identity of that trigger has long eluded scientists. Suspecting that the environmental trigger for MS rests within the gut microbiome, Timothy Vartanian, MD, PhD, a neurologist and neuroscientist at NewYork-Presbyterian/Weill Cornell Medicine, and physician-scientists, including Christopher Mason, PhD, and Gregory Sonnenberg, PhD, from NewYork-Presbyterian/Weill Cornell Medicine led a collaborative novel research effort using highly sensitive polymerase chain reaction (PCR) detection to show that people with MS were more likely to harbor and to have a greater abundance of epsilon toxin-producing strains of the C. perfringens bacteria within their gut microbiomes compared to healthy controls. This discovery holds promise for the development of new treatments that could halt MS by neutralizing epsilon toxin, thereby offering hope to people who suffer from the disease. The results of this research study were recently published in the Journal of Clinical Investigation.

Chronic stroke patients with hemiparesis often experience functional disuse of their hand and approximately 50 percent of survivors with upper limb paralysis continue to experience functional deficits four years after stroke. Studies have shown that highly repetitive and task-specific training is very helpful in upper limb recovery, however, there are obstacles that can prevent patients from undergoing this type of rehabilitation program, including visiting therapy clinics, insurance and reimbursement limitations, and lack of access to therapists with specialized training.

Epsilon toxin in multiple sclerosis

Robotic devices assist in increased upper limb repetitions for post-stroke rehabilitation but primarily target proximal segments of the shoulder and elbow. Studies with these devices have shown that robotic training produces improved function in the proximal joints. They also have found a disparity of motor recovery between proximal and distal joints that leads to detrimental compensatory grasp patterns.

To address this disparity, Columbia Rehabilitation and Regenerative Medicine specialists and their Mechanical Engineering colleagues have developed a robotic orthosis designed to assist the paretic hand after stroke. The wearable and fully user-controlled device serves as a therapeutic tool that enables patients to perform device-mediated hand exercises for neuromuscular function recovery, as well as an assistive device for use in everyday activities.

Graphical abstract of the study published in the Journal of Clinical Investigation.

Eleven chronic stroke patients with moderate muscle tone underwent a month-long training protocol using the orthosis. The 12-session training program, comprising three sessions per week for four weeks, involved 30 minutes of training time in which the participants practiced a variety of grasp and release tasks with everyday objects and were then evaluated with a battery of clinical assessments pre- and post-intervention. Fugl-Meyer post-intervention scores without robotic assistance showed improvement focused specifically at the distal joints of the upper limb. Action Research Arm Test (ARAT) scores post-intervention with robotic assistance showed that the device may serve an assistive role in grasping tasks.

The authors note, however, that while trends in the data suggest this device might serve two distinct purposes – rehabilitation or assistive – for different subsets of the stroke population, the results also highlight limitations and point towards possible areas for future improvements, including longer training periods.