, compared with alternative interventions with medicines. “The findings suggest for the first time that physical behavioral change therapy can significantly stimulate cortical neuroplasticity in a degenerative central nervous system disorder,” said the authors of research presented at the virtual meeting of the Consortium of Multiple Sclerosis Centers (CMSC).
CIMT, an intervention involving 3.5 hours/day of therapist-supervised treatment over 10 consecutive weekdays, has been shown to significantly improve paretic limb use for patients with progressive MS, and the effects are long lasting.
For patients with asymmetric upper limb nonuse, the treatment “is highly successful for promoting increased use by the more-affected arm for everyday activities,” said lead author Victor W. Mark, MD, an associate professor and medical director of the Constraint-Induced Movement Therapy Research Programs at the University of Alabama at Birmingham. “The improvements after CIMT can be found to remain as much as 1 year after the completion of the treatment, and even later. That by itself is novel for MS,” he said.
The team’s previous research in Neurorehabilitation and Neural Repair showed that the CIMT intervention is associated with statistically significant changes in white matter integrity in the brain. In this new study, Dr. Mark and colleagues sought to determine whether the effects would also translate to improvements in cortical gray matter.
Promoting neuroplasticity, improving motor function
For their study, they enrolled 20 adults with chronic MS who were matched with respect to unilateral arm disability. The participants were randomly assigned to receive 35 hours of either CIMT or a holistic complementary alternative medicine program, which included yoga, aquatic therapy, massage, and/or relaxation techniques, over the course of 2 weeks.
Both groups expressed the same degree of expectancy of benefits from the intervention. Those who received CIMT showed a significantly larger effect size on the Motor Activity Log, a measure that has been validated against real-world upper-limb accelerometry, compared with the control group (d = 3.2, vs. d = 0.7).
Imaging with tensor-based morphometry showed an increase in the thickness of the primary motor cortex in patients who underwent CIMT but not those who received the alternative medicine treatment. Furthermore, a change in the primary motor cortex was observed in the CIMT group on voxel-based morphometry, suggesting an increase in cortical density or volume, or both. Similar changes were not seen in the alternative medicine group.
“We evaluated the density of the brain cortical gray area before and after treatment, and we found increased gray matter in the area of the brain that is concentrated with voluntary limb movement (the motor cortex),” Dr. Mark said. “As in (previous) studies, we did not find such changes, or any changes, after the other form of treatment,” he said.
The results are important, Dr. Mark noted, “because CIMT seems to specifically promote neuroplasticity changes that appear to be healthy, for what is otherwise a chronically progressive degenerative neurological disorder.”
In addition to the improvements in MS, CIMT has led to improvement in motor function for patients who have experienced other central nervous system injuries, including stroke, traumatic brain injury, cerebral palsy, and, in musicians, focal hand dystonia.
The new findings offer intriguing insights into the effects in progressive MS, commented rehabilitation specialist Patricia Bobryk, MHS, a physical therapist with the UCHealth Yampa Valley Medical Center, in Colorado Springs.
“There is more evidence for CIMT in the area of stroke, which is more acute onset and with more potential recovery, especially early on, so this is exciting initial work in terms of MS,” she said.
“If we’re trying to find new avenues in the brain for better pathways, rather than using something that’s damaged in MS, it makes perfect sense that CIMT really forces and drives those connections, because you’re doing a repetitive, high-intensity patterning throughout the day, so you set up that environment for things to progress, especially in motor functioning,” she said.