Deep Brain Stimulation Improves Motor Ability in Stroke Survivors
Post by Rebecca Hill
The takeaway
Stroke survivors’ motor abilities are often impacted over the longer term, especially in their arms and hands. Deep brain stimulation applied to the area in the brain involved in motor coordination results in an improvement in motor abilities in the arms and hands of stroke survivors.
What's the science?
Strokes can cause lasting and life-impacting effects on motor capabilities that leave survivors reliant on others for care. Neuroplasticity, the ability of neural cells to change their pathways and adapt to trauma, can be induced using continuous deep brain stimulation. Previous work in rodent models of stroke found that deep brain stimulation in the cerebellar dentate nucleus, part of the pathway in the brain that coordinates motor function, can promote recovery from brain trauma - but this has not yet been explored in humans. This week in Nature Medicine, Baker and colleagues used deep brain stimulation to activate neural plasticity and improve stroke survivor’s upper-extremity motor abilities in the arms and hands.
How did they do it?
The authors enrolled 12 participants in the study who were survivors of stroke and showed moderate-to-severe weakness in the arms and hands. The participants were implanted with a deep brain stimulation system and had stimulation delivered continuously for 4 months while also completing physical rehabilitation. Rehabilitation involved repetitive strength-building exercises in the clinic with a physical therapist and independently at home for 3-5 other days of the week. Deep brain stimulation implants consist of electrodes that can deliver stimulation to the target brain area: the cerebellar dentate nucleus. Participants were scored on their motor abilities using an assessment that evaluates motor impairment in the arms and hands.
What did they find?
The authors found an overall increase in participants’ arm and hand motor abilities after deep brain stimulation combined with physical rehabilitation. This suggests that this combination of treatments targeting the dentate nucleus could effectively treat stroke survivors with impaired motor function. The strength of the effect of treatment was not related to the amount of time it had been since the stroke had happened. This suggests that this treatment can be helpful and effective for survivors of stroke even up to 3 years after the initial incident.
What's the impact?
This study is the first to show that the dentate nucleus in the cerebellum is a promising target location for DBS to improve motor function in stroke survivors. These results support a new and safe approach to treating stroke survivors with seemingly no adverse effects. With more testing, this treatment may be broadly applied to the great population of stroke survivors and greatly improve health outcomes after stroke.