Researchers at the Burke Medical Research Institute are geared up for an exciting and productive 2014. Three new journal publications in January report on advances in robotic therapy, ophthalmology, and electrical brain stimulation.
“Robotic measurement of arm movements after stroke establishes biomarkers of motor recovery.” Stroke. January 2014.
BMRI author: Avrielle Rykman
With an aging population and improved medical care, more people are surviving stroke but living with stroke-induced disabilities. Among the challenges of clinical trials for stroke treatments is assessment of a patient’s condition before and after treatment—which currently requires multiple human raters who have undergone extensive training. In this study, researchers used interactive robotic technology—MIT-Manus robots—to measure arm movement after stroke in over 200 patients. Compared with 4 well-known clinical assessments (performed by trained clinicians), the robotic measurements were good predictors of clinical outcome over several months. The researchers believe robotic measurements may offer an efficient and reliable method to track patient progress after stroke.
“Intersublaminar Vascular Plexus: The Correlation of the Retinal Blood Vessels With Functional Sublaminae of the Inner Plexiform Layer.” Investigative Ophthalmology & Visual Science. January 2014.
BMRI authors: Elena Ivanova, Ph.D., Abduqodir H. Toychiev, Ph.D., Christopher W. Yee, Botir T. Sagdullaev, Ph.D.
The retina is an extension of the brain and also has the highest oxygen demand of any tissue in the body, making it an ideal site to study the interactions between neurons, glia, and blood vessels. Retinal blood vessels lack autonomic control, and blood flow appears to be regulated locally through neurovascular interactions. In this study, researchers describe a previously unreported network of blood vessels, the intersublaminar plexus, located within the inner plexiform layer of the retina. Immunohistochemistry showed that the intersublaminar plexus is closely associated with glia (Müller cells) and neurons (OFF cholinergic amacrine cells), suggesting a key role in neurovascular interactions. These neurovascular interactions may help mediate retinal blood flow and their disruption may underlie certain retinal diseases.
“Electrical Stimulation of Motor Cortex in the Uninjured Hemisphere after Chronic Unilateral Injury Promotes Recovery of Skilled Locomotion through Ipsilateral Control.” Journal of Neuroscience. January 8, 2014.
BMRI author: Jason B. Carmel, M.D., Ph.D.
Injury to one side of the motor cortex causes impairment in the opposite side of the body because most corticospinal fibers are crossed. However, a small number of same-sided connections exist and have the potential to compensate when crossed connections are damaged. Previous studies in rats showed that targeted electrical brain stimulation soon after injury can strengthen these same-sided connections and improve motor function. In the latest study, researchers found that electrical stimulation was effective even months (equivalent to years in humans) after injury. In rats with chronic unilateral injury, ten days of electrical stimulation to the uninjured motor cortex led to almost complete recovery of motor skills. (To demonstrate that the recovery was indeed due to strengthened same-sided connections from the uninjured motor cortex, the researchers pharmacologically inactivated that part of the brain and showed that the impairment returned.) Ultimately, the researchers hope that electrical brain stimulation to boost spared connections may help patients regain motor function even long after injury.