LAS VEGAS—After stroke, many patients have chronic arm or hand weakness that years of standard therapy fail to improve. Vagal nerve stimulation (VNS) paired with an aggressive rehabilitation regimen may be a feasible and safe treatment alternative, according to interim data reported at the 18th Annual Meeting of the North American Neuromodulation Society. Interim data from this pilot study are encouraging, said Jesse Dawson, MD, Clinical Reader at the University of Glasgow Western Infirmary.
Dr. Dawson and colleagues enrolled 20 patients with ischemic stroke and chronic upper limb deficits into a randomized controlled proof-of-concept trial. Participants had an Action Research Arm Test (ARAT) score of between 15 and 50, indicating moderate to severe deficits in upper limb function. After a baseline assessment phase, patients were randomized to rehabilitation therapy alone or rehabilitation therapy plus VNS.
Rehabilitation therapy consisted of thrice-weekly in-clinic sessions for six weeks. During each session, the participants performed between 300 and 400 goal-oriented, repetitive, and intensive tasks. For the nine patients who received VNS implantation, each movement therapy task was accompanied by a 0.5-s period of stimulation.
The researchers assessed the participants again after the last therapy session. The study’s primary end point was safety and feasibility. Secondary end points included measures of upper limb function such as Upper Limb Fugl Meyer (ULFM) score and ARAT score.
Both groups showed improvement at the trial’s completion. Improvement was significantly greater, however, among patients who received VNS. The average change in ULFM was 7.8 for patients who received VNS and 2.7 for patients who received rehabilitation alone. An increase of 6.6 points from baseline was considered clinically meaningful.
Five of the eight patients who received VNS and for whom data were available had a clinically meaningful improvement in ULFM from baseline to study conclusion. In contrast, two of the nine participants who received rehabilitation alone and for whom data were available had a clinically meaningful improvement in ULFM.
“In the full analysis set, there was a difference of six points on the Fugl Meyer score on average,” said Dr. Dawson. “That did reach statistical significance.” Approximately 75% of the participants had a clinically meaningful response.
“We have numerous patient testimonies that these are functional gains,” he continued. “This is predominantly an impairment scale that we saw the difference on, but they were functional gains in the eyes of the patient.”