Electrical stimulation of the vagus nerve, which originates in the brain and then branches widely throughout the neck, chest and abdomen, seems to help some people with Alzheimer's disease. The study primarily shows that VNS (vagus nerve stimulation) is well tolerated and safe in patients with Alzheimer's disease for up to 12 months. Furthermore, the study gave an indication that VNS may be of benefit, as a cognitive enhancing therapy Researchers from the Karolinska Institute in Sweden previously reported beneficial effects of VNS during a 6-month pilot study involving 10 patients with Alzheimer's disease. This report includes an additional 7 patients with follow-up for at least 1 year. All the patients in the study chose to continue VNS therapy after one year of treatment. Just over 40 percent of the participants showed improvement or no decline in mental abilities on a standard Alzheimer's disease assessment scale after a year of treatment. Most patients completed the year without any changes in their cognitive-enhancing medications. It is important to emphasize that VNS is not an approved therapy for Alzheimer's disease, but the study was performed in order to evaluate if it was safe and tolerated and if it could bring any benefit to patients with a severe chronic neurodegenerative disorder. However, further studies are needed to tell whether VNS can enhance cognition or be of benefit in Alzheimer's disease.
Journal of Clinical Psychiatry,
September 2006