Investigational use of deep brain stimulation for Alzheimer’s disease has arrived in the United States.
As a part of a new multicenter trial funded by the National Institute on Aging and Functional Neuromodulation, the Advance Study, Johns Hopkins University neurosurgeons recently implanted the first device into a patient with mild Alzheimer’s disease. Via two implanted ultrathin wires, the device delivers 4-8 V electrical charges directly to the fornix on both sides of the brain. The fornix, one of the first brain regions to be destroyed by Alzheimer’s, is involved in memory formation, and serves to relay signals between the hippocampus and hypothalamus.
A second patient is scheduled for the same procedure this month, according to Johns Hopkins, in Baltimore. About 40 patients are expected to receive the deep brain stimulation implant over the next year or so at Johns Hopkins; the University of Toronto; the University of Pennsylvania, Philadelphia; the University of Florida, Gainesville; and Banner Health System in Phoenix.
Half of the patients in the study will have the devices activated 2 weeks after surgery, while the others will have the device turned on after 1 year. All study participants will be regularly assessed for at least 18 months to measure their rate of Alzheimer’s progression.
As part of a preliminary safety study in 2010, the devices were implanted in six Alzheimer’s disease patients at the University of Toronto. Researchers found that patients with mild forms of the disorder showed sustained increases in glucose metabolism, an indicator of neuronal activity, over a 13-month period (Ann. Neurol. 2010;68:521-34). Most Alzheimer’s disease patients show decreases in glucose metabolism over the same period.