An initial study indicates that patients with mild Alzheimer’s may benefit from deep brain stimulation, a technique already used for people with other neurodegenerative diseases (including Parkinson’s.
Deep brain stimulation as a possible Alzheimer’s treatment was discovered by accident when a 50-year-old man was undergoing deep brain stimulation as an experimental obesity treatment.
The hope was that electrical stimulation of the brain would help regulate appetite. But in the midst of surgery, the patient was flooded with detailed memories more than a decade old. Over the next year, researchers discovered that the man – who had a normal memory prior to the surgery – scored much higher on memory tests when the current was on.
This led to hope that the technique could be used to improve memory in Alzheimer’s patients. Dr. Andres M. Lozano, chairman of neurosurgery at the University of Toronto and Canada Research Chair in Neuroscience, initiated a small study with six Alzheimer’s patients.
For 12 months, implanted electrodes continuously stimulated areas of the brain known to affect memory. Patients also remained on medication throughout the study. Researchers expected patients’ memories to worsen over the year; however, patients did not worsen, and some had improvements in their cognitive function.
Lozano outlined the results in a paper appearing in the Annals of Neurology. Imaging scans of patients in the study found heightened glucose metabolism in areas of the brain damaged by Alzheimers, indicating a higher level of brain activity.
According to researchers, the procedure appears to work by driving activity in less damaged areas of the brain and reactivating brain circuits that are responsible for cognitive functioning. The technique appears to be more effective for those with mild Alzheimer’s.
While the study showed no negative effects of the treatment, deep brain stimulation is an invasive technique with significant risk as it involves drilling a hole through the skull and putting a needle through the brain to implant the electrode. Voltage delivered to the brain is controlled by a power pack implanted in the patient’s chest and connected to the electrode by wires under the skin
Researchers are now embarking on a larger second phase of the study to determine if deep brain stimulation will prove a helpful technique for Alzheimer’s patients.
DeMarco, B., Alzheimer’s Reading Room (alzheimersreadingroom.com)
Gardner, A., HealthDay (healthday.com)