Washington, May 8 (ANI): A device that sends continuous electrical impulses to specific "memory" regions of the brain appears to increase neuronal activity in people with suspected mild Alzheimer's disease (AD), suggest a new study.
Results of the study using deep brain stimulation, a therapy already used in some patients with Parkinson's disease and depression, may offer hope for at least some with AD, an intractable disease with no cure.
AD is a progressive and lethal dementia that mostly strikes the elderly. It affects memory, thinking and behaviour.
"While our study was designed mainly to establish safety, involved only six people and needs to be replicated on a larger scale, we don't have another treatment for AD at present that shows such promising effects on brain function," said the study's first author, Gwenn Smith, Ph.D., a professor in the Department of Psychiatry and Behavioral Sciences at the Johns Hopkins University School of Medicine.
The research was conducted while Smith was on the faculty at the University of Toronto, and will be continuing at Toronto, Hopkins and other U.S. sites in the future.
Andres M. Lozano, chairman of the Department of Neurosurgery at the University of Toronto, led the study.
One month and one year after implanting a device that allows for continuous electrical impulses to the brain, Smith and her colleagues performed PET scans that detect changes in brain cells' metabolism of glucose, and found that patients with mild forms of AD showed sustained increases in glucose metabolism, an indicator of neuronal activity.
The increases, the researchers said, were larger than those found in patients who have taken the drugs currently marketed to fight AD progression.
Other imaging studies have shown that a decrease in glucose metabolism over the course of a year is typical in AD. Alzheimer's disease cannot be precisely diagnosed by brain biopsies until after death.
The team observed roughly 15 percent to 20 percent increases in glucose metabolism after one year of continuous stimulation. The increases were observed, to a greater extent, in patients with better outcomes in cognition, memory and quality of life. In addition, the stimulation increased connectivity in brain circuits associated with memory.
Deep brain stimulation (DBS) requires surgical implantation of a brain pacemaker, which sends electrical impulses to specific parts of the brain.
For the study, surgeons implanted a tiny electrode able to deliver a low-grade electrical pulse close to the fornix, a key nerve tract in brain memory circuits. The researchers - most with the University of Toronto - reported few side effects in the six subjects they tested.
Just as importantly, stated Smith, was seeing that DBS appeared to reverse the downturn in brain metabolism that typically comes with AD.
The study was published in the Archives of Neurology. (ANI)