Researchers from Toronto Western Hospital have discovered a way of enhancing memory that may prove benefi cial in helping those suffering from memory disorders such as Alzheimer’s disease.
The memory-improving treatment is a surgical procedure called deep brain stimulation (DBS). During the procedure, an electrode is implanted in the patient’s brain and then stimulated, to excite a specifi c area of the brain. The electrode is wired under the skin to a battery-operated controller that sits beneath the collarbone and acts as the stimulator. Deep brain stimulation has been approved by the Food and Drug Administration as a treatment for Parkinson’s disease, This is believed to be the first time it has been used in relation to memory function.
The link between DBS and memory was stumbled upon by Dr. Andres Lozano and his team of researchers. While conducting a unique study using DBS in an attempt to suppress the appetite of an obese 50-year-old man, an electrode was placed in the man’s hypothalamus, an almond-sized part of the brain that controls hunger and thirst. When the researchers stimulated the electrode, the result surprised them. The man, who was awake during the procedure, suddenly recalled a memory from his youth. As the stimulation intensity increased, so did the clarity of his recollection.
“We knew that was somewhat of an eureka moment, this was something quite unusual,” said Dr. Lozano, Canada Research Chair in neuroscience and the senior investigator of the study. “We have now direct evidence that by stimulating in this area, we are driving activity in the memory circuit.”
After observing these miraculous results, Lozano and his team changed the focus of their research, testing the memory-enhancing capabilities of deep brain stimulation more rigorously. Psychological tests given to the man before and after the surgery were analyzed. The team found that the patient’s memory scores had improved considerably since undergoing DBS.
“Selectively, only his memory functions seem to have improved and they’ve improved quite signifi cantly,” said Dr. Lozano.
He believes that this research has the potential to develop new treatments for memory disorder sufferers, as it shows that it is possible to manipulate memory circuits to enhance their performance. “Specifi cally, it may be possible to access these circuits in patients who have memory deficits and to try to enhance them and bring them to a more normal level of function,” he said. As a first step towards making these treatments a reality, the team of Toronto Western Hospital researchers are currently pursuing a new line of research involving six patients diagnosed with early Alzheimer’s. They are hopeful that if this research shows DBS to be a safe way of treating memory disorders, it will be possible to run larger experiments in the future.
“If this is reliable, which means we can replicate it and show it again and again, it could be quite profound,” said Mary Pat McAndrews, a neuropsychologist at Toronto Western Hospital who worked on the study. “What we’re hoping to do is to provide some symptomatic relief, changes in memory function, that in the long run may actually preserve independence and quality of life for a longer period.”
The study can be found in the American Neurological Association’s Annals of Neurology Journal
