Deep Brain Stimulation May Boost Memory
Patient Flashes Back Decades in Time After Getting Deep Brain Stimulation
Jan. 30, 2008 -- Deep brain stimulation may boost memory, Canadian doctors
Deep brain stimulation is used to treat conditions including Parkinson's disease, essential tremor, and multiple sclerosis. Surgeons implant electrodes at certain
spots in the brain and use electricity to stimulate those parts of the
Toronto Western Hospital's Clement Hamani, MD, PhD, and colleagues performed
deep brain stimulation on a 50-year-old man who was morbidly obese.
Deep brain stimulation isn't a typical treatment for obesity. But the
patient had already tried other obesity treatments and refused to get weight loss surgery, such as gastric bypass.
After informing the man about the procedure's risks -- and getting his
approval -- the doctors performed deep brain stimulation. They positioned the
electrodes to target a brain area called the hypothalamus, in the hopes that
stimulating the hypothalamus would curb eating.
When the electrodes were stimulated at a certain threshold, the man reported
feeling like he was about 20 years old, in a park with the friends and
girlfriend he had had at that age. And those memories got more intense at
Later, the man performed better on a memory test while the electrodes were
being stimulated, compared with his test performance when the electrodes were
"It may be possible to apply electrical stimulation to modulate memory
function," the researchers write in today's advance online edition of the
Annals of Neurology.
As for the patient's weight, deep
brain stimulation wasn't the answer.
The man weighed nearly 420 pounds
before getting surgery to implant the deep brain stimulation
electrodes. His weight didn't budge during the first six months of deep
brain stimulation. After that, his doctors tried deep brain stimulation at a
lower frequency, and he lost about 26 pounds over five months without changing
his diet or activity; he said he didn't crave food or want to binge eat as much
as he had in the past.
But then the patient decided to
turn off his deep brain stimulator on some evenings because he "had a
desire to eat and he felt it might help him sleep," write the
researchers. Over five months, the patient regained the weight he had