What is deep brain stimulation?

Deep brain stimulation, or DBS, is a concept that dates back 70 years, but has only been in clinical use since the 1990s.

The DBS device, or implant, is much like a pacemaker. The neurostimulator is a battery-operated device that generates mild electrical impulses, and it is implanted under the skin of the chest. The surgeon identifies the proper location in the brain to insert the leads, then implants these leads on both sides of the patient’s formix (the C-shaped, main structure of the hippocampal formation). The leads are then connected to the extensions which are implanted beneath the skin of the neck, and the extensions are connected to the neurostimulator.

Once everything is connected, the DBS device is turned on and generates tiny electrical impulses into the brain 130 times per second. The patient does not feel the current. The device usually remains in place for the remainder of the individual’s life, yet, the batteries typically need to be replaced every five or six years.

DBS therapy is most commonly used for individuals with Parkinson’s or essential tremors, dystonia, epilepsy and obsessive compulsive disorders. Researchers are studying its effectiveness to treat severe depression, anorexia, chronic pain and addiction.

A small Canadian study showed that a DBS implant increased glucose metabolism in the brain, which meant that the neurons were more active and energized, thus patients in the study scored higher on memory tests. From this small study, researchers at Johns Hopkins and other institutions launched the ADvance trial in late 2012, in which at least 40 patients with mild Alzheimer’s disease began receiving the DBS implant.

Researchers will measure disease progression over an 18-month period. The theory is the DBS device could slow the onset of the damage to the formix, create new brain cells in the hippocampus (region of the brain responsible for maintaining long-term memory) and trigger the release of chemicals that protect the brain’s circuitry.

Treatment using the DBS device can come with some risks, such as elevated or depressed moods, infection, brain hemorrhage or general device hardware breakdown.

The number of people age 65 and older with Alzheimer’s disease is expected to triple by 2050 unless an effective treatment and/or cure can be found. Researchers are hopeful that deep brain stimulation, which has shown positive results in the treatment of Parkinson’s, might someday prove to be a useful mechanism in treatment for Alzheimer’s disease, too.

Questions about Alzheimer’s disease or a related dementia disorder? Contact Dana Territo, the Memory Whisperer, Director of Services at Alzheimer’s Services of the Capital Area, (225) 334-7494, advice@alzbr.org, or visit the organization at 3772 North Blvd., Baton Rouge.