For years, deep-brain stimulation—in which a neurosurgeon drills a hole in the skull and inserts an electrode far into a patient’s brain tissue—was considered a radical treatment, reserved for the most severe cases of Parkinson’s disease. Now neurologists are exploring the treatment for disorders ranging from depression to Alzheimer’s disease.
In 2009 two clinical trials began testing deep-brain stimulation (DBS) to ease intractable depression. The process was given a green light by the Food and Drug Administration to treat the worst cases of obsessive-compulsive disorder after a small pilot study showed promising results. Mount Sinai School of Medicine neurologist Giulio Pasinetti is in the early stages of testing DBS for Alzheimer’s disease, and neurosurgeon Bomin Sun of the Center of Functional Neurosurgery at Shanghai Jiao Tong University is harnessing it to treat anorexia.
Across a range of disorders, deep-brain stimulation works much the same way: A pacemaker-like device in the chest transmits a signal to the implanted electrode via wires that run underneath the scalp. The device is thought to modulate electrical activity in the circuitry of the dysfunctional brain, explains Oxford University neurosurgeon Tipu Aziz, who is exploring DBS as a treatment for cluster headaches.
The new studies build on work by Emory University neurologist Helen Mayberg. In 2005 she showed that direct modulation of specific brain circuits could help severely depressed patients who had not responded to other treatments. “The concept of tuning brain circuits is a new strategy,” she says. Neuroimaging can pinpoint regions of dysfunctional brain activity, making it possible to understand the underlying biology of a disorder and correct abnormal rhythms of the brain.