Neurosurgeons hope to treat some of the most intractable mental disorders by putting advanced arrays of electrodes into patients’ brains.
When Emad Eskandar talks about one of his neurosurgery patients with obsessive compulsive disorder, he’s not talking about someone who arranges his record collection by color, size, and name. Or someone who ritualistically touches the knob on the stove twice before leaving the house and says, “Sorry, I’m a little OCD.”
Eskandar’s OCD patients take three-hour showers. They spend eight hours cleaning their surroundings with bleach. They get stuck at the bathroom sink in their hotel room on appointment days, unable to stop washing their hands until someone comes to get them. OCD affects an estimated 2.5 million adult Americans. But only those who have exhausted all other treatment options—Luvox, Anafranil, Prozac, cognitive behavioral therapy—end up on Eskandar’s operating table at Massachusetts General Hospital. By then, they are desperate enough to try almost anything—even deep brain stimulation (DBS), an option of last resort that Eskandar has spent the last 15 years mastering and refining.
In an initial surgery, Eskandar drills two dime-size holes in the top of the patient’s skull and sinks 42-centimeter-long electrodes about seven centimeters deep into the gray matter of the brain. In a second surgery, usually a couple of days later, he creates a pocket under the skin in the chest or abdomen, implants a device incorporating a battery and pulse generator into this newly created space, and runs a wire up to the skull, connecting it with the electrodes. When turned on, the device emits an electrical current that stimulates the neural fibers carrying information from primitive brain areas associated with motivation to the frontal lobe. In 50 percent of Eskandar’s cases, a miracle follows: the obsessions and compulsions fade and then disappear.
Though the treatment sounds extreme, in some respects his OCD patients are the lucky ones. There is no such FDA-approved last-resort option for the millions of Americans suffering from other psychiatric illnesses, such as depression, post-traumatic stress disorder, or schizophrenia. Or for borderline personality disorder and traumatic brain injuries. But for all these conditions, that may soon change.
Deep brain stimulation has been used for almost two decades to treat patients with severe forms of Parkinson’s (and since 2009 to treat a far smaller number of patients with OCD). As many as 125,000 people are living with electrodes implanted in their brains. As part of President's Brain Initiative, Eskandar is co-leading a team of doctors, scientists, and engineers that is one year into a five-year, $30 million effort to use DBS to treat severe psychiatric disorders, most of which have been considered too complex and mysterious for any such system currently on the market. Conditions like schizophrenia, PTSD, and depression are characterized by unpredictable changes in the brain that lead to intermittent episodes. Taming them will require a new kind of device capable not just of stimulating the brain but of monitoring brain activity in real time and detecting anomalies that, in many cases, neuroscientists have not yet identified.
By Adam Piore
MIT Technology Review
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