Addiction Subtraction: Brain Damage Curbs Cigarette Urge
Brownlee, C., Science News
Scientists have identified an area of the brain where damage seems to quickly halt a person's desire to smoke. The region could form a target for novel therapies to help people quit smoking, the researchers say.
Led by neuroscientist Antoine Bechara of the University of Southern California in Los Angeles, the team homed in on this brain area after learning about an unusual stroke patient whom they identify only as N. From age 14, N. had been a heavy smoker. But after his stroke at age 28, he never lit up again.
Smokers typically undergo well-characterized emotional and physical withdrawal symptoms that make quitting extremely difficult However, N. effortlessly quit smoking immediately after his stroke and never relapsed. He told doctors, "My body forgot the urge to smoke."
Bechara says, "What is striking is that it was as if a switch had been turned off--he quit just like that, without any effort at ally
To see whether brain damage caused by N's stroke played a role in his smoking cessation, Bechara and his colleagues scanned N.'s brain to identify the stroke-affected area. They spotted damage in the insula, a region deep inside the cerebral cortex. The insula had previously been associated with monitoring the body's internal conditions and controlling conscious urges, such as the desire to eat.
The researchers next identified 69 smokers or former smokers with a variety of damaged brain areas caused by strokes, surgery, or other factors. Nineteen of these patients had damaged insulas, and all had quit smoking. …