By William Lee Adams, Matthew Hutson, published on July 1, 2008 - last reviewed on November 20, 2015
Keith Lucas makes a mess when his mother changes his diaper, bangs his head during meals, and often puts his thumbs in his mouth. But Keith isn't a toddler—he's 16 years old. And he isn't just sucking his thumbs; he's trying to gnaw them off.
Keith lives with Lesch-Nyhan Syndrome (LNS), an inherited condition marked by a compulsion to injure oneself. Sufferers chew their lips, rub their skin raw, and dig open sores. Although they experience pain as intensely as the rest of us, they can't restrain themselves during self-injurious episodes.
"It's hard to find another disorder where the behavior is so frequent and so extreme," says H.A. Jinnah, a neurologist at Johns Hopkins University who has been studying the condition for more than 20 years. We all experience irrational, destructive thoughts—What would happen if I jumped in front of that train?—a tendency Edgar Allan Poe called "the imp of the perverse." But LNS urges are uncontrollable, Jinnah says. "LNS kids have the same impulses we do. They just lack the frontal lobe 'editing' of behavior."
Patients typically start exhibiting self-injurious behavior between the ages of 2 and 6, and physical symptoms such as gout and kidney stones are present from birth, due to an overproduction of uric acid. Sufferers display serious motor deficits and never develop the ability to walk. Doctors frequently misdiagnose LNS as cerebral palsy.
Self-injurious episodes come on randomly, but seem to increase when patients are bored or unoccupied. Philip Baker, 37, can sometimes sense an impending attack moments beforehand. His mother says that his face will involuntarily twitch and his tongue extend, alerting her to move him away from tables, which he might kick or ram his head on. He sometimes begins cursing at family members, and always apologizes afterward. Outbursts occur less when his mind is focused on something else. (His favorite distractions are surfing MySpace and watching the Mets on TV.)
Although the average IQ of an LNS patient is only 70 (which represents mild to moderate mental retardation), many possess normal intelligence and can think critically about their condition. Keith, for instance, appreciates the physical restraints his family provides. He wears leather arm splints so he can't bite his hands and sleeps with four leg and arm restraints so he won't poke his eyes or throw himself out of bed. "He asks to be protected," says his mother, Michelle Lucas.
In addition to self-harm, the impulse to injure can be directed externally. Keith sometimes head-butts his parents and throws food in their faces during meals. He also plays mind games with them. When his grandparents died, he taunted his mother about her loss. "It's almost like he tries to push away those he loves the most," she says. —William Lee Adams
In the last few years, scientists have been experimenting with a new therapy for Lesch-Nyhan Syndrome: deep brain stimulation (DBS). DBS, a common treatment for Parkinson's disease, uses electrodes inserted deep into the brain and connected to a battery pack. In several LNS patients, electrical stimulation of the basal ganglia has reduced self-injurious behavior, but the trials have not all been successful. The treatment was discovered by accident in a patient whose parents hoped to reduce his dystonia and found that he also bit his hands less with the implants. —Matthew Hutson