Pacemaker for the Brain
Brain surgery isn't something people normally volunteer for. But for Parkinson's sufferer Kenneth Golby, 63, the hope of getting some mobility back was worth the risk. After reading about deep brain stimulation (DBS) - a treatment where wires attached to a pacemaker-like device are implanted in the centre of the brain - Golby spoke with the specialists at Toronto Western Hospital and had the operation in 2000. "I was absolutely terrified," recalls the retired York University Spanish professor, who had been struggling with Parkinson's for at least 14 years. "The thought of someone opening up your head is very different from somebody opening up your stomach."
First tested as a treatment for Parkinson's in 1987, DBS is no miracle cure: the stimulation doesn't stop the disease's progression or reduce its characteristic stiffness and slowness more than levodopa, the most common Parkinson's medication. Also, only about 10 per cent of patients are eligible for the procedure since they must be in good physical and mental health to undergo serious surgery. But for the right patient, DBS can make a huge difference. The side effects of Parkinson's drugs often become unbearable after about five years. Patients end up "frozen" - unable to move, sometimes for several hours - before their next dose kicks in. "They can't go out or they can't keep a job because they never know when they're going to be mobile," says Dr. Anthony Lang, director of the Movement Disorders Clinic at Toronto Western Hospital, which was one of the early pioneers of DBS. Its advantage: as well as keeping patients at a stable level of mobility, DBS also reduces the tremors that are a side effect of drugs. "My tremors were so violent," says Golby, who lives in a rural area northeast of Toronto, "that I used to tie myself to the bed to stop myself from falling to the floor. That stopped almost immediately after the surgery."
How DBS reduces stiffness and tremors remains a mystery. "Probably the current interferes with some abnormal activity in the brain," says neurologist Dr. Elena Moro. "Actually, though, we don't know." One of Moro's jobs is to adjust the electrical impulses that the pacemaker sends to the brain, a process that involves some trial and error. But the results have been interesting enough to encourage experimentation on other movement disorders such as Huntington's disease and Tourette's syndrome. Earlier this year, U.S. surgeons performed the first DBS surgery on a 31-year-old Ohio man, Jeff Matovic, with Tourette's - curing him of the uncontrollable vocalizations and movements he had been suffering from since he was 6. There is now talk that this type of electrical stimulation could help some psychiatric problems - everything from obsessive-compulsive disorder to depression and even eating disorders. No one would suggest that the technique should be used as routine treatment, says Dr. Lang - it's brain surgery, after all. But it could provide hope in special cases.
Maclean's August 2, 2004