"Deep Brain Stimulation" (DBS) sounds like a term from a sci-fi novel: "I was afraid of this. The aliens have enhanced their intelligence with Deep Brain Stimulation!" Or maybe some new-age ritual: "I did a wheat grass juice cleanse and then we did some Deep Brain Stimulation, and now I'm polishing my aura." Actually it's neither. Instead it's cutting-edge surgery (sorry!) that can restore a great deal of motor function to patients who suffer from Parkinson's Disease, Benign Essential Tremor, or Dystonia. Here is a good basic look at the operation. Essentially what the procedure does is equip patients with a battery that zaps a part of the brain that goes haywire in patients. A device is implanted, and pulses a tiny jolt of current that discourages the misbehaving portion of the brain from acting up. It's easiest to think of DBS as a "pacemaker for the brain."
In my case, the surgery was done about six years ago in San Francisco, and results have been impressive. My tremor is no longer prominent, I am able to walk without "freezing" much more frequently, my "on" time is longer, my sleep is less fitful, and my bladder urgency is much tamer. I am also able to get by with substantially less medication than pre-DBS days, and this minimizes unwanted side-effects.
While DBS can have great impact on motor difficulties, it is not helpful for the troublesome non-motor problems associated with PD. These include loss of balance, depression, constipation, apathy, cognitive problems and more. And DBS can exacerbate balance and speech problems as well as inducing depression and mild cognitive problems.
Why am I telling you all this? Because a team of practitioners who perform the operation at Swedish Hospital in Seattle recently made the trek North to give an informational meeting on the procedure, and what's new in the world of DBS. I went and compulsively took notes. Having compiled the information, what can I do but share it?
The session was sponsored by Medtronic one of the two manufacturers of FDA-approved DBS devices. Dr. Peter Nora introduced himself, and visiting members of his surgical team, and then went around the room taking questions. I made notes of what seemed to me significant and new. Here is what I gleaned.
1) You still must be a "good candidate " to qualify for and to benefit from the operation, but exactly what that means is an evolving standard. They still do not perform the operation on patients with significant dementia problems, and noted that it can actually worsen dementia. Dr. Nora explained that the diagnosis of dementia had to be done by a neuropsychologist as dementia can be difficult to sort out from apathy or depression, which can also be present in PD. Another still-standing requirement is a good response to levedopa. A significant cut in symptoms when l-dopa therapy is introduced is correlated to a successful outcome with DBS surgery.
What is different now is that, in Dr. Nora's view, it is appropriate to consider the operation much earlier in the course of the disease, instead of as a last resort, when all drug interventions are no longer effective. He urged the gathering to decide for themselves when they are ready for the operation, not be sidetracked for reasons of "It's not time." His question: "Who better than the actual patient can say when they are ready?" He acknowledged that caution was in order. The dangers of brain surgery are significant, infection, and/or bleeding can occur. But they only happen in "One percent of one percent" of operations" says Nora, who has had 850 DBS patients. A number of recent studies have shown that the earlier an intervention is introduced, the better the long-term outcome.
2) DBS, in Dr. Nora's view is a bridge to cross on the way to better treatments down the road. In the immediate future he predicted that improvements coming to the mechanism itself are a system that will automatically modify the discharge it emits based on feedback it gathers from the brain.
3) Does DBS slows disease progression? I asked this question based on recent reports that this is true. Dr. Nora agreed that it does, with many caveats. He pointed out that there is no empirical proof, in the form of a double blind study showing difference between a control with sham-DBS and an actual DBS implanted person. The cases of Azilect and Eldepryl, both of which seemed to show slowing of the disease but ultimately were found not to affect progression after investigations that took significant time and expense, show how tough this is to actually prove.
When I asked him if there was an underlying explanation that could account for DBS-slowed disease progression, his theory was that DBS enabled a return to the ability to exercise and socialize, to participate more fully in an active "normal" life. These activities have been correlated with better long-term outcomes for Parkinson's patients. The more DBS allows you to undertake healthy activity, the better-off you are.
4) Long-term lasting effect of DBS is fairly strong. Over ten years there was found a 20% decline in effectiveness.
5) A moment of heresy. Dr. Nora "I'm going to get shot for this, but patients are the best prescribers of medicine." He went on to explain that patients who were in tune with their symptoms are in a better position to modify dosages through careful experimentation than doctors who oversee hundreds of people's drug regimes.
6) Dr. Nora said that we were lucky to have an unusually high number of good neurologists in Anchorage. Take a bow, local practitioners!