Blogging with Parkinson's

A personal perspective on Young Onset Parkinson's

Deep Brain Stimulation (DBS) in Early Stage Parkinson’s

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Yikes! It’s bad enough taking medication that can have unpleasant side effects (even if I do seem to be very good at avoiding them thus far*), without considering brain surgery. Yet brain surgery is widely accepted as a treatment for later stage Parkinson’s. The main reason that I haven’t mentioned it thus far is that it isn’t relevant to my own experience. And it still isn’t; I’m not planning on surgery any time soon. But there is talk of DBS in early stage PD being a disease-modifying strategy…

I did meet a lady at the CPT meeting in London who told me that she had had DBS and that it worked wonders for her. She had no symptoms whatsoever, she said. She thought it was a marvellous treatment and that it should be promoted more. She was, it has to be said, a good advert for the procedure. But I don’t know what stage she would have been at when she went under the knife.

However, DBS is not usually performed during the early stages of the disease, probably in part because of the risks. Surgical techniques are improving all the time, and those risks are getting smaller, but they still exist. Why expose yourself to the risk of stroke or other brain damage when you’re mostly getting on fine?

But. Apparently, there is some suggestion that early recourse to DBS can slow the  progression of the condition. No symptoms plus slower progression? Almost sounds like a win-win situation…

Researchers in Nashville, Tenessee have initialised a study on DBS in early stage PD.  It’s early days (and so any protective effect is unlikely to be visible), but so far their subjects seem to be doing well. The abstract says:

Background Recent evidence suggests that deep brain stimulation of the subthalamic nucleus (STN-DBS) may have a disease modifying effect in early Parkinson’s disease (PD). A randomised, prospective study is underway to determine whether STN-DBS in early PD is safe and tolerable.

[…]

Conclusions The perioperative adverse events in this trial of subjects with early stage PD are comparable with those reported for STN-DBS in advanced PD. The active contact position used in early PD is not significantly different from that used in late stage disease. This is the first report of the operative experience from a randomised, surgical versus best medical therapy trial for the early treatment of PD.

“Deep brain stimulation in early stage Parkinson’s disease: operative experience from a prospective randomised clinical trial”
Elyne Kahn,Pierre-Francois D’Haese, Benoit Dawant, Laura Allen, Chris Kao, P David Charles, Peter Konrad.

Published in J Neurol Neurosurg Psychiatry 2012 Feb. Vol 18 (2); 164-170

That got me wondering about the “recent evidence” that suggests a “disease modifying effect”. I found a report (dating from March 2010) on the Michael J Fox Foundation’s Web site of a study by the same group that began in 2006. David Charles is quoted as saying:

“DBS has proven beneficial in the advanced stages of Parkinson’s, and we believe that if the therapy were applied very early, it might modify the disease progression and the development of disability. […] The big question — could DBS modify disease progression — can’t be answered until we do a large-scale trial.”

“Deep Brain Stimulation for Early Parkinson’s Shows Promise”, by Leslie Hast, The Vanderbilt Reporter

When I searched for further evidence, it all seemed to come bck to this one group. There was an “Illustrative Case” published online in September last year in which Charles et al concluded that, for the gentleman under discussion, there was an improvement:

Results:  The subject showed a lower STN to substantia nigra ratio of neuronal activity than advanced PD patients, and higher firing rate than non-PD patients. The subject’s total UPDRS and UPDRS-III scores improved during the two-year follow-up, while his OFF UPDRS-III score and levodopa equivalent daily dose increased. Quality of life, verbal fluency, and verbal learning improved. He did not experience any serious adverse events.

“Deep Brain Stimulation for Early-Stage Parkinson’s Disease: An Illustrative Case”
Chandler E. Gill BS; Laura A. Allen BE; Peter E. Konrad MD, PhD; Thomas L. Davis MD; Mark J. Bliton PhD; Stuart G. Finder PhD; Michael G. Tramontana PhD; C. Chris Kao MD, PhD; Michael S. Remple PhD; Courtney H. Bradenham MD; P. David Charles MD

Published in Neuromodulation: Technology at the Neural Interface, Volume 14, Issue 6, pages 515–522, November/December 2011

I can’t help but wonder why these are the only people interested in applying the procedure at such an early stage. No doubt there is a financial element – this sort of procedure must be frighteningly expensive – and perhaps there is an ethical element (going back to the “if it isn’t all that broken yet, why try to fix it if you run the risk of breaking it even worse” idea alluded to above). But if there is that much promise… why aren’t we hearing more about it? It’s got a wonderfully media-friendly potential for controversy, too.

Maybe I just missed the coverage until now.

* The only side effect that I can recall having to a drug was being violently sick when I had the mild painkiller entonox (also known as gas and air) during labour for my first child. The second child arrived quite promptly once labour had started; we were discussing pain relief when she decided that enough was enough, she was coming out!

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5 thoughts on “Deep Brain Stimulation (DBS) in Early Stage Parkinson’s

  1. Any operation is a scary prospect though isn’t it? Thinks go wrong in unexpected ways, no matter how safe it seems, that would be the major disincentive for me, but it seems like there needs to be a bigger trial anyway.

    I was horribly sick on gas and air too, ew, not fond memories.

  2. Your points are well taken but…

    The literature I’ve seen says that, while DBS improves quality of life for (most) PD patients, it is often associated with measurable cognitive deficits such as word retrieval. True enough, we need more longitudinal studies to understand the long-term effects. The papers I have read are generally six-month followups.

    Single-patient case studies are just a step up from anecdotal evidence. They aren’t useless, but you cannot reliably generalize from them. As such, they are in no way a replacement for large-population studies. Meeting someone who says they have “no symptoms whatsoever” just doesn’t cut it (at least, not for me).

    DBS is a very invasive procedure and I’ve seen firsthand what happens when things go wrong: the infection and ensuing encephalitis were not a pretty sight; furthermore, one of the probes was placed just a little off the mark, resulting in depression. The neurosurgeon was highly experienced. I would have no problems placing my life in his hand, but you have to be aware that these things can happen. And there’s always the possibility of a stroke, as you note.

    DBS is often described as “pacemaker for the brain” in the media. This is a misleading metaphor. We know why pacemakers work. Nobody really knows why DBS works. I think it is better to know the pros and cons, weigh them with your neurologist, and then make your decision.

    • Joseph, thanks you for your measured response. I daresay that my own scepticism didn’t quite show through in the post. I’m not about to demand DBS (it hasn’t been offered, which is not very surprising, considering the risks). Mostly, I’m intrigued by the suggestion that this procedure may hold the elusive promise of a “cure”. I suspect that there is a great deal of work to be done to refine it before that becomes anything close to reality. If it does. If it can.

  3. Glad it’s being studied.
    Not keen to voluneteer my brain – it’s the only one I have.
    Can’t see this ever becoming mainstream; too much cost and risk, although maybe for us early onset people, where there is perhaps 40 years of benefit to be had (if it actually works like that).

  4. You’ve got a very candid discussion going on here and it is good to lay out pros and cons from every angle when one has a lot to absorb. You may be interested in some of our blog topics at parkinsonswomen.com. Specifically, http://parkinsonswomen.com/2013/06/01/deep-brain-stimulation-how-we-do-it-at-kaiser-permanente-redwood-city/ Love the painted portrait.

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