This is probably a tricky subject for many. Not everybody likes even to acknowledge the possibility let alone make any kind of provision for such an eventuality. And it’s true that the odds are good. Whereas variable positive outcomes are commonplace, disastrous failures are rare. Depending on prior expectations, the results generally fall somewhere between mild disappointment through to outright ecstasy. And this is the territory in which the vast majority of prospective DBS patients will inhabit. When you ask most of those who have had DBS whether they would do it again, the answer generally is a resounding ‘yes’.
And, as someone about to undergo the procedure, that’s very encouraging.
But, in a spirit of full disclosure, let’s not forget that there is a tiny number of patients for whom failure is not simply a lack of significant benefit but a genuine life-threatening emergency.
When you consider the mechanics of it all, it’s not surprising that there are a proportion of such outcomes. A very very small proportion of the total undergoing the procedure but a finite number nonetheless. And that’s probably not surprising. Although very fine wires to the naked eye, electrodes are, in neuronal terms, enormous. A nerve cell body maybe 25 µm across, vascular lining cells of similar dimensions. Electrodes on the other hand, even of such delicacy as these, are at least an order of magnitude larger. As they push their way through the brain towards the subthalamic nucleus, brain cells are pushed aside like ice flows at the bow of an icebreaker. Some inevitably will be damaged or forced into a slightly different part of the neuronal real estate that is your brain. These are minor inconveniences, tiny tribulations and a small price to pay for the benefits to come. But every once in awhile the electrode will puncture a blood vessel and initiate a bleed.
A bleed in the brain is an entirely different kettle of fish from a nick while shaving or a scratch with a thorn. You cannot apply cotton-wool or dab antiseptic on the site of bleeding. Cauterising works on surface vessels but not deep down. The deeper you go beneath the brain surface, the less aid you can expect. It’s like a mountaineer climbing alone above 25,000 feet. You are on your own.
Once again I feel the need to reassure you, dear reader, that such eventualities are extremely rare. Certainly they should be factored into your own go/no-go decision but not fretted upon.
So with that in mind, how should one respond to that tiny but finite risk? Brush it aside in a moments thought with a derisive snort? Surround yourself with ‘you – have – a – greater – risk – of – being – struck – by – lightning’ friends? (Incidentally those odds are wrong – lightning is much less common). The same but with London buses as the denominator? Subject yourself to deep introspection and dwell on all possible results?
On the whole, most of the above are unhelpful. But then equally unhelpful is the head in the sand approach – you can’t change things so just roll with it. Fatalistic nonsense.
My approach falls I think somewhere between these different extremes. But if you are uncomfortable with this, just stop reading. And since I have broadly skirted round the subject to this point, let’s be clear what outcomes we are talking about. These are essentially a disabling stroke or, worst of all, death.
I like to think that I’m approaching this in the manner of a checklist, ticking off each item without dwelling on the likelihood. I don’t plan to describe every last detail here. But certain matters are obvious. My will is written and witnessed. Tick. I have already notified key people of my wishes with respect to my remains. Tick. And so on.
Most of it is straightforward. But the last part is more important. Specifically, there will be three letters written before I go into hospital, one to each of my children. Each will be personal to that child and will tell them all the things that I want them to know going forward. How much I love them, unconditionally and without limit. I will tell them how much joy they’ve brought me over the years. I will let them know how proud I am of them. And I will speak to them of being true to themselves, of standing strong and of looking after their siblings.
I will probably forget my toothbrush when going into hospital. That’s just me. But, trust me, I won’t forget those letters.