Last Friday was turn-on day for my DBS system, and so far it’s been a combination of “rather remarkable” and “no big deal.” As I had been repeatedly told by the doctor, the Medtronic rep, and the doc’s very supportive and capable assistant, there has been no “flipping a switch” change in the symptoms, and frankly right now I don’t feel all that different than I did before. As with other elements of my treatment for this disease, the neurologist is planning to take a slow, careful approach to turning on the stimulator, which essentially means that I’ll be “titrating up” in electricity just like I have in the past for new drugs. I suppose that neurology, like long-term investing, shouldn’t be exciting – it’s the eventual results that matter, not the thrill and rush of getting there. Still, I was a little disappointed that there was no “oh-my-gosh-i-can-run-jump-and-play-look-at-my-hands-move” moment. I’ve found that you don’t really need an excuse to drink champagne, though – they sell it everywhere.
The actual programming session didn’t take long at all, although I had to stay at the neurologist’s office for about two hours after it was done (presumably to see if I would suddenly start picking up radio stations or opening garage doors with my head). The neurologist began by explaining that he would first test the electrical integrity of the leads, and then he would adjust the parameters (as far as I can tell, they include amplitude, pulse repetition frequency, and pulse width in a baseband sinusoidal wave) to determine how I responded. He was clear that I would leave this first session with the device set at a low level and probably without noticeable effects, and that I would come back in two weeks to have the system tweaked again.
With my expectations properly set (and steam rising from the campfire), he began. I couldn’t see the screen of his handheld programming device, so I didn’t know what was going to HOLY CRAP, WHAT WAS THAT? I felt a buzzing twitch run down my right arm, and the fingers of my right hand momentarily went into business for themselves. It shut off as abruptly as it started, and I said, “that was strange.”
“Yes – that means that the electrode on the left side of your brain is working.” For reasons that are not clear to me, the left side of the brain controls motor activity on the right side of the body and vice versa. I started to comment on that fact, when my left hand and arm began to twitch and tingle, and my hand became more rigid and immobile than usual. It also was returned to my conscious control quickly, and I had a fleeting thought about the Control Voice at the beginning of the old “Outer Limits” TV show from the early 60’s – “There is nothing wrong with your brain. Do not attempt to control your own body. We will control the horizontal, we will control the vertical. We can make you twitch and shake, and if you upset us we will make you slap yourself repeatedly.”
Things were quiet for a few moments, as the neurologist and the medical device expert discussed next steps in low tones. I was anxiously waiting for the next lightning bolt in some part of my body, but all I felt was a few minor tickles and buzzes here and there. I began to relax (always a mistake), and as I tried to settle into the chair and get comfortable, I found that I couldn’t. There was no pain or real discomfort, but I couldn’t stay still.
“Well, THIS is weird,” I said. My wife, who was recording the session, said, “what’s happening?”
“I can’t sit still,” I said.
“Are you just trying to get comfortable?”
“No,” I replied. “I think I’m trying to dig a hole in the chair.”
The neurologist had adjusted the voltage level of the stimulator on my right brain side/left body side to 1 volt, and it caused an immediate and uncontrollable bout of dyskinesia; again, not painful, just strange. He adjusted the voltage down to a lower level of 0.6 volts, and the dyskinesia evaporated like rain on a Texas street.
It’s common to experience side effects like dyskinesia or temporary worsening of symptoms during the tuning process – my brain will have to become accustomed to the small trickle of electric current that the stimulator provides just as my body initially had to get used to the Parkinson’s medications. The difference is in the level and type of ongoing side-effects – I have a hope and a reasonable expectation that, when I do become accustomed to an electrified existence, that I’ll get benefits with a much lower level of side effects. That’s why I’m doing this, after all, and my initial experience with DBS stimulation reinforced that hope. The electrodes are placed in exactly the right spot, and this initial foray into stimulation shows that it has an effect on the movement characteristics that are associated with the disease. I remain optimistic about the next few programming sessions and the longer-term future, and I’m glad I did this.
Hope is a funny thing – sometimes you have it without knowing it, and just a little extra information changes the picture. In my post following the surgery, I talked about the neurosurgeon’s satisfaction with the electrode placement, and his comments about how the “signals were great.” I’ve since learned that those signals come from something called “microelectrode recording” or MER. During the implantation, the neurosurgeon first implants a thin recording probe, and measures the electrical activity along the path of the electrode as it approaches the subthalamic nucleus. Although they record the signals as electrical impulses, they actually listen to the sound of the signal in the operating room over a speaker. This helps the surgical team to determine if the implantation is proceeding according to plan, and to decide when they’ve reached the target. Each region of the brain has a distinctive sound – hissing, popping, crackling or rumbling sounds that indicate the level and type of electrical activity.
Here are some example sounds from SoundCloud of various parts of the brain:
I found that the neurosurgeon’s comment that the “signals were great” indicated two things – that the difference in sound between my STN and my cortex, midbrain, and other structures indicated they were in just the right spot. But beyond that, the sound that the electrical signals from my STN make indicate that there is no question but that I have Parkinson’s disease.
You’d think that would be no surprise to me, but I had been holding out some minor hope that I fell into the 15% – 25% of Parkinson’s patents who are misdiagnosed. Diagnosis by neurological exam, medical history, and ruling things out still leaves room for uncertainty, and in a small number of cases, post-mortem testing shows that a person treated for Parkinson’s for years never actually had the disease. In a hidden place inside me, I was still hoping that I would one day wake up without symptoms, and find that this had all just been a colossal misunderstanding. Even after experiencing classic PD symptoms for years, being diagnosed by 5 of the best medical professionals in the US, and showing improvement in symptoms after taking levodopa.
I still have hope – for an eventual cure, for a productive, happy, and long remainder to my life with people who I love, for a manageable progression to this disease, and that DBS will prove to be effective for me. I finally have to put away the unreasonable hope that I don’t really have this disease, though.