April 26, 2018

Debugging my brain

Today was my fifth session with Dr. Nengchun Huang trying to adjust the signals going to my brain to improve my Parkinson's symptoms. I've been doing this every two weeks. Each session has lasted an hour to an hour and a half, as the doctor adjusts the signals and watches my reaction: does my thumb wiggle, my eyes droop or blink rapidly, does my foot twist uncontrollably or steady. Periodically he asks me to do various tasks -- tap my thumb and fingers together like playing castinets; touch my nose and then his finger, back and forth; tap my foot rapidly and evenly.  Periodically we take off the collar and I get up and go out to walk down the hall and back while he watches the regularity of my pace and whether my hand shakes while I'm walking. It's almost always been possible to stop the tremor for a moment by focusing my attention on the body part (like with yoga or tai chi), but usually only for a few seconds. "Don't suppress the tremor", he reminds me often, but it's often reflex.
The ideal is "no symptoms, steady state", and each session has gotten better. For example, the strong impulse to close my eyes is less. My remote control (here wired to the PC) allows me to adjust the overall voltage slightly, and choose between the latest and one of three previously saved programs.

They call this "programming" but it's more like debugging; not modern debugging but the old-fashioned kind, where you're pawing through core dumps and using binary search.

Here's what I think is going on

 The device implanted below my right collarbone communicates wirelessly with the programmer. There are eight contacts one after another on the end of the electrodes skewering my Globus Pallidus Interna on each side, different parts of which are connected to different parts of the brain, controlling movement of my legs and feet and hands and other parts. Each electrode can emit pulses at a given frequency (up to 179 hz) for a periodic burst (I think, the "pulse width") and a given voltage or amperage. Pulses can be monopolar or bipolar  (not sure, but I'm guessing either negative only or negative and positive). The bipolar signals have a narrower effect; the monopolar signals are stronger.
There's no exact map of which parts of the GPi connect to which function of the brain. I think the theory is that the pulses disrupt the beta-rhythms which synchronize the brain function.  Anyway, the Boston Scientific device I have is new, giving the programmer lots of options not possible before.

February 7, 2018

My procedure


was on all the forms I had to sign, describing what was done to me...

"Stereotactic image" (the 3D result of an MRI scan on Tuesday and a CT scan Friday morning)
"... guided" (the team looked at the 3D image to plan the route of the wires into my brain)
"Implantation" (skewering) 
"of bilateral" (both sides)
"GPi" (globus pallidus interna -- the part of my brain they were targeting)
"deep brain" (well, it was pretty deep in there, and hard to get to)
"stimulation electrodes" (two thin cables with 8 strands each leading to 8 points within the GPi)
"with volumetric analysis" (checking the path so they don't skewer something important)
"using Mazor robot" (a device they attached to a 'platform' that was screwed into my skull first thing Friday morning after first making me a numb-skull, then drilling pilot holes and screwing in; the Mazor robot then guides the surgery exactly)
"and implantation" (this one goes in a little pocket they cut in my chest)
"of right" (only one)
"infraclavicular" (under my collar bone, the electrode leads pushed under scalp, neck skin, down chest)
"pulse generator" (the thing that will send pulses to the electrodes)

Right now my brain is recovering from the trauma of this disturbance... my Parkinson's symptoms are  mainly worse than usual -- both hands shaking, having trouble standing, using a walker to scoot around the house, speech soft and distorted enough that Alexa doesn't understand me, mild headache, among other indignities. 
Today I get to shower! Yay! 

My appointment for having the whole thing turned on and to start tuning the pulses to my body is February 16th.  Happy Birthday!

The process of fine tuning can take 6 months of appointments every two weeks.   Each of 8 leads on each side, with their own pulse intensity, frequency and width ... I'm assuming there's some method to it, will let you know. 

January 25, 2018

Going Bionic

I hadn't talked about it publicly, but it's pretty obvious now if you see me in person: my hands (often) shake, my foot (often) drags. I have Parkinson's disease -- first diagnosed 12 years ago, its a slowly progressive condition. There are whole books about all the horrible potential symptoms, but  I've been fortunate (among the millions with it) that my symptoms have been relatively mild. Medications, exercise and determination mainly controlled the worst.

But progressive diseases progress, and interfere with getting on with life.

I'm mainly risk-averse, but (after declining 5 years ago) I'm now scheduled next week for a surgical treatment called "Deep Brain Stimulation": like a pacemaker, but for the brain rather than the heart, and more of a pace-disruptor than -maker.

The procedure is described as "minimally invasive"  and "reversible" and it's been done 100,000 times (300 by my surgeon). But still, it requires MRI and CAT scan to place wires to the exact spot without hitting good brain or blood vessels. (I got a Rift VR tour of some patient's anonymized brain as part of the explanation.)

Besides the wires in my brain ("Will I be able to listen to the radio without a radio?"), there will be wires under skin from scalp down to a not-so-tiny controller implanted -- wirelessly charged and programmed, battery rated to last 15 years. The "programming" usually takes months of adjustment.

I remember ~40 years ago admiring someone's programming skills, to the point I told people "he's so good I'd let him program my pacemaker". I'm not going to ask Boston Scientific to review their source code, but I do hope they aspire to better than "five nines".

Wish me luck...

1/31 added: for all the good wishes, expressed and felt: thank you, its meant a lot...