DBS Journal: Device Tuning #4

Yes, the last time I saw the doctor was in February. Time flies. I’m happy to report a potentially really good session was had on short notice this afternoon.

To recap, we thought we had found a reasonable balance of relief between the two sides: my left, controlled by medicine, and my right, controlled by the battery-driven implant. We needed a certain level of meds to control the left side, but not so much that it would overstimulate the right side.

What we were left with was a right side that had a barely tolerable level of stimulation — right knee didn’t track properly, right arm just about to break into dyskinesia. And the left side was “off” more than half of the day, at a peak level of tremor that left it nearly without function.

We didn’t change any of the meds today, so I’m not expecting anything on the left side. But the right side changes are subtle, at least so far, and significant. My right knee doesn’t pull toward the center anymore, and that made the 90-minute ride home much more comfortable.

My right arm is also working better. It is apparently free of the dyskinesia — the unwanted muscle movement that greeted every attempt to grab objects at full reach. This bodes well for the healing of my “tennis elbow,” caused by chronic tension in the forearm muscles (I don’t play tennis).

The key benefit of today’s tuning is a return to a more focused “head.” I had a lousy night of sleep, so it’s hard to tell at this point if the change is merely a temporary boost in mental energy. But I am very excited about this aspect of the session.

Technical details:

The lead — the bit that is implanted in my brain — has four contact points. Each contact point can deliver electricity into my subthalamic nucleus, a specialized bunch of brain cells near the top of the brain stem. We had been delivering a charge through just one of these points. Today we turned on a second contact. That changed the shape of the field, from round (radial) to a pear shape. We also turned up the pulse frequency.

The next few days, especially tomorrow, will tell me more about how effective the changes have been. So far, it’s very encouraging. I’m past my intellectual limit when it comes to the arcane details of tuning the device. I’m fortunate to have a doctor who can not only do this work, well, but can also articulate the details of why it works to a third-year medical school student who looked way more stressed than I did!