Apr 032013

Back to the brain-injury-recovery routine, except it's not routine. Oh sure, it's the same-old TTC to clinic, get wired up, play games on the computer with my brain (no hands, Ma!) routine, but now there’s a twist and a change.

After my 19-point EEG, evoke potentials study, and earlier computer assessments last month, we’re now adding some stimulation, specifically transcranial direct current stimulation (tDCS).

You may have heard of those big, round magnets doctors put over the heads of people with depression? The magnets create an electrical current, which penetrates 1.5 to 5 cm into the brain and changes the activity of the brain. I've never seen repetitive transcranial magnetic stimulation (rTMS) in real life, but in pictures the magnets look huge, and I’ve heard the repetitive clicking sound and seen the forms patients must fill in every time they go to the Toronto Western Hospital. Well, tDCS is the tinier, friendlier version.

tDCS comprises an active electrode and a reference electrode (the Wikipedia article on tDCS is flagged for improvement). The inactive reference electrode completes the circuit and, with the device used on me, is placed on the shoulder opposite to where the active electrode is put. The active electrode can be an anode (positive) or cathode (negative). I understand the anode is usually used. As Dave Siever, CET, wrote in his paper on tDCS:

“... anodal stimulation depolarizes the local neurons from their typical rest- ing potential of 65 mv, by 5-10 mv, to 55 mv, which in turn will require less dendritic input to fire (depolarize) the neuron. The negative electrode, termed the cathode, hyperpolarizes the neuron slightly and it will require increased dendritic input to fire it.” (NeuroConnections, Spring 2013, PDF)

Siever wrote that according to one study, the anode decreases GABA in the area it stimulates, while increasing blood flow and beta and gamma brainwaves.

tDCS has a wider area of influence than the electrodes used in brain biofeedback. Still, it seems to be smaller than rTMS. This is important. As the ADD Centre told me, we only want to work on those issues the client finds troubling and not affect anything else. Even if the tests show anomalies in areas that the client says no prob for them — they don't complain of corresponding symptoms — then they won't work on those areas. In other words, people are entitled to their quirky parts.

The ADD Centre felt I would benefit from active stimulation of certain areas that are busy snoozing right now or at best chillin’. They use the Canadian-made Mind Alive device for tDCS. For me, they chose to put the anode over F3-C3 and the reference electrode on the shoulder (wipe off that arnica cream I just slathered on my skin!). The battery-operated device powers the anode. It freaked me out a little having a spongy anode create an electrical current in my brain, but my trainer said: Look, it's just a battery powering it! Oh, OK, if you put it like that. She continued: You’ll probably feel nothing, but a few can feel tingling.

Raise your hand if you’re surprised moi did feel that tingling. A lot. But that wasn't the biggest problem. The biggest problem was keeping the stretchy headband that holds the anode in place on my head. My hair is rather silky, and headbands have a habit of popping or sliding right off. I finally adjusted it to where I knew it would stay on as long as I held still, and I held on to it while she tucked the anode in place. Ten minutes later (of chit chat and questions and trying to breathe deeply), she took it off, and I immediately scratched my head where the anode had been. A common reaction, apparently. But one vigorous scratch, and I was good.

The next change for the first day back to biofeedback was switching the electrode for brain biofeedback from CZ to between the O1 and PZ positions. That’s left back on the head. Needless to say my vision became real sharp. (The occipital lobe is where the visual cortex resides, although my vision improved in my left eye even though one would think it would be only the right eye.) The sharpness began diminishing about a half hour after my appointment but the clarity didn't.

For the first day back, they wanted to see only what would happen if we reduced 7 to 11Hz in order to determine how to proceed in future. We still had gamma being measured and enhanced, and so, in a way, the training of it continued. My muscle tension wasn't great, but I did get it down to 2.

I didn't think I was ready for the first day back. But a change is as good as a rest, and I'm excited again (it helps I survived my brain being stimulated with no side effects but that temporary itch).

So the second day back was the start of the new brain biofeedback routine. The ADD Centre people had discussed the results of the first day back and had slightly modified things.

We will begin the hour with tDCS, remembering to clean the arnica cream off my shoulder if we want to get a connection! Then the trainer will hook me up to the computer: breathing belt, heart rate monitor, skin temperature monitor, electrodes on ears, and the scalp electrode now at the PZ-O1 position (which takes a bit longer to locate than the old CZ position but should become easier over time). We will first do the usual three-minute EEG assessment, though it’s really three minutes and eight seconds to ensure the CardioPro program will analyze the results fully to monitor my heart and to see if we’re getting improvement in HRV (heart rate variability; I’ll write more on this later, but basically by activating the brain at PZ-O1 hopefully we’ll access the insula [Wikipedia article] and get it to wake up so as to allow my heart to work properly. Maybe.)

The PZ-O1 area of my brain on the 19-point EEG was very much hanging out in the alpha zone so we want to wake that up. If that area is more active, hopefully that will mean I’ll be able to integrate and synthesize info when reading. If it activates the insula indirectly: bonus.

That’s why the training is now focussing on reducing 8 to 10 Hz while monitoring 2 to 4 Hz and enhancing gamma.

The tDCS is placed over areas to do with working memory, short-term memory, impulsivity, co-ordination and should help with my reading, as well as to balance out the right side in order to generate positive emotions.

I don't really feel any different after stimulation. I'm getting the usual post-gamma happy. But whether the stimulation is contributing to that I don't know. My chest did feel lighter after the second session, and I tolerated the pre-rush hour crush on the TTC better than when I was on my way to biofeedback. It’s like I could tune out the annoyingness. And like after the first session, my sight was better.