A looks at External Stim v Internal Stim
Today’s DBS is considered ‘non-invasive’- it is undo-able. Can’t say the same for ablative; that’s ‘invasive’ as it can’t be corrected.
M J Fox had ablative DBS just about the time non-ablative came out in 1997. To ablate is to destroy. In this case, to burn out. It actually has a remarkably similar result to introducing a small pulsating electrical current that today’s DBS offers. The trouble is obvious; ablation is a one-way street. Once removed, it’s…er…gone. But that said, why has M J Fox done so well? Is quite possible that he had additional DBS with stimulus (stim) versus destruction in a different part of the basal ganglia system – new sites have been found since his initial op. I actually don’t know.
So today’s DBS (founded by Prof. Alim-Louis Benabid) is reversible. That means electrodes, wires, IPGs – all can be taken out – no harm done – when the cure comes.
In the interim however, new technologies are rearing their heads. Some rely on the fact that we have the mental retention of roadkill. They are to be considered with profound sobriety:
- MRgFUS: Magnetic Resonance-guided Focused Ultrasound (yup – the one John Grisham wrote about; absolutely fabulous in the right setting!). This entails wrapping your shaved head in a cold water shower-cap thing (but bigger) and using several targeted ultrasound beams to the pre-chosen site, to ablate and destroy. It’s explained better here. It works if you like a permanent hole in the head. Oddly, Focused Ultrasound claim their procedure to be non-invasive on the grounds that there are no entry wounds. Not sure I agree…?
- tDCS: Transcranial Direct Current Stimulation: deliver a small, constant electrical current to the brain via electrodes that are placed on the forehead.
- tRNS: Transcranial Random Noise Stimulation: pretty much the same as the tDCS devices, but offering AC (alternating current).
- rTMS: Transcranial magnetic stimulation: an insulated coil is placed over the targeted area over the brain which is then zapped repeatedly with pulses similar to an MRI. This is mainly used in treating depression.
There are also ‘stim-to-go’ units coming to market so you can fry your brain in the comfort of your own home – lovely! The reason all these fads are being looked at is really more to do with the cost of DBS in the US markets; insurance, lobbying, politicking, and all that nasty-ass stuff. When you consider that ECT (Electro-Convulsive Therapy) or Shock Treatment is considered a ‘non-invasive’ treatment, try sticking your wet finger in a socket!