A few days ago I received an question from a CurePSP support group leader about whether focused ultrasound has potential for PSP. Here are my words of wisdom:

Over the past few years, high-intensity focused ultrasound has become mainstream as an alternative to deep brain stimulation (DBS) for Parkinson’s, isolated tremor and other things.  It works by killing a small volume of brain tissue that’s over-active because the disease process has deprived it of its normal inhibitory input.  DBS, which has been in wide use for 25 years, accomplishes the same thing, but by over-stimulating the over-active area to the point of paralyzing it.  Before DBS came along, the same thing was accomplished by inserting a metal electrode deep into the brain that emitted microwaves from its tip to permanently destroy the over-active chunk of brain.

The advantage of high-intensity focused ultrasound is that unlike DBS, it requires no holes in the skull or hardware in the brain or under the skin of the chest, and no further stimulator adjustments.  Its disadvantage is that once it’s done, it’s permanent, so if it’s not quite in the right place, you can’t just reposition it or fiddle with the stimulator unit’s settings.  You can only make another lesion in a slightly different spot or a larger lesion in the same spot, with no effect on whatever adverse effects might have resulted from mis-positioning of the first lesion.  But this is all academic for people with PSP, where there is no over-stimulated area of brain for a destructive lesion to address. 

However, it’s possible to non-destructively stimulate the brain using low-intensity focused ultrasound, and PSP definitely produces under-active areas of the brain, particularly in the cerebral cortex.  Early experiments with Parkinson’s and other conditions have shown that measurements of the electrical activity of the cortex do improve with low-intensity focused ultrasound, but there’s no clinical benefit for Parkinson’s so far, according to one published report.  There are no results at all for PSP to date.  So far, the technique seems feasible only for the most superficial areas of the brain such as the cerebral cortex rather than for the primary areas of trouble in PSP much deeper in the brain.

Bottom line:  Low-intensity focused ultrasound of the cortex could prove useful for PSP once it’s refined by painstaking trial and error .  The degree of benefit would probably be limited, but it would be low-risk and better than what we have now.  Of course, that sounds like the age-old formula for snake oil, so we just have to be cautious about medical charlatans pushing this treatment before long-term, controlled trials prove it safe and effective.