Dystonic tremor is an interesting condition. Rather than being a disease, dystonic tremor really manifests with patients who have a shake, usually in their hand and often a task-specific shake. So when they’re doing something, rather than resting. And of course this is a big distinction from Parkinson’s disease, where most of the tremor is a rest tremor, as opposed to a dystonic tremor where people are having difficulty using their hands.
The cause of dystonic tremor isn’t really well known, but it doesn’t seem to be degenerative – so cells aren’t dying in the brain. It might be the fact that a little damage has been done – a tiny blood vessel gets blocked off. Or alternatively, we see it in patients who might have a specific profession like bricklayers or musicians, where they’re doing a repeated action that they don’t think about – repetitively. Interestingly, what causes the tremor is this dystonic phenomenon and dystonia is something that you may not have heard of, but you will have heard of dystonic conditions, such as writers cramp or torticollis. So torticollis is where the neck is twisted off by contractions of the neck muscles. Whereas writers cramp, of course as you’re writing the hand goes into a spasm.
With dystonic tremor you have this situation, for example, if I do this with my fingers, these muscles have to pull, these muscles have to relax and if I do that these muscles, they have to pull these muscles and these have to relax. But if both of them go off together, you get a bit of a tug-of-war – and this is what we’re seeing in dystonic tremor. It doesn’t usually progress like one of the degenerative diseases of the brain and often we can relieve the symptoms with some tablets or other simple measures.