Treating left-handed patients with TMS

Do you treat a left-handed patient differently than a right-handed patient with TMS?

The standard response, when asked this question, is that left-handed people should be given the same treatment as right-handed people and then if it doesn’t work, do the other side. That’s what I’ve been told by several people. I look a little bit deeper.

The first question I ask, is how left-handed are they? Are they all the way? Do you do anything with your right hand? That’s the way I do it, to ascertain if they’re left-handed or if they’re mixed dominant. There is a questionnaire called the Edinburgh Handedness Questionnaire that also differentiates the mixed dominance from the ‘only left-sided’.

I think the people who are purely left-handers have a higher rate of needing to be stimulated on the other side. I think, for the people with the mixed dominance, it’s not as clear which side. Sometimes you have to try both and find out what works. Now, if you stimulate a person on the left DLPFC with a standard theta burst or ten hertz stimulation and they say they feel worse, they say they feel like they can’t focus, they feel foggy and they say their mood is worse, I take that as a sign, especially in the first couple of treatments.

If we try on the other side and they feel much better, I think there’s little doubt on how to treat left-handers if you’re aware of the response to the first couple of treatments. I think the treatment of left-handed and mixed dominant patients will be different in the future.