My wife had a D.a.T. Scan a few weeks ago. I never heard of it before. She was given it due to her tremors. It detects causes of Parkinsonianism. While it cannot different between different causes, or even if it is true Parkinson's disease, if it does detect damage doctors can use this information to select medications to help minimize the tremors. It finds a cause 5-15% of the time.
It found nothing. I talked with the neuropsychiatrist today and she said my wife has two tremors. Her head, which is familial and cannot be helped, and her hand (which results in her whole body shaking but her right hand is worst). This 2nd tremor is mostly the result of meds, but partly due to her FTD. They have taken her off of Clonopin and we see a huge improvement in tremor. Unfortunately now now have to look at other meds for her paranoia and psychosis (which the Clonompin was keeping in check).
This is the toughest brain scan we have encountered. Preparation, which is mostly waiting, is 4 hours. And the scan is 30 or 60 minutes. So I do not recommend it for someone with dementia unless a tremor is affecting their quality of life.
I'm so sorry you and your wife had to endue this, especially since the test has such a low success rate. From what I hear, these anti-psychotic drugs have awful side effects but that's medicine has offer. I hope they are able to find one that works and also has fewer side effects.
It was useful in that the doctor then knew not to try an entire range of drugs. The tremors were a bit worse this weekend, I think it varies on its own. I could see the difference between the head and hand tremors. The staff is very good about observing her whenever they make med changes. I only need to notify them about stuff which I don't think they would observe, such as her frequency of phone calls and that she has stopped leaving messages on my voicemail.