Arizona Brain Bank – Final Report

By:Holly Shill, MD & Brittany Dugger, PhD

The brain bank at Banner Sun Health Research Institute in Sun City, AZ was funded by the IETF beginning in 2012, to look at the feasibility of establishing a mechanism to study the clinical features of ET and correlate them with the findings that are seen in the brain at autopsy.

This last year, ending in June, has been the final year of funding. During this past year, Drs. Holly Shill and Charles Adler had two main goals: First, to re-examine all the brain areas to see if there were any hot spots which might be abnormal in ET, and second, to continue to examine the cerebellum to see if evidence of degeneration can be found.

For the first goal, there were 67 ET patients who had come to autopsy and these were compared with 43 controls who did not have tremor. Overall, the groups were very similar in terms of age and cognitive functioning. They could find no differences in the amount of Alzheimer’s or Parkinson’s disease pathology. Furthermore, people with ET were no more likely to have strokes or other vascular changes. There was no drop in the white matter (or connectivity) in the brain of those with ET. In short, there did not seem to be a place in the brain where standard degenerative pathologies were more likely to occur in ET.

With respect to the cerebellum, they examined the cerebellar volume and also looked at inflammatory cells in the cerebellum. If ET had specific degeneration in the cerebellum, it might be expected the cerebellum would have more inflammation in the brain (as is typical of other neurodegenerative diseases like Alzheimer’s) and the cerebellum would start to shrink (or atrophy) over time. This was a smaller study, but they did not find either of these to be true in ET.

So, as this study comes to a close we realize we have learned quite a bit. We have learned we can indeed establish a brain bank where we study people over time when they are alive and then examine the features of the brain after death. We have learned that ET does not seem to be associated with a higher risk for other degenerative conditions. We have also learned ET does not seem to cause degeneration of the cerebellum itself. We are beginning to find clues in other neurotransmitter systems in the brain that may be associated with ET. We will continue to work on these hypotheses and share our results with the ET community as we do.