Postmortem changes in the motor vs. non-motor cerebellum of essential tremor (P3.001)

This is the authors' abstract. We don't add key points for this paper.

Objective: To compare postmortem changes in motor vs. non-motor regions of the cerebellum in essential tremor (ET) cases. Background: ET is a progressive neurological disease. Detailed postmortem studies have documented a variety of neuropathological changes in the ET cerebellum centered on the Purkinje cell (PC) and neighboring neuronal populations. To date, motor vs. non-motor regions of the cerebellum have not been compared in terms of the extent of these changes. Design/Methods: 15 ET case brains were harvested through the Essential Tremor Centralized Brain Repository. For each case, a formalin-fixed cerebellar parasagittal slice was processed to create tissue blocks from motor (anterior lobules IV-V) and non-motor (posterior lobules Crus I & II) regions. Paraffin sections (7-μm) were stained with Luxol fast blue-Hematoxylin and Eosin and Bielschowsky stains. Each of the following neuropathological changes was quantified: PC linear density, PC heterotopias, torpedoes, PC dendritic swellings, and extent of basket cell plexus surrounding the PC soma (“basket rating”). Results: Comparing motor vs. non-motor regions, there were no differences in PC linear density = 4.69 ± 1.05 vs. 4.42 ± 0.82 (p = 0.45), number of dendritic swellings = 1.7 ± 2.8 vs. 2.5 ± 4.0 (p = 0.71), or basket rating = 20% low, 40% intermediate, 40% high vs. 40% low, 40% intermediate, and 20% high (p = 0.51). PC heterotopias were fewer in the motor cerebellum = 26.8 ± 24.7 vs. 72.1 ± 59.2 (p = 0.01); torpedoes were greater in the motor cerebellum = 63.3 ± 48.8 vs. 27.3 ± 21.9 (p = 0.02). Conclusions: These data preliminarily suggest that there may be neuropathological differences between motor and non-motor regions of the cerebellum in ET cases. Further studies with larger samples are needed to further elaborate these results. Study Supported by: NIH R01 NS088257. Disclosure: Dr. Tate has nothing to disclose. Dr. Kelly has nothing to disclose. Dr. Faust has nothing to disclose. Dr. Louis has nothing to disclose.