Handedness in FTLD (P07.168)

Abstract

Objective: To describe the prevalence of non-right handedness in Frontotemporal Lobar Degeneration. Background Non-right handedness - ambidexterity and left handedness - occurs in 8-10% of the population. 95% of right handed individuals have left lateralized language localization and associated structural asymmetry L>R, most notable in the temporal planum. Non-right handed individuals have greater variability in language distribution. Non-right handedness is also associated with an increased frequency of learning disability. Rogalski et al. reported increased rates of learning disability in patients with Primary Progressive Aphasia. We hypothesized that structural and functional differences in handedness might reveal themselves among various types of neurodegenerative disease. Design/Methods: We reviewed our entire PPA (LPA, n= 56; NFV-PPA, n=64; SV-PPA n=135) and PSP cohorts (n=89). Results: 9% of the LPA cohort (n=5 of 56) is non-right handed, consistent with handedness in the general population. 14% of the SV-PPA cohort is non-right handed (n=19 of 135) compared to 5% of the NFV-PPA/PSP cohort (n=7 of 151). Chi-square analysis of observed versus expected, reveals a statistically significant increase of non-right handedness in SV-PPA with an expected 8% rate of non-right handedness (p Conclusions: There appears to be a handedness bias among FTLD diagnoses. Given the high clinicopathological correlation between SV-PPA and NFV-PPA/PSP, with TDP-43 and Tau respectively, this analysis supports dichotomization of handedness among underlying pathologies. In the context of increased learning disability in non-right handed patients and PPA, this observation integrates both of these findings and may help with future diagnostic discrimination. Supported by: NIH/NIA P01 AG019724, P50 AG023501, T32 AG23481. Disclosure: Dr. Miller has nothing to disclose. Dr. Rankin has nothing to disclose. Dr. Gorno Tempini has nothing to disclose. Dr. Miller has received personal compensation for activities with Allon Therapeutics, Inc. and TauRx Therapeutics, Ltd. Dr. Miller has received research support from Novartis.