Abstract Introduction Rapid eye movement (REM) sleep behavior disorder (RBD) is the single strongest predictor of Parkinson’s disease (PD) risk. Given neurotrauma and psychiatric morbidity, the aging post-9/11 Veteran cohort is a target population for understanding probable RBD frequency and neuroprotection opportunities. We previously reported over 50% of post-9/11 Veterans screened positive for probable RBD. We aimed to examine frequencies of prodromal PD markers and polysomnography (PSG)-confirmed RBD in post-9/11 Veterans. Methods Veterans with probable RBD based on the single-question RBD screen (n=12) were recruited from the Translational Research Center for Traumatic Brain Injury (TBI) and Stress Disorders (TRACTS) Houston cohort. Participants were assessed for subthreshold parkinsonism (Unified Parkinson’s Disease Rating Scale-III Motor score >3, excluding action tremor), olfactory loss (12-item Sniffin’ Sticks), TBI exposures, autonomic symptoms, orthostasis, excessive daytime sleepiness, post-traumatic stress disorder (PTSD), and psychiatric comorbidities. PSG studies were conducted per American Academy of Sleep Medicine guidelines. A board-certified sleep physician confirmed the presence of REM sleep without atonia. We compared the frequency of prodromal marker positivity between participants with and without subthreshold parkinsonism. Results All 12 participants were male (6 [50%] Black, 3 [25%] Hispanic) with a mean (SD) age of 44.4 ± 6.7 years. PSG data (n=10) revealed REM sleep without atonia in 5 (50%), moderate obstructive sleep apnea (OSA) in 2 (20%), and severe OSA in 2 (20%) participants. Five (41.6%) participants had mild motor dysfunction suggestive of subthreshold parkinsonism on the UPDRS-III (M±SD score of 8.6 ± 5.9), while 7 participants had normal or low UPDRS-III ratings (2.3 ± 1.3; p=0.02). Veterans with subthreshold parkinsonism had lower Sniffin’ Sticks scores than those without (M±SD 9.4 ± 2.07 vs. 11.29 ± 0.76; 95% CI: 0.01–3.76, p=0.049). Conclusion This pilot study suggests that motor and olfactory prodromal PD markers are frequent in post-9/11 Veterans with probable RBD. Larger prospective cohort studies are required to further quantify REM sleep without atonia and assess synuclein-specific biomarkers in this population. Support (if any) Center for Alzheimer’s and Neurodegenerative Diseases at Baylor College of Medicine [MJ]; VA CSR&D (#IK2CX002363-01A1) [MJ]; VA RR&D (B9268-X) [RJ]; NIH/NIA/NINDS (U19-AG071754 & R34-AG056639) [ES]; and AASM [ES].
The advantages of frontotemporal degeneration drug development (part 2 of frontotemporal degeneration: The next therapeutic frontier)
Frontotemporal degeneration (FTD) encompasses a spectrum of related neurodegenerative disorders with behavioral, language, and motor phenotypes for which there are currently no effective therapies. This is the second of two articles that summarize the presentations and discussions that occurred at two symposia in 2011 sponsored by the Frontotemporal Degeneration Treatment Study Group, a collaborative group of academic and industry researchers that is devoted to developing treatments for FTD. This article discusses the current status of FTD clinical research that is relevant to the conduct of clinical trials, and why FTD research may be an attractive pathway for developing therapies for neurodegenerative disorders. The clinical and molecular features of FTD, including rapid disease progression and relatively pure molecular pathology, suggest that there are advantages to developing drugs for FTD as compared with other dementias. FTD qualifies as orphan indication, providing additional advantages for drug development. Two recent sets of consensus diagnostic criteria will facilitate the identification of patients with FTD, and a variety of neuropsychological, functional, and behavioral scales have been shown to be sensitive to disease progression. Moreover, quantitative neuroimaging measurements demonstrate progressive brain atrophy in FTD at rates that may surpass Alzheimer's disease. Finally, the similarities between FTD and other neurodegenerative diseases with drug development efforts already underway suggest that FTD researchers will be able to draw on this experience to create a road map for FTD drug development. We conclude that FTD research has reached sufficient maturity to pursue clinical development of specific FTD therapies.