Association between Excessive Daytime Sleepiness and the Cholinergic Ascending Reticular System in Parkinson's Disease.

BACKGROUND: Excessive daytime sleepiness (EDS) in Parkinson's disease (PD) may occur because of dysfunction on the brain areas in controlling wakefulness; however, the pathophysiology of EDS in PD has not been completely clarified. The Pb component of a middle-latency auditory evoked response (MLR) is generated from the cholinergic ascending reticular activating system (ARAS) projecting to the auditory cortex via the thalamus. We examined the association between EDS and the Pb component in patients with PD. METHODS: Participants were 38 patients with nondemented PD and 18 age-matched controls. EDS was evaluated using the Japanese version of the Epworth Sleepiness Scale (JESS). PD patients were classified into the high sleepiness (HS) group and the low sleepiness (LS) group by the score of JESS. MLRs were recorded from the scalp with each earlobe as a reference under presentation of 1-Hz and 65- to 90-dB click sounds. RESULTS: There was no difference in age, duration, and motor function between the HS PD and the LS PD groups. Peak latencies of Pb were not different between PD group and controls; however, Pb amplitudes were significantly increased in the HS PD group compared with the LS PD group and controls. CONCLUSION: One of the mechanisms of EDS in PD was suggested to be dysregulation of cholinergic neurons from the ARAS projecting to cortical cholinergic neurons.

Prevalence of and factors associated with dilated choroidal vessels beneath the retinal pigment epithelium among the Japanese.

Pachyvessels are pathologically dilated large choroidal vessels and are associated with the pathogenesis of several pachychoroid-related disorders, including central serous chorioretinopathy. We aimed to investigate the prevalence of and risk factors for pachyvessels in the Japanese population. We included 316 participants (aged ≥ 40 years) with normal right eyes. The presence of pachyvessels (vertical diameter > 300 µm, distance to the retinal pigment epithelium < 50 µm) was determined using 6 × 6 mm macular swept-source optical coherence tomography images, and associated risk factors were investigated. Subfoveal choroidal thickness was measured, and its associated risk factors investigated. The overall prevalence of pachychoroids was 9.5%. Regression analysis showed that a younger age, shorter axial length, male sex, and smoking were significantly associated with the presence of pachyvessels (p = 0.047; odds ratio [OR] 0.96 per year, p = 0.021; OR 0.61 per 1 mm, p = 0.012; OR 3.08 vs. female, and p = 0.011; OR 3.15 vs. non-smoker, respectively) and greater choroidal thickness (p < 0.001, p < 0.001, p < 0.003, and p < 0.017, respectively). The results were consistent with other research findings which showed that pachychoroid-related disorders such as central serous chorioretinopathy were associated with younger age, male sex, shorter axial length, and smoking. Smoking may be associated with choroidal circulatory disturbance in the Japanese population.