廣瀬 真里奈

Procrastination behavior has been reportedly associated with the evening preference. This study aimed to evaluate its difference between patients with circadian rhythm sleep-wake disorders with phase delay (CRSWDswPD) and healthy controls in terms of evening preference and comorbid psychiatric disorders. Thirty patients with CRSWDswPD and 29 healthy participants were included. In both groups, the general procrastination scale (GPS), Beck Depression Inventory (BDI), and Morningness-Eveningness Questionnaire (MEQ) were administered. Additionally, Adult ADHD Self-Report Scale (ASRS) and autism spectrum quotient (AQ) were also assessed in the patient group. Unexpectedly, GPS was not statistically different between patients with CRSWDswPD and healthy controls. GPS was significantly higher with lower MEQ in the healthy group, whereas the opposite tendency was observed in the patient group. Higher AQ, ASRS, and BDI tended to be associated with higher GPS in the patient group, with the first two being statistically significant. The results suggest that general procrastination is not significantly associated with CRSWDswPD, although it is associated with evening preference in healthy participants. Procrastination in the patient group may be associated with developmental disorders or depression tendencies. Future studies should include simultaneous measurement of circadian markers, other behavioral assessments, a larger population, and untreated patients.

OBJECTIVES: We evaluated the continuity and effectiveness of oral appliances (OAs) for treating obstructive sleep apnea (OSA) in a psychiatric sleep clinic, specifically focusing on mild cases and those with psychiatric comorbidity. METHODS: We retrospectively examined the medical records of 106 OSA patients treated with OA. Survival analysis was performed to assess the discontinuation of OA use. Clinical Global Impression-Improvement (CGI-I) scale were obtained from medical records. The apnea-hypopnea index (AHI), measured by polysomnography (PSG), and Epworth Sleepiness Scale (ESS) were compared between diagnosis and after post-OA treatment if a second PSG for efficacy assessment was conducted. RESULTS: Among all 106 patients, Kaplan-Meier analysis estimated a discontinuation rate of 16.8% at 1 year. This tended to be higher for OSA patients with psychiatric comorbidity (22.7%) than those without (11.6%), though it was not statistically significant (P=0.08). The overall rate of improvement in CGI-I scale was 37.7% and was significantly lower in OSA patients with psychiatric comorbidity (25.0%) than those without (48.3%). Among the 74 patients who underwent a second PSG, AHI and ESS were significantly lower after OA treatment for the entire group and subgroups of OSA severity at diagnosis and psychiatric comorbidity, except for ESS in the moderate OSA severity subgroup. CONCLUSION: OA continuation was relatively good, and sleepiness was relieved by OA use, even in mild OSA patients and those with psychiatric comorbidity. However, the continuation and subjective improvement of symptoms were slightly lower in OSA patients with psychiatric comorbidity.

Delayed sleep phase disorder (DSPD) and mood disorders have a close relationship. However, the shared mechanisms by DSPD and mood disorders have not been well-elucidated. We previously found that micro-fluctuations in human behaviors are organized by robust statistical laws (behavioral organization), where the cumulative distributions of resting and active period durations take a power-law distribution form and a stretched exponential functional form, respectively. Further, we found that the scaling exponents of resting period distributions significantly decreased in major depressive disorder (MDD). In this study, we hypothesized that DSPD had similar characteristics of the altered behavioral organization to that of MDD. Locomotor activity data were acquired for more than 1 week from 17 patients with DSPD and 17 age- and gender-matched healthy participants using actigraphy. We analyzed the cumulative distributions of resting and active period durations in locomotor activity data and subsequently derived fitting parameters of those distributions. Similar to patients with MDD, we found that resting period distributions took a power-law form over the range of 2-100 min, with significantly lower values of scaling exponents γ in patients with DSPD compared with healthy participants. The shared alteration in γ suggests the existence of similar pathophysiology between DSPD and MDD.

BACKGROUND: The minimum narcolepsy criteria "mean sleep latency (MSL) ≤8 min and ≥2 sleep onset rapid eye movement (REM) periods (SOREMPs) on polysomnography (PSG) and the multiple sleep latency test (MSLT)," according to The International Classification of Sleep Disorders, Third Edition (ICSD-3), are not specific to narcolepsy. Recently, the characteristic sleep stage sequences preceding SOREMPs in narcolepsy have received attention, but their diagnostic utility remains unclear. METHODS: We retrospectively reviewed PSG/MSLT records and chart data for 102 Japanese patients with hypersomnia and at least one SOREMP. We examined the sporadic rates of two sleep stage sequences preceding the SOREMPs-wakefulness or stage 1 to REM (W/S1→R) and stage 2 to REM (S2→R)-comparing these between patient groups with narcolepsy type 1 (N = 28), narcolepsy type 2 (N = 19), and other hypersomnia (N = 55). We also examined the utility of three simple indices using the occurrence of W/S1→R SOREMPs for distinguishing between narcolepsy and other hypersomnia in patients who satisfied the minimum narcolepsy criteria. RESULTS: W/S1→R SOREMPs were significantly more frequent in narcolepsy than in other hypersomnia, and this tendency was also observed even in the patients who satisfied the minimum narcolepsy criteria. The three indices had moderate sensitivities and specificities for distinguishing between narcolepsy and other hypersomnia in patients satisfying the minimum narcolepsy criteria. CONCLUSIONS: The W/S1→R pattern was observed significantly more frequently in narcolepsy than in other hypersomnia, suggesting it may help with differentiating narcolepsy from other hypersomnia in patients demonstrating the narcolepsy criteria, although its ability to do so may be modest.

OBJECTIVES: Idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) is characterized by abnormal and potentially violent behaviors during REM sleep, typically observed in older adult subjects. Previous reports have described a high risk for neurodegeneration in patients with iRBD; however, to date, no published study has analyzed an adequate number of Japanese patients. We retrospectively analyzed the incidence of neurodegenerative disorders among patients diagnosed with iRBD in our department. METHODS: The data were retrospectively collected from patients' medical records. The patients included in the study were diagnosed with iRBD using polysomnography in our department, from May 1, 2005 to November 30, 2018, with a follow-up of ≥6 months. Using the Kaplan-Meier (KM) method, we estimated the incidence of later diagnoses of neurodegenerative disorders among this cohort of patients with iRBD. RESULTS: Among 57 consecutive patients diagnosed with iRBD, 14 (24.6%) were later diagnosed with neurodegenerative disorders. Using the KM method, we estimated that the incidence was as high as 18.5% and 68.1% at 5 and 10 years, respectively. Of the 14 patients who developed neurodegenerative disorders, 12 (85.7%) had α-synucleinopathies (Parkinson's disease in eight patients, Lewy body dementia in three, Alzheimer's-type dementia in two, and multiple system atrophy in one). CONCLUSIONS: The results of this study suggest the high likelihood that iRBD may subsequently progress to neurodegenerative disorders in Japanese patients, a finding similar to those previously reported by studies performed overseas. Further studies using standardized prospective evaluation methods must be performed in Japan.