Clinical features of sleep apnea syndrome and cognitive impairment in multiple sclerosis.

BACKGROUND: Complications of obstructive sleep apnea (OSA) have been reported in patients with multiple sclerosis (MS). Patients with sleep apnea syndrome (SAS) due to OSA also show cognitive decline, with similar clinical characteristics to that manifested in MS. SAS due to OSA is a treatable condition, and the associated cognitive decline is expected to improve. This study investigates clinical features of SAS in people living with MS and contribute to improve cognitive dysfunction of MS. METHODS: A case-control study was conducted. Cognitive functions were evaluated by the Symbol Digit Modalities Test (SDMT) and the Paced Auditory Serial Addition Test 2 (PASAT-2) and 3 (PASAT-3). The Respiratory Event Index (REI) was measured using Out of Center Sleep Testing (OCST). We defined subjects with REI ≥ 5 as OSA and divided participants into two groups with or without SAS due to OSA. Cognitive and respiratory characteristics were statistically compared between patients with MS and healthy controls. RESULTS: We enrolled 67 people living with MS and 31 age- and sex-matched controls. OCST detected OSA in people living with MS and controls, and the prevalence rates were 28.4 % and 25.8 %, respectively. REI values (5.2 ± 7.9 vs 3.9 ± 5.2, p = 0.509) and number of participants with REI ≥ 5 (19 vs 8, p = 0.793) were similar between the MS and control group. The SDMT, PASAT-2, and PASAT-3 scores were significantly lower in the MS group than the control group (p < 0.001, p = 0.001, and p < 0.001, respectively). The interaction effect of MS and SAS on cognitive function was not significant in the SDMT (p = 0.078), but in the PASAT-2 (p = 0.043) and PASAT-3 (p = 0.020). CONCLUSION: This study revealed the prevalence rates of SAS in Japanese people living with MS and the usefulness of OCST for detection of SAS. This study also revealed that concomitant SAS can facilitate cognitive decline in people living with MS. These findings suggest that an appropriate intervention for OSA can be beneficial for people living with MS with cognitive decline.

Symbol digit modalities test predicts decline of off-road driving ability in Japanese patients with multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is a chronic progressing neurological disease with exacerbations and remissions. Patients with MS can show a variety of neurological symptoms. Cognitive decline is noticed as one of them and is related with deterioration of daily life quality in a clinical practice. Driving a car is one of the common activities required in daily life and is also an important issue in MS patients. METHODS: To clarify the relationship between cognitive function and driving ability in MS patients, the symbol digit modalities test (SDMT) and a driving simulator were evaluated. We enrolled 24 patients with MS (5 males, 19 females, 39.04 ± 8.27 years old) and age- and sex-matched 24 healthy controls (5 males, 19 females, 40.54 ± 9.78 years old) in this study. They underwent the SDMT and also used a driving simulator to measure a total of 12 response values related to driving ability. In order to evaluate the relationship between SDMT and driving ability, MS patients were divided into two groups according to the median SDMT score: group A (SDMT 51 or more) and group B (SDMT less than 51). The data were statistically analyzed among control group, MS group A, and MS group B using Jonkheere-Terpstra trend test and Bonferroni's multiple comparison test. RESULTS: The group with higher scores on the SDMT tended to have significantly higher driving performance. Multiple comparison analysis among three groups showed that the reaction values for speed of response behavior were significantly higher in MS group B than control group. CONCLUSION: This study revealed a relationship between driving abilities and SDMT scores. Clinical evaluation using the SDMT may help to detect cognitive decline and to make a decision on driving a car in patients with MS.

A cross-sectional study of Parkinson's disease and the prodromal phase in community-dwelling older adults in eastern Japan.

Introduction: Parkinson's disease (PD) is more prevalent in the aging population, and epidemiological evidence must be constantly updated to provide an accurate understanding of PD prevalence. Various nonmotor symptoms of PD precede the onset of motor symptoms and prodromal PD. The detection of such symptoms is crucial yet remains challenging. In this study, we aimed to clarify the current prevalence of PD and prodromal PD. Methods: We enrolled 714 community-dwelling older adults (330 men and 384 women) aged ≥ 65 years (mean age 76.3 years). We used a self-administered questionnaire based on the International Parkinson and Movement Disorder Society prodromal PD criteria to obtain information on prodromes and calculate PD probability. Patients with a probability of ≥ 0.3 were considered as having prodromal PD. We analyzed the crude prevalence rates of PD and prodromal PD. Results: The crude prevalence rate of PD in our sample was 279.7 per 100,000 persons. The crude prevalence rate of prodromal PD and PD probability were 5034.5 per 100,000 persons and 0.057 ± 0.121, respectively. Never smoker (61.4%), physical inactivity (47.0%), regular pesticide exposure (30.7%), and urinary dysfunction (26.5%) were frequent positive prodromes. Subjects with higher PD probability possessed more variable prodromal markers than those with lower probability. Conclusion: We examined current prevalence rates of PD and prodromal PD in community-dwelling older adults aged ≥ 65 years in Japan. Our questionnaire-based approach to examine prodromal PD provided valuable evidence for the prevalence of prodromal PD in the aging population.