Increased Serum Cystatin C in Early Parkinson’s Disease with Objective Sleep Disturbances

Background：Sleep disturbance is one of the major non-motor symptoms which cause the disability of Parkinson’s disease （PD） patients. Cystatin C （CysC） is a more sensitive biomarker than serum creatinine or estimated glomerular filtration rate. Previous studies have reported altered CysC levels in neurodegenerative disorders and sleep disorders. This study aimed to explore the correlations of serum CysC levels and objective sleep disturbances in early PD.Methods：We recruited 106 early PD patients and 146 age- and sex-matched controls. All participants underwent clinical investigation and video-polysomnography. Sleep parameters and serum levels of CysC were measured. Then, we investigated the relationships between CysC and clinical variables and objective sleep disturbances in early PD patients.Results：The mean serum level of CysC was significantly higher in patients with early PD （1.03 ± 0.19 mg/L） compared to controls （0.96 ± 0.15 mg/L, P = 0.009）. There were significantly positive correlations between serum CysC levels and age （r = 0.334, P 〈 0.001）, gender （r = 0.264, P = 0.013）, and creatinine levels （r = 0.302, P = 0.018） in early PD patients. Increased serum CysC levels in early PD patients were significantly associated with higher apnea and hypopnea index （AHI） （r = 0.231, P = 0.017）, especially hypopnea index （r = 0.333, P 〈 0.001）. In early PD patients, elevated serum CysC levels were positively correlated with oxygen desaturation index （r = 0.223, P = 0.021）, percentage of time spent at oxygen saturation （SaO2） 〈90% （r = 0.644, P 〈 0.001）, arousal with respiratory event during sleep （r = 0.247, P = 0.013）. On the contrary, the elevated serum CysC levels were negatively correlated with mean and minimal SaO2 （r = ？0.323, ？0.315, both P = 0.001） in PD patients.Conclusions：The level of serum CysC was higher in early PD patients. PD patients with elevated serum CysC levels had more respiratory events and more severe oxygen desaturation. Therefore, the serum CysC levels may predict the severities of sleep-disordered breathing problems in early PD patients.

Posterior circulation ischemia due to carotid artery dissection with hyperhomocysteinemia in a 51-year-old man

To the Editor:Persistent trigeminal artery(PTA)is one of the most common remaining fetal anastomoses.During embroyotic development,the link between the carotid and vertebral basilar circulation would normally regress.Carotid artery dissection(CAD)is a common cause of cerebral ischemia in young people,which can be caused by hyperhomocysteinemia(HHcy)possibly due to gene mutation.We report a case of posterior circulation ischemia caused by CAD.

Sleep disorders and acute stroke: profile and research opportunities

Stroke is the leading cause of disability and mortality worldwide.More than half of stroke patients have sleep disorders,including sleep breathing disorders,non-apnea sleep disturbances,and circadian rhythm disruption.Therefore,sleep disturbances,particularly obstructive sleep apnea(OSA),have long been speculated as new preventive and therapeutic targets for stroke.Whether the specific roles of the above sleep disorders in stroke outcome or the efficacy of OSA treatment with continuous positive airway pressure(CPAP)therapy to prevent cerebrovascular events remains uncertain yet.It is noteworthy that there are important limitations among these studies.Here,we briefly reviewed representative studies and subsequently addressed the opportunities mainly for clinical research.The main recommendations are outlined at the end.