Short-term outcomes of ulnar, median, tibial, and common fibular neurolysis in leprosy neuropathy: A prospective study of pain, sensory function, and muscle strength.

With the accelerating pace of global aging, cognitive impairment has emerged as a critical public health challenge, especially in China, where the older adult population is growing at an unprecedented rate (The Lancet, ). Cognitive function encompasses multiple domains – such as memory, attention, executive function, language, and processing speed (Harvey, ) – which are intrinsically interconnected and generally decline with advancing age (Murman, ). Epidemiological studies highlight a substantial burden of cognitive impairment among older adults in China: mild cognitive impairment (MCI) and dementia affect an estimated 15.5% and 6% of the population aged 60 and older, respectively (Jia et al., ). The number of people living with dementia is projected to 48.98 million by 2050 (Li, Qin, Zhu, & Jia, ). Cognitive decline imposes a multifaceted burden encompassing not only direct healthcare costs but also substantial informal caregiving demands, reduced quality of life, and profound psychosocial effects on both patients and their families (Gläser et al., ; Pérez Palmer, Trejo Ortega, & Joshi, ; Wimo et al., ). Notably, rural older adults experience a higher prevalence of cognitive decline and impose additional burden on family caregivers compared to their urban counterparts (Jia et al., ; Wiese et al., ). Previous studies have identified several risk factors for cognitive impairment, including female sex, depressive symptoms, and poor sleep quality (Jia et al., ; Li, Wang, & Dupre, ). Sleep disorders, psychological distress, and cognitive impairment frequently co-occur in older adults. Sleep disorders are common in this population and typically present as altered sleep architecture, reduced sleep duration, and fragmented sleep patterns (Pavlova & Latreille, ; Yaremchuk, ). Poor sleep quality has been linked to increased risk of neurodegenerative processes and cognitive decline (Casagrande, Forte, Favieri, & Corbo, ; Leng et al., ). Liu et al. reported that both sleep initiation difficulties and daytime sleepiness increased the risk of MCI, with daytime sleepiness further linked to a higher risk of dementia (Liu et al., ). Similarly, psychological distress, especially symptoms of depression and anxiety, is prevalent among older adults and often accelerates cognitive deterioration (Sutin, Stephan, & Terracciano, ). Previous studies have demonstrated bidirectional associations between sleep quality and psychological distress (Alimoradi et al., ; Madrid-Valero et al., ). Moreover, the complex interplay among sleep, psychological distress, and cognitive function has been supported by evidence suggesting that impaired sleep and heightened psychological distress synergistically contribute to cognitive impairment (Kim, Park, Zhu, & Fritschi, ). Despite these findings, much of the existing literature relies on cross-sectional designs or short-term follow-ups, limiting insights into temporal and causal dynamics, particularly in under-researched rural populations. posits that adverse experiences can leave lasting ‘’ on an individual’s psychological and physiological well-being, leading to long-term functional impairment (Allemand, Grünenfelder-Steiger, & Flückiger, ). Over time, psychological issues may not only affect current cognitive function but can also exert persistent effects on future cognitive abilities (Farina et al., ; Gulpers et al., ). Moreover, sleep alterations have been recently conceptualized as biological ‘scars’ of depression (Palagini et al., ). In parallel, theorize those impairments in cognitive functioning (e.g. executive functioning deficits) act as predisposing factors that heighten susceptibility to psychological difficulties like fear and worry. For instance, Zainal et al. found that difficulties in working memory and inductive reasoning predict increased levels of uncontrollable worry (Zainal & Newman, ). Taken together, these two theoretical frameworks generate distinct directional predictions. Determining which predominates requires longitudinal examination of symptom temporal ordering to identify primary drivers and intervention targets.