Investigation of the Effects of Different Rehabilitation Approaches on Cognitive Functions, Dual Task Performance, and Manual Dexterity in Older Adults With Mild Cognitive Impairment

The number of individuals aged 65 and older is increasing worldwide, leading to a rise in the elderly population. As this demographic grows, the prevalence and diversity of health problems associated with aging are also increasing. The most common health issues in aging individuals include cognitive impairments, dementia, cardiovascular diseases, arthritis, type 2 diabetes mellitus (DM), and cancer.

The primary underlying causes of the frequent health problems in elderly individuals stem from negative changes in their physical, psychosocial, and cognitive conditions. Notably, structural, physiological, and functional declines in cognitive domains significantly impact the lives of elderly individuals. Cognitive function encompasses a broad range of processes and structures, including emotion, memory, reasoning, language, sensory processing, comprehension, analysis, interpretation, learning, and motor skills. Aging leads to structural deterioration, functional decline, dysfunction, and eventual loss of these cognitive abilities, contributing to various levels of cognitive impairment in elderly individuals. Depending on the severity and the affected cognitive domains, aging individuals may develop different neurological disorders. The most prevalent neurological conditions associated with aging include Mild Cognitive Impairment (MCI), Alzheimer's disease (AD), Parkinson's disease (PD), multiple system atrophy, Lewy body dementia, amyotrophic lateral sclerosis (ALS), progressive supranuclear palsy, and frontotemporal dementia.

Mild Cognitive Impairment is characterized by memory loss or other cognitive deficits that are not severe enough to interfere with daily activities but represent a transitional phase between normal cognitive function and early dementia. Other cognitive deficits include attention, sensory processing, language, visual-spatial perception, praxis, and motor skills. In elderly individuals with MCI, the type and severity of cognitive impairment vary depending on the affected structures within the central nervous system. Although these cognitive impairments manifest at different levels, most elderly individuals with MCI can still perform many daily activities independently.

Motor functions are defined as learned skills aimed at achieving specific goals, with hand motor skills involving a series of complex movements. Hand movement is directly linked to the motor and somatosensory homunculus through short U-shaped fibers that pass beneath the central sulcus. The distribution of these short U-shaped fibers follows the topographic organization of the primary motor and somatosensory cortex. Compared to other body regions, there are greater interconnections between finger regions, and the cortical areas allocated for tactile and proprioceptive information from the fingers are more extensive than those for other body parts.

The neuronal connections that maintain and support the functionality of fine and gross motor skills of the hand interact with the cortical areas of the brain. Therefore, any degenerative changes in these neuronal connections and cortical areas may influence individuals' cognitive and motor functions. The cortical areas of the brain govern high-level cognitive functions such as attention, thought, memory, perception, reasoning, awareness, coordination, language, comprehension, and speech. The relationship between cognitive functions and hand skills is still a topic of debate.