Psychometric Measures of Instruments of Occupational Performance in Children With Developmental Coordination Disorder: A Systematic Review.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by extracellular amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau protein. The abnormal accumulation of Aβ and tau proteins disrupts neuronal activity and neural circuit function, ultimately resulting in significant cognitive dysfunction, particularly in learning and memory. The glymphatic system is a newly identified pathway of the perivascular fluid transport system that directs the clearance of metabolic waste in the brain. Dysfunction of the glymphatic system leads to the accumulation of neurotoxic substances. Emerging evidence suggests that the glymphatic system plays a pivotal role in contributing to the deposition of pathological proteins of AD., Impaired brain clearance mechanisms may be the final common pathway to dementia. In 2017, Taoka et al. developed a non‐invasive, image‐based measure called diffusion tensor imaging (DTI) analysis along the perivascular space (ALPS), which assesses perivascular clearance activity in the human brain using diffusion magnetic resonance imaging (MRI). The ALPS index has been proposed to be an indirect indicator that may reflect some aspects of glymphatic function, partly based on an early study showing a correlation with glymphatic clearance function which is evaluated by the classical detection method (calculated on MRI after the intrathecal administration of gadolinium). The ALPS has been studied in the field of AD and other various neurological disorders., , , , A previous study has revealed that the ALPS index was positively associated with cognitive performance. Another study found that the ALPS index was negatively associated with Aβ or tau deposition in cerebrospinal fluid (CSF) and positron emission tomography (PET) images. The ALPS index was also demonstrated to predict clinical progression and cognitive decline in patients with AD. In addition to cognitive decline, another typical clinical manifestation of AD is cerebral atrophy. AD is characterized by gray matter (GM) atrophy in the insula, middle frontal gyrus, and medial temporal lobes. Patterns of cortical atrophy have even been shown to accurately track the disease progression of AD. While both glymphatic dysfunction and brain atrophy participate in AD progression, their relationship has not been fully elucidated despite advances in relevant studies. This study used the ALPS index to investigate the potential associations between glymphatic activity and the clinical features of AD. Previous studies have shown that a lower ALPS could predict GM atrophy in AD signature regions and even cognitive decline. Therefore, in this study we hypothesize that a lower ALPS index is associated with decreased cognitive function and lower gray matter volume (GMV), and that the glymphatic system causes cognitive impairment by leading to cerebral atrophy in AD.