Sensory deficiencies correlate with tau protein and dementia.

Sensory decline is a common feature of aging and an early sign of a high risk of developing neurodegenerative diseases. Abnormal protein deposits of tau are also observed in sensorial areas in early stages of Alzheimer's disease and related dementia (ADRD), indicating that these two features are associated with common neuropathological changes in the affected brain areas. Alterations in taste and smell are evident in subjects with cognitive decline, but sensory decline is perceived in olfaction, vision, hearing (at early times of degeneration), and even touch, which correlates with disease progression. Consequently, affected individuals may suffer from varying altered behaviors that emerge from the declined capability to process and perceive information, suggesting that differences in sensory perception of the environment may play a key role in explaining these behavioral variations in subjects with cognitive impairment. This commentary discusses some of the alterations in sensory functionality and how these could contribute to the development of neurodegenerative disorders, such as ADRD.