Connection between peripheral nerves and Alzheimer's disease

Evidence is emerging that lower extremity peripheral nerve impairments are associated with and may even precede dementia.

This has been demonstrated clinically: slowed walking speed and poor gait have been shown to predict dementia, and motor and sensory impairments have been associated with Alzheimer disease.

Although the mechanisms linking the peripheral nervous system to dementia are unclear, pathogenic factors support the relationship.

A typical pattern of peripheral neuropathy sensory loss (distal, bilateral, symmetrical) has been described in the elderly.

This pattern is thought to be due to loss of energy production in the cell bodies in the dorsal root ganglia as a result of metabolic, toxic, and neurodegenerative etiologies.

In addition, neurodegenerative proteins have been found in the dorsal root ganglia suggesting that the same process that occurs in brain neurons in the CNS is also occurring in the peripheral nervous system.