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age-associated changes in the peripheral nervous system

The peripheral nervous system undergoes change with aging. Physiology: 1) loss of spinal motor neurons 2) decreased cranial nerve function 3) decreased lower extremity vibration sensation [7] 4) decreased thermal sensitivity 5) decline in number & function of sensory nerves [5] - decreased sensory nerve (sural nerve) action potential amplitude [7] - sural sensory nerve action potential nonrecordable in 25% > 80 years [7] - relative preservation of pain sensation [7] 6) decreased size of large myelinated fibers 7) increased heterogeniety of axon myelin sheaths 8) slowed propagation of action potentials 9) loss of neuromusclar junctions [5] 10) decrease in fine motor control 11) decrease in maximal strength of muscle contraction [5] 12) delay in initiating movement [5] 13) decreased Achilles tendon reflex [7] - relative preservation of patellar reflex Complications: - peripheral neuropathy is associated with excess risk of mobility impairment in the elderly [6]

Related

peripheral nerve peripheral nerve disease; peripheral neuropathy peripheral nervous system

General

age-related physiological changes

References

  1. Essentials of Clinical Geriatrics, 4th ed, Kane RL et al (eds) McGraw Hill, NY, 1999
  2. UCLA Intensive Course in Geriatric Medicine & Board Review, Marina Del Ray, CA, Sept 29-Oct 2, 2004
  3. The Merck Manual of Geriatrics, 3rdh ed, Merck & Co, Rahway NJ, 2000
  4. Taffet GE, Physiology of Aging, In: Geriatric Medicine: An Evidence-Based Approach, 4th ed, Cassel CK et al (eds), Springer-Verlag, New York, 2003
  5. Geriatric Review Syllabus, 7th edition Parada JT et al (eds) American Geriatrics Society, 2010 - Geriatric Review Syllabus, 8th edition (GRS8) Durso SC and Sullivan GN (eds) American Geriatrics Society, 2013
  6. Ward RE et al. Sensory and motor peripheral nerve function and incident mobility disability. J Am Geriatr Soc 2014 Dec; 62:2273 PMID: 25482096
  7. Taams NE et al. Age-related changes in neurologic examination and sensory nerve amplitude in the general population: Aging of the peripheral nervous system. Neurology 2023 Aug 4; [e-pub]. PMID: 37541844 https://n.neurology.org/content/early/2023/08/04/WNL.0000000000207665