Persistent reduction of conduction velocity and myelinated axon damage in vibrated rat tail nerves.
Loffredo-MA; Yan-JG; Kao-D; Zhang-LL; Matloub-HS; Riley-DA
Muscle Nerve 2009 Jun; 39(6):770-775
Prolonged hand-transmitted vibration exposure in the workplace has been recognized for almost a century to cause neurodegenerative and vasospastic disease. Persistence of the diseased state for years after cessation of tool use is of grave concern. To understand persistence of vibration injury, the present study examined recovery of nerve conduction velocity and structural damage of myelinated axons in a rat tail vibration model. Both 7 and 14 days of vibration (4 h/day) decreased conduction velocity. The decrease correlated directly with the increased percentage of disrupted myelinated axons. The total number of myelinated axons was unchanged. During 2 months of recovery, conduction velocity returned to control level after 7-day vibration but remained decreased after 14-day vibration. The rat tail model provides insight into understanding the persistence of neural deficits in hand-arm vibration syndrome.
Animals; Animal-studies; Exposure-assessment; Exposure-levels; Exposure-methods; Hand-injuries; Hand-tools; Injuries; Laboratory-animals; Laboratory-testing; Muscles; Muscle-tissue; Nerve-damage; Nerve-fiber-excitation; Nerve-fibers; Nerve-function; Nerves; Nerve-tissue; Neurological-reactions; Neuropathy; Occupational-exposure; Occupational-hazards; Power-tools; Sensory-disorders; Vibration; Vibration; Vibration-disease; Vibration-effects; Vibration-exposure;
Author Keywords: hand-arm vibration syndrome; occupational Raynaud disease; demyelination; nerve edema; peripheral nerve
Danny A. Riley, Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226
Muscle and Nerve
Medical College of Wisconsin, Milwaukee, Wisconsin