Transient Cervical Nerve Root Compression in the Rat Induces Bilateral Forepaw Allodynia and Spinal Glial Activation: Mechanical Factors in Painful Neck Injuries

STUDY DESIGN: An in vivo rat model of transient cervical nerve root compression. OBJECTIVES: To investigate the potential for cervical nerve root compression to produce behavioral hypersensitivity and examine its dependence on compression. SUMMARY OF BACKGROUND DATA: Clinically, nerve root injury has been hypothesized as a potential source of neck pain, particularly because cervical nerve roots are at mechanical risk for injury during neck loading. Lumbar radiculopathy models of nerve root ligation show that mechanical allodynia and spinal glial changes depend on nerve root deformation magnitude. However, no investigation has been performed to examine cervical nerve root compression as a cause of pain. METHODS: Two compressive forces (10 and 60 grams force [gf]) were transiently applied to the C7 nerve…