The Duration of a Nerve Root Compression Modulates Evoked Neuronal Responses in a Rat Model of Painful Injury

The annual incidence for neck pain in the adult population is 30–50% [1]. The cervical nerve roots are at risk for mechanical injury due to impingement of surrounding structures which can result in pain and numbness [2]. During nerve root compression, an immediate, brief increase in spontaneous afferent activity and a gradual decrease in electrically evoked axonal conduction have been reported [3,4]. Although previous studies demonstrate that a transient cervical nerve root compression induces persistent behavioral sensitivity [5,6], it is not known how the tissue mechanics during loading modulate neuronal function or how they relate to the onset of pain. Therefore, the goal of this study was to quantify neuronal activity in the spinal cord as a function of the duration of applied compression by measuring both electrically-evoked and spontaneous afferent activity during a transient compression of the cervical nerve root in a rat model of pain [5,6].