Recurrent Sensitivity

Recurrent Sensitivity, sensation of pain that occurs upon irritation of the anterior or motor roots of the spinal cord, caused by the presence of sensory fibers that enter them from the posterior roots through a loop-like turn. This turn occurs at the point where both roots connect or within the mixed trunk of the peripheral nerve. When the anterior roots are severed, the sensation of pain is obtained only when the peripheral end is irritated, simultaneously with muscle contraction; however, irritation of the central severed end does not cause any sensation. When the corresponding posterior root is severed, sensitivity in the anterior part disappears. The same phenomenon of recurrent sensitivity is observed in peripheral nerves (spinal and cranial).