Development of mirror pain following trigeminal nerve injury: a case report and review of neuropathic mechanisms.

Following injury to a peripheral nerve, patients may complain of pain over the distribution of the same contralateral nerve, a phenomenon referred to as contralateral pain or mirror pain (MP). Symptoms of MP usually begin after the neuropathic pain from the original nerve injury has become chronic. Chronic neuropathic pain can lead to sensitization and spread of pain. Because the diagnosis of MP can be missed, patients may undergo multiple treatment procedures that prove to be ineffective in relieving the pain. This article presents a case of MP that appeared approximately 20 months following inferior alveolar nerve injury that occurred during placement of a dental implant in the region of the first molar. Acutely painful nerve injuries must be aggressively treated to prevent changeover to a chronic pain state characterized by sensitization and spread of pain beyond the initial injury. Consequently, clinicians need to begin effective, early pain management to prevent the changeover to chronic pain that has become centralized and refractive to treatment.