Suspected trigeminal nerve neuropathy causing persistent idiopathic facial pain: a report of four cases.

Persistent idiopathic facial pain is often a disabling condition for patients. Due to a lack of agreed upon diagnostic criteria and varied symptomatology, the diagnosis of persistent idiopathic facial pain is elusive and remains one of exclusion. It is typically described as a unilateral, deep, poorly localized pain in the territory of the trigeminal nerve, however there are a number of case reports that describe bilateral symptoms. Unlike trigeminal neuralgia, the condition encompasses a wider distribution that does not conform or relate to a specific dermatome. In addition, the pain is typically continuous, with no periods of remission and there are no signs or symptoms suggestive of autonomic involvement. Reports documenting the response to various conservative treatments for persistent idiopathic facial pain have been widely variable likely due to the heterogeneity of the condition. Four cases of persistent idiopathic facial pain due to suspected trigeminal nerve neuropathy and their management are presented. A specific form of targeted, manual, instrument-assisted, intra-oral vibration therapy appeared to provide relief in the four cases described.