13.1.2 Painful trigeminal neuropathy


Facial pain in the distribution(s) of one or more branches of the trigeminal nerve caused by another disorder and indicative of neural damage. The primary pain is usually continuous or near-continuous, and commonly described as burning or squeezing or likened to pins and needles. Superimposed brief pain paroxysms may occur, but these are not the predominant pain type. This combination distinguishes painful trigeminal neuropathy from the subtypes of trigeminal neuralgia. There are clinically detectable sensory deficits within the trigeminal distribution, and mechanical allodynia and cold hyperalgesia are common, fulfilling IASP criteria for neuropathic pain. As a rule, allodynic areas are much larger than the punctate trigger zones present in trigeminal neuralgia.