Because there are a large number of conditions that can cause facial pain, TN can be difficult to diagnose. Finding the cause of the pain is important as the treatments for different types of pain may differ.
Secondary Symptomatic Trigeminal Neuralgia (STN): Pain resulting from another condition such as a tumor or multiple sclerosis.
Post- Herpetic Neuralgia (PHN): pain resulting from a herpes zoster outbreak (shingles) along the trigeminal nerve.
Trigeminal Neuropathic Pain (TNP): facial pain resulting from unintentional injury to the trigeminal system from facial trauma, oral surgery, ear, nose and throat (ENT) surgery, root injury from posterior fossa or skull base surgery, stroke, etc. This pain is described as dull, burning, or boring and is usually constant because the injured nerve spontaneously sends impulses to the brain. The injured nerve is also hypersensitive to stimulation, so attacks of sharp pain can also be present. The area which is sensitive to touch and triggers these sharp attacks is the same area where the pain occurs. Numbness and tingling are also signs of a damaged nerve.
Trigeminal Deafferentation Pain (TDP): facial pain in a region of trigeminal numbness resulting from intentional injury to the trigeminal system from neurectomy, gangliolsys, rhizotomy, nucleotomy, tractotomy, or other denervating procedures. Despite the loss of sensation, constant pain is felt in the numb area(s), which varies in intensity and can include sensations of burning, crawling, tingling, boring, stinging, and/or unpleasant aching.
Symptoms of Trigeminal Neuropathic Pain that is not TN:
- Occurs soon after unintentional injury to the trigeminal system
- The pain is better described as constant, dull, burning or boring pain with intermittent sharp pain.
- A destructive procedure used for classic TN could make neuropathic pain much worse.