Diagnosis of Trigeminal Neuralgia
There are many causes and types of facial pain, and most are not trigeminal neuralgia. Other disorders such as atypical facial pain are harder to treat and do not respond to the treatments for trigeminal neuralgia. Therefore it is important to get an accurate diagnosis to decide what treatments can be effective.
There is no laboratory or imaging test that makes the diagnosis of trigeminal neuralgia. Instead the diagnosis of trigeminal neuralgia must be made by an experienced neurosurgeon or neurologist through patiently taking a detailed history. There are many characteristics of the pain that are matched to the specific features of trigeminal neuralgia. The physical examination typically reveals no neurological abnormalities. The laboratory tests done will include imaging studies such as an MRI of the brain with and without an injection of contrast material. This helps to rule out other abnormalities including a brain tumor or other vascular lesion that could be responsible. Often, an MRA (magnetic resonance angiogram) is done, preferably on a high field strength magnet to show the small blood vessels in the brain around the trigeminal nerve. This means the test cannot be performed on an "open magnet" because thse are not strong enough.