"Other disorders that cause facial pain should be ruled out before trigeminal neuralgia is diagnosed. Some disorders that cause facial pain include postherpetic neuralgia (nerve pain following an outbreak of shingles), cluster headaches, and temporomandibular joint disorder (TMJ, which causes pain and dysfunction in the jaw joint and muscles that control jaw movement). Most people with TN eventually will undergo a magnetic resonance imaging (MRI) scan to rule out a tumour or multiple sclerosis as the cause of their pain."