Because there are many possible causes for facial pain, getting an accurate diagnosis is important.
Before looking for trigeminal neuralgia, your doctor may order additional tests to rule out other conditions. Typical tests or procedures your doctor will use to diagnose trigeminal neuralgia include:
Physical and neurological examinations. By thoroughly examining parts of your face, your doctor can discover the exact source of the pain and can determine which parts, if any, of the trigeminal nerve may be involved. They may also perform reflex tests to decide if your symptoms are caused by a compressed nerve or another condition.
Magnetic resonance imaging (MRI). Your doctor may order an MRI to rule out other possible causes for the TN, including multiple sclerosis and a tumor. In some cases, your doctor may inject a dye into a blood vessel to view the arteries and veins and highlight blood flow (magnetic resonance angiography).