Trigeminal neuralgia (tic douloureux) produces extremely severe, sharp shooting pain “like a bolt of lightning” in the face, brought about by touching a specific area and lasting about 60 seconds. Patients are in their 60s and have a completely normal neurologic exam. The only finding on physical may be an unshaven area in the face (the trigger zone, which the patient avoids touching). MRI is done to rule out organic lesions. Treatment with anticonvulsants is often successful (notably carbamazapine). If not, radiofrequency ablation can be done. Some surgeons believe pounding from a nearby vessel may be responsible, and they advocate an operation to separate them.
Reflex sympathetic dystrophy (causalgia) develops several months after a crushing injury. There is constant, burning, agonizing pain that does not respond to the usual analgesics. The pain is aggravated by the slightest stimulation of the area. The extremity is cold, cyanotic, and moist. A successful sympathetic block is diagnostic, and surgical sympathectomy is curative.