Trigeminal autonomic cephalalgias: diagnosis and treatment.

The trigeminal autonomic cephalalgias (TACs) are a group of primary headache disorders characterized by unilateral head pain that occurs in association with ipsilateral cranial autonomic features. The TACs include cluster headache, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and its close relative short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA). These syndromes cause patients considerable disability and certainly very significant suffering. They are distinguished by the frequency of attacks of pain, the length of the attacks, and very characteristic responses to medical therapy, such that the diagnosis can usually be made clinically, which is important because it completely dictates therapy. The management of TACs can be very rewarding for physicians and highly beneficial to patients.