Trigeminal autonomic cephalalgias

Trigeminal autonomic cephalalgias (TACs) are a group of severe headaches characterized by intense pain around one side of the head, often near the eye, accompanied by autonomic symptoms such as tearing, redness, nasal congestion, or drooping eyelid. They involve abnormal activity in the trigeminal nerve, which transmits facial sensation, and the autonomic nervous system that controls involuntary functions. Common types include cluster headaches, paroxysmal hemicrania, and SUNCT. These headaches are often sudden, extremely painful, and may occur in predictable patterns, requiring specific treatments to manage their attacks.