Trigeminal autonomic cephalalgia sine headache.

Cluster headache without headache (CH-H) has been described several times. We add three new CH-H patients and a patient with (probable) paroxysmal hemicrania without headache (PH-H). We searched the literature and found some more cases of CH-H and PH-H. CH-H attacks may have a shorter minimal attack duration than CH attacks. We propose the term trigeminal autonomic cephalalgia without headache (TAC-H) for autonomic attacks and/or extracephalic pain or sensory symptoms with an attack duration and distribution and/or response to therapy suggesting one of the trigeminal autonomic cephalalgias, but without accompanying headache. Secondary TAC-H may develop after treatment for painful TAC attacks. We discuss pathophysiological issues, particularly the central role of the hypothalamus and the suggestion that the superior salivatory nucleus (SSN) might be triggered by the diencephalic pacemaker without nociceptive activation.