Trigemino AuT onomiC CephAl AlgiA And Argyll r ober TSon pupil

. The group comprises episodic and chronic clus-ter headache, chronic and episodic paroxysmal hemicra-nia, and SUNCT syndrome. SUNA syndrome (short-lasting unilateral neuralgiform headache attacks with cranial au-tonomic symptoms), although not classified as a TAC, also shares some common characteristics with this group and may include the SUNCT definition. Despite their common elements, the TACs differ in response to therapy, frequen-cy and duration of attacks. They must be differentiated from secundary TACs because of the possible serious and treatable underlying causes, like mass lesions, subarach-noid hemorrhage, pathology in the base of the skull and others