Other unilateral primary headache syndromes with autonomic symptoms, which are sometimes grouped together with cluster headache as trigeminal autonomic cephalgias, should be excluded: SUNCT (short-lasting unilateral neuralgiform headache with conjunctival injection and tearing) and short-lasting unilateral neuralgiform headache attack (SUNA): Attacks are very brief (5 to 250 seconds) and occur at high frequency (up to 200 attacks / day).