RT Book, Section A1 Spierings, Egilius L.H. A2 Warfield, Carol A. A2 Bajwa, Zahid H. SR Print(0) ID 3411866 T1 Chapter 22. Chronic Daily Headache T2 Principles & Practice of Pain Medicine, 2e YR 2004 FD 2004 PB The McGraw-Hill Companies PP New York, NY SN 9780071443494 LK accessanesthesiology.mhmedical.com/content.aspx?aid=3411866 RD 2024/10/10 AB Chronic daily headache relates to the daily or almost-daily occurrence of headache. However, not all daily or almost-daily headaches fall under this denominator, as is the case with the daily or almost-daily headaches of (chronic) cluster headache and paroxysmal hemicrania, as well as those of hypnic headache or nocturnal migraine. These conditions can be referred to as paroxysmal daily headaches in which the headaches occur in well-defined attack patterns. In cluster headache, the attack pattern is that of headaches occurring once or twice a day and lasting 1 to 2 hours, whereas in paroxysmal hemicrania, it is that of headaches occurring 5 to 15 times per day and lasting 10 to 30 minutes. In hypnic headache or nocturnal migraine, the headaches occur once a day, waking the patient from sleep at night, usually between 4 and 6 am, and lasting for a variable amount of time, also depending on the efficacy of treatment.