Frequently-recurring headache attacks developing only during sleep, causing wakening and lasting for up to four hours, without characteristic associated symptoms and not attributed to other pathology.
A. Recurrent headache attacks fulfilling criteria B-E
B. Developing only during sleep, and causing wakening
C. Occurring on ≥10 days per month for >3 months
D. Lasting ≥15 min and for up to 4 hr after waking
E. No cranial autonomic symptoms or restlessness
Headache Classification Committee of the International Headache Society (IHS) (2013). The International Classification of Headache Disorders, 3rd edition (beta version). Cephalalgia 2013; 33: 9-807.