The following diagnostic criteria are given for<unk> : # Headache for more than 3 months fulfilling other 3 criteria: # All of the following characteristics: #* Unilateral pain without side-shift #* Daily and<unk> us, without pain-free periods #* Moderate intensity, but with exacerbations of severe pain # At least one of the following autonomic features occurs during exacerbations and ipsilateral to the side of pain: #* Conjunctival injection and/or lacrimation #* Nasal congestion and/or rhinorrhea #* Ptosis and/or miosis # Complete response to therapeutic doses of indomethacin, although cases of<unk>  that do not resolve with indomethacin treatment have been documented. A variant on<unk>  has also been described, in which the attacks may shift sides, although meeting the above criteria in all other respects. There is no definitive diagnostic test for<unk> . Diagnostic tests such as imaging studies may be ordered to rule out other causes for the headache. When the symptoms of<unk>  are present, it's considered "diagnostic" if they respond completely to indomethacin. The efficacy of indomethacin may not be long term for all patients, as can eventually become ineffective. Differential diagnosis The factor that allows<unk>  and its exacerbations to be differentiated from migraine and cluster headache is that<unk>  is completely responsive to indomethacin. Triptans and other abortive medications do not affect<unk> . Classification The International Headache Society's International Classification of Headache Disorders classifies<unk>  as a primary headache disorder.
Hemicrania continua
Arachnoid cyst
Meningohydroencephalocoele
Periventricular leukomalacia
Hydrocephalus
Subdural hygroma
Intraventricular hemorrhage
Cerebrospinal fluid leak