Paroxysmal hemicrania

Paroxysmal hemicrania (PH) is a rare primary headache disorder classified among the trigeminal autonomic cephalalgias (TACs). It is characterized by severe, strictly unilateral headache attacks typically localized to the orbital, supraorbital, or temporal region. Each attack lasts between 2 and 30 minutes and occurs multiple times per day, often averaging more than five episodes daily. The pain is accompanied by ipsilateral cranial autonomic symptoms, which may include conjunctival injection (eye redness), lacrimation (tearing), nasal congestion, rhinorrhea, forehead and facial sweating, miosis (pupil constriction), ptosis (drooping eyelid), and eyelid edema on the affected side. Paroxysmal hemicrania exists in two forms: episodic paroxysmal hemicrania, in which attack periods are separated by pain-free remission phases lasting at least three months, and chronic paroxysmal hemicrania (also known as Sjaastad syndrome), in which attacks occur for more than one year without remission or with remission periods lasting less than three months. The condition affects the trigeminal-autonomic nervous system pathways and predominantly impacts the head and face. Women are affected more frequently than men. A hallmark diagnostic feature of paroxysmal hemicrania is its absolute and complete response to the nonsteroidal anti-inflammatory drug indomethacin, which is considered both a therapeutic and diagnostic criterion. Patients typically experience dramatic and sustained relief with therapeutic doses of indomethacin. This response to indomethacin distinguishes paroxysmal hemicrania from other TACs such as cluster headache. Secondary causes must be excluded through neuroimaging before the diagnosis is confirmed. For patients who cannot tolerate indomethacin, alternative treatments such as verapamil, topiramate, or other agents have been tried with variable success, though none match the efficacy of indomethacin.

Common questions about Paroxysmal hemicrania