Paroxysmal hemicrania (PH) is classified as a trigeminal autonomic cephalgia (TAC.) It is characterized by relatively short attacks1 of severe trigeminal pain accompanied by autonomic symptoms in the same region.

It is described as a claw-like, boring pain on one side of the face. Pain is located in, around, and/or behind the eye and sometimes wraps around the side of the head or the back of the neck. Attacks may be episodic (EPH) or chronic (CPH) and it is common for the paroxysms of pain to occur on top of a baseline of unremitting pain, leaving the patient with both types of PH and no break from pain. PH is sometimes informally referred to as atypical cluster headache. The syndrome affects predominantly women.1 Although it is much more common to adults, there are reported cases of children as young as six years old with PH.

Autonomic symptoms of PH can be any/all of the following, on the same side of the face as the pain:

  • red eye
  • tearing
  • nasal congestion
  • runny nose
  • forehead/facial sweating
  • eyelid edema
  • dilated/constricted pupil

Additionally, PH patients often cite dull pain, soreness, and tenderness in the affected area between attacks. The attacks are strictly unilateral, with the pain persistently confined to the ocular/periocular area. Generally, the pain is severe and neuralgic in character.

The hallmark of PH is the absolute cessation of the headache with indomethacin.2

Diagnostic criteria:
A At least 20 attacks fulfilling B–D
B Severe unilateral orbital, supraorbital, or temporal pain lasting 2–30 minutes
C Headache is accompanied by at least one of the following:
    (1) Ipsilateral conjunctival injection and/or lacrimation
    (2) Ipsilateral nasal congestion and/or rhinorrhea
    (3) Forehead and facial sweating
    (4) Ipsilateral eyelid edema
    (5) Ipsilateral forehead and facial sweating
    (6) Ipsilateral miosis and/or ptosis
D Attacks have a frequency above five per day for more than half the time, although periods with lower frequency may occur
E Attacks are prevented completely by therapeutic doses of indometacin
F Not attributed to another disorder
Episodic paroxysmal headache
Description: Occurs in periods lasting seven days to one year separated by pain free periods lasting one month or more
Chronic paroxysmal headache
Description: Attacks occur for more than one year without remission or with remissions lasting less than one month

Table: J Neurol Neurosurg Psychiatry 2005;76:301-305 doi:10.1136/jnnp.2004.036012

1. Göbel H1, Göbel C, Heinze A. [Paroxysmal hemicrania and SUNCT] Schmerz. 2011 Dec;25(6):689-701. doi: 10.1007/s00482-011-1108-2.
2. Prakash S1, Patell R. Paroxysmal hemicrania: an update. Curr Pain Headache Rep. 2014 Apr;18(4):407. doi: 10.1007/s11916-014-0407-6.

Further reading:
P J Goadsby. Trigeminal autonomic cephalalgias: fancy term or constructive change to the IHS classification? J Neurol Neurosurg Psychiatry 2005;76:301-305 doi:10.1136/jnnp.2004.036012
T. Sprenger, MD, H. Boecker, MD, T. R. Tolle, MD PhD, G. Bussone, MD, A. May, MD and M. Leone, MD, Specific hypothalamic activation during a spontaneous cluster headache attack. Neurology February 10, 2004 vol. 62 no. 3 516-517.
Benoliel, Rafael. Trigeminal Autonomic Cephalgias. British Journal of Pain 6.3 (2012): 106–123.
Michele Viana, Cristina Tassorelli, Marta Allena, Giuseppe Nappi, Ottar Sjaastad, Fabio Antonaci. Diagnostic and Therapeutic Errors in Trigeminal Autonomic Cephalalgias and Hemicrania Continua: a Systematic Review The Journal of Headache and Pain, 14.1 (2013): Page 1
Leonne, M. Bussone, G. Pathophysiology of Trigeminal Autonomic Cephalalgias Lancet Neurology 8.8 (2009): 755-64
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