Headache - - Trigeminal autonomic cephalalgias!!

Lets talk some neurology, as this month Iam doing neurology! When discussing headache, we came across this entity called  'Trigeminal autonomic cephalgias' -- a group of headache disorders with pain referred to the 1st branch of trigeminal nerve associated with cranial autonomic symptoms including lacrimation, injection of the eye and rhinorrhea. They all share the same pathophysiologic etiology....which is largely unknown!!! But there is some eveidence of posterioir hypothalamus in modulating this craniofacial pain, as found out by functional imaging of brain (Lancet 2009)There are 3 types, and they vary in their frequency and duration..

1.Cluster headache - 1 to 8 attacks per day with the mean duration of each attack being 60 min.
2.Paroxsmal hemicrania -  11 to 15 attack per day with a mean duration 15 min/attack
3.SUNCT syndrome (Short lasting Unilateral neuralgiform headache with Conjuctival injection and Tearing) - roughly 20 atatcks per day with a mean duration  of 30 sec to 2 min/attack.

Well this sounds like, that someone just wanted to classify them to make it difficult for others to remember. But it turns out that differentiating these 3 on the basis of duration is important as treatment options are different!
*Indomethacin works well in paroxysmal hemicrania(PH) and SUNCT, whereas it does not help patients with Cluster headache(CH).
*Sumatriptan and Oxygen can help CH, whereas they dont help PH & SUNCT
*For prophylactic treatment for CH, PH, & SUNCT...the drug of choice are Verapamil, Indomethacin & Lamotrigine respectively.
Have a look at this article from UK which explains in detail about these 3 headaches. Especially peek at the table on page 118.(Current Neuro & neurosci report 2007). Looks like ..we may need to be more specific with timing and duration of headaches, as we do for evaluation of chest pains!