Cluster Headache associates a severe pain generally unilateral and autonomi
c symptoms with a remarkable periodicity. In the first part we fried to exp
lain the conception of physiopathology of these short lasting headache synd
romes and in the second part we described the clinical features. The short
lasting primary headaches are divided into two groups: those with marked au
tonomic activation which comprise chronic and episodic paroxysmal hemicrani
a, short lasting unilateral neuralgiform headache with conjunctival injecti
on and tearing (SUNCT syndrome) and cluster headache. The second group incl
udes two entities, one without autonomic activation: Hypnic Headache and on
e with mild autonomic features: Hemicrania Continua. The paroxysmal hemicra
nias are characterized by attack frequency ranges from 15 to 20 per day of
short lasting attacks of unilateral pain that typically last 2 to 10 minute
s, the severe pain is associated with autonomic symptoms and responds to tr
eatment with indomethacin. The SUNCT syndrome has a less severe pain but ma
rked autonomic activation during attacks, this syndrome is actually resista
nt to proposed therapy. The Hypnic Headache and the Hemicrania Continua hav
e yet less severe pain with very mild or without autonomic features.