ABSTRACT
This chapter will discuss the distinct headache disorders known as the trigeminal-autonomic cephalgias (TACs). This group of primary headaches is characterized by short-duration unilateral head pains and associated ipsilateral autonomic symptoms. Recognized TACs include cluster headaches, chronic paroxysmal hemicrania (CPH), episodic paroxysmal hemicrania (EPH) and the syndrome of short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT); see Table 6.1. Cluster headaches are a fairly common condition while CPH and SUNCT may never be seen by physicians in their entire practice lifetime. What sets these headaches apart from the other primary headache disorders such as
migraine and tension-type headache is the extreme intensity of the headache and the unique associated symptoms representing both parasympathetic nervous system activation (eye lacrimation, conjunctival injection, nasal congestion or rhinorrhea) and sympathetic nervous system dysfunction (miosis, ptosis, partial Horner’s syndrome). What distinguishes each of the TACs from each other is the duration of the headache attacks. SUNCT has the shortest attacks lasting 5 to 250 s (Figure 6.1), with CPH lasting 2 to 45 min (Figure 6.2) and cluster headaches lasting 15 to 180 min (Figure 6.3). What ties the syndromes together is a linkage between headache and autonomic symptoms. This clinical phenotype can be explained by an underlying trigeminal-autonomic reflex pathway which consists of a brainstem connection between
Table 6.1 The differential diagnosis for cluster headache involves the other known trigeminalautonomic cephalgias: SUNCT, CPH, EPH, idiopathic stabbing headache and trigeminal neuralgia. Based on individual attack duration, attack frequency and associated symptoms, a correct diagnosis of cluster can be made. In the United States it takes an average of 6 years before a cluster patient is correctly diagnosed. It should not be difficult to make a diagnosis of cluster if a good headache history is taken. PPT, precipitant. Reproduced with permission from reference 1
Feature Cluster CPH EPH SUNCT Stabbing Trigeminal headache neuralgia
Gender (M:F) 4:1 1:3 1:1 2.3:1 F > M F > M Attack 15-18 min 2-45 min 1-30 min 5-250 s <1 s <1 s
duration Attack 1-8/day 1-40/day 3-30/day 1/day-30/h Few-many Few-many
frequency Autonomic + + + + - -
features Alcohol PPT + + + + - - Indomethacin +/ - + + - + -
effect
the trigeminal nerve and the facial nerve (the site of the cranial parasympathetic outflow system). It is very important for the clinician to recognize the TACs as distinct headache disorders outside of migraine and tension-type headache, because treatment strategies are different for each headache. For example, CPH is an indomethacin-responsive headache syndrome, while cluster headaches and SUNCT do not respond to this non-steroidal antiinflammatory agent. In the following paragraphs short descriptions of the distinct TACs will be given, following which a pictorial presentation of the TACs will be made including images on epidemiology, pathogenesis, clinical characteristics and treatment strategies (Figures 6.1-6.35).
