Trigeminal Autonomic Cephalgias

The trigeminal autonomic cephalalgias (TACs) is a collective name for a group of primary headaches which present with pain on one side of the head in trigeminal nerve area and different “autonomic” features on the same side. "Autonomic" means changes in our body which are not under volitional control. They may include redness (conjunctival injection) or watering (lacrimation) of the eye, one-sided nasal congestion or discharge (rhinorrhea), forehead and facial sweating, constriction of a pupil (miosis), as well as drooping (ptosis) and swelling of an eyelid (eyelid edema).


Trigeminal autonomic cephalalgias include:


Despite many resembling features, the TACs differ in attack duration and frequency:

  • Cluster headache - lasts minutes to hours and frequency is up to 8 a day
  • Paroxysmal hemicrania - lasts minutes and frequency is up to 40 a day
  • SUNCT - lasts seconds to minutes and frequency is up to 200 a day
  • LASH – lasts 1-3 days and frequency is up to 1 in 3 days


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2. Goadsby, PJ. Trigeminal autonomic cephalalgias. Pathophysiology and classification. Rev Neurol (Paris) 2005;161:692.

3. Headache classification subcommittee of the International Headache Society. The International Classification of Headache Disorders: 2nd edition. Cephalalgia 2004; 24 Suppl 1:9.

4. Goadsby, PJ. Pathophysiology of cluster headache: a trigeminal autonomic cephalgia. Lancet Neurol 2002; 1:251.

5. Drummond, PD. Mechanisms of autonomic disturbance in the face during and between attacks of cluster headache. Cephalalgia 2006; 26:633.

6. Benoliel, R, Sharav, Y. Trigeminal neuralgia with lacrimation or SUNCT syndrome? Cephalalgia 1998; 18:85.

7. Goadsby, PJ, Matharu, MS, Boes, CJ. SUNCT syndrome or trigeminal neuralgia with lacrimation. Cephalalgia 2001; 21:82.

8. Goadsby, PJ. Trigeminal autonomic cephalalgias (TACs): Another fancy term or a constructive change to the International Headache Classification? J Neurol Neurosurg Psychiatry 2005; 76:301.