[Unusual varieties of cluster headache]

Atypical forms of cluster headache (CH) are characterized by the association of CH to other headaches and facial neuralgias. Cluster-tic syndrome causes headaches similar to CR and pains similar to trigeminal neuralgia. The disorder is usually of unknown nature and its course is either episodic or chronic. Carbamazepine together with medication for CH is the treatment of choice. A characteristic sensory aura usually develops immediatedly before the attacks of headache in CH-Migraine (CHM). These attacks respond dramatically to subcutaneous sumatriptan and the prophylaxis of CHM is that of CH. CH variant comprises different types of pain and responds to indomethacin. Other unusual varieties of CH are the subchronic and the combined forms, probably related to chronic CH. Finally, the characteristics of CH may be modified by its treatment and chronic abuse of steroids may change the evolution of an episodic CH into a chronic unilateral paroxysmal headache with resembles to but is different from chronic CR. This headache could be called transformed CH (TCH) and to the best of our knowledge the disorder has not been reported up to now. TCH goes undiagnosed and does not respond to the usual treatments of CH. Patients suffering from TCH are frequently sent for surgical treatment which is absolutely contraindicated. Withdrawal of steroids, which is difficult to accomplish, changes TCH into a the former and typical episodic CH, which can now be treated in the usual way.