Diagnosis and clinical features of trigemino-autonomic headaches.

Although severe short-lasting headaches are rare, they can be considered disabling conditions with a major impact on the quality of life of patients. These headaches can divided broadly in to those associated with autonomic symptoms, so called trigeminal autonomic cephalgias (TACs), and those with few or no autonomic symptoms. The TACs include cluster headache, paroxysmal hemicranias, hemicrania continua, and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms as well as short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing syndrome. In all of these syndromes, half-sided head pain and ipsilateral cranial autonomic symptoms such as lacrimation or rhinorrhea are prominent. The paroxysmal hemicranias have, unlike cluster headaches, a very robust response to indomethacin, leading to a notion of indomethacin-sensitive headaches. The diagnosis of TACs is exclusively a clinical task. Because of the fact that cluster headache is strictly half-sided, typically involves the region around the eye and temple and often starts in the upper jaw, most patients first consult a dentist or ophthalmologist. No single instrumental examination has yet been able to define, or ensure, the correct diagnosis, or differentiate idiopathic headache syndromes. It is crucial that a trained neurologist sees these patients early so that management can be optimized and unnecessary procedures can be avoided. Although TACS are, in comparison to migraine, quite rare, they are nevertheless clinically very important for the neurologist to consider as they are easy to diagnose and the treatment is very effective in most patients.