[Symptomatic cluster headache? Apropos of 4 case reports].

Four patients were referred to our headache unit with characteristic clinical features of cluster headache which was subsequently attributed to other underlying conditions. To the previously reported occurrence of meningioma of the lesser wing of the sphenoid and cerebral arteriovenous malformation, we may now add for the first time two cases of maxillary sinusitis. In addition to accurate history taking, some factors are relevant for the diagnosis of these symptomatic forms of cluster headache, such as the occurrence of neurological abnormalities during or between the attacks; these should prompt the clinician to carry out neuroradiological studies, in spite of the low prevalence of these symptomatic forms in our series of 100 patients. We review the several etiologies reported in the literature, and we discuss the pathogenetical mechanism whereby these conditions may result in a type of headache of such peculiar chronological features.