RESUMEN
Spontaneous basilar artery dissection is a rare condition and a diagnostic challenge with a high potential for morbidity and mortality if untreated. It has an estimated incidence of 1 to 1.5 cases per 100,000 people. Few cases have been described in the literature up to the present day. The clinical outcomes, prognosis and treatment remain uncertain. The authors report the rare case of a 55-year-old female patient who presented to the Interventional Neuroradiology service at Hospital São Marcos, Teresina, in the state of Piauí, Brazil, with a history of severe headache located in the occipital region and in the nape with no improvement using common analgesics. A magnetic resonance imaging of the brain showed a saccular dilatation in the basilar artery, and a digital cerebral angiography showed a basilar artery dissection associated with a dissecting aneurysm.