Hereditary multiple exostoses (HME) is an inherited genetic condition, characterized by the formation of multiple osteochondromas, developing throughout childhood and into puberty. Vascular complications associated with HME are uncommon.A case of a patient with HME who was admitted to hospital with subarachnoid hemorrhage (SAH), as a result of acute rupture of a basilar tip aneurysm (BTA), will be presented. Relevant literature on this topic will be systematically reviewed.We describe a rare case of a 48-year-old male patient presenting multiple exostoses in both upper and lower limbs, with no familial history of such lesions. The patient experienced an episode of loss of consciousness, followed by tonal seizures, after a short (five-day) history of headache, proved finally to be secondary to SAH due to rupture of a BTA. There was no antecedent of trauma, neck manipulation, or previous infection. Aneurysm was successfully treated with the intravascular procedure (aneurysm occlusion with coil). Progressively, the patient recovered from dysphasia and tetraparesis, almost completely, following the appropriate treatment and rehabilitation program.In the systematic review, eight cases (including the one presented) of vertebrobasilar vascular system stroke secondary to solitary spinal osteochondroma or multiple osteochondromas were found, but only the present case was associated with basilar artery aneurysm.Despite the fact that the etiopathogenesis of basal artery aneurysm presentation in a patient with osteochondromas remains unknown, medical society needs to be aware of this rare condition, as SAH may be a severe complication.
