Rupture of megadolicho basilar artery anomaly.

To cite: Watari T, Shimizu T, Tokuda Y. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2014208368 DESCRIPTION Enlargement and ectasia of the basilar artery as a consequence of fusiform aneurysm is described as megadolicho basilar artery (MBA) anomaly. MBA can cause ischaemic events of the posterior circulation or compression of the adjacent nerves; or, rarely, subarachnoid haemorrhage (SAH). Non-invasive diagnostic tests for delineating MBA include three-dimensional CTangiography and MR angiography. 2 We report a case of a 70-year-old woman who presented with sudden onset of dysarthria and mild left hemiparesis. Head CT scan showed a markedly tortuous and dilated basilar artery without haemorrhage (figure 1A). Diffusion-weighted MRI at this point revealed a high-intensity area at right pons, indicating a small area of infarction (figure 1B). MR angiography revealed a basilar artery extending 20 mm beyond the dorsum sellae, where a saccular and fusiform aneurysm was observed (figure 1C). Three hours after arrival in hospital, and during insertion of a nasogastric tube, the patient became comatose. An additional plain head CT scan revealed massive SAH, especially in the basal, prepontine and insular cisterns (figure 2). The imaging appearance of SAH suggested that it was caused by the rupture of the MBA. The patient’s condition deteriorated rapidly and she died a few hours later.