Bilateral angiographic vasoconstriction of the middle cerebral and internal carotid arteries after subarachnoid haemorrhage in patients with and without aneurysms. A retrospective study.

A retrospective study of cerebral angiographies from 173 patients with subarachnoid haemorrhage (SAH) were investigated and divided into three groups. The diameters of the middle cerebral artery and the internal carotid artery were measured and correlated with time elapsing between the onset of SAH and the angiographic study. A significant (p less than 0.001) reduction in vascular diameter was found at all levels of intra- as well as extradural parts of the internal carotid artery in patients with aneurysms (group I). Also, bilateral angiographic investigation from 70 patients showed a significant (p less than 0.001) reduction at all levels on both sides, regardless of whether aneurysms were present (group II) or not (group III). Moreover, the reduction in vascular diameter was more pronounced in patients with than in patients without aneurysms. The most pronounced reduction in vascular diameter was found in one of the extradural parts of the internal carotid artery in both group II and III. However, reduction in vascular diameter did not correlate significantly with the cerebral circulation time despite a tendency towards it. On the other hand, layering of the contrast medium along the posterior wall of the internal carotid artery was more often found in patients with prolongation in cerebral circulation time suggesting a reduced cerebral blood flow in these patients. It is suggested that the significant reduction in vascular diameter of intra- as well as extradural parts of the internal carotid artery, might reflect an adaptation to altered cerebral metabolism after SAH.