Subarachnoid Hemorrhage Attributable to Bilateral Aplastic or Twiglike Middle Cerebral Artery

Twig-like middle cerebral artery: Embryological persistence or secondary consequences?

“…One was a network of small tortuous vessels without an original main trunk of MCA, 4 and the other was abnormal network exhibiting whitish, calcified degeneration in the place of normal M1 portion. 12 Although absence of proximal M1 portion would lead us to consider this segment had never developed, this is not correct. Even in patients with twig-like MCA, ICA and MCA should be formed initially similar to ICA agenesis, rete mirabile, and MMD, where ICA and MCA are formed normally.…”

“…Shin et al subsequently reported four cases in 2014. 5 Common angiographical features of these cases are as follows; 1) a steno-occlusive lesion at the unilateral MCA, 4,5,10,11 except for one bilateral case, 12 2) plexiform arterial network replacing the proximal MCA trunk, 3) LSAs arising from the plexiform arterial network, 4) normal cortical branches beyond the affected MCA trunk with anterograde flow, and 5) compromised blood flow to the distal MCA with compensatory leptomeningeal collaterals from anterior and posterior cerebral arteries. 9 Almost half of the cases presented with intracranial hemorrhage, and few cases were found incidentally.…”

Ruptured aneurysm associated with a twig-like middle cerebral artery: An illustrative case report

“…is anomaly has been related with ischemic or hemorrhagic events; however, there is a very low information about the association with cerebral aneurysms as the cause of hemorrhagic episodes. [28,31] Due to the difficulty of diagnosing this anomaly on noninvasive imaging modalities such as CT and MR angiography, it is often misdiagnosed as arteriovenous malformation or pseudo-occlusion of the MCA. In patients that underwent a DSA, the Ap/T-MCA was present 0.11% and 1.17% of them.…”

“…e twig-like appearance of the vessels may be confused with the MMD; however, there is no evidence of a progressive internal carotid artery occlusion leading to the formation of the Moyamoya vessels, as occurs in MMD. [19] At present, there are 42 cases in the international literature of aneurysms associated with the Ap/T-MCA anomaly, of which 26 presented as SAH, [3,4,[6][7][8][10][11][12][13][14][15]17,20,[24][25][26][27][28]30,32,35] 27 associated with intracerebral [9,14,15,17,18,20,21,23,24,26,27,31,32,24] or intraventricular hemorrhage, [3,14,16,25,27,[29][30][31][32]35] three incidental, [2,26,…”

“…This anomaly has been related with ischemic or hemorrhagic events; however, there is a very low information about the association with cerebral aneurysms as the cause of hemorrhagic episodes. [ 28 , 31 ]…”