Infraoptic Course of Both Anterior Cerebral Arteries

Abstract

A 28-year-old woman was referred to our hospital with a sudden, very severe headache. Brain computed tomographic angiography showed a saccular cerebral aneurysm at the bifurcation of the left middle cerebral artery and infraoptic courses of both anterior cerebral arteries. The anterior cerebral arteries were seen to arise from the ipsilateral internal cerebral arteries at the level of the origin of the ophthalmic artery, passed underneath the ipsilateral optic nerve, and turned upward at ventral portion of the optic chiasm.Infraoptic course of the proximal anterior cerebral artery is an extremely rare anomaly and is often associated with cerebral aneurysms. We report the clinical features, radiological findings, and possible genesis of this anomaly with a literature review.

The Infraoptic or Infrachiasmatic Course of the Anterior Cerebral Artery Emerging an Elongated Internal Carotid Artery

“…Bilateral proximal infraoptic A1 segments of the ACAs were found arising inferior to the optic strut [ 7 ]. Few cases of bilateral proximal infraoptic A1 segments of the ACAs were reported until recently [ 4 , 5 , 7 , 13 , 15 , 16 , 17 , 18 , 19 ].…”

“…Different authors reported cases of aneurysms associated with infraoptic ACAs [ 20 ]. These were found on the AComA or on the A1 or A2 segments of the ACA [ 4 , 5 , 7 , 8 , 13 , 18 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. An aneurysm on an infraoptic A1 segment of an azygos ACA was also reported [ 14 ].…”

“…Infraoptic A1 segments of the ACA were found to originate from a low bifurcation of the ICA (a bifurcation of the proximal intradural segment of the ICA); such infraoptic A1 segments have a horizontal–medial course below the ipsilateral optic nerve, and further turn superiorly on the anterior side of the optic chiasm [ 4 , 5 , 6 , 7 ]. Such infraoptic A1 segments could even pierce the ipsilateral optic tract [ 8 ].…”

An Unruptured Anterior Communicating Artery Aneurysm with Bilateral Infraoptic Anterior Cerebral Arteries. Case Report and Review of the Literature

“…Bilateral infraoptic ACAs are less common than unilateral anomalies. 8) One report describes an associated gyral abnormality. 11) The anomalous ACA usually arises from the intra-dural ICA near the level of the ophthalmic artery, as it did in the presented case, or rarely from the extra-dural ICA.…”

“…The most important clinical association of such an anomaly is the high incidence of intracranial aneurysms of the ACA-ACoA complex. 5) 8) 14) Recognition of this anomaly is important in planning surgery for ACA-ACoA complex aneurysms in order to identify proximal arterial control of the aneurysm. Failure to account for this anomaly might result in unnecessary dissection along and possible damage to the optic apparatus or inferior frontal lobe during aneurysm repair.…”