Progression of Stenosis Into Occlusion of the Distal Posterior Cerebral Artery Supplying an Occipital Arteriovenous Malformation Manifesting as Multiple Ischemic Attacks

Abstract

A 31-year-old healthy male presented with a rare case of cerebral arteriovenous malformation (AVM) manifesting as repeated ischemic attacks and cerebral infarction causing left sensori-motor disturbance. Neuroimaging revealed cerebral infarction in the right thalamus as well as right occipital AVM without bleeding. The AVM was mainly fed by the right angular artery, and the right posterior cerebral artery (PCA) showed mild stenosis and segmental dilation at the P 2 -P 3 portion. After referral to our hospital, transient ischemic attacks causing left homonymous hemianopsia, and left arm and leg numbness were frequently recognized. Additional imaging revealed a new ischemic lesion in the occipital lobe, and repeated cerebral angiography showed right PCA occlusion at the P 2 -P 3 segment. Cerebral AVM presenting with cerebral infarction due to occlusion of feeding arteries is rare. In our case, intimal injury due to increased blood flow or spontaneous dissection of the artery were possible causes. We should monitor any changes in the architecture and rheology of the feeding vessels during the clinical course to prevent ischemic complications.

Cerebral Arteriovenous Malformation Presenting as Acute Lacunar-Like Infarct Associated with Vascular Steal

“…1 Focal neurological deficits due to cerebral infarction are quite rare (<0.1%). 4 Previous studies have reported large artery territory infarcts associated with AVM. [3][4][5] Unlike the previous studies, the present case uniquely manifested as an acute lacunar-like, that is, a small, solitary infarct.…”

“…Cerebral infarction associated with AVM may result from various etiologies, including coincidental cardioembolic or atherothrombotic lesions, 4,5 steno-occlusion of a feeding artery due to fibromuscular proliferation or endothelial injury associated with turbulent high velocity blood flow, 4,6,7 or vascular steal, which diverts blood flow from adjacent brain tissue into the low resistance network of the AVM. 3 Although hypertension might have predisposed our patient to the "lacunar" infarct in this case, hypoperfusion associated with vascular steal could have contributed much more to the development of the lesion, given the imaging findings of chronic ischemia exclusively involving the right hemisphere around the AVM with sparing of the left hemisphere.…”

Anatomy of the feeding arteries of the cerebral arteriovenous malformations

“…trigeminal neuralgia [34]. The mentioned endothelial proliferation and media coat changes can sometimes produce arterial stenosis which, along with an additional process of thrombosis or wall dissection, may progress to a complete occlusion of a feeder [16,23].…”

“…The mentioned haemodynamic processes in the AVMs may have another consequence, that is, a certain endothelial disorder, activation of the coagulation cascade and thrombosis of a feeding artery [3,23,55]. An embolism of the feeders or their parent arteries can occur as well, usually from the cardiac, carotid, or aneurysmal sources.…”

“…According to certain post-mortem investigations, only 12% of the AVMs become symptomatic during life [16]. As regards the clinical manifestations, a focal motor or sensory deficit may occur, as well as dizziness, visual or speech disorders, or epileptic seizures [9,16,23,24,29,33,35,36,62,80]. Headaches are one of the most frequent symptoms.…”