Anomic aphasia in the absence of hemianopia due to proximal posterior cerebral artery occlusion

•Isolated anomic aphasia due to posterior cerebral artery (PCA) occlusion is rare.•Aphasia can occur due to posterior circulation lesions.•Anomic aphasia localizes to the dominant posterior-medial or basal temporal lobe.•Visual field deficits are a hallmark of PCA occlusion.•Yet collateral flow can preserve the visual cortices following PCA occlusion. To our knowledge, anomic aphasia in the absence of sustained visual field deficits due to proximal posterior cerebral artery (PCA) occlusion has never before been reported. We present a case of a 65-year-old man with medial temporal, occipital and thalamic infarcts due to a left proximal PCA occlusion. The patient initially presented with aphasia and right-sided homonymous hemianopia; the latter resolved with intravenous recombinant tissue plasminogen activator (IV rt-PA). Post-rt-PA angiography revealed a fetal origin of the left PCA with persistent proximal PCA occlusion, with extensive collateralization from the left middle cerebral artery (MCA) providing retrograde flow into the distal PCA territory. This case illustrates how proximal PCA occlusion can result in anomic aphasia in the absence of sustained visual field deficits.