Right anterior choroidal artery syndrome: revisited

Abstract

A 72-year-old male with hypertension and an old-leftmiddle-cerebral-artery (MCA) stroke presented with
symptoms of left-sided hemiparesis, left facial drop, leftsided neglect syndrome, and left-partial homonymous
hemianopia. Symptoms were suggestive of a right MCA
infarct; however, advanced neuroimaging was inconclusive. Conventional diagnostic angiogram of the right
internal carotid artery (ICA) was suggestive of absent
right anterior choroidal artery (AChA) compared with a
previous angiogram. The AChA supplies structures such
as the posterior limb of the internal capsule causing contralateral hemiparesis.1
Hemisensory loss is due to damaged ventral posterolateral nucleus of the thalamus.1
Homonymous hemianopia is secondary to damaged lateral geniculate body.1
Features distinguishing AChA
from larger arterial pathology such as superficial MCA
involves the absence of aphasia, depressed level of consciousness, or headache.1 Anatomically the AChA originates from the posterior wall of the ICA, 2–5 mm distal
to the posterior communicating artery and 2–5 mm proximal to the carotid bifurcation.2 Visualization may be
challenging owing to its small diameter or secondary to
the MCA branches obscuring it.2 A thorough knowledge
about cerebral vascular anatomy including the small
penetrators such as the AChA is important to diagnose
such rare types of stroke. In the end, our case demonstrates the utility of a diagnostic cerebral angiogram to
confirm the involvement of small vessels such as the
AChA by providing optimal visualization.