Multifocal intracranial aneurysms and a clinical diagnosis of ruptured retinal arterial macroaneurysm in presumed hepatitis B-associated polyarteritis nodosa: A case report.

Polyarteritis nodosa (PAN) is a necrotizing medium-artery vasculitis; intracranial aneurysms are rare. A woman in her early thirties with hypertension and hepatitis B surface antigen (HBsAg) positivity presented with thunderclap headache, vomiting, and blurred vision. Available records described intracranial hemorrhage associated with a right posterior cerebral artery (PCA) aneurysm, but the index computed tomography/angiography images and full report were unavailable to classify the hemorrhage. The aneurysm was coil embolized with intentional parent-vessel sacrifice. Subsequent magnetic resonance imaging showed right occipitotemporal and thalamic infarction with hemorrhagic transformation-an expected consequence of right PCA sacrifice. A small acute left caudate infarct outside the treated territory raised a separate multifocal or embolic mechanism. Time-of-flight magnetic resonance angiography showed the partially occluded right P2p/P3 PCA aneurysm and 2 distal left internal carotid artery aneurysms. During the same admission, subhyaloid and intraretinal hemorrhage led to a clinical diagnosis of ruptured retinal arterial macroaneurysm; no fundus photograph, fluorescein angiogram, or optical coherence tomography angiography was available, and follow-up structural optical coherence tomography did not show the lesion. Elevated inflammatory markers, neuropathic symptoms, multifocal aneurysms, and HBsAg positivity led rheumatology to a working diagnosis of HBV-associated PAN. Because no biopsy or visceral angiography was performed and accepted classification criteria were not securely met, the diagnosis is described as presumed. The teaching point is attribution: the dominant stroke was iatrogenic; the contralateral infarct and multifocal aneurysms prompted systemic evaluation; ocular hemorrhage may be a clue but does not establish shared vasculitic causation.