Abstract TP383: Intracranial aneurysms in polyarteritis nodosa: A systematic review and descriptive analysis

Introduction: Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis characterized by inflammation of medium-sized arteries. CNS involvement occurs in as many as 14.8% of cases and is a poor prognostic indicator. Neurologic involvement is characterized by peripheral neuropathy, ischemic stroke, extracranial or intracranial aneurysm formation, hemorrhage, seizures or headache. Laboratory markers are nonspecific; tissue biopsy remains the gold diagnostic standard. CNS PAN is diagnosed with systemic disease, a compatible clinical presentation and supportive neurovascular imaging. Angiographic findings include small- and medium-sized arterial aneurysms, luminal irregularities or occlusions. Despite PAN representing a unique, rare, dangerous and treatable etiology of aneurysm formation, current literature is limited to case reports, and no prior studies have characterized the clinical features or outcomes of aneurysms in PAN. Methods: We performed a systematic literature review to characterize intracranial aneurysms in PAN. Searches of PubMed, Ovid and Google Scholar were performed using key terms and Boolean operators. Studies were screened against inclusion/exclusion criteria and data was extracted. Results: Thirty articles (n=30 patients) met inclusion criteria. Mean age was 31 years and 60.5% were male. 63% first presented a ruptured aneurysm. Complications included aneurysmal subarachnoid hemorrhage (40%), intracerebral hemorrhage (10%), intraventricular hemorrhage and cavernous sinus syndrome. Presentations included cranial neuropathies, monocular vision loss, gait disturbance, hemiparesis, hemisensory loss, ptosis, limb ataxia, loss of consciousness, headache or seizures. In 48%, PAN diagnosis followed aneurysm identification. Aneurysms were located in the anterior circulation (53%), posterior (40%), or both (17%); 67% had > 2 aneurysms. 10% either underwent clipping or endovascular embolization while 80% did not undergo an intervention. 97% received steroids and 60% also received immunosuppressants. Mean follow-up was 30 months; 15% died during this period. 49% recovered without recurrence. 15% experienced progressive or relapsing symptoms. Conclusion: To our knowledge, this study is the first to describe the clinical features, treatment and outcomes of intracranial aneurysms in PAN. Although rare and treatable, aneurysms pose significant morbidity and mortality in PAN. We aim to inform practitioners about the spectrum of neurovascular disease in PAN.