Successful Treatment of Polyarteritis Nodosa With Multifocal Intracranial and Mesenteric Stenoses Using Endovascular Stenting and Tocilizumab

Polyarteritis nodosa (PAN) rarely affects both intracranial and mesenteric arteries. Evidence on optimal timing of revascularisation and the role of interleukin-6 blockade remains limited. A 73-year-old man with longstanding ankylosing spondylitis presented with weight loss and elevated inflammatory markers. Imaging revealed multifocal stenoses in the basilar, anterior, middle and posterior cerebral arteries, alongside a critical 4-cm superior mesenteric artery (SMA) stenosis. Temporal artery histology was negative; anti-neutrophil cytoplasmic antibodies (ANCA) and viral serologies were also negative. A diagnosis of systemic PAN was made. High-dose glucocorticoids and cyclophosphamide normalised inflammatory markers, but severe post-prandial abdominal pain persisted. Endovascular SMA stenting, performed during biochemical remission, resolved the angina and enabled weight recovery. Two years later, the patient developed a lacunar stroke alongside an inflammatory flare and worsening intracranial stenoses. Monthly tocilizumab induced rapid clinical and serological remission, sustained for 18 months. This case highlights that concomitant intracranial and mesenteric stenoses signal high-risk PAN. Additionally, deferring revascularisation until remission improves outcomes, and tocilizumab is a viable steroid-sparing option after cyclophosphamide failure, including cases of PAN with central nervous system involvement.