Primary Angiitis of Central Nervous System related intracranial aneurysm with spontaneous occlusion after immunomodulatory treatment.

Primary Angiitis of the Central Nervous System (PACNS) is an uncommon disease with kaleidoscopic clinical manifestations. Ischemic strokes are commoner than their hemorrhagic counterpart. Intracranial pseudoaneurysms are rarely reported in PACNS cohorts. We hereby describe the case of a 39-year-old female, who presented for evaluation of acute onset of left middle cerebral artery (MCA) ischemic stroke, with cerebral angiogram showing multifocal stenosis and irregularities in intracranial blood vessels with an aneurysm arising from the lenticulostriate branch of the left MCA M1 segment. A diagnosis of probable PACNS was made and patient initiated on immunomodulatory treatment with corticosteroids. 12 weeks follow up neuroimaging studies revealed resolution of the previously described intracranial aneurysm, thereby postulating the possibility of a pseudoaneurysm related to the underlying angiitis.