Overview
Introduction
Primary angiitis of the central nervous system (PACNS) is a rare, organ‑restricted vasculitis that attacks small‑ and medium‑sized arteries within the brain and spinal cord.
Primary angiitis of the central nervous system (PACNS) is a rare, organ‑restricted vasculitis that attacks small‑ and medium‑sized arteries within the brain and spinal cord. Inflammation thickens the vessel wall, narrows the lumen, and can rupture, producing both ischemic infarcts and intracerebral haemorrhage. Because the disease is confined to the CNS, systemic features such as fever, rash, or overt vasculitic organ damage are typically absent, making the diagnosis one of exclusion. Early recognition matters: untreated PACNS rapidly progresses to irreversible neurological loss, yet aggressive immunosuppression carries serious toxicities that must be balanced with vigilant monitoring.