Primary central nervous system vasculitis – An update on diagnosis, differential diagnosis and treatment

Importance Primary angiitis of the central nervous system (PACNS) is a rare condition which is often misdiagnosed. In order to avoid mistakes in the management, a step by step approach is necessary. Observations The most common presenting symptoms of PACNS are encephalopathy-related cognitive and affective abnormalities, headaches and multifocal symptoms associated with recurrent episodes of ischemia or hemorrhage. Seizures and spinal cord lesions may also occur. Diagnostic work up includes MRI, CSF examination, angiography and brain biopsy. Since all reported signs and findings lack specificity, the exclusion of differential diagnoses is essential before immunosuppressive therapy is started. Important differential diagnoses include reversible cerebral vasoconstriction syndrome, cerebral involvement of systemic vasculitides or rheumatic diseases, moyamoya angiopathy and infectious vasculopathies Effective treatment has been reported with glucocorticoids in combination with cyclophosphamide or rituximab; however, randomized clinical trials of PACNS treatment do not exist. Conclusions and relevance PACNS is an important but rare differential diagnosis in daily neurological practice. The strict adherence to diagnostic criteria and the avoidance of inappropriate therapies in non-inflammatory vasculopathies and infectious diseases are essential.