Primary angiitis of the CNS and reversible cerebral vasoconstriction syndrome: A comparative study

Objectives To further improve the distinction between primary angiitis of the CNS (PACNS) and reversible cerebral vasoconstriction syndrome (RCVS). Methods We compared 2 large French cohorts of patients with PACNS (n = 110, retrospectively and prospectively enrolled) and RCVS (n = 173, prospectively enrolled). Results Patients with RCVS were predominantly female ( p p p p = 0.002) than patients with PACNS. Headache, especially thunderclap headache, was more frequent in RCVS (both p p p p p = 0.006), subarachnoid hemorrhage and vasogenic edema predominated in RCVS ( p = 0.04 and p = 0.01, respectively). Multiple small deep infarcts, extensive deep white matter lesions, tumor-like lesions, or multiple gadolinium-enhanced lesions were observed only in PACNS, whereas cervical artery dissection was found only in RCVS. Conclusions Our study confirms that careful analysis of clinical context, headache features, and patterns of brain lesions can distinguish PACNS and RCVS within the first few days of admission in most cases. However, diagnosis remains challenging in a few cases.