Objective: Primary angiitis of the central nervous system (PACNS) has been considered a rare and highly fatal disorder when untreated. In recent years the disease has been increasingly diagnosed by cerebral angiography, often without histologic confirmation. We have questioned whether cases of PACNS diagnosed on the basis of angiography alone are equivalent to histologically confirmed cases.
Methods: All cases of PACNS reported from 2 sources, including all cases reported in the English medical literature through January of 1990 as well as from the case records of the Cleveland Clinic Foundation were reviewed. Sixty-five variables were analyzed including demographic data, clinical signs and symptoms, treatment, outcome, diagnostic modalities and associated conditions. The cases were divided into 3 groups based on method of diagnosis. Group A referred to those diagnosed by angiography alone, but unconfirmed by histology, Group A & P for those who had positive histologic evidence angiitis confined to the central nervous system and a positive angiogram and Group P containing those diagnosed on the basis of histology who either never underwent angiography or who had angiographic findings other than arteritis.
Results: Cases of PACNS defined by angiography alone (Group A) appear often to be clinically distinctive, occurring more frequently in young women, often presenting with the sudden onset of focal neurologic deficit and associated with a relatively benign cerebral spinal fluid analysis. Patients defined in such manner frequently have a self-limited clinical course and may not require combination therapy with corticosteroids and cytotoxic drugs.
Conclusion: We believe that PACNS is more clinically heterogeneous than is recognized and that a distinct and possibly more benign subset of disease that can be diagnosed on clinical and angiographic grounds has been identified.