Idiopathic granulomatous angiitis of the central nervous system. Diagnostic challenges.

Objective: Granulomatous angiitis of the central nervous system (CNS) is a rare cause of vasculitis involving the brain and spinal cord and is included in lists of disorders causing strokes. To determine the frequency of strokes (eg, sudden onset of focal symptoms) as a presenting complication and to determine the sensitivity of angiography and other technologies in detecting vasculitis in histologically proved cases of idiopathic granulomatous angiitis of the CNS (IGANS), we reviewed the published literature.
Data Sources: A biopsy-proved case of IGANS in a patient presenting without strokes and with a normal angiogram is reported. Additional cases of pathologically proved IGANS where results of angiography or other neuroimaging procedures were available were found by search of MEDLINE and bibliographies of pertinent articles and books.
Data Extraction: We compared our case with 39 reported cases of histologically proved granulomatous angiitis of the CNS not associated with Hodgkin's disease, herpes zoster, sarcoidosis, or other proximate cause. We included only those cases that had been evaluated with angiography or other neuroimaging techniques before death or biopsy.
Data Synthesis: Analysis of these cases shows that strokes as presenting complications are rare in IGANS. Most patients present with a diffuse encephalopathy and, when focal symptoms develop, they tend to develop gradually. Including our case, 56% of 41 angiograms performed in 31 reported patients with histologically proved IGANS were abnormal, but only 27% were diagnostic for vasculitis.
Conclusions: We conclude that stroke is uncommon as a presenting complaint in IGANS and angiography is insensitive as a screening test for these patients.