Hypertrophic pachymeningitis as an important neurological complication of granulomatosis with polyangiitis

Headache is a common symptom in patients with granulomatosis with polyangiitis (GPA) mainly due to chronic sinusitis or orbital disease. Meningeal involvement may thus remain unrecognized for a long time. This can lead to a significant delay in accurate diagnosis, serious local damage of the central nervous system and high relapse rates. New diagnostic techniques such as contrast MRI allow one to identify inflammation of the dura mater in the course of GPA more frequently. The objective of this article is to characterize hypertrophic pachymeningitis (HP) in patients with GPA and report diagnostic difficulties associated with this complication.