The pathymeningitis is a very rare neurologic manifestation of PAN. We report a case of pathymeningitis misdiagnosed as subdural hematoma by brain CT in a patient with PAN. A 45-year old man who diagnosed as PAN through arteriography and skin biopsy in the ischemic finger 6 months ago. He complained of sudden headache, nausea, and diplopia 3 days before admission. In emergency room, noncontrast brain CT findings suggested small amount of subdural hematoma. But subsequent MRI findings revealed pachymeningitis of bilateral paratentoria and falx. He was treated with high-dose steroid and cyclophosphamide pulse therapy. Thereafter, his symptoms were gradually resolved. As far as we know, this is the first report of a case of pachymeningitis complicating PAN in Korea.

Keywords: Pachymeningitis, Polyarteritis nodosa