Abstract
We report a 38-year-old man who showed Jacksonian march epilepsy from the left arm at first, the cause of which was hypertrophic cranial pachymeningitis localized to the right parietal area. There were some abnormal laboratory findings including positive PR-3 ANCA and a slightly elevated level of IgG4 in serum. Brain biopsy disclosed thickened meningeal tissues with heavy infiltration of mononuclear cells, but the vast majority of them lacked IgG4 immunoreactivity. There was no granuloma formation. Histopathological findings with chronic inflammation and positive PR-3 ANCA in serum indicated that localized hypertrophic pachymeningitis was caused by granulomatosis with polyangiitis (GPA). Since two cycles of steroid pulse therapy did not result in complete remission of the patient’s neurological disorder, methotrexate was added to oral administration of predonisolone. MRI at 40 days after this treatment revealed disappearance of thickened meninges with local edema of the involved cortex, and the patient then returned to his previous work. The localized form of hypertrophic cranial pachymeningitis might be one manifestation of GPA occurring only at the dura, and the combination of methotrexate and predonisolone was considered to be useful for the treatment of this intractable meningitis.
