Reversible Sensorineural Hearing Loss due to Pachymeningitis Associated with Elevated Serum MPO-ANCA

Hypertrophic pachymeningitis is a progressive disease resulting in a diffuse thickening of dura mater due to inflammation, tumor or autoimmune diseases, but most cases are idiopathic. It is seldom reported to be related to sensorineural hearing loss, but it can cause sensorineural hearing loss which can be potentially reversed through treatment. Here, we report the case of a 54-year-old woman who had progressive, bilateral, worse in the left, sensorineural hearing loss and visual disturbance with an accompanying headache over several months. Brain MRI showed diffusely thickened dura mater, highly enhanced after gadolinium administration, which was consistent with pachymeningitis. It was assumed to be related to autoimmune pathogenesis on the basis of elevated serum myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) titers. After empirical steroid and cyclophosphamide therapy, auditory impairment improved, especially in the high frequency region of the pure tone audiogram, and significant improvement in the word recognition test. Moreover, a follow-up MRI revealed much decreased enhancement of the dura mater, and the MPO-ANCA titer decreased to within the normal range. In the case of rapidly progressive sensorineural hearing loss or hearing impairment accompanying other cranial neuropathy, pachymeningitis should be taken into consideration, and brain MRI with gadolinium enhancement is the best method of detecting it. Also, to ensure proper treatment, a cautious evaluation including an ANCA work-up should be performed.