[Recurrent idiopathic hypertrophic pachymeningitis after surgery of chronic otitis media with cholesteatoma: a case report].

A 70-year-old woman visited our hospital because of a chronic headache four years ago. MRI demonstrated almost symmetrically thickened dura mater in the frontal and parietal regions. She was diagnosed with idiopathic hypertrophic pachymeningitis and received corticosteroid therapy. Corticosteroid therapy improved her clinical symptoms and thickening of the dura mater. She remained free of neurological symptoms after prednisolone was tapered to 5 mg/day. However, three years ago, she developed ear pain, otorrhea and hearing loss on the left side. She was diagnosed as having otitis media with cholesteatoma last year, and underwent mastoidectomy and tympanoplasty on the left side three months ago. After surgery, she recovered from the ear symptoms, but noticed a headache on the left side. Three months after the surgery, MRI demonstrated the recurrence of hypertrophic pachymeningitis in the frontal and parietal regions, particularly on the left side. Corticosteroid therapy again improved the headache and thickening of the dura mater. The finding that the patient recovered after corticosteroid therapy alone suggests that non-infectious inflammation played a major role in the pathogenesis. Chronic inflammation associated with otitis media with cholesteatoma or surgical invasiveness might induce the recurrence of idiopathic hypertrophic pachymeningitis.