Possible steroid-resistant IgG4-related pachymeningitis treated with parenteral methotrexate

Pachymeningitis is an uncommon disease with multiple etiologies with fibrosis of leptomeninges. One type of this disease is related to immunoglobulin G4 (IgG4). The most frequent manifestations include chronic cephalgia and focal neurological deficits. The case of a 31-year-old man with chronic cephalgia localized to the left hemicranium and left dysmetria is presented. Nuclear magnetic resonance imaging showed image hyperintensity and perilesional edema located at the infratentorial and left parietal occipital levels. The results of cerebral angiography and a cerebrospinal fluid examination were normal. A biopsy of the central nervous system (CNS) ruled out neoplastic lesions, granulomatous lesions, infection, and arteriovenous malformation and indicated thickened meningeal fragments. Elevated serum IgG4 levels were found. The antinuclear antibodies (ANAs), antibodies to extractable nuclear antigens (ENAs), anti-native DNA antibodies (anti-DNA), topoisomerase I antibodies (Scl-70), antibodies to cyclic citrullinated peptides (anti-CCP), and rheumatoid factor (RF) were negative. After an initial diagnosis of idiopathic hypertrophic cranial pachymeningitis, the patient received treatment with high doses of glucocorticosteroids for two years, without response, and developed Cushing's syndrome, cataracts, and osteoporosis. During the follow-up, dactylitis, distal upper limb sclerosis, and Raynaud's phenomenon occurred. A capillaroscopy indicated capillaries with dilated loops, microhemorrhaging, disorganization of the capillary architecture, and megacapillaries, which led to a diagnosis of limited systemic scleroderma. Although an association between scleroderma and pachymeningitis was originally proposed, review of the literature suggests that these are two different entities. Treatment with methotrexate, 25 mg weekly, allowed the withdrawal of glucocorticoids and resolution of neurological symptoms.