{'fraction_non_alphanumeric': 0.03058321479374111, 'fraction_numerical': 0.010668563300142247, 'mean_word_length': 5.424657534246576, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A Case of Definite IgG4-Related Pachymeningitis

Immunoglobulin G (IgG)4-related disease is a recently defined disease entity that is characterized by elevated serum IgG4 levels and abundant infiltration of IgG4-positive plasma cells and high-grade sclerosis of the affected region.1 This disease includes autoimmune pancreatitis, Mikulicz disease, pseudotumor of the lung, tubulointerstitial nephritis, and Riedel thyroiditis,2 but the only CNS involvement that has been reported so far is hypophysitis.3

In this report, a case of intracranial IgG4-related pachymeningitis, IgG4-related disease involving the dura mater, is reported. This is a definite case of pachymeningitis that was both serologically and histologically proven, and whose clinical course and serum IgG4 levels with treatment were followed.

### Classification of evidence.

This study provides Class IV evidence that IV methylprednisolone followed by oral prednisolone is effective in improving the symptoms and signs of IgG4 disease affecting the CNS.

### Case report.

A 54-year-old woman with anterior uveitis and scleritis of the left eye, left perceptive deafness, and hypothyroidism was treated with steroid and levothyroxine. Bilateral uveitis relapsed repeatedly, and her vision gradually deteriorated. When she was 56 years old, she had pain, bulging, ptosis, and ophthalmoplegia involving her left eye, sensory impairment …