{'fraction_non_alphanumeric': 0.022988505747126436, 'fraction_numerical': 0.004310344827586207, 'mean_word_length': 5.539906103286385, '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}}
[IgG4- and MPO-ANCA-associated hypertrophic pachymeningitis].

INTRODUCTION
Idiopathic hypertrophic pachymeningitis is a fibroinflammatory immune-mediated disease of the dura mater. Its diagnosis requires the preclusion of infectious, tumoral and other inflammatory diseases. In recent years new entities have been reported that can present with hypertrophic pachymeningitis, such as IgG4-associated disease and MPO-ANCA+ pachymeningitis, as a form of vasculitis limited to the central nervous system.


CASE REPORT
We describe the case of a 64 years-old male with headaches and cervicalgia, predominantly at night, and clinical signs and symptoms of spinal cord compression. Following the diagnosis of craniocervical hypertrophic pachymeningitis provided by the magnetic resonance imaging study, an aetiological study was conducted. Infectious and tumoral diseases were precluded. The clinical features did not show any systemic involvement and high levels of IgG4 and MPO-ANCA+ were found in the results of the analyses. The clinical signs and symptoms quickly improved following treatment with corticoids.


CONCLUSIONS
IgG4-related disease and MPO-ANCA-associated vasculitis limited to the central nervous system can account for a high percentage of the cases of hypertrophic pachymeningitis that were considered idiopathic, and their diagnosis requires a biopsy and a histological study.