The Spectrum of Intracranial Hypertrophic Pachymeningitis at an Eastern Indian Tertiary Care Center

Introduction:Hypertrophic pachymeningitis (HP) is a treatable, rare inflammatory disease, either primary or secondary to systemic causes.Aims:To characterize the etiology, clinical manifestations, and treatment outcomes of HP patients and determine the factors influencing the radiological resolution of the pachymeningeal enhancement and recurrence of symptoms within the follow-up period.Materials and Methods:We collected data for this prospective observational study between March 1, 2021 and May 31, 2022, at the Bangur Institute of Neurosciences, Kolkata, and the patients were followed for a 6-month period. Demographic, clinical, laboratory, and treatment-related data were collected. A univariate logistic regression model was used for comparison between patients with and without radiological resolution of pachymeningitis and between patients with and without symptom recurrence.Results:Among 44 patients, the male: female ratio was 1.2:1. The median age at disease onset was 35.5 (28.5-49.5) years. The etiologies were idiopathic (56.8%), tuberculosis (22.8%), immunoglobulin G subtype 4 (IgG4) disease (9.2%), other infections (6.8%), and neoplastic (4.4%). Headache was the most common presentation (95.4%), followed by cranial neuropathies (68.2%). Optic and oculomotor neuropathies were the most common. In terms of radiological features, 27.27, 29.54, and 43.18% of patients had diffuse, focal regular, and focal irregular enhancement, respectively. Temporal (50%), followed by cavernous sinus (38.63%) enhancement, was the most common. Recurrence occurred in 36 and 50% of idiopathic and IgG4-related HP cases, respectively. Mycophenolate mofetil was added to their steroid regimen with no further recurrences.Conclusion:The cohort had a marked absence of (antineutrophil cytoplasmic antibodies) ANCA-associated HP. The severity of clinical manifestations or distribution of pachymeningitis did not differ significantly among the etiological groups. The presence of idiopathic etiology and focal regular enhancement had a significantly higher chance of radiological resolution. The response to therapy was satisfactory. Recurrence was significantly related to shorter steroid courses (<median duration of 5.2 months).