This research aims to delineate the clinical, epidemiological, and radiological profile of hypertrophic pachymeningitis in a tertiary neurology center in Brazil and propose a diagnostic algorithm for its etiology. Secondary objectives include evaluating therapeutic approaches, assessing recurrence of primary pathology, and measuring improvements in MRI outcomes.

Clinical, laboratory, neuroradiological, and therapeutic data from 51 patients were retrospectively analyzed. All underwent complete blood analysis, biochemical tests, HIV serology, and various autoantibody tests. Imaging included chest tomography and gadopentate-enhanced MRI. Additionally, cerebrospinal fluid analysis encompassed routine tests and specific stains.

The cohort included 14 men and 37 women, with a mean age of 47.85 years (range: 19 to 74 years), and 49% were aged 40 to 60 years. The most common initial clinical manifestations were headaches, reported by 80.39% of patients, and cranial nerve involvement in 84.31% (notably cranial nerves II, VI, and V). Laboratory results showed that 15.7% had elevated erythrocyte sedimentation rate (ESR) and 19.6% had increased C-reactive protein (CRP) levels, with 39.2% exhibiting both elevated markers. Additionally, 16% tested positive for antinuclear antibodies (ANA).

Radiological findings indicated that 74.5% of patients had localized dural thickening, primarily affecting the tentorial, parasellar, and falx regions. Furthermore, 51% displayed hyperproteinorrachia.

Regarding etiological diagnosis, 14 patients were classified as undefined, 9 had granulomatosis with polyangiitis, 7 were diagnosed with neurosarcoidosis, and another 7 were considered idiopathic.

These findings offer valuable insights into hypertrophic pachymeningitis, emphasizing the need for increased awareness and further research to address its clinical profile and diagnostic challenges.