Case report: hypertrophic pachymeningitis associated with Sjögren’s syndrome

[A case of meningitis due to anti-centromere antibody-positive Sjögren syndrome]

A 79-year-old woman was diagnosed with Sjögren's syndrome (SjS) at the age of 73 years by lip biopsy, gum test, and salivary gland scintigraphy with positive antinuclear (ANA), positive anti-centromere (ACA), and negative anti-Ro/SS-A antibodies. Seven days before admission, the patient developed gait disturbance, which progressed to difficulty in walking two days before admission. She was hospitalized because of subacute gait disturbance. Neurological examination showed gait disturbances characterized by small steps, wide-based gait, left upper limb clumsiness, and frontal lobe dysfunction. Laboratory tests confirmed positive ANA and ACA and negative anti-Ro/SS-A and anti-La/SS-B antibodies. Cerebrospinal fluid analysis showed mildly elevated protein levels and increased monocyte count. Brain MRI showed hyperintensity in the bilateral frontal regions on fluid-attenuated inversion recovery (FLAIR)/contrast-enhanced T1-weighted imaging, and N-isopropyl-p-123I-iodoamphetamine single-photon emission computed tomography (123I-IMP SPECT) showed decreased accumulation in the frontal region. After excluding cancerous, infectious, and immune-mediated causes, ACA-single-positive SjS-related meningitis was diagnosed. The patient responded well to steroid therapy. The patient was able to walk short distances and showed improvement in frontal lobe function. Follow-up MRI and 123I-IMP SPECT demonstrated the resolution of previous abnormalities. Knowingly, there have been no reported cases of SjS-related meningitis with positive ACA. Considering that anti-Ro/SS-A antibodies are involved in the pathogenesis of meningitis, this case is extremely rare. We propose that ACA-positive SjS be considered in the differential diagnosis of aseptic meningitis.

Immune-Mediated Hypertrophic Pachymeningitis and its Mimickers: Magnetic Resonance Imaging Findings

Hypertrophic pachymeningitis (HP) is a rare and chronic inflammatory disorder presenting as localized or diffuse thickening of the dura mater. It can be idiopathic or an unusual manifestation of immune-mediated, infectious, and neoplastic conditions. Although some cases may remain asymptomatic, HP can lead to progressive headaches, cranial nerve palsies, hydrocephalus, and other neurological complications, which makes its recognition a fundamental step for prompt treatment. Regarding the diagnosis workup, enhanced MRI is the most useful imaging method to evaluate dural thickening. This article addresses the MR imaging patterns of immune-mediated HP, including immunoglobulin G4-related disease, neurosarcoidosis, granulomatosis with polyangiitis, rheumatoid pachymeningitis, and idiopathic HP. The main infectious and neoplastic mimicking entities are also discussed with reference to conventional and advanced MR sequences.

Hypertrophic pachymeningitis in ANCA-associated vasculitis: Clinical and immunopathological features and insights

Hypertrophic pachymeningitis (HP) is an inflammatory disorder characterized by intracranial and spinal thickened dura mater, leading to several neurological manifestations including headaches, cranial neuropathies, seizures, and sensorimotor disorders. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a crucial disease that is implicated in the development of immune-mediated HP. HP is observed throughout the clinical course of AAV, and 3%-4% of patients with AAV experience HP as the initial clinical episode. However, patients with ANCA-related HP are unclassifiable in the classification criteria of AAV when HP is the only manifestation, suggesting that ANCA-related HP can be identified as a central nervous system-limited type of AAV. Among patients with AAV, those who develop HP have predominantly been classified as having granulomatosis with polyangiitis (GPA). Myeloperoxidase-ANCA positivity has been more frequently demonstrated than proteinase 3-ANCA positivity in patients with ANCA-related HP. The ear, nose, and throat manifestations, such as otitis media, sinusitis, and mastoiditis, as well as mucous membranes/eyes manifestations including sudden visual loss, are robustly associated with HP in AAV. The histology of thickened dura mater tissues includes fibrotic changes and infiltration of several immunocompetent cells, but the typical findings of GPA, such as granulomatous inflammation with necrotizing vasculitis, are not observed in all patients with ANCA-related HP. Corticosteroids are the first-line therapy for ANCA-related HP, while the concomitant use of immunosuppressive agents including cyclophosphamide, methotrexate, and mycophenolate mofetil, is an ideal strategy for achieving remission. Rituximab is a useful agent in refractory ANCA-related HP.