Hypertrophic pachymeningitis: significance of myeloperoxidase anti-neutrophil cytoplasmic antibody

MPO-ANCA-Associated Hypertrophic Pachymeningitis Mimicking IgG4-Related Disease: A Case Report and Literature Review

Hypertrophic pachymeningitis (HP) is a rare and chronic clinical disease characterized by thickening of the dura mater, leading to persistent headache, cranial neuropathy, seizures, and other neurological symptoms. Immune-mediated causes, particularly antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis and IgG4-related disease (IgG4-RD), are among the most common etiologies. We report a case of a 54-year-old female with recurrent headache, blepharoptosis, hearing loss, and markedly elevated inflammatory markers. Blood tests, and serum levels of IgG4 were within normal ranges. Contrast enhanced cranial MRI revealed thickening and enhancement of bilateral cerebral hemispheres and tentorial dural maters. Additional findings included mild left lacrimal gland enlargement, bilateral middle ear mastoiditis, and tympanic tegmen destruction. Abdominal high-resolution computed tomography (CT) showed enlarged retroperitoneal lymph nodes. Histopathology demonstrated dense lymphoplasmacytic and neutrophilic infiltration with 80 IgG4-positive plasma cells per high-power field and an IgG4+/IgG+ cell ratio of 20%. An initial diagnosis of possible IgG4-RD was made. However, the patient's symptoms responded poorly to prednisolone (20 mg/day), and fever ensued. Pseudomonas aeruginosa, nocardia malleis, and leptocyclus virus were found in the cerebrospinal fluid measured by NGS. Subsequent laboratory testing showed positive p-ANCA and anti-myeloperoxidase antibodies (anti-MPO), with a negative anti-nuclear antibodies panel, leading to a revised diagnosis of MPO-ANCA-associated HP. Treatment was escalated to intravenous methylprednisolone (40 mg/day), cyclophosphamide, and anti-infectious agents, leading to improved symptoms and decreased inflammatory markers. However, there was a recurrence during the taper of prednisolone. The addition of rituximab achieved complete remission. MPO-ANCA-associated HP is a rare inflammatory disorder that brings diagnostic challenges and requires comprehensive differential diagnosis. In relapsed or refractory cases, rituximab may be a valuable therapeutical option.

Nervous system involvement in ANCA-associated vasculitis: Single center experience from Latin America

INTRODUCTION

Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (AAV) present heterogeneous neurological symptoms that are often misdiagnosed, contributing to delays in identification and prompt treatment. Few studies in Latin America have described the frequency of neurological involvement in AVV; none have explicitly described the characteristics of nervous system involvement.

DESIGN/METHODS

This case-control study examined patient records for AVV treated at a university hospital in Colombia between 2005 and 2023. Patients with and without neurological manifestations were compared and a survival analysis was performed.

RESULTS

Forty-eight cases and seventy-nine controls were included. The median age was 58 years, 57.5 % were female. The diagnosis was made in 67.7 % of cases during the hospital stay, and in-hospital mortality was 14 %. Nervous system involvement was more frequent in undifferentiated AAV (100 %), followed by eosinophilic granulomatosis with polyangiitis (75 %), microscopic polyangiitis (33.3 %), and granulomatosis with polyangiitis (25.9 %). The most common neurological manifestations were peripheral neuropathy (50 %), patient-reported symptoms of sensory dysfunction (43.7 %), and cranial neuropathy (39.6 %); headache was frequent among patients with neurological involvement. Patients with neurological manifestations presented a lower median creatinine at admission and a lower proportion of patients with a five-factor score > 2. No differences in one-year all-cause mortality were observed.

CONCLUSIONS

This study presents an exhaustive clinical characterization of the neurological profile of patients with AAV from a single center in Latin America. Patients with nervous system involvement showed less severe renal involvement and a lower proportion of 5-year risk of mortality scores; one-year all-cause mortality was similar between groups.

Long-Term Clinical Landscapes of Spinal Hypertrophic Pachymeningitis With Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis

BACKGROUND AND OBJECTIVES

Spinal hypertrophic pachymeningitis (HP) is an extremely rare disorder characterized by the thickening of the spinal dura mater, which harbors distinct repertoires of immune cells due to the unique partitioning of the arachnoid blood-CSF barrier. The objectives were to identify the pathogenesis and therapeutic strategies for spinal HP.

METHODS

This retrospective cohort study analyzed the clinical and pathologic profiles of patients with idiopathic/immune-mediated HP including spinal HP.

RESULTS

Among 61 patients with idiopathic/immune-mediated HP, all 6 Japanese patients with spinal HP, with a median observation period of 88.8 months, were myeloperoxidase (MPO)-anti-neutrophil cytoplasmic antibody (ANCA)-seropositive. The MPO-ANCA+ spinal HP cohort had the following characteristics: (1) a predominance of older women; (2) all patients were classified as having microscopic polyangiitis based on the 2022 American College of Rheumatology/European League Against Rheumatism criteria; (3) 83% of patients developed subacute/chronic myelopathy due to extramedullary spinal cord compression; (4) 50% of patients had lesion extension to the epidural compartment and vertebral column; (5) 50% of patients presented with chronic sinusitis, otitis media, or mastoiditis; (6) 33% of patients had involvement of the lower airways or kidneys; (7) a higher disease activity of the nervous system was noted based on the Birmingham Vasculitis Activity Score (BVAS), in contrast to MPO-ANCA+ cranial HP; (8) granulomatous inflammation with myofibroblasts, immune cells including granulocytes, and B-cell follicle-like structures were observed in the thickened dura mater; (9) immunotherapies (with or without surgical decompression) were effective in reducing the modified Rankin Scale score and reduced BVAS during the first active insults; (10) combined immunotherapies with glucocorticoids and cyclophosphamide/rituximab helped in reducing relapses in the long term; and (11) surgical decompression, including laminectomy and duraplasty, was necessary for compressive myelopathy. These data suggest that MPO-ANCA+ spinal HP shares common features with MPO-ANCA+ cranial HP (1, 2, 6, 8, 9, and 10), but also has unique clinical features (3, 4, 5, 7, and 11).

DISCUSSION

Our findings highlight the significant pathogenic role of ANCA in spinal HP. MPO-ANCA+ spinal HP, as an organ-threatening disease, should be positioned as having unique characteristics, whether limited to the CNS or as part of a generalized form in ANCA-associated vasculitis.

Distinct features of ANCA-associated hypertrophic pachymeningitis compared with other etiologies: findings from a study of 74 patients

OBJECTIVES

We aimed to characterize the clinical and radiological features, and outcomes, of a large cohort of hypertrophic pachymeningitis (HP) patients from a single centre.

METHODS

We conducted a retrospective study at a tertiary referral centre, encompassing patients diagnosed with HP between 2003 and 2022. The diagnosis of HP relied on the identification of thickening of the dura mater via MRI of the brain or spine.

RESULTS

We included 74 patients, with a mean age of 43.6 ± 14.2 years, of whom 37 (50%) were male. Among the 74, 32 (43.2%) had an immune-mediated origin, including 21 with granulomatosis with polyangiitis (GPA) (predominantly PR3-ANCA positive), four with SLE, three with IgG4-related disease, three with idiopathic HP, and one with RA. Non-immune-mediated HP accounted for 45 cases (56.8%). Within this category, 21 (28.4%) were infectious cases, with 14 having Mycobacterium tuberculosis infection (TB-HP), and 21 (28.4%) having malignancy-associated HP. The clinical and MRI characteristics exhibited variations among the four etiological groups. Hypoglycorrhachia was primarily observed in infectious HP and malignancy-associated HP. Immune-mediated HP was associated with a peripheral pattern of contrast enhancement and the Eiffel-by-night sign. MRI features strongly indicative of TB-HP included leptomeningeal involvement, brain parenchymal lesions, and arterial stroke. MPO-ANCA GPA was associated with a higher prevalence of spinal HP.

CONCLUSIOS

Within our cohort, GPA and Mycobacterium tuberculosis emerged as the predominant causes of HP. We identified significant disparities in clinical and radiological features among the various etiologies, which could have implications for diagnosis.

Myelopathy Due to Hypertrophic Pachymeningitis Associated With ANCA Vasculitis: A 10-Year Follow-up Case Report

This case report describes a rare presentation of antineutrophil cytoplasmic antibodies-associated hypertrophic pachymeningitis in a 49-year-old woman with cranial and spinal lesions. Initial management comprised decompressive laminectomy and steroid therapy, with the subsequent addition of immunosuppressant therapy following symptom recurrence. After a ten-year follow-up, significant symptom improvement and return of motor function were noted. This case emphasizes the crucial role of early diagnosis, a multidisciplinary approach, and combined medical therapy in managing this rare condition.

Cranial hypertrophic pachymeningitis with myelodysplastic syndrome

Hypertrophic pachymeningitis (HP) is a rare inflammatory disease characterized by thickening of the dura mater. HP develops with several inflammatory diseases. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis and IgG4 related disease are reported as 2 major causes. With hematologic diseases, only 3 cases have been reported. We report the case of myelodysplastic syndrome (MDS) developing HP. Our case provides a thought-provoking hypothesis regarding the potential relationship between MDS and HP.

Clinical, Radiological, and Etiological Aspects of Pachymeningitis: A Study of 24 Cases

Introduction and importance Hypertrophic pachymeningitis (HP) is an uncommon disorder with varied etiological origins and heterogeneous clinical presentation. Establishing the etiological diagnosis poses a challenge, but prompt identification provides a treatment window, potentially leading to a reversal of symptoms. MRI is the reference examination, allowing not only the early diagnosis of pachymeningitis but also the assessment of its extent and importance, detection of possible complications, and suggestion of etiology. Case presentation We conducted a retrospective study involving 24 patients recruited over 5 years for who brain imaging had revealed the presence of pachymeningitis. The average age of the patients was 40 years, with a male-to-female ratio of 0.6. Clinical discussion Headache was present in 54.17% of patients. All the patients underwent MRI examinations utilizing different sequences, with subsequent Gadolinium injection showing localized and asymmetrical meningeal thickening in 13 cases, and diffuse in the rest. The cerebrospinal fluid study unveiled an inflammatory fluid characterized by a lymphocytic predominance and hyperproteinorrhea, noted in 50% of the patients. The histopathological analysis of a stereotactic biopsy conducted on an individual patient revealed non-diagnostic results. The etiological investigation was dominated by tuberculosis, which was detected in 33.3% of cases. Idiopathic origin was identified in 16.7% of patients. Conclusion Meningeal thickening is rare, and the multitude of potential causes makes the etiological investigation challenging unless they fall within the scope of secondary meningeal disorders; otherwise, a dural biopsy becomes necessary, and the prompt initiation of treatment, along with determining the etiology influences the prognosis.

Risk of Misdiagnosis in Spinal Hypertrophic Pachymeningitis: A Report of Two Cases

Hypertrophic pachymeningitis (HP) is a rare inflammatory disease of the central nervous system. It typically manifests in the cranium; cases involving the spinal cord are rare (8.6%). This report includes two cases of spinal HP encountered among 666 spinal operative cases. The purpose of this study is to present the initial imaging findings, final diagnosis, and course of treatment in these two cases of spinal HP and to present the possible risk of misdiagnosis with a literature review. In case 1, a 69-year-old female presented with back pain. The initial radiological diagnosis with magnetic resonance imaging (MRI) was a meningioma. However, her blood test showed a mild elevation of C-reactive protein level (3.16 mg/dL), with positive IgG4 and myeloperoxidase anti-neutrophil cytoplasmic antibody results, suggesting an autoimmune disease. We performed a biopsy of the thickened dura and an expansive duraplasty. Serological and pathological diagnosis suggested IgG4-related HP. In case 2, a 67-year-old male presented with bilateral thigh pain. MRI revealed a mass resembling a disc hernia at the L2/3 intervertebral level. The mass was surgically removed. Pathological examination and cerebrospinal fluid analysis confirmed the diagnosis of HP associated with IgG4-related disease. In both cases, immunosuppressive therapy was administered, and follow-up MRI scans revealed the disappearance of the mass. The study concludes that a spinal HP can potentially be misdiagnosed when its images resemble those of tumors or disc hernias owing to its rarity.

Stage-dependent immunity orchestrates AQP4 antibody-guided NMOSD pathology: a role for netting neutrophils with resident memory T cells in situ

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease of the CNS characterized by the production of disease-specific autoantibodies against aquaporin-4 (AQP4) water channels. Animal model studies suggest that anti-AQP4 antibodies cause a loss of AQP4-expressing astrocytes, primarily via complement-dependent cytotoxicity. Nonetheless, several aspects of the disease remain unclear, including: how anti-AQP4 antibodies cross the blood-brain barrier from the periphery to the CNS; how NMOSD expands into longitudinally extensive transverse myelitis or optic neuritis; how multiphasic courses occur; and how to prevent attacks without depleting circulating anti-AQP4 antibodies, especially when employing B-cell-depleting therapies. To address these knowledge gaps, we conducted a comprehensive 'stage-dependent' investigation of immune cell elements in situ in human NMOSD lesions, based on neuropathological techniques for autopsied/biopsied CNS materials. The present study provided three major findings. First, activated or netting neutrophils and melanoma cell adhesion molecule-positive (MCAM+) helper T (TH) 17/cytotoxic T (TC) 17 cells are prominent, and the numbers of these correlate with the size of NMOSD lesions in the initial or early-active stages. Second, forkhead box P3-positive (FOXP3+) regulatory T (Treg) cells are recruited to NMOSD lesions during the initial, early-active or late-active stages, suggesting rapid suppression of proinflammatory autoimmune events in the active stages of NMOSD. Third, compartmentalized resident memory immune cells, including CD103+ tissue-resident memory T (TRM) cells with long-lasting inflammatory potential, are detected under "standby" conditions in all stages. Furthermore, CD103+ TRM cells express high levels of granzyme B/perforin-1 in the initial or early-active stages of NMOSD in situ. We infer that stage-dependent compartmentalized immune traits orchestrate the pathology of anti-AQP4 antibody-guided NMOSD in situ. Our work further suggests that targeting activated/netting neutrophils, MCAM+ TH17/TC17 cells, and CD103+ TRM cells, as well as promoting the expansion of FOXP3+ Treg cells, may be effective in treating and preventing relapses of NMOSD.

Intrathecal injection of methotrexate and dexamethasone for vasculitis granuloma of the fourth ventricle: a case report and literature review

Granulomatosis with polyangiitis (GPA) is a pauci-immune small vessel vasculitis characterised by neutrophil-mediated vasculitis and granuloma. The presence of intracranial parenchymal space-occupying lesions is rarely seen in GPA patients. In this manuscript, we report a case of GPA with granuloma of the fourth ventricle accompanied by obstructive hydrocephalus. Treatment with glucocorticoids (GCs) and multiple immunosuppressants cyclophosphamide (CYC), mycophenolate mofetil (MMF), and rituximab (RTX) showed poor efficacy in this case. After removal of the granuloma by craniotomy, GPA relapsed within 3 months. Under the premise of GC and MMF treatment combined with intrathecal injection of dexamethasone (DXM) and methotrexate (MTX), the intracranial granuloma gradually shrank, and the patient's general condition was alleviated, showing that this is an effective treatment method. Key Points • To date, there are few reports of granulomatous vasculitis combined with granuloma of the fourth ventricle, and our case is the second. • In this case, multiple immunosuppressants and rituximab were ineffective treatments, and the intracranial granuloma was effectively controlled by intrathecal injection of dexamethasone (DXM) and methotrexate (MTX). • Based on this report, it can be suggested that intrathecal injection is effective in treating patients with GPA and central nervous system involvement, but large-scale sample studies are needed.

Antineutrophilic Cytoplasmic Antibody-Related Spinal Pachymeningitis

Isolated spinal pachymeningitis is rarely encountered in clinical practice. Narrowing down the specific cause in individual patients is challenging as the possible etiologies are broad, there is substantial overlap in clinical presentation, and obtaining adequate data is complex, often affected by prior empiric treatments, including steroids. Here, we describe a rare patient with spinal pachymeningitis resulting in subacute to chronic progressive lower extremity weakness and eventually paraplegia. We discuss how we obtained the final diagnosis, provide our diagnostic framework, and offer practical advice in evaluating these patients.

Hypertrophic Pachymeningitis: An Unusual Cause of Headache

Hypertrophic pachymeningitis (HP) is a rare condition characterized by inflammation and thickening of the dura mater. It can be idiopathic or secondary to various causes, including infections, tumors, or systemic inflammatory diseases. Diagnosis is challenging due to its rarity and the overlap of symptoms with other conditions. We present the case of a 42-year-old Hispanic woman with diabetes mellitus type 2 and end-stage kidney disease who presented with chest pain, dry cough, mild dyspnea, and chronic occipital headaches. Physical examination revealed cranial VI nerve palsy. Imaging showed pulmonary cavitary lesions and mediastinal lymphadenopathy. Elevated inflammatory markers and positive autoimmune tests, including rheumatoid factor and antineutrophil cytoplasmic antibody (ANCA), led to further investigation. Brain imaging revealed dural thickening, confirming HP. The patient's medical history revealed double ANCA positivity and a lung biopsy confirmed granulomatous pneumonitis. A diagnosis of ANCA-associated vasculitis (granulomatosis with polyangiitis (GPA)) was established, and treatment with rituximab and high-dose corticosteroids led to symptom improvement. GPA rarely involves meningeal inflammation, but severe and persistent headaches are common early symptoms. Inflammatory markers are often elevated, and around two-thirds of HP cases related to GPA have positive serum ANCA. MRI is the primary diagnostic tool, with characteristic findings of dural thickening and contrast enhancement. This case highlights HP as a rare cause of chronic headaches and the importance of a comprehensive medical history in diagnosis. Early recognition and treatment are crucial for improving outcomes in GPA-related HP.

Granulomatosis with polyangiitis presenting headache: A case report and review of literature

RATIONALE

Central nervous system involvement is a rare manifestation of active-phaselocalized Granulomatosis with polyangiitis (GPA). In hypertrophic dura meningitis, GPA with headache is typical. In this case, cerebral magnetic resonance (MR) enhancement revealed no meningeal thickening, to our knowledge, this manifestation had not been found previously.

PATIENT CONCERNS

The patient presented to the Rheumatology and Immunology Clinic with severe headache and hearing loss, and central nervous system granulomatosis with polyangiitis was confirmed after a series of examinations. The patient had no significant effect after treatment with cyclophosphamide (CTX), but after the use of rituximab, the headache and hearing loss were significantly improved, and laboratory indicators returned to normal levels.

DIAGNOSIS

We comprehensively screened for craniocerebral infection and malignant tumors, diagnosed central nervous system granulomatosis with polyangiitis.

INTERVENTIONS

We gave sequential treatment of rituximab.

OUTCOMES

All indicators are mostly back to normal when the patient was monitored at the outpatient clinic.

LESSONS

GPA and severe headache are more prevalent in hypertrophic dura meningitis, but the patient early headache could not be explained by hypertrophic dura meningitis or localized granulomatous lesions that invaded the central nervous system. Patients with severe headaches likely have vascular inflammation and local bone destruction at the base of the skull.

Clinical characteristics of hypertrophic cranial pachymeningitis in granulomatosis with polyangiitis: a retrospective single-center study in China

BACKGROUND

Hypertrophic cranial pachymeningitis (HCP) is uncommon but a poorly understood complication of granulomatosis with polyangiitis (GPA).

OBJECTIVES

We conducted this retrospective study to elucidate the clinical characteristics and factors independently associated with granulomatosis with polyangiitis (GPA) complicated by hypertrophic cranial pachymeningitis (HCP) in China.

METHODS

We collected the medical records of 78 patients diagnosed with GPA who were admitted to the inpatient department of Peking Union Medical College Hospital between January 2003 and September 2021. Clinical features, laboratory and radiological findings, and Birmingham Vasculitis Activity Scores (excluding meningitis score) were recorded. A binary logistic regression analysis was performed to analyze factors independently associated with GPA-related HCP.

RESULTS

Headache (100%) and cranial nerve palsy (61.5%) were common manifestations of HCP. Compared to 52 GPA patients without HCP, 26 patients with HCP required more time from initial symptoms to diagnosis, with a lower ratio of pulmonary and renal involvement, a higher ratio of myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) positivity, conductive or sensorineural hearing loss, mastoiditis, and decreased vision or sudden visual loss. Binary logistic regression analysis indicated that proteinase 3-antineutrophil cytoplasmic antibody (PR3-ANCA) negativity (OR 10.698, p = 0.001), conductive or sensorineural hearing loss (OR 10.855, p = 0.005), and decreased vision or sudden visual loss (OR 8.647, p = 0.015) were significantly associated with GPA-related HCP. Of the 26 patients, 18 received methylprednisolone pulse treatment, and 18 received intrathecal injections of dexamethasone and methotrexate.

CONCLUSIONS

HCP was a severe manifestation of GPA in our study. Independent factors associated with the occurrence of HCP in patients with GPA included PR3-ANCA negativity, conductive or sensorineural hearing loss, and decreased vision or sudden visual loss. Furthermore, GPA-related HCP was associated with higher disease activity, requiring more intensive treatments.

Granulomatosis with Polyangiitis Presenting with Thrombovasculitic and Necrotizing Pachy- and Leptomeningitis Accompanied by a Brain Tumor-like Lesion

We report a case of granulomatosis with polyangiitis (GPA) presenting with hypertrophic pachymeningitis with a huge brain tumor-like lesion. A 57-year-old man acutely developed consciousness disturbance. Magnetic resonance imaging revealed a right frontal lobe mass with thickened, contrast-enhanced dura. Computed tomography revealed sinusitis and multiple lung nodules. The presence of proteinase 3-anti-neutrophil cytoplasmic antibody indicated GPA. Histopathology of the excised brain tissues revealed thrombovasculitis with heavy neutrophilic infiltration in the pachy- and leptomeninges covering an ischemic cerebral cortex. The patient improved with corticosteroids and rituximab. Our case warrants considering GPA as a cause of hypertrophic pachymeningitis with brain-tumor like lesions.

Prognostic Factors Affecting Hearing in Otitis Media With ANCA-Associated Vasculitis Patients: A Systematic Review and Meta-Analysis

Objectives: To conduct a systematic review and meta-analysis of clinical studies describing the possible prognostic factors affecting hearing outcomes in Otitis media with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (OMAAV) patients. To provide guidance for clinical work, avoiding profound irreversible hearing loss affecting patients' lives. Methods: A literature search was performed in PubMed, MEDLINE, EMBASE, Cochrane, Scopus, and Web of Science to identify English articles published before December 1, 2022. After screening the articles, the Newcastle-Ottawa Scale (NOS) was used to assess the risk of bias of the extracted literature, and studies with high quality (score > 6) were included. Results: Four studies were included: 1 was a retrospective cohort study, and 3 were case-control studies. We performed a meta-analysis of 4 factors: facial palsy, hypertrophic pachymeningitis, ANCA-negative status, and the period from onset to diagnosis. The results showed that there was a significant association between facial palsy [odds ratio (OR) 1.51; 95% confidence interval (CI) 1.07-2.15; I2 = 0%; P = .02], hypertrophic pachymeningitis (OR 1.73; 95% CI 1.18-2.53; I2 = 24%; P = .005), ANCA negativity (OR 1.75; 95% CI 1.11-2.77; I2 = 33; P = .02), and poor hearing prognosis in OMAAV patients. However, the period from onset to diagnosis (SEM ± SD 2.54; 95% CI -1.56 to 6.64; I2 = 98%; P = .22) of OMAAV was not significantly associated with poor hearing outcomes. Conclusion: We found that OMAAV patients with facial palsy, hypertrophic pachymeningitis, and ANCA negativity have a significant association with poor hearing prognosis, which provides diagnosis and treatment guidance in protecting patients' hearing.

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 ( Collapse

Key Words

• Hypertrophic pachymeningitis
• IgG4
• idiopathic
• recurrence
• resolution
• tuberculosis

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Affiliation(s)

Suman Das Department of Neuromedicine, North Bengal Medical College, Darjeeling District, West Bengal, India Department of Neuromedicine, Bangur Institute of Neurosciences, Kolkata, West Bengal, India
Biman Kanti Ray Department of Neuromedicine, Bangur Institute of Neurosciences, Kolkata, West Bengal, India

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Dural and Leptomeningeal Diseases: Anatomy, Causes, and Neuroimaging Findings

Meningeal lesions can be caused by various conditions and pose diagnostic challenges. The authors review the anatomy of the meninges in the brain and spinal cord to provide a better understanding of the localization and extension of these diseases and summarize the clinical and imaging features of various conditions that cause dural and/or leptomeningeal enhancing lesions. These conditions include infectious meningitis (bacterial, tuberculous, viral, and fungal), autoimmune diseases (vasculitis, connective tissue diseases, autoimmune meningoencephalitis, Vogt-Koyanagi-Harada disease, neuro-Behçet syndrome, Susac syndrome, and sarcoidosis), primary and secondary tumors (meningioma, diffuse leptomeningeal glioneuronal tumor, melanocytic tumors, and lymphoma), tumorlike diseases (histiocytosis and immunoglobulin G4-related diseases), medication-induced diseases (immune-related adverse effects and posterior reversible encephalopathy syndrome), and other conditions (spontaneous intracranial hypotension, amyloidosis, and moyamoya disease). Although meningeal lesions may manifest with nonspecific imaging findings, correct diagnosis is important because the treatment strategy varies among these diseases. ©RSNA, 2023 Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available through the Online Learning Center.

Granulomatous polyangiitis involving the fourth ventricle: Report of a rare case and a literature review

Granulomatous polyangiitis (GPA) is a rare systemic autoimmune vasculitis disease that is highly correlated with anti-neutrophil cytoplasmic antibodies (ANCAs). It was formerly called as "Wegener's granulomatosis." The clinical manifestations are diverse, mainly involving the upper respiratory tract, lungs, and kidneys, and this disease can involve the brain parenchyma as an isolated solid mass. Only one case has been reported thus far. To provide further information on this rare case, we report a case of GPA involving the fourth ventricle and review the relevant literature. A 32-year-old Chinese female developed fever, cough, and shortness of breath for 20 days. An 80 mm × 80 mm skin ulcer was seen on the right lower limb. CT showed multiple large patches of increased density in both lungs. The patient's serological ANCA was positive. Later, the patient developed dizziness and headache. Magnetic resonance imaging of the head showed a mass of approximately 21 mm × 24 mm in the fourth ventricle. The patient had a craniotomy for mass resection, and macroscopically, the mass was gray-red and measured 25 mm × 20 mm × 20 mm, was soft, had local hemorrhage and necrosis, and had no capsule. The main microscopic features included necrotizing granulomatous vasculitis, the patient's immunohistochemistry was positive for CD68 and negative for glial fibrillary acidic protein, and the acid-fast staining and hexaamine silver staining were negative. Combined with the clinical history, serology, and imaging, the pathological diagnosis was GPA in the fourth ventricle. The patient was switched to rituximab combined with steroid therapy because she did not tolerate cyclophosphamide. After 5 months of follow-up, the patient's lung lesions and skin ulcers had completely improved, but the brain lesions had further progressed. When a patient has multiple system diseases, abnormal clinical manifestations, and positive serological ANCAs, a diagnosis of GPA should be carefully considered, and biopsies of easy-to-access sites should be performed. If the patient's histopathological manifestations include vasculitis, granuloma, and necrosis, a diagnosis of GPA is more likely. If a patient subsequently develops an intraventricular mass, the clinicians should consider a diagnosis of GPA, which can rarely involve the cerebral ventricle to avoid an unnecessary biopsy or surgical treatment of intracranial lesions. When a patient is intolerant to the traditional treatment drug cyclophosphamide and needs to be switched to rituximab, the treatment effect of intracerebral lesions is not ideal; therefore, the treatment of lesions involving GPA in the ventricle is worthy of further exploration.

Neurosarcoidosis: Diagnostic Challenges and Mimics A Review

PURPOSE OF REVIEW

Neurosarcoidosis is a rare manifestation of sarcoidosis that is challenging to diagnose. Biopsy confirmation of granulomas is not sufficient, as other granulomatous diseases can present similarly. This review is intended to guide the clinician in identifying key conditions to exclude prior to concluding a diagnosis of neurosarcoidosis.

RECENT FINDINGS

Although new biomarkers are being studied, there are no reliable tests for neurosarcoidosis. Advances in serum testing and imaging have improved the diagnosis for key mimics of neurosarcoidosis in certain clinical scenarios, but biopsy remains an important method of differentiation. Key mimics of neurosarcoidosis in all cases include infections (tuberculosis, fungal), autoimmune disease (vasculitis, IgG4-related disease), and lymphoma. As neurosarcoidosis can affect any part of the nervous system, patients should have a unique differential diagnosis tailored to their clinical presentation. Although biopsy can assist with excluding mimics, diagnosis is ultimately clinical.

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.

IgG4-related hypertrophic pachymeningitis with ANCA-positivity: A case series report and literature review

Background

Hypertrophic pachymeningitis (HP) is a rare inflammatory disorder characterized by local or diffuse thickening of the intracranial or spinal dura mater. The most frequent cause of HP is antineutrophil cytoplasmic antibodies (ANCA), followed by IgG4. However, few cases of IgG4-HP coexpressing ANCA have been reported. Herein, we present three cases of IgG4-HP coexpressing ANCA and review the relevant literature to document the overlap of these two HP causes as a potential clinical pattern.

Methods

We retrospectively analyzed three patients with IgG4-HP coexpressing ANCA in our center and consulted the PubMed database to find other relevant cases reported in English from 1976 to April 2022. We used the following keywords: pachymeningitis, meningitis, dura, antineutrophil cytoplasmic antibody, myeloperoxidase, and proteinase-3. We analyzed the clinical, serological, radiological, and pathological characteristics of the obtained cases based on the ACR and Chapel Hill criteria and the exponential moving average (EMA) algorism for ANCA-associated vasculitis (AAV) and the IgG4-RD Comprehensive Diagnostic Criteria.

Results

We analyzed a total of 10 cases: seven literature reports and our three patients (52- and 61-year-old women and a 65-year-old man). The IgG4-related disease (IgG4-RD) diagnoses were definitive in four cases, and probable and possible in three cases. Eight patients had ANCA against myeloperoxidase (MPO), and two had ANCA against proteinase-3 (PR3). Two patients had both IgG4-RD and AAV, while the others only had ANCA seropositivity without additional clinical or pathological markers of AAV.

Conclusion

With regard to HP, we reconfirmed the existence of the IgG4-RD and AAV overlap syndrome. Meanwhile, our review does not support the hypothesis that ANCA positivity in IgG4-RD results from an excessive B-cell response. We speculate that IgG4-RD and AAV have similar or associated pathogeneses, although uncovering the role of IgG4 and ANCA in these pathophysiological processes requires further investigation.

Locations and Predictive Factors of Hypertrophic Pachymeningitis in Otitis Media With Antineutrophil Cytoplasmic Antigen-Associated Vasculitis

OBJECTIVE

To determine the locations and predictive factors of hypertrophic pachymeningitis (HP), a serious central complication of otitis media with antineutrophil cytoplasmic antigen-associated vasculitis (OMAAV).

STUDY DESIGN

Retrospective study.

SETTING

University hospital.

PATIENTS

Thirty-six patients with OMAAV underwent contrast-enhanced magnetic resonance imaging (CE-MRI) of the brain, of whom 18 and 18 had or did not have HP, respectively.

MAIN OUTCOME MEASURES

The location of HP lesions, which were detected as dural thickening on CE-MRI, was reviewed. Clinical characteristics, laboratory data, and audiometric data before treatment were correlated with the occurrence of HP.

RESULTS

HP lesions were most frequently observed in the middle cranial fossa, followed by the internal auditory meatus, tentorium cerebelli, and posterior cranial fossa, which were adjacent to the middle ear primary lesion. Headache was more frequently observed in patients with HP than without HP. The neutrophil-to-lymphocyte ratio (NLR) of the HP (+) group (median, 3.91; interquartile range, 2.50-6.06) was higher than that of the HP (-) group (median, 2.40; interquartile range, 2.01-3.03). The area under the receiver operating characteristic curve for the NLR was 0.741. An NLR of 3.46 had the highest sensitivity (61.1%) and specificity (94.4%) for predicting HP. Other markers of systemic inflammation and comorbidities of systemic diseases were not different between the groups.

CONCLUSIONS

HP may not be a systemic manifestation of OMAAV but may be related to local lesions in the adjacent brain. A high NLR may be a predictive factor for comorbid HP. Therefore, CE-MRI should be considered for patients with a high NLR.

Hypertrophic pachymeningitis in ANCA-associated vasculitis: a cross-sectional and multi-institutional study in Japan (J-CANVAS)

BACKGROUND

This study investigated the characteristics of hypertrophic pachymeningitis (HP) in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), using information from a multicenter study in Japan.

METHODS

We analyzed the clinical information of 663 Asian patients with AAV (total AAV), including 558 patients with newly diagnosed AAV and 105 with relapsed AAV. Clinical findings were compared between patients with and without HP. To elucidate the relevant manifestations for HP development, multivariable logistic regression analyses were additionally performed.

RESULTS

Of the patients with AAV (mean age, 70.2 ± 13.5 years), HP was noted in 30 (4.52%), including 20 (3.58%) with newly diagnosed AAV and 10 (9.52%) with relapsed AAV. Granulomatosis with polyangiitis (GPA) was classified in 50% of patients with HP. A higher prevalence of GPA was significantly observed in patients with HP than in those without HP in total AAV and newly diagnosed AAV (p < 0.001). In newly diagnosed AAV, serum proteinase 3 (PR3)-ANCA positivity was significantly higher in patients with HP than in those without HP (p = 0.030). Patients with HP significantly had ear, nose, and throat (ENT) (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.03-2.14, p = 0.033) and mucous membrane/eye manifestations (OR 5.99, 95% CI 2.59-13.86, p < 0.0001) in total AAV. Moreover, they significantly had conductive hearing loss (OR 11.6, 95% CI 4.51-29.57, p < 0.0001) and sudden visual loss (OR 20.9, 95% CI 5.24-85.03, p < 0.0001).

CONCLUSION

GPA was predominantly observed in patients with HP. Furthermore, in newly diagnosed AAV, patients with HP showed significantly higher PR3-ANCA positivity than those without HP. The ear and eye manifestations may be implicated in HP development.

Hypertrophic Pachymeningitis with Characteristics of Both IgG4-related Disorders and Granulomatosis with Polyangiitis

We herein report a 73-year-old man with isolated hypertrophic pachymeningitis (HP) showing serological and pathological characteristics of both IgG4-related disorders and granulomatosis with polyangiitis. The patient presented with chronic onset headaches and ophthalmalgia. Brain magnetic resonance imaging (MRI) revealed a hypertrophic enhanced dura mater. Serum IgG4 and myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) levels were elevated. A dura mater biopsy showed infiltration of numerous IgG4-positive plasma cells and granulomatous inflammation without apparent vasculitic lesions, storiform fibrosis, or obstructive phlebitis. Corticosteroid treatments improved his clinical symptoms and MRI findings. There have been reports of MPO-ANCA-positive IgG4-related HP presenting as granulomatous inflammation in the dura mater.

Hypertrophic Pachymeningitis Development in Eosinophilic Granulomatosis with Polyangiitis at Relapse of Disease: A Case-Based Review

Hypertrophic pachymeningitis (HP) presents with thickening of the dura mater in the cerebrum and spine, and its symptoms vary depending on the affected location. The association of HP with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis has been recognized, and most cases are complicated by granulomatosis with polyangiitis. We report the case of a 47-year-old man who presented with HP upon relapse of eosinophilic granulomatosis with polyangiitis (EGPA), with literature review. He presented with disturbance of consciousness, and magnetic resonance imaging (MRI) revealed thickening of the dura mater around the left parietal lobe. Although myeloperoxidase (MPO)-ANCA was positive on EGPA diagnosis, the elevation of MPO-ANCA was not documented at the onset of HP. Brain perfusion scintigraphy showed an increase in blood flow in the left parietal lobe and temporal lobe, and electroencephalogram (EEG) revealed slow waves in the left parietal lobe. He was treated with a high dose of corticosteroid and rituximab, and the slow waves on EEG and brain perfusion were normalized. Although the most frequent symptom of HP is headache, disturbance of consciousness can be the manifestation of HP, and inflammation of HP could affect the cerebral parenchyma, which can be documented as abnormal EEG and perfusion scintigraphy. Literature review revealed that most of the HP in EGPA developed when EGPA relapsed, and was observed in patients with MPO-ANCA positivity. HP develops without evidence of other clinical features of EGPA; therefore, adequate imaging, including contrast-enhanced MRI, is necessary. Rituximab may be effective for treating HP complicated with EGPA.

Optic neuropathy secondary to granulomatosis with polyangiitis in a patient with Graves' disease: a case report

Background

Dysthyroid optic neuropathy is the most commonly suspected diagnosis of optic neuropathy in Graves’ patients; however, other causes need to be ruled out. We present a unique case of optic neuropathy secondary to hypertrophic pachymeningitis with antineutrophil cytoplasmic antibody-associated vasculitis, which was suspected to be antithyroid drug related.

Case presentation

A 79-year-old Japanese male presented with acute visual loss in the left eye. He had a 24-year history of Graves’ disease and was taking methimazole. Best-corrected visual acuity was 0.8 in the right eye and light perception in the left eye, and relative afferent pupillary defect in the left eye was seen. Ocular movement was normal, and there were no findings explaining visual loss in intermediate optic media and fundus in the left eye. Contrast-enhanced magnetic resonance imaging demonstrated thickened dura mater. Tests for myeloperoxidase-antineutrophil cytoplasmic antibody, proteinuria, and hematuria were positive; pulmonary nodule lesions and a blood clot in the left lower leg were also found. After excluding the presence of diseases that could lead to hypertrophic pachymeningitis, we diagnosed optic neuropathy due to hypertrophic pachymeningitis with granulomatosis with polyangiitis—a subtype of antineutrophil cytoplasmic antibody-associated vasculitis. Since he had history of using methimazole, antineutrophil cytoplasmic antibody-associated vasculitis was considered as drug related. We started high-dosage steroid pulse therapy followed by 1 mg/kg body weight daily of oral prednisolone, and subsequently tapered. Methimazole was stopped. Best-corrected visual acuity recovered to 0.9, 2 weeks after starting treatment. Though myeloperoxidase-antineutrophil cytoplasmic antibody remained negative, the symptom relapsed 6 months after treatment initiation. We gave a second high-dose steroid pulse therapy followed by prednisolone tapered together with methotrexate. Remission remained, and using 4 mg/week methotrexate without prednisolone, myeloperoxidase-antineutrophil cytoplasmic antibody was kept within the normal limit until now, 4 years after onset.

Conclusion

We present a case of optic neuropathy with hypertrophic pachymeningitis related to antineutrophil cytoplasmic antibody-associated vasculitis, which was suspected to be drug related. The patient had good visual recovery after quitting the drug and receiving immunosuppressive therapy with systemic steroids. Hypertrophic pachymeningitis with antineutrophil cytoplasmic antibody-associated vasculitis related to antithyroid drugs should be considered as a differential diagnosis for optic neuropathy in Graves’ patients in whom optic nerve compression is not obvious.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13256-021-03207-4.

Vanishing tumefactive ANCA-associated hypertrophic pachymeningitis: A case report

We report a case of a 59-year-old man with hypertrophic pachymeningitis (HP), initially presenting as a tumefactive lesion that disappeared spontaneously. He developed headache and left abducens nerve palsy 2 years before admission, and cerebral magnetic resonance imaging (MRI) revealed a round mass lesion. Meningioma was initially considered, but the lesion disappeared spontaneously along with the symptoms. However, 6 months before admission, left abducens nerve palsy reappeared. Repeated MRI revealed multiple intracranial tumefactive lesions. HP was diagnosed based on the pathological analysis of the biopsied specimen. HP can appear as a vanishing tumor, and pathological evaluation is essential for a precise diagnosis. If spontaneous disappearance of tumefactive intracranial lesions is encountered, the possibility of HP should be considered.

Hypertrophic pachymeningitis in polyarteritis nodosa: a case-based review

Hypertrophic pachymeningitis (HP) is a rare neurological disorder with focal or diffuse thickening of the dura mater, which usually causes headache, cranial neuropathies, seizures, and motor or sensory impairments. The development of HP is attributed to an immune-mediated mechanism, and some autoimmune diseases have been implicated in the development of HP. Herein, we describe the case of a 73-year-old woman with persistent headache ascribable to HP, which developed approximately 3 years after a diagnosis of polyarteritis nodosa (PAN). She was treated with high-dose corticosteroid and cyclophosphamide that resulted in immediate disappearance of headache and improved radiological findings of thickened dura mater. In addition, she was subsequently administered methotrexate, ultimately resulting in maintenance of remission and regular reduction of prednisolone. In our review of published English articles, only two cases of HP in patients with PAN have been reported to date, suggesting that HP is a rare complication in PAN. However, it should be recognized that HP may develop as a neurological involvement related to PAN.

Hypertrophic Pachymeningitis in Eosinophilic Granulomatosis with Polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is one of the anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV), which is characterized by systemic small vessels vasculitis with associated eosinophilia. Hypertrophic pachymeningitis (HP) is an inflammatory disease in which the cerebral or spinal dura mater is thickened. AAV other than EGPA may sometimes develop HP; however, patients with EGPA rarely develop HP. This is the case of myeloperoxidase-ANCA-positive EGPA that presented with headache and blurred vision and was diagnosed with HP. It was successfully treated with pulsed steroid therapy and intravenous cyclophosphamide without any relapse for more than four years.

Successful Treatment with Rituximab for Granulomatosis with Polyangiitis and Multiple Cranial Neuropathies

We herein report a case of granulomatosis with polyangiitis in a 73-year-old man. He had experienced bilateral ptosis, redness of both eyes, right facial weakness, and hearing loss in the right ear for two months. Myeloperoxidase anti-neutrophil cytoplasmic antibody was positive. Corticosteroids and intravenous cyclophosphamide pulse therapy yielded a response. After the fourth pulse of cyclophosphamide, he developed headache, diplopia, restricted left eye movement, right facial palsy, and hearing loss in the right ear. A one-year remission period was achieved by increasing the steroid and rituximab doses. Rituximab was effective against the relapse of granulomatosis with polyangiitis and cranial neuropathy.

Hypertrophic spinal pachymeningitis caused by ANCA-associated vasculitis revealed by 18F-FDG PET/CT: A case report

RATIONALE

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) can involve the central nervous system in estimatedly 15% of patients. Hypertrophic pachymeningitis causes inflammatory hypertrophy of the cranial or spinal dura mater and patients present with various neurological deficits. ANCA-associated hypertrophic spinal pachymeningitis has rarely been reported in literature. We report a case of AAV presenting with hypertrophic spinal pachymeningitis detected by 18F-FDG PET/CT.

PATIENT CONCERNS

A 66-year-old woman diagnosed with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis developed back pain, bilateral lower limb weakness, dysuria, and dysporia 1 month ago.

DIAGNOSIS

Contrast-enhanced MRI showed thickening and enhancement of the dura mater in the thoracic cord. Intraspinal hypermetabolism in the corresponding region was observed on 18F-FDG PET/CT. The patient was finally diagnosed with ANCA-associated hypertrophic spinal pachymeningitis.

INTERVENTIONS

The patient was treated with a higher dose of prednisone and cyclophosphamide.

OUTCOMES

After 2-week treatment, the patient's neurological symptoms improved rapidly and laboratory findings were ameliorated. A repeated contrast-enhanced MRI showed partial improvement of the disease in the thoracic cord.

LESSONS

18F-FDG PET/CT and contrast-enhanced MRI can aid in the clinical diagnosis and surveillance in AAV-associated hypertrophic spinal pachymeningitis and potentially facilitate early recognition and intervention to prevent irreversible neurological impairment.

A clinical approach to hypertrophic pachymeningitis

IMPORTANCE

Hypertrophic pachymeningitis (HP) is a non-usual manifestation of rheumatologic, infectious, and neoplastic diseases. Etiological diagnosis is a challenge, but when made promptly it creates a window of opportunity for treatment, with the possibility of a total reversal of symptoms.

OBSERVATIONS

HP is an inflammatory process of the dura mater that can occur as a manifestation of sarcoidosis, granulomatosis with polyangiitis, and IgG4-related disease. The HP case evaluation is extensive and includes central nervous system imaging, cerebrospinal fluid analysis, serology, rheumatologic tests, and systemic survey for other manifestations sites. After systemic investigation, meningeal biopsy might be necessary. Etiology guides HP treatment, and autoimmune disorders are treated with corticosteroids alone or associated with an immunosuppressor.

CONCLUSION

HP is a manifestation of several diseases, and a precise etiological diagnosis is crucial because of the difference among treatments. An extensive investigation of patients with HP helps early diagnosis and correct treatment.

Hypertrophic Pachymeningitis in a Southern Chinese Population: A Retrospective Study

Aims: To investigate the causes, clinical characteristics, imaging features, and therapeutic implications of hypertrophic pachymeningitis (HP) in a southern Chinese population.

Methods: We retrospectively analyzed 48 patients with HP with different causes from 1 January 2006 to 31 December 2018. Clinical manifestation, laboratory findings, and neuroimaging results were evaluated in all HP patients.

Results: The mean age at onset was 50 ± 12 years. The most common diagnosis was idiopathic HP (67%), followed by antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (15%), tuberculous meningitis (8%), viral meningitis (6%), and bacterial meningitis (4%). Headache was the most common symptom. The most frequently changed laboratory finding was elevated erythrocyte sedimentation rate (ESR). Imaging was characterized by cerebral or spinal dura mater enhancement in MRI scan with contrast. Enhancements were mainly located in the posterior fossa for idiopathic HP; frontal, parietal, and occipital lobes for ANCA-related HP; and posterior fossa for tuberculous-associated HP. Diffuse enhancement was found in most cases, except for tuberculous-associated HP. Glucocorticoid or immunosuppressive treatment was applied in most cases.

Conclusions: The etiology of HP varied among patients, with idiopathic HP being the most common. MRI showed enhancement of the dura mater, which differed according to different etiologies. Glucocorticoid or immunosuppressive agents were the primary drugs for treatment.

An Update on Idiopathic Hypertrophic Cranial Pachymeningitis for the Headache Practitioner

PURPOSE OF REVIEW

We aim to review idiopathic hypertrophic cranial pachymeninigitis (IHCP), describe common head pain patterns and features associated with the disorder, suggest potential classification of head pain syndromes based on the recently published International Classification of Headache Disorders-3, explore pathophysiology found to be associated with cases of IHCP, and indicate common treatment for the disorder.

RECENT FINDINGS

It is suggested that a subset of IHCP is an IgG4-related autoimmune disorder. Patients with IHCP were found to have elevated cerebrospinal fluid (CSF) protein and lymphocytic pleocytosis. Corticosteroids are a mainstay of treatment. Other immunosuppressive agents and steroid sparing agents as add-on therapy may have utility in the treatment of cases refractory to corticosteroids alone. Clinical manifestations of IHCP depend upon the location of the inflammatory lesions and compression of the adjacent nervous system structures. Headache and loss of cranial nerve function were the most common presenting features of hypertrophic cranial pachymeninigitis. Several headache diagnoses may result from IHCP. Gadolinium-enhanced MRI is the standard imaging modality for diagnosing. Although the pathophysiology is poorly understood, many cases of hypertrophic pachymeninigitis (HP) are thought to be closely related to inflammatory disorders. Cases of HP previously thought to be idiopathic may have IgG4 pathophysiology. CSF and serological studies are helpful. Treatment involves immunosuppressive agents. Advancement in neuroimaging, assays, tests, and further delineation of inflammatory disorders affecting the nervous system may provide further insight to the etiology of cases of HP previously considered and diagnosed as idiopathic.

Clinical characteristics, the diagnostic criteria and management recommendation of otitis media with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (OMAAV) proposed by Japan Otological Society

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a form of necrotizing vasculitis with few or no immune deposits. It primarily affects small and medium blood vessels. AAV is classified into three categories, granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangitis (EGPA), and two major ANCAs, proteinase 3 (PR3)-ANCA or myeloperoxidase (MPO)-ANCA are involved in their pathogenesis. Intractable otitis media frequently occurs in patients with GPA, MPA or EGPA, although all patients show similar clinical features, regardless of the type of AAV. Furthermore, approximately 15% patients with otitis media caused by AAV do not show ANCA positivity, histopathological evidence, or any other AAV-related lesions at the initial visit; therefore, these patients do not fulfill the ordinary diagnostic criteria for systemic AAV. Thus, we first proposed that this condition could be categorized as "otitis media with AAV (OMAAV)". Subsequently, the Japanese Otological Society (JOS) conducted a nationwide survey between December 2013 and February 2014 and identified 297 patients with OMAAV. The survey revealed that OMAAV is a disease that initially occurs in the middle ear and subsequently spreads to other organs such as the lungs and kidneys, with eventual involvement of all body organs. Severe sequelae such as facial palsy, hypertrophic pachymeningitis, complete deafness, and subarachnoid hemorrhage resulting in death can also occur. In this review, we introduce the clinical features, diagnostic criteria, and treatment strategies recommended by JOS for early diagnosis and treatment of OMAAV.

Significant association between clinical characteristics and immuno-phenotypes in patients with ANCA-associated vasculitis

OBJECTIVES

To elucidate the association between clinical characteristics and immuno-phenotypes in patients with ANCA-associated vasculitis (AAV).

METHODS

Peripheral blood from 36 patients with active AAV and 18 healthy controls was examined for numbers of circulating T cells, B cells, NK cells, dendritic cells, monocytes and granulocytes using flow cytometry. These immuno-phenotyping data were subjected to cluster analysis and principal components analysis to divide AAV patients into subgroups. Associated organ involvement or therapeutic prognosis were assessed for each subgroup.

RESULTS

AAV patients had higher proportions of plasma cells, plasmablasts, activated T cells, CD14++ CD16+ monocytes, eosinophils and neutrophils than healthy controls. Immuno-phenotyping findings were similar between patients with microscopic polyangiitis, granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis. Cluster analysis indicated that AAV patients could be divided into three subgroups according to peripheral immune cell numbers: antibody production-related (n = 9), cytotoxic activity-related (n = 4) and neutrocytosis/lymphocytopenia-related (n = 23). The antibody production-related or cytotoxic activity-related group was associated with CNS involvement, and the neutrocytosis/lymphocytopenia-related group was associated with high incidence of kidney involvement. Incidence of severe infection was markedly higher in the neutrocytosis/lymphocytopenia-related group than the other two groups. Incidence of disease relapse was comparable among the three groups.

CONCLUSION

Patients with active AAV can be divided into three subgroups based on immuno-phenotyping. These results may provide a hint to understanding disease pathophysiology and prognosis, and determining appropriate treatment.

Clinicopathological case: headache and systemic inflammatory illness—Occam vs Hickam

A 63-year-old woman presented with a sudden headache, which persisted and subsequently changed in character. Over time, constitutional features developed, leading to an unexpected diagnosis. This report documents the clinicopathological conference at the Association of British Neurologists Annual Meeting 2019.

Cerebrospinal fluid biomarkers implicated in the pathogenesis of anti-neutrophil cytoplasmic antibody-related hypertrophic pachymeningitis

OBJECTIVE

Hypertrophic pachymeningitis (HP) related to anti-neutrophil cytoplasmic antibody (ANCA) is the most frequently seen immune-mediated HP. We investigated cerebrospinal fluid (CSF) biomarkers related to the pathogenesis of ANCA-related HP (ANCA-HP).

METHODS

The levels of B cell activation factor of the tumor necrosis factor family (BAFF), a proliferation-inducing ligand (APRIL), and transforming growth factor beta 1 (TGF-β1) in the CSF were compared between patients with ANCA-HP (n = 12), other types of immune-mediated HP (other HP; n = 12), multiple sclerosis (MS; n = 14), and non-inflammatory neurological disorders (NIND; n = 10). In addition, we evaluated whether ANCA would be detected in CSF.

RESULTS

CSF levels of BAFF, APRIL, and TGF-β1 were significantly increased in ANCA-HP and other HP. In particular, BAFF and APRIL levels were significantly correlated with the IgG index in ANCA-HP. In other HP, BAFF and APRIL levels were significantly correlated with cell counts and protein levels in CSF. Of 12 patients with ANCA-HP, the CSF of 7 patients (58%) tested positive for myeloperoxidase (MPO)- or proteinase 3 (PR3)-ANCA, while none of the CSF samples from other HP, MS, or NIND patients tested positive.

CONCLUSION

The levels of BAFF, APRIL, and TGF-β1 may serve as useful CSF biomarkers for assessing the disease activity of immune-mediated HP. Moreover, BAFF and APRIL in the CSF may be implicated in the pathogenesis of ANCA-HP via promoting autoreactive B cells, while detecting MPO- or PR3-ANCA in the CSF may be found in some patients with ANCA-HP.Key Points• CSF BAFF, APRIL, and TGF-β1 levels increase significantly in immune-mediated HP.• CSF BAFF and APRIL levels are significantly correlated with IgG index in ANCA-HP.• Detection of MPO- or PR3-ANCA in the CSF is found in some patients with ANCA-HP.• BAFF, APRIL, and ANCA in the CSF may be implicated in the pathogenesis of ANCA-HP.

Propionibacterium acnes-associated chronic hypertrophic pachymeningitis followed by refractory otitis media: a case report

BACKGROUND

Hypertrophic pachymeningitis (HP) is a rare disorder that involves localized or diffuse thickening of the dura mater. HP is associated with various inflammatory, infectious, and malignant diseases, such as rheumatic arthritis, sarcoidosis, anti-neutrophil cytoplasmic antibody-associated vasculitis, IgG4-related disorders, syphilis, tuberculosis, bacterial and fungal infections, cancer, and idiopathic diseases, when evaluation fails to reveal a cause. Among them, chronic infection with Propionibacterium acnes is a rare etiology of HP, and its pathology remains unclear.

CASE PRESENTATION

An 80-year-old man having refractory otitis media with effusion of the right ear presented with progressive right-sided headache and nausea. Post-contrast brain magnetic resonance imaging revealed right mastoiditis and remarkable thickening of the dura mater and enhancement of pia mater extending from the right middle cranial fossa to the temporal lobe. HP secondary to middle ear infection was suspected, and a biopsy of the right mastoid was performed. An anaerobic culture of the biopsied right mastoid showed the growth of P. acnes, and histopathological examination using P. acnes-specific monoclonal antibody (PAB antibody) revealed the infiltration of inflammatory cells with P. acnes. Moreover, using PAB antibody, P. acnes was detected in the biopsy specimen of the thickening dura mater. No granulomas were identified in either specimen. HP was resolved with long-term administration of antibiotics and steroids.

CONCLUSION

This is the first documentation of pathologically demonstrated chronic HP associated with P. acnes infection followed by refractory otitis media. This report showed that chronic latent P. acnes infection induces chronic inflammation.