Idiopathic hypertrophic pachymeningitis: Clinical, laboratory and neuroradiologic features in China

Non-infectious hypertrophic pachymeningitis associated with orbital inflammatory disease: a pooled analysis

PURPOSE

To describe four cases of non-infectious hypertrophic pachymeningitis (HP)-associated with orbital inflammatory disease (OID). This study summarises the clinico-radiological features, outcomes, and management of HP-associated OID.

METHODS

Retrospective case-series of patients with radiological evidence of HP and OID. Comprehensive literature review of all published English-language non-infectious causes of HP-associated OID. Reference lists were screened for inclusion of relevant articles.

RESULTS

Thirty-seven cases of HP-associated OID (Mean age: 49.2 ± 17.4 years old; Male: 15) were identified, including four cases from our institution. Aetiologies included ANCA-associated vasculitis (12/37), non-specific/idiopathic (11/37), IgG4/multifocal fibrosclerosis (11/37), neurosarcoidosis (1/37), inflammatory myofibroblastic tumour (1/37), and giant cell arteritis (1/37). Orbital pain, headache, visual deterioration, and cranial nerve palsies were common clinical presentations. Both "focal" and "diffuse" HP were observed, with the most common sign of orbital involvement being an inflammatory orbital mass, typically with orbital apex involvement. Orbital myositis and dacryoadenitis were less common. The cavernous sinus was the most common site of extra-orbital inflammation. There was no single differentiating specific radiological feature between non-specific and specific forms of HP-associated OID.

CONCLUSION

The clinico-radiological manifestations of HP-associated OID differ from those described in isolated HP or OID. There is no single specific radiological marker differentiating non-specific/idiopathic disease from secondary causes; however, the co-existence of HP in OID should prompt suspicion of an underlying cause. The disease may be refractory or resistant to initial treatment, although guidelines surrounding its management and the long-term prognosis remain to be determined.

Misleading Rare Case of Idiopathic Hypertrophic Pachymeningitis

Idiopathic hypertrophic pachymeningitis (IHP) is a rare disease with diffuse thickening of the dura mater that has no specific clinical symptoms and manifestations and it causes neurosurgeons to misdiagnose. A 4-year-old girl presented at the emergency room of our hospital with speech difficulty and severe headache. Head computed tomography scans (CT scan) on admission revealed a large fluid collection over the right temporoparietal region with mass effect, and the neurosurgeon drained it with the initial diagnosis of subdural hematoma. However, the postoperative CT scan demonstrated the failure of surgical drainage; therefore, magnetic resonance imaging (MRI) was requested for the patient. MRI identified diffuse nodular dural thickening with internal septations and different internal hemorrhagic stages on the right side with no evidence of brain parenchymal involvement and according to the serology and autoimmune screening tests, and IHP was diagnosed for the patient. The patient underwent craniotomy. There was an immediate improvement of neurologic symptoms. The patient had good clinical and radiologic outcome at 3 -months follow-up. IHP should be part of the differential diagnosis of some cases of noncommunicating hydrocephalus; however, the rarity of the disease and the absence of specific clinical symptoms make the diagnosis difficult.

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.

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.

Idiopathic hypertrophic pachymeningitis with anticardiolipin antibody: A case report

RATIONALE

Idiopathic hypertrophic pachymeningitis (IHP) is a rare neurological disorder without a definite etiology. Diagnosis is mainly based on exclusion of other etiologies.

PATIENT CONCERNS

A 41-year-old male patient presented with insidious onset headache of 3-month duration.

DIAGNOSES

Contrast-enhanced brain magnetic resonance imaging (MRI) revealed diffuse pachymeningeal enhancement over bilateral cerebral hemispheres and the tentorium cerebelli. Lumbar puncture showed increased pressure, lymphocytic pleocytosis, and elevated protein level with normal glucose concentration. Blood tests detected elevated erythrocyte sedimentation rate (ESR) and C-reactive protein. Pathological examination of the dura mater from the right frontal convexity disclosed coarse collagenous deposition with focal lymphoid aggregation. After malignancy and infectious etiologies were excluded, a diagnosis of IHP was made.

INTERVENTIONS

Oral prednisolone and azathioprine followed by methotrexate were administered.

OUTCOMES

During the 7-year follow-up period, although the patient was not totally headache-free, medical therapy significantly reduced the severity of headache. Follow-up MRI studies showed a reduction in meningeal enhancement and serial ESR measurements revealed a trend of improvement.

LESSONS

Methotrexate therapy may be considered in cases of steroid-resistant IHP. In addition to clinical evaluation, serial ESR testing may be considered to guide the treatment strategy and assess the response to therapy.

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.

Neurosurgical and neuro-immunological management of IgG4-related hypertrophic sclerosing pachymeningitis. A literature survey and discussion of a unique index case

BACKGROUND

Dural thickening is observed in lymphoma, dural carcinomatosis, meningioma, tuberculosis, and autoimmune diseases. We encountered a patient with dural thickening and complaints of neck and back pain, numbness and loss of strength in the hands. The patient also suffered from polychondritis and had previously received steroid and methotrexate treatment for this indication. The patients' serum was also positive for ANA, yet she did not have any other findings suggesting lupus. Our radiological and pathological analysis revealed IHSP (IgG4-related hypertrophic sclerosing pachymeningitis). In this review study, we provided a detailed literature survey to increase the awareness about IHSP in the neurosurgical community.

METHODS

MRI (magnetic resonance imaging)-based radiological analyses revealed a posterior extramedullary spinal mass extending from C2 to T2-T3 level. The dural mass was surgically excised and a broad panel of immunohistochemical markers including S100, EMA, CD246/ALK-1, CD45, CD20, CD79a, CD138, CD68, CD1a and CD34 was studied. Immunoglobulin heavy chain/kappa chain gene rearrangement analysis was performed which ruled out a lymphoproliferative disorder.

RESULTS

MRI and pathological findings suggested IHSP. As the disease relapsed with a new anterior extramedullary multilobulated lesion extending from C5 to T1 level, the patient is now closely monitored for further medical and surgical treatment.

CONCLUSIONS

IHSP is a relatively novel entity of hypertrophic pachymeningitis and should be included in the differential diagnosis of dural thickening. The fibrosis accompanying IHSP may not respond to medical treatment, which includes steroids and immunosuppressive agents. Additionally, neurological deficits, seizures, spinal decompression, hydrocephalus, or brainstem compression necessitate early surgical intervention. A continued vigilance is also necessary as the disease may relapse long-term following surgical treatment.

Hypertrophic Pachymeningitis in Chinese Patients: Presentation, Radiological Findings, and Clinical Course

Background

Hypertrophic pachymeningitis (HP) is generally regarded as a rare inflammatory disease, which results in a diffuse thickening of the dura mater. We retrospectively collected data from patients with HP.

Methods

A total of 16 patients with HP were included in our study. The clinical features, laboratory evaluation, imaging findings, treatment, and outcome were reviewed.

Results

Of the 16 cases, half were male, with a mean age of 52.6 ± 13.2 years. The mean duration from onset to diagnosis was 8.6 months. The most frequent presenting symptoms in HP cases were a recurrently chronic headache (81.3%) and multiple cranial nerve injury (50%). Antineutrophil cytoplasmic antibody- (ANCA-) related HP was found in 5 cases and IgG4-related HP in 1 case. The intracranial pressure was elevated in 4 cases. The cerebrospinal fluid (CSF) had lymphocytosis in 5 cases and increased protein in 12 cases. Immunoglobulins (IgG, IgA, and IgM) and protein showed linear relationships in the CSF. On magnetic resonance imaging (MRI), localized or diffuse dura maters were thickened in all cases. HP combined with subacute subdural hemorrhage or hypertrophic spinal pachymeningitis was also observed in individual cases. Biopsy of the dura mater in one case showed amounts of inflammatory cells infiltrating, with an increased percentage of IgG4-positive plasma cells. Of all cases referring to glucocorticoid treatment, the symptoms have improved significantly in 10 cases. In other 6 cases, mycophenolate mofetil or azathioprine was added. All patients showed clinical improvement at the follow-up visits.

Conclusion

The clinical characters of HP are chronic onset, recurrently chronic headache, and multiple cranial nerves paralysis. Inflammatory changes in CSF caused by intrathecal synthesis of immunoglobulin, characteristic dural enhancement on MRI, and pathologic biopsy are all helpful for diagnosis. The addition of immunosuppressant, especially mycophenolate mofetil, is a good choice for steroid-resistance HP.

Distinguishing magnetic resonance imaging features between idiopathic hypertrophic pachymeningitis and secondary hypertrophic pachymeningitis

Background

Hypertrophic pachymeningitis (HP) is a rare chronic inflammatory disorder characterized by marked fibrous thickening of the cerebral and/or spinal dura mater. This condition is caused by infection, inflammation, autoimmune disorder, neoplasms, or idiopathic. Magnetic resonance imaging (MRI) may play an important role in differentiating idiopathic HP from secondary HP, may avoid unnecessarily invasive dural biopsy, and prompt specific treatment.

Objective

To determine the specific MRI findings for differentiation between idiopathic HP and secondary HP.

Method

A total of 34 patients underwent MRI of the brain and cervical spine from January 2003 to December 2015. In all, 23 patients were diagnosed idiopathic HP and 11 patients were secondary HP. Demographic data and imaging findings reveal the following: configuration, thickness, signal intensity on T1-weighted image (T1WI), T2-weighted image (T2WI), and enhancement pattern of the lesions. The data were analyzed by T-test and Fisher’s exact test.

Result

Secondary HP were significantly located at anterior and middle cranial fossa (P = 0.033). There is no significant difference of lesions in configurations, T1 and T2 signal intensity and patterns of enhancement. There was significant and exclusive difference in T2 hypointense/dark intensity and homogeneous enhancement in idiopathic HP (75%, P = 0.044).

Conclusions

MRI may play a complimentarily important role in distinguishing idiopathic HP from secondary HP. Idiopathic HP is probably preferred diagnosis in the lesions with T2-rim pattern and T2 hypointense/dark intensity with homogeneous enhancement.

Hide and seek

A 51-year-old woman with a previous history of rheumatoid arthritis experienced painless progressive visual loss in the left eye for 3 weeks. Fundus examination revealed optic disk pallor in her left eye. Magnetic resonance imaging of the brain and orbits showed enhancement of the pachymeninges and hypersignal at the left optic nerve. Meningeal biopsy was performed. Immunohistochemical staining for IgG4 revealed several IgG4-positive plasma cells, which in some areas reached the number of 50 cells/high-power field. In this case, the clinical and histopathological features of the patient met diagnostic criteria for rheumatoid arthritis and IgG4-related disease, respectively. Rheumatoid arthritis sometimes occurs with abundant IgG4 plasma cells and fulfills the histological diagnostic criteria for IgG4-related disease. This case demonstrates that overlapping features of IgG4-RD and rheumatoid arthritis may present in a single patient.

Cerebral Venous Sinus Thrombosis Secondary to Idiopathic Hypertrophic Cranial Pachymeningitis: Case Report and Review of Literature

BACKGOUND AND IMPORTANCE

Idiopathic hypertrophic cranial pachymeningitis (IHCP) is a rare fibrosing inflammatory process involving the dura mater. Currently, there is no consensus on the treatments for IHCP, and the usefulness of immunosuppressive agents as a first-line option remains controversial. Cerebral venous sinus occlusion (CVSO) and cerebral venous sinus thrombosis (CVST) secondary to IHCP, which may cause progressive intracranial hypertension and venous obstructive parenchymal lesions, make the diagnosis and treatment of IHCP more complicated.

METHODS

We present a case of IHCP. We also review previous cases of IHCP with secondary CVSO/CVST and then summarize the clinical characteristics of these patients.

CLINICAL PRESENTATION

A 52-year-old female patient with IHCP developed secondary CVST. She had a severe headache with a hyperintense lesion on computed tomography, which was considered as subarachnoid hemorrhage. Lumbar tapping with a cerebrospinal fluid test, in addition to gadolinium contrast-enhanced magnetic resonance imaging, suggested IHCP. Secondary CVST was identified by digital subtraction angiography and magnetic resonance venography. Fatal intracranial hypertension with severe neurologic deficits occurred, despite mannitol, furosemide, and corticoid therapy. After administration of intravenous pulse cyclophosphamide, she obtained complete remission.

CONCLUSIONS

We experienced a patient with CVST secondary to IHCP, who was successfully treated with cyclophosphamide pulse therapy. Because IHCP with secondary venous obstruction has various differential diagnoses, venography is necessary to avoid misdiagnosis. The use of immunosuppressive agents may be promising but needs further verification.

A case of idiopathic hypertrophic pachymeningitis presenting with chronic headache and multiple cranial nerve palsies: A case report

RATIONALE

Idiopathic hypertrophic pachymeningitis (IHP) is a rare condition, characterized by a chronic fibrosing inflammatory process usually involving either the intracranial or spinal dura mater, but rarely both. Here, we report a rare case of IHP affecting both the intracranial and spinal dura mater. We also discussed the diagnosis, management, and outcome of IHP.

PATIENT CONCERNS

We reviewed the case of a 60-year-old woman presenting with chronic headache, multiple cranial nerve palsies and gait disturbance. Magnetic resonance imaging (MRI) of her head revealed thickened and contrast-enhanced dura in the craniocervical region as well as obstructive hydrocephalus and cerebellar tonsillar herniation. The patient had a suboccipital craniectomy and posterior decompression through C1 plus a total laminectomy. The dura was partially resected to the extent of the bony decompression, and a duroplasty was performed.

DIAGNOSES

Microscopic examination of the surgically resected sample showed chronic inflammatory changes, lymphoplasmacytic cell infiltration, fibrous tissue hyperplasia, and hyaline degeneration. Blood tests to evaluate the secondary causes of hypertrophic pachymeningitis (HP) were unremarkable.

INTERVENTIONS

Steroid was used to treat suspected IHP.

OUTCOMES

Postoperatively, the patient showed gradual improvement in her headache, glossolalia, and bucking. Prior to discharge, a follow-up MRI showed improvement of the dura mater thickening.

LESSONS

IHP is a chronic inflammatory disorder of the dura mater that usually causes neurological deficits. Clinical manifestations of IHP, MRI findings, and laboratory abnormalities are the essential components for making an accurate diagnosis. When the radiological or laboratory evaluation is uncertain, but neurological deficits are present, a prompt surgical approach should be considered. Postoperative steroid therapy and close observation for recurrence are necessary to ensure a good long-term outcome.

Idiopathic hypertrophic pachymeningitis mimicking hemicrania continua: An unusual clinical case

Background Hemicrania continua (HC) is a primary headache syndrome characterized by a unilateral, moderate, continuous headache with exacerbations marked by migrainous and cranial autonomic symptoms. However, clinical phenotypes similar to primary HC may be subtended by several disorders. Case report We report the case of a 62-year-old man experiencing, over the previous year, a headache completely consistent with HC and its absolute responsiveness to indomethacin therapy. Later, the patient developed diplopia caused by sixth cranial nerve palsy ipsilateral to headache. In this frame, clinical, laboratory and neuroimaging characteristics supported the diagnosis of idiopathic hypertrophic pachymeningitis (IHP). Conclusions IHP is a rare fibrosing inflammatory disorder leading to a localized or diffuse dura mater thickening. IHP clinical manifestations are a progressively worsening headache and signs related to cranial nerves involvement and venous sinus thrombosis. Here, we report, for the first time, a HC phenotype subtended by IHP.

Focal status epilepticus as a manifestation of idiopathic hypertrophic cranial pachymeningitis

BACKGROUND

Idiopathic hypertrophic cranial pachymeningitis (IHCP) is an uncommon disease of unknown etiology characterized by thickening of the cerebral dura mater with possible associated inflammation. The most frequently described clinical symptoms include headache, cranial nerve palsy, and cerebellar dysfunction. Epilepsy and/or status epilepticus as main presentation is very uncommon.

CASE PRESENTATION

Two consecutive cases are presented of patients manifesting focal status epilepticus secondary to IHCP, with clinical, laboratory [blood test and cerebrospinal fluid (CSF) analysis], neuroradiologic [magnetic resonance imaging (MRI) at 3 Tesla and digital subtraction angiography (DSA)], and therapeutic data. One patient underwent meningeal biopsy; pathology findings are also included. Corticosteroid therapy resulted in clinical improvement in both cases, and neuroimaging showed decreased abnormal morphology, compared to initial findings.

CONCLUSION

In the diagnostic approach to focal status epilepticus or epilepsy, IHCP must be considered a potential, although extremely infrequent, cause. Anti-inflammatory treatment is an effective addition to antiepileptic drug therapy in patients with IHCP.

Pachymeningeal enhancement-a comprehensive review of literature

Pachymeningeal enhancement, synonymous with dural enhancement, is a radiological feature best appreciated on a contrast-enhanced magnetic resonance imaging (MRI). The vasculature of the dura mater is permeable, facilitating avid uptake of contrast agent and subsequent enhancement. Thin, discontinuous enhancement can be normal, seen in half the normal population. In patients complaining of postural headaches worse on sitting, gadolinium-enhanced MRI findings of diffuse pachymeningeal enhancement is highly suggestive of benign intracranial hypotension. In these cases, the process of pachymeningeal enhancement is explained by the Monro-Kellie doctrine as compensatory volume changes by vasocongestion and interstitial oedema of the dura mater due to decreased cerebrospinal fluid (CSF) pressure. Focal and diffuse pachymeningeal enhancement can also be attributed to infectious or inflammatory, neoplastic and iatrogenic aetiologies. Correction of the underlying pathology often results in spontaneous resolution of the pachymeningeal enhancement. There have also been reports of pachymeningeal enhancement associated with cerebral venous sinus thrombosis, temporal arteritis, baroreceptor reflex failure syndrome and arteriovenous fistulae.

Infiltrative mass of the skull base and nasopharynx: A diagnostic conundrum

Inflammatory skull base masses are enigmatic and often behaviourally unpredictable. We present a case of idiopathic hypertrophic pachymeningitis (IHP) forming a central skull base mass to illustrate the process required when one investigates such skull base lesions. This is the first description of mass forming or tumefactive IHP extending into the nasopharynx. A 32-year old woman presented with frontal headaches and nasal discharge. She then deteriorated and was admitted with worsening headaches, serosanguinous nasal discharge and bilateral ophthalmoplegia. Multimodality imaging confirmed a destructive central skull base soft tissue mass involving the posterior clivus, floor of sphenoid sinus, nasopharynx and extending into both cavernous sinuses. Unfortunately, the patient continued to deteriorate despite treatment with broad-spectrum antibiotics. Cerebrospinal fluid, blood tests and transnasal biopsies for histology and microbiology did not reveal a diagnosis. Further neuroimaging revealed extension of the mass. Early corticosteroid treatment demonstrated radical improvement although an initial reducing regime resulted in significant rebound deterioration. She was stable on discharge with slowly reducing low dose oral prednisolone and azathioprine. We discuss the complexity of this case paying special attention to the process followed in order to arrive at a diagnosis of idiopathic hypertrophic pachymeningitis based on both the clinical progression and the detailed analysis of serial skull base imaging. Knowledge of the potential underlying aetiologies, characteristic radiological features, common pathogens and the impact on blood serology can narrow the potential differentials and may avoid the morbidity associated with extensive resective procedures.

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Timely thorough investigation is critical to reduce the risk of irreversible damage.

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Prompt biopsy is essential to exclude both neoplasia and inflammatory conditions.

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Early corticosteroid administration is necessary to limit local infiltration.

Arachnoid involved in idiopathic hypertrophic pachymeningitis

The cerebrospinal fluid (CSF) shows inflammatory changes in patients with idiopathic hypertrophic pachymeningitis (IHP), which is a rare disorder. However, systemic CSF research including immunoglobulins in patients with IHP are substantially lacking. In the study, clinical, laboratory, neuroradiologic and therapeutic data from 9 patients with IHP were retrospectively studied, and CSF changes were analyzed. Intracranial pressure was elevated in 4 patients. Protein levels in CSF were elevated in 5 patients (< 1g/L). IgA was elevated in 7 patients (> 0.5mg/dL), IgG was elevated in 8 patients (> 3.4 mg/dL) and IgM was elevated in 6 patients (>0.13 mg/dL) with IHP. CSF immunoglobulins, including IgA, IgG and IgM, were significantly elevated compared with levels in the control (P = 0.021, 0.018, 0.019). There were no linear correlations between IgG, IgM and protein in CSF, but there was a linear correlation between IgA and protein. In conclusion, CSF in IHP shows inflammatory changes, and protein levels are low to moderately elevated. CSF immunoglobulins, including IgA, IgG and IgM, also increased. The arachnoid is involved in IHP, a proportion of immunoglobulins may originate from the blood because of damage to the blood-CSF barrier at the arachnoid. Other intrathecal synthesis of immunoglobulins may be a secondary change due to alteration in the CSF's content to stabilize the internal environment or may be secreted by activated immune memory cells in the brain, which need further research.