The neurology of IGG4-related disease

Analysis of extraocular muscle volumes in idiopathic hypertrophic pachymeningitis patients

BACKGROUND

Idiopathic hypertrophic pachymeningitis (HP) is a rare chronic inflammatory condition without an identifiable cause characterized by fibrous thickening of the dura mater, which can involve the extraocular muscles (EOM).

OBJECTIVE

To evaluate volumetric changes of EOM in idiopathic HP patients compared with healthy controls (HC) and study the correlation with ocular motility disturbance.

MATERIALS AND METHOD

Twenty-two idiopathic HP patients diagnosed and underwent 3T MRI between 2017 to 2021 at Siriraj Hospital and 22 age- and sex-matched HC were included in this retrospective study. EOM was manually segmented from the T1W image using 3D Slicer software, and volume was calculated using FSL software. T-tests and Mann-Whitney U tests were used to compare EOM volumes between the idiopathic HP and control groups. Pearson's correlation coefficient was then used to assess the correlation between ocular motility and EOM enlargement.

RESULTS

In idiopathic HP patients, the average EOM volumes, including the medial rectus (p = 0.002 each), inferior rectus (right p = 0.08, left p < 0.01), inferior oblique (right p = 0.009, left p = 0.005), right lateral rectus (p = 0.005), right superior oblique (p = 0.004), and left superior rectus (p = 0.005) muscles, were significantly larger compared to those in HC, particularly in the left IR and both MR. However, there was no significant correlation between the enlargement of these 9 EOMs and the extraocular movement limitation.

CONCLUSION

In idiopathic HP patients, significantly larger EOM volumes were found compared to control subjects. This enlargement could be due to the diffuse infiltrative histopathology potentially involving microstructures in the EOM. Extraocular movement limitations may be related to cranial nerve involvement. However, the enlarged EOM volumes show no significant correlation with extraocular movement limitation.

A Rare Presentation of a Spinal Lesion: Immunoglobulin G4-Related Hypertrophic Spinal Pachymeningitis

Immunoglobulin G4-related disease is a rare systemic condition that can affect multiple organs, though involvement of the central nervous system is uncommon. This report discusses an unusual case of a 64-year-old man who experienced neurological symptoms due to a spinal lesion. Imaging revealed a compressive mass at the cervical spine level, which was surgically removed and later confirmed to be IgG4-related hypertrophic spinal pachymeningitis. This case highlights the importance of considering rare inflammatory conditions in the differential diagnosis of spinal lesions and emphasizes the role of histopathological confirmation for accurate diagnosis and treatment planning.

Immunoglobulin G4-Related Disease Presenting With Peripheral Neuropathy, Membranous Nephropathy and Interstitial Lung Disease: A Case Report

Immunoglobulin G4-related disease (IgG4-RD) is a chronic, progressive inflammatory disease with fibrosis that affects multiple organs, while symptomatic peripheral nerve invasion is very rare. Here we present a Chinese male aged 77 years with peripheral neuropathy, membranous nephropathy, and interstitial lung disease diagnosed with IgG4-RD. The patient exhibited elevated levels of IgG4 and IgG4/IgG ratios in the blood. A chest computed tomography (CT) showed interstitial pneumonia in both lungs and multiple mediastinal lymphadenopathy. Additionally, electromyography shows neurogenic lesions in both lower extremities and axonal lesions involving motor nerves. Biopsies of the kidney showed membranous nephropathy with numerous IgG4-positive plasma cells. Patients treated with cyclophosphamide and high-dose methylprednisolone showed improvement in neuropathy, proteinuria, and interpulmonary severity. This case demonstrates the unusual presentation of IgG4-RD where peripheral neuropathy is the main feature with multisystem involvement but without mass lesions. It underscores the varied clinical manifestations of this disease.

Perineural Spread of Orbital Immunoglobulin G4-Related Disease: A Case Report

Immunoglobulin G4-related disease (IgG4-RD) is a rare, immune-mediated fibroinflammatory condition that can affect multiple organs. It is characterized by elevated serum IgG4 levels, lymphoplasmacytic infiltration, storiform fibrosis, and obliterative phlebitis. Diagnosis can be challenging due to limited awareness amongst clinicians and its wide range of clinical manifestations. We present a case of an elderly woman with bilateral orbital IgG4-RD and perineural spread, a rare manifestation of the disease. Serological testing showed markedly elevated IgG4 levels, and imaging revealed bilateral extraocular muscle enlargement and inflammatory involvement of the lacrimal glands, orbital fat, and trigeminal nerves. The patient initially responded to oral prednisone but discontinued therapy due to side effects. Rituximab, a second-line treatment, caused anaphylaxis, prompting a switch to azathioprine, which led to normalization of IgG4 levels and resolution of symptoms. This patient's positive response to azathioprine highlights the importance of individualized therapeutic strategies in managing this complex condition. This case also underscores the importance of recognizing IgG4-RD as a potential cause of orbital and neurological symptoms. Increased awareness of its diverse clinical and imaging features can facilitate early diagnosis and treatment. To date, this is one of the few documented cases of orbital IgG4-RD with perineural spread, emphasizing the need for further research and reporting to enhance understanding of this rare manifestation.

Extrapulmonary sarcoidosis

Sarcoidosis is a chronic disease of unknown origin that develops when a genetically susceptible host is exposed to an antigen, leading to an exuberant immune response characterized by granulomatous inflammation. Although lung involvement is almost universal as well as the leading cause of morbidity and mortality, virtually any organ can be affected. In particular, sarcoidosis of the heart, nervous system, and eyes can be devastating, leading to death, debilitation and blindness, and a multidisciplinary approach involving expert specialists is required for prompt diagnosis and appropriate treatment. Sarcoidosis of the skin can be disfiguring, thus posing a substantial psychologic and social impact on the patients. The diagnosis is often straightforward in the presence of compatible clinical manifestations in patients with biopsy-proven sarcoidosis, but is challenging when extrapulmonary signs/symptoms occur in isolation. Corticosteroids remain the first line therapy, with immunosuppressive or biologic agents being reserved to patients failing or experiencing side effects from steroids or developing refractory disease.

Cardiac sarcoidosis and neurosarcoidosis - multidisciplinary approach for diagnosis

PURPOSE OF REVIEW

The current review aims to highlight the role of multidisciplinary approach in the diagnosis of patients with cardiac and neurosarcoidosis. Multidisciplinary approach integrates the available clinical information, imaging and histopathological results aiming to reach a definite or at least provisional diagnosis and allow appropriate management. Multidisciplinary approach is the reference standard for diagnosis of interstitial lung disease and should be strongly considered in complex clinical conditions such as cardiac sarcoidosis (CS) and neurosarcoidosis.

RECENT FINDINGS

Histopathological confirmation of noncaseating granulomatous inflammation provides a definite diagnosis of sarcoidosis involving any organ. However, a provisional high confidence or even definite clinical diagnosis can be reached using multidisciplinary evaluation of all available evidence. The diagnosis of cardiac sarcoidosis and neurosarcoidosis requires the integration of different expertise based on the current diagnostic criteria sets. Identifying typical or at least compatible patterns on advanced imaging modalities (CMR and Fluro-Deoxy-Glucose Positron Emission Tomography (FDG-PET)) seems key for the diagnosis of CS, while a confident diagnosis of extra-cardiac disease supports an at least provisional diagnosis. Similarly, in neurosarcoidosis integrating compatible MRI appearances and cerebrospinal fluid results in patients with systemic sarcoidosis allows an at least provisional diagnosis. Exclusion of alternative differential diagnoses is crucial and requires high clinical suspicion, imaging review expertise and appropriate tests performance.

SUMMARY

There have been considerable advances in the diagnostic approach of patients with cardiac and neurosarcoidosis. Multidisciplinary approach for both diagnosis and management is required to reach a confident clinical diagnosis and should be applied when possible.

Intrathecal IgG4 synthesis in IgG4 related spinal hypertrophic pachymeningitis: a case report

Immunoglobulin G4 (IgG4) related hypertrophic pachymeningitis of the spinal cord is a rare condition, characterized by infiltration of the spinal meninges with IgG4-producing plasma cells and subsequent hypertrophic fibrosis. Here, we report on a 65-year-old woman with IgG4 associated hypertrophic spinal pachymeningitis, in whom cerebrospinal fluid (CSF) analysis was a decisive diagnostic tool. Not only could we demonstrate an intrathecal IgG4 production, but also IgG4 positive plasma cells in CSF. Following decompressive surgery, diagnosis of IgG4 associated hypertrophic pachymeningitis was confirmed histologically. Surgery and immunosuppressive therapy with rituximab were associated with clinical improvement. This case highlights CSF analyses as diagnostic tool for detection of IgG4 related hypertrophic pachymeningitis.

Successful remission induction of IgG4-related ophthalmic disease by obinutuzumab therapy: a retrospective study of 8 patients

OBJECTIVES

To evaluate the therapeutic efficacy and safety of obinutuzumab in remission induction for IgG4-related ophthalmic disease (IgG4-ROD) patients.

METHODS

Eight IgG4-ROD patients were retrospectively enrolled. They were intravenously administered 1000 mg obinutuzumab at baseline and examined for changes in physical signs, orbital structure imaging parameters, IgG4-related disease responder index (IgG4-RD RI), serological index, and adverse events during treatment. The number of treatment sessions was based on treatment response.

RESULTS

The mean IgG4-RD RI scores of all patients at baseline (7.75 ± 2.92) and after treatment (2.00 ± 0.76) were highly significantly different (P < 0.001). Six patients achieved complete remission (CR) (75%) and two patients achieved partial remission (25%). The mean serum IgG4 levels at baseline (9.45 ± 6.95 g/L) and after treatment (1.55 ± 1.09 g/L) showed a mean decrease of 83% (P = 0.0079). The serum IgG4 level correlated well with IgG4-RD RI at baseline and that after each treatment (r = 0.852, P < 0.01; r = 0.78, P < 0.001). In patients with CR, the serum IgG4 levels at baseline correlated positively with dose numbers required for CR (r = 0.86, P < 0.05). Five patients (62.5%) experienced infusion-related reactions (IRRs) during the first obinutuzumab infusion, while only one (12.5%) experienced IRRs during all subsequent eight infusions.

CONCLUSION

Obinutuzumab is a safe and promising therapeutic option for IgG4-ROD. It rapidly reduces ocular inflammation and serum IgG4 levels to avoid excessive corticosteroid usage and reduce potential risk of adverse events.

A case of IgG4-related ophthalmic disease after SARS-CoV-2 vaccination: case report and literature review

Coronavirus disease 19 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is affecting the world with a surge in cases. A variety of autoimmune diseases occur after SARS-CoV-2 infection or vaccination, of which IgG4-related disease (IgG4-RD) is an important type. IgG4-RD can involve multiple organs of the body. The ocular manifestation of IgG4-RD is called IgG4-related ophthalmic disease (IgG4-ROD). We herein report a patient diagnosed with IgG4-ROD. The patient developed ptosis and vision loss after SARS-CoV-2 vaccination, and the symptoms worsened after SARS-CoV-2 infection. After excluding other diseases like myasthenia gravis and Eaton-Lambert syndrome that may cause ptosis, the diagnosis of IgG4-ROD was confirmed by pathological examination. We discussed the predisposing factors, diagnosis and treatment of this patient to provide a more empirical and theoretical basis for clinical diagnosis and treatment. We conducted a literature review of previously reported cases of IgG4-RD following SARS-CoV-2 infection or vaccination. We retrieved a total of 9 cases, of which 5 developed symptoms after vaccination and 4 after infection. Demographic and clinical characteristics were summarized. In conclusion, our case represents the first case of proven IgG4-ROD after COVID-19 vaccination. We believe that IgG4-ROD and SARS-CoV-2 infection or vaccination are closely related, and the immune system disorder caused by SARS-CoV-2 infection or vaccination may be a key factor in the pathogenesis of IgG4-RD. But for now, there is no direct evidence that there is a causal relationship between SARS-CoV-2 infection or vaccination and IgG4-ROD, which still needs more research and exploration to confirm.

Immunoglobulin G4-related hypertrophic pachymeningitis with an isolated scalp mass mimicking a brain tumor: a case report and literature review

Immunoglobulin G4-related disease (IgG4-RD) is an autoimmune disorder associated with fibroinflammatory conditions that can affect multiple organs. Hallmark histopathological findings of IgG4-RD include lymphocytic infiltration of IgG4-positive plasma cells, storiform fibrosis, and obliterative phlebitis. However, little is known about central nervous system involvement of IgG4-RD. Hypertrophic pachymeningitis (HP) has recently been reported as a manifestation of IgG4-RD, which may have previously been demonstrated in a significant percentage of idiopathic cases. Herein, we report a rare case of a 63-year-old male who presented with a scalp mass that mimicked a brain tumor. He was diagnosed with IgG4-related HP (IgG4-RP) after surgery. This case suggests that awareness of a possibility of IgG4-RP in patients with isolated scalp masses, even in the absence of systemic symptoms, is crucial. A combination of careful history taking, evaluation of serum IgG4-levels and imaging as an initial work-up, followed by tissue biopsy, is important for the differential diagnosis of IgG4-RP, malignancy, and other infectious diseases.

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

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

IgG4-Related Disease of the Central Nervous System: A Case Series

IgG4-related disease (IgG4-RD) is a rare and often misdiagnosed disorder with limited literature that highlights the different neurological presentations of this treatable disease. The diagnosis of IgG4-RD could be challenging, while imaging is fundamental for the diagnosis, biopsy is considered the gold standard. Most cases respond well to steroids and immunosuppressive therapy. This is a case series study that illustrates the varied neurological presentations of IgG4-RD through three different patients that were followed at the Montreal Neurological Institute. This paper takes you through the diagnostic strategy that we followed to accurately diagnose and treat those patients.

A selected case series of idiopathic hypertrophic pachymeningitis in a single center: Pathological characteristics and case-oriented review

Hypertrophic pachymeningitis (HP) is a relatively rare disease of the central nervous system characterized by local or diffuse fibrous thickening of the dura mater. At present, there is still insufficient research on the pathogenesis and treatment strategies of this disease. We reported a continuous case series of seven patients with idiopathic HP (IHP), and also details one case of immunoglobulin G4-related HP requiring surgical intervention. Early diagnosis and appropriate surgical intervention for IHP could prevent the progression of permanent neurological damage and spinal cord paraplegia.

Differential Diagnosis of Tumor-like Brain Lesions

Purpose of Review

Tumor-like brain lesions are rare and commonly suggest a neoplastic etiology. Failure to rapidly identify non-neoplastic causes can lead to increased morbidity and mortality. In this review, we describe 10 patients who presented with atypical, non-neoplastic tumor-like brain lesions in which brain biopsy was essential for a correct diagnosis and treatment.

Recent Findings

There has been increasing recognition of autoimmune conditions affecting the nervous system, and many of those diseases can cause tumor-like brain lesions. Currently available reports of non-neoplastic tumor-like brain lesions are scarce. Most case series focus on tumefactive demyelinating lesions, and a comprehensive review including other neuroimmunological conditions such as CNS vasculitis, neurosarcoidosis, histiocytic and infectious etiologies is lacking.

Summary

We review the literature on tumor-like brain lesions intending to increase the awareness and differential diagnosis of non-neoplastic brain tumor mimics. We advocate for earlier brain biopsies, which, in our case series, significantly changed diagnosis, management, and outcomes.

IgG4-related pachymeningitis-Long term follow up and outcome of six patients

OBJECTIVE

Our understanding of IgG4-RD and pachymeningitis has grown substantially, but the optimal approach for diagnosis, management, and long-term outcomes is still an area of uncertainty.

METHODS

HUVAC is a database for IgG4-RD patients, this database was retrospectively evaluated for pachymeningeal disease. Demographic, clinical, serological, imaging, histopathological data, and treatment details were re-interpreted in patients with pachymeningitis.

RESULTS

Among 97 patients with IgG4-RD, 6 (6.2%) had pachymeningitis. None of these patients had extracranial features, and also, in most of the patients, serum IgG4 levels were normal. Tentorium cerebelli and transverse sinus dura were the most commonly involved in the posterior fossa. During 18 months of median follow-up on steroid+-rituximab, none of them relapsed as pachymeningitis.

CONCLUSION

Our patients were mainly older males with sole neurological involvement. Non-specific headache was the most common manifestation, and serum IgG4 levels were not useful for diagnosis. Typical radiology and tentorial thickening should suggest IgG4-RD and prompt an early biopsy. Moreover, accompanying hypophysitis could also be a clue. With steroids+ rituximab treatment, no relapse related to meningeal involvement was seen in long-term follow-up.

Complete remission of central nervous system manifestations of IgG4-related disease with rituximab - a case report

IgG4-related disease (IgG4-RD) is an emerging immune-mediated chronic fibrotic disease characterized by tumour-like mass formation. Reports of brain parenchymal involvement in IgG4-RD are rare and complete treatment-related remission of lesions has never been reported. Here, we present a woman in her mid-50s who developed headache and seizures. Brain magnetic resonance imaging revealed frontal bilateral pachymeningitis and a left frontal lobe parenchymal lesion, and pathologic findings were consistent with an IgG4-RD central nervous system manifestation. She had a history of tumour-like growth around the right optic nerve, orbital and maxillary cavities treated successfully with corticosteroids 28 years ago, and was receiving infliximab as a maintenance therapy for uveitis for the last 14 years. After initial high-dose corticosteroid treatment, the patient was treated with rituximab, and after 3 months, the patient presented with complete remission of IgG4-RD lesions and associated symptoms. This case illustrates the chronic, decades-spanning nature of IgG4-RD, and a complete response to rituximab even with intracerebral mass lesions that had emerged despite the use of infliximab, a therapy previously reported successful in IgG4-RD.

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.

Pachymeningitis associated with IgG4-related disease and ANCA positivity: Case report and review of the literature

OBJECTIVE

Hypertrophic pachymeningitis is a rare clinical disorder involving localized or diffuse thickening of the dura mater. Considering pachymeningitis is both in the clinical spectrum of IgG4-RD and ANCA vasculitis (specifically granulomatosis with polyangiitis), an overlap syndrome is discussed.

METHODS

We report a case of hypertrophic pachymeningitis revealed by headache and cranial nerve dysfunction, and coexistence of biopsy-proven IgG4-RD pachymeningitis and MPO-ANCA positivity. Furthermore, all cases previously reported in the literature of pachymeningitis with IgG4-RD and presence of ANCA were analyzed.

RESULTS

Thirteen patients with pachymeningitis, IgG4-RD and ANCA were analyzed. Patients with HP-related IgG4 and ANCA are mainly male (8, 62%). Median age at diagnosis was 64 years. Main clinical manifestations at diagnosis were localized to the head and neck with headaches (10, 77%), cranial nerve dysfunction (7, 54%), hearing impairment (6, 46%) and vertigo (4, 31%). Except 1 patient with diffuse aortitis, no other systemic manifestation was observed at diagnosis and during follow-up. Serum IgG4 was often elevated (11, 85%) and ANCA was mainly with myeloperoxidase specificity (11, 85%). Seven patients had cerebrospinal fluid analyse with lymphocytic pleocytosis in 5 cases (71%), elevated proteins in 4 cases (57%), positive oligoclonal bands in 3 cases (42%) and decreased glucose in one case (14%). On the MRI, the thickening of the dura mater concerned most often the posterior fossa, in 7 cases (54%). Among 10 cases with histological findings, all showed increased IgG4-positivity of plasma cells, 50% lymphocytic infiltrate but none presented the three major histological criteria of IgG4-related disease. Three (30%) showed histological signs of vasculitis with vascular wall damage and/or giant cells. Among the 12 patients treated with steroid therapy, a clinical improvement was noted in 11 cases (92%). Relapse occurred during tapering in 4 patients (33%). An immunosuppressive drug was added in 2nd line for 7 cases (54%), with a clinical improvement in all.

CONCLUSION

Pachymeningitis with IgG4 and ANCA seems a localized disease to the head and neck. Leptomeningeal biopsy commonly found IgG4 criteria and no vasculitis. All patients responded well to steroid therapy and immunosuppressive drugs, especially rituximab, with clinical and radiological improvement but relapse and/or sequelae are not uncommon.

Immune Mechanisms in Epileptogenesis: Update on Diagnosis and Treatment of Autoimmune Epilepsy Syndromes

Seizures and epilepsy can result from various aetiologies, yet the underlying cause of several epileptic syndromes remains unclear. In that regard, autoimmune-mediated pathophysiological mechanisms have been gaining attention in the past years and were included as one of the six aetiologies of seizures in the most recent classification of the International League Against Epilepsy. The increasing number of anti-neuronal antibodies identified in patients with encephalitic disorders has contributed to the establishment of an immune-mediated pathophysiology in many cases of unclear aetiology of epileptic syndromes. Yet only a small number of patients with autoimmune encephalitis develop epilepsy in the proper sense where the brain transforms into a state where it will acquire the enduring propensity to produce seizures if it is not hindered by interventions. Hence, the term autoimmune epilepsy is often wrongfully used in the context of autoimmune encephalitis since most of the seizures are acute encephalitis-associated and will abate as soon as the encephalitis is in remission. Given the overlapping clinical presentation of immune-mediated seizures originating from different aetiologies, a clear distinction among the aetiological entities is crucial when it comes to discussing pathophysiological mechanisms, therapeutic options, and long-term prognosis of patients. Moreover, a rapid and accurate identification of patients with immune-mediated epilepsy syndromes is required to ensure an early targeted treatment and, thereby, improve clinical outcome. In this article, we review our current understanding of pathogenesis and critically discuss current and potential novel treatment options for seizures and epilepsy syndromes of underlying or suspected immune-mediated origin. We further outline the challenges in proper terminology.

Optic perineuritis

PURPOSE OF REVIEW

This review paper aims at discussing pathogenesis, etiology, clinical features, management, and prognosis of OPN.

RECENT FINDINGS

Optic perineuritis (OPN) is an inflammatory process primarily involving the optic nerve sheath. Clinically, OPN usually presents with unilateral, gradual decline of visual function, eye pain, and/or pain on eye movements, disc edema and various features of optic nerve dysfunction, including visual field defects. It can mimic typical optic neuritis. In most cases of OPN, the disease is isolated with no specific etiology being identified, however, it can also occur secondary to a wide range of underlying systemic diseases. OPN is clinically diagnosed and radiologically confirmed based on the finding of circumferential perineural enhancement of the optic nerve sheath on magnetic resonance imaging (MRI).

SUMMARY

Unlike optic nerve, OPN is not typically self-limited without treatment. High-dose oral corticosteroids are the mainstay of treatment in OPN. The initiation of therapy usually causes rapid and dramatic improvement in signs and symptoms. In general, OPN usually has a relatively good visual prognosis, which is influenced by delays between the onset of visual loss and the initiation of steroid therapy as well as the presence of underlying systemic diseases.

IgG4-related Inflammatory Pseudotumor with Imaging Findings Similar to Meningioma: A Case Report

IgG4-related inflammatory pseudotumor is a feature of IgG4-related disease and develops in various organs. Intracranial IgG4-related inflammatory pseudotumor is rare, and data on the clinical course and response to treatment are insufficient in the literature. We herein report a patient with IgG4-related inflammatory pseudotumor who had magnetic resonance imaging findings similar to meningioma. Tumorectomy was discontinued because of the intraoperative rapid diagnosis, which revealed the infiltration of lymphocytes and plasma cells. She received oral prednisolone therapy for IgG4-related inflammatory pseudotumor, and the tumor size had significantly decreased after six months of treatment.

Clinical Reasoning: A 51-Year-Old Woman With Diplopia and Headache

Background, focus, and key pointsA 51-year-old woman presented with a pressure-like headache behind her right eye and horizontal diplopia. On exam, she was unable to abduct or adduct the right eye but had intact vertical eye movements. Her deficits could not be overcome using the oculocephalic reflex. Imaging initially was interpreted as optic neuritis, but on careful review with radiology, a diffuse enhancing hyperintense signal within the orbital apex confirmed an orbital infiltrate. The focus of this case study is to review the localization approach for diplopia and build a differential diagnosis for orbital processes. Another key point is the importance of relying on the physical exam as the guide to a patient's management rather than imaging findings, which can often be misleading.