Extensive brainstem lesions in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD): A case report

Myelin oligodendrocyte glycoprotein antibody-associated disease is a group of central nervous system demyelinating disorders caused by autoantibodies. While myelin oligodendrocyte glycoprotein antibody-associated disease typically presents as optic neuritis and myelitis in adults, this case report details a patient with brainstem lesions. A 45-year-old male presented with episodes of vertigo, nystagmus, and diplopia in left lateral gaze, which had persisted for 2 months, accompanied by headache. Computed tomography showed hyperdensity extending from the left side of the pons to the middle cerebellar peduncle. Magnetic resonance imaging revealed lesions exhibiting heterogeneous diffusion restriction, with enhancement that included granular and linear patterns. 18F-fluorodeoxyglucose positron emission tomography demonstrated increased uptake in these lesions. Following further evaluation, myelin oligodendrocyte glycoprotein antibody-associated disease was diagnosed. Treatment with high-dose corticosteroids initially alleviated symptoms, but symptoms flared upon reduction of the steroids. This case underscores the importance of considering myelin oligodendrocyte glycoprotein antibody-associated disease in the differential diagnosis of brainstem lesions and discusses distinguishing imaging features from similar conditions.

Erdheim-Chester Disease Masquerading as CLIPPERS

OBJECTIVES

To present 4 patients with Erdheim-Chester disease (ECD) based on clinical, radiologic, histopathologic, and molecular genetic findings who had enhancing brainstem lesions and were initially believed to have chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS).

METHODS

Case series.

RESULTS

Although patients with ECD can demonstrate clinical and imaging features similar to CLIPPERS, refractoriness to corticosteroids, lack of fulfillment of specific MRI criteria (i.e., enhancing lesions >3 mm, T2 abnormalities that exceed areas of T1 postgadolinium enhancement), and systemic findings such as "hairy kidney" appearance and metadiaphyseal osteosclerosis on 18F-fluorodeoxyglucose PET-CT help discriminate it from CLIPPERS.

DISCUSSION

ECD is a histiocytic neoplasm characterized by multiorgan infiltration of clonal histiocytes carrying activating variants of the MAPK-ERK pathway. Neurologic involvement occurs in up to 40% of ECD with frequent brainstem lesions that can mimic acquired neuroinflammatory disorders, such as CLIPPERS. ECD is an important CLIPPERS mimic with distinct pathophysiology and targeted treatments. We highlight the need to consider histiocytic disorders among other alternate diagnoses when findings are not classic for CLIPPERS.

Unusual CLIPPERS presentation with a predominant spinal cord involvement: case report and review of the literature

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a discrete nosological entity characterized by punctate and curvilinear gadolinium enhancement "peppering" the pons and a strong response to steroids. MRI images typically show pontine and cerebellar punctate-enhancing lesions, which occasionally spread up to the juxtacortical areas and down to the spinal cord. Interestingly, the more distant the lesion is from the pons, the less intense they become. Herein, we describe an extremely rare case of CLIPPERS presenting with predominant spinal cord involvement; then, we searched in the literature the available cases with a similar presentation. Our case focuses attention on a rare MRI CLIPPERS presentation. Since CLIPPERS has a dramatic response to corticosteroid treatment, it is fundamental to promptly recognize its MRI pattern to start treatment as soon as possible.

18 F-FDG Brain PET/MRI in Chronic Lymphocytic Inflammation With Pontine Perivascular Enhancement Responsive to Steroids

ABSTRACT

An 89-year-old man presented with progressive gait disturbance, diplopia, and ataxia. Initial brain MRI demonstrated T2/FLAIR hyperintense signal abnormality in the pons extending along the middle cerebellar peduncles into the cerebellum, with associated punctate, patchy, and linear enhancement on postcontrast imaging. Initially, this was attributed to brainstem encephalitis; however, sarcoidosis, histiocytosis, and paraneoplastic/autoimmune encephalitis remained on the differential. One month after initial MRI, 18 F-FDG brain PET/MRI was performed and showed marked pontine hypermetabolism corresponding to the signal abnormality and enhancement on structural imaging. Collectively, these findings are characteristic of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids.

Headache As the Sole Symptom in Chronic Lymphocytic Inflammation With Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS): A Case Report and Literature Review

Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS) is a rare central nervous system inflammatory condition usually presenting with a range of symptoms, including ataxia, diplopia, dysarthria, seizures, and headaches. We present a unique case of a 22-year-old woman exhibiting headache as the sole symptom. Imaging and biopsy confirmed the diagnosis, and initial steroid treatment provided relief, though it relapsed on tapering. Long-term management with low-dose steroids and mycophenolate mofetil achieved remission. This case highlights the importance of recognizing atypical presentations of CLIPPERS, emphasizing the need for prompt diagnosis and appropriate treatment plans to improve patient outcomes. Further research is necessary to enhance our understanding and management of CLIPPERS.

Clinicoradiological features of probable chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) syndrome

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a recently described chronic inflammatory central nervous system disease. This case report describes a young female patient presenting with weakness in bilateral upper and lower limbs and tinnitus for 2 months. A neurological examination revealed signs of brainstem and cerebellar involvement. MRI brain showed characteristic features of CLIPPERS, with punctate and nodular enhancement in the pons and cerebellum. Differential diagnoses were systematically considered and excluded. The patient showed significant clinical and radiological improvement with steroid therapy. No clinical or radiological red flags occurred during the follow-up. This case underscores the critical role of integrating clinical and radiological findings to effectively diagnose and manage CLIPPERS. It emphasises the importance of ruling out alternative diagnoses through a thorough evaluation.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS): contemporary advances and current controversies

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is an inflammatory syndrome with characteristic clinical, radiological, and pathological features, and can be effectively treated with corticosteroid-based immunotherapies. The exact pathogenesis of CLIPPERS remains unclear, and specific diagnostic biomarkers are not available. According to the 2017 diagnostic criteria, probable CLIPPERS should be considered in middle-aged patients with subacute onset of pontocerebellar symptoms and typical punctuate and curvilinear gadolinium enhancement lesions ("salt-and-pepper" appearance) located in the hindbrain (especially pons) on magnetic resonance imaging. In addition, CLIPPERS-mimics, such as central nervous system (CNS) lymphoma, and several antibody-associated autoimmune CNS diseases (e.g., myelin oligodendrocyte glycoprotein antibody-associated disease, autoimmune glial fibrillary acidic protein astrocytopathy, and anti-N-methyl-D-aspartate receptor encephalitis), should be extensively excluded. The prerequisite for definite CLIPPERS is the perivascular T-cell-predominant inflammatory infiltration observed on pathological analysis. A biopsy is strongly suggested when clinical/radiological red flags are present. Most patients with CLIPPERS respond well to corticosteroids and have a good prognosis. Long-term low-dose corticosteroid maintenance therapy or corticosteroids coupled with immunosuppressants are recommended to prevent the recurrence of the syndrome. The potential progression of CLIPPERS to lymphoma has been suggested in some cases; therefore, at least 2-year clinical and radiological follow-up is essential. Here, we critically review the recent developments and provided an update on the clinical characteristics, diagnostic criteria, differential diagnoses, and therapeutic management of CLIPPERS. We also discuss the current controversies in this context that can be resolved in future research studies.

Inflammatory lesions of the brainstem: Keys for the diagnosis by MRI

OBJECTIVE

To describe the magnetic resonance imaging (MRI) findings for the most common inflammatory and immune-mediated diseases that involve the brainstem.

CONCLUSION

Inflammatory lesions involving the brainstem are associated with a wide range of autoimmune, infectious, and paraneoplastic syndromes, making the differential diagnosis complex. Being familiar with these entities, their clinical characteristics, and their manifestations on MRI, especially the number of lesions, their shape and extension, and their appearance in different sequences, is useful for orienting the radiological diagnosis.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids triggered by Hodgkin's lymphoma: A case report and brief literature review

Key Clinical Message

We presented a patient, diagnosed with lymphoma-associated CLIPPERS, 11 years after lymphoma treatment. Therefore, CLIPPERS may be paraneoplastic neurological syndrome of lymphoma, which needs to be considered in the follow-up of lymphoma cases.

Abstract

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare central nervous system disorder with a recent increase in incidence. There are few reports of lymphoma-associated CLIPPERS, although the relationship between these two diseases and the pathophysiology of CLIPPERS in general need further investigation. Here, we present a patient with a history of Hodgkin's lymphoma (HL) more than 10 years before the onset of CLIPPERS, in contrast to the majority of previously reported lymphoma-associated cases, and discuss the possibility that CLIPPERS is the paraneoplastic neurological syndrome of HL. This highlights the need to consider CLIPPERS as a differential diagnosis during follow-up of patients with a history of lymphoma.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) syndrome: Treatment approach depends on disease course

INTRODUCTION

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare inflammatory central nervous system (CNS) disorder, chiefly involving the brainstem, especially the pons. The diagnosis is challenging, requires careful exclusion of alternative diagnoses and a targeted therapeutic approach. CLIPPERS is known to respond well to corticosteroids, but the treatment needs to be long-term and can cause significant side-effects. Moreover, subsequent corticosteroid withdrawal often leads to a relapse. It has been suggested that anti-CD20 molecules could benefit several antibody-mediated CNS inflammatory diseases, including CLIPPERS.

CASE REPORT

This paper describes two cases of CLIPPERS. The first demonstrates the benefit of early introduction of corticosteroids with side effects in cases of long-term use. The second demonstrates the efficacy of ocrelizumab (anti-CD20 molecule) in a severe course of CLIPPERS.

CONCLUSION

These two cases bring attention to this rare, often misdiagnosed but treatable disease.

Supratentorial Lymphocytic Inflammation with Parenchymal Perivascular Enhancement Responsive to Steroids (SLIPPERS)-Does it Really Exist?

Supratentorial Lymphocytic Inflammation with Parenchymal Perivascular Enhancement Responsive to Steroids (SLIPPERS) is a rare variant of the CLIPPERS spectrum with less than ten reports published so far. There is ongoing discussion regarding whether SLIPPERS is a disease entity on its own or just an acronym encompassing many underlying diagnoses, such as sarcoidosis, vasculitis and anti-glial fibrillary acidic protein (GFAP)-associated disease. A 40-year-old woman presented with episodes of language and attention impairment. Magnetic resonance imaging (MRI) revealed T2/FLAIR hyperintense lesions in the subcortical white matter associated with a micronodular, curvilinear perivascular contrast-enhancement. Alternative diagnoses were excluded. There was a remarkable response to steroids. A relapse occurred after six years, and the biopsy showed perivascular T-cell lymphocytic infiltrate, without granulomas, vasculitis, or neoplasia. There was complete resolution of the relapse after steroids. This case represents the longest reported follow-up of a patient diagnosed with SLIPPERS, and brain biopsy after 6 years did not suggest alternative diagnoses. This report contributes to the discussion regarding the possibility that exclusive supratentorial CLIPPERS-like pathology might be an isolated disease entity, but more biopsy-proven cases with a longer follow-up are needed to support this hypothesis. Recently, GFAP astrocytopathy has been characterized and might correspond to a significant number of cases previously diagnosed as CLIPPERS or SLIPPERS.

A Case of Radiologically Compatible Chronic Lymphocytic Inflammation With Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS) With Demyelinating Lesions

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a recently identified diagnosis that can cause a variety of severe symptoms, including ataxia, dysarthria, diplopia, paraparesis, and vertigo. These symptoms rarely present in isolation but often accompany one another in various combinations. Magnetic Resonance Imaging (MRI) of the brain is critical for making the diagnosis and typically reveals scattered enhancement within the pons and adjacent structures. The syndrome responds well to high-dose steroids, and maintenance therapy is required to prevent a recurrence. In this report, we present a case of a 62-year-old man who developed CLIPPERS syndrome. The patient presented with hemiparesis and dysarthria, which developed over four months and then acutely worsened within 24 hours. After diagnosing CLIPPERS, the patient was placed on high-dose steroids and experienced rapid clinical improvement, as well as improvement on repeat MRI. The patient's treatment was complicated by an incidental diagnosis of tuberculosis, which required simultaneous management with isoniazid.

Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS Syndrome): A Case Report and Literature Review

CLIPPERS is a rare, chronic inflammatory neurological syndrome affecting multiple regions of the brain including the brainstem, cerebellum, and spinal cord. More than 100 cases have been documented globally since its initial description in 2010. This article reports the first case of the CLIPPERS syndrome in Nepal. Clinical and radiological evidences of the patient lead to the diagnosis of this disease. Brain MRI reveals punctate and curvilinear gadolinium enhancement in the pons and cerebellum, which is diagnostic for the disease. Steroid therapy has been reported to be effective in treating CLIPPERS syndrome. Although its pathophysiology indicates an immune-mediated process, the etiology is yet unknown. The treatment and prognosis of this illness depend on an early and accurate diagnosis.

The Elusive SLIPPERS Syndrome (Supratentorial Lymphocytic Inflammation with Parenchymal Perivascular Enhancement Responsive to Steroids): A Case Report and Literature Review

Background

In 2015, the term "SLIPPERS" was created to refer to a rare type of encephalomyelitis called CLIPPERS syndrome that affects the pons and sometimes other nearby structures, but in this case, it primarily affects the supratentorial region. This variation of the condition is responsive to treatment with steroids.

Case Description

We report the case of a patient who presented with seizures and visual field deficit and had typical radiological and histopathological characteristics of SLIPPERS syndrome.

Conclusion

Although the literature is inundated with CLIPPERS syndrome, its supratentorial variant is extremely rare. To our knowledge, this is fourth case of SLIPPERS syndrome to be reported in literature and serves to enhance clinicopathological understanding of this elusive entity.

The pathogenesis hypothesis and research progress of CLIPPERS: A literature review

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is still a rare autoimmune disease in the world. In recent years, there are more and more reports about the clinical manifestations of CLIPPERS, but the specific etiology and pathogenesis are not clear. In this paper, by collating the literature reported in recent years, in the reported effective treatment cases, we found the current hypothesis about the pathogenesis of CLIPPERS. Three pathogenesis hypotheses: organ-specific autoimmunity; virus infection affects autoimmunity; and helper T lymphocyte 17 mediates autoimmunity. Although it is hypothetical, it is expected to further clarify the pathogenesis, evolution characteristics, and treatment of CLIPPERS, so as to provide a reference for further understanding of the disease. In the future, more observations and studies are needed to further verify the feasibility of the hypothesis. This article expands on atypical clinical manifestations and summarizes treatment options. Hope to provide a reference for clinical diagnosis and treatment of CLIPPERS.

Spectrum of Autoimmune Diseases—Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS)—Clinical Case

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) syndrome is a rare inflammatory disease of an undetermined aetiology. The condition is characterised by a range of clinical manifestations generally associated with damage to brainstem structures, the cerebellum, with characteristic magnetic resonance imaging (MRI) findings. The main feature is a good clinical and radiological response to glucocorticosteroid (GCS)-based immunosuppressive treatment. The diagnosis of CLIPPERS is difficult and requires extensive differential diagnosis. A specific biomarker in serum or cerebrospinal fluid (CSF) for this disorder is currently unknown. The pathogenesis of CLIPPERS remains poorly understood and its nosological position has not yet been established. Whether CLIPPERS represents an independent, genuine new disorder or a syndrome in the course of diseases with heterogeneous aetiology and/or their precursor stages remains debatable and incompletely clarified. We present a case report of a patient who was diagnosed with CLIPPERS syndrome on the basis of her clinical and radiological features and by performing an extensive differential diagnosis. The patient has been under neurological follow-up for five years.

CLIPPERS Syndrome After Vaccination. An Unusual ASIA Presentation

The chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) and autoimmune/inflammatory syndrome induced by adjuvants (ASIA) were described a decade ago. There are a limited number of reports and these diseases are still underdiagnosed. We presented a 35 years-old patient with clinical manifestations of cerebellum affection and enhancement in the MRI, with the influenza vaccine as the only triggering factor. Infectious diseases, malignancy, and additional systemic involvement were ruled out; therefore, on suspicion of CLIPPERS syndrome, the patient received corticosteroid therapy with an adequate response. The knowledge of CLIPPERS syndrome as an unusual ASIA presentation and high response to the corticosteroids may lead to a timely diagnosis, appropriate treatment, and follow up with better outcomes for patients.

Neuroimaging Patterns of Intracranial Infections: Meningitis, Cerebritis, and Their Complications

Neuroimaging provides rapid, noninvasive visualization of central nervous system infections for optimal diagnosis and management. Generalizable and characteristic imaging patterns help radiologists distinguish different types of intracranial infections including meningitis and cerebritis from a variety of bacterial, viral, fungal, and/or parasitic causes. Here, we describe key radiologic patterns of meningeal enhancement and diffusion restriction through profiles of meningitis, cerebritis, abscess, and ventriculitis. We discuss various imaging modalities and recent diagnostic advances such as deep learning through a survey of intracranial pathogens and their radiographic findings. Moreover, we explore critical complications and differential diagnoses of intracranial infections.

CLIPPERS Responsive to Cladribine as a Durable Steroid-Sparing Agent

Objective

We report a case of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) who achieved durable and steroid-free remission after IV cladribine.

Methods

A 25 year-old man presented with progressively worsening headaches, polydipsia, dysarthria, diplopia and vertigo, and obtundation requiring respiratory support. CSF revealed lymphocytosis, and MRI revealed a perivascular pattern of punctate enhancement involving the pons. An extensive workup for inflammatory, autoimmune, infective, and malignant explanations was unrevealing. He responded dramatically to steroids, compatible with CLIPPERS as a diagnosis of exclusion. Attempts to wean prednisone over the ensuing year resulted in 2 clinical relapses and persistent punctate enhancement. Given significant steroid side effects, steroid-sparing agents were considered.

Results

IV cladribine IV (0.0875 mg/kg adjusted body weight daily × 4 days at 0, 4, 8, and 16 months) was selected, given its favorable side effect profile including lower risks of malignancy and infertility and the potential for long-lasting effects. The only side effect was short-term fatigue at the time of infusion. At 20 months after cladribine initiation, he was able to wean-off prednisone altogether. Now at 33 months, he remains in clinical and MRI remission.

Discussion

Cladribine is a rational candidate steroid-sparing treatment for presumed neurologic autoimmune conditions such as CLIPPERS.

Classification of Evidence

This study provides Class IV evidence that cladribine is a steroid-sparing treatment consideration in CLIPPERS.

The role of MRI in the early diagnosis of chronic lymphocytic inflammation (CLIPPERS syndrome)

ABSTRACT Background. Chronic lymphocytic inflammation with perivascular contrast enhancement in the pons responsive to steroids (CLIPPERS) is a rare and relatively "new" pathology and MRI is highly important in its diagnosis. Clinical Case Description. Chronic lymphocytic inflammation with perivascular contrast enhancement in the pons responsive to steroids (CLIPPERS) is a rare and relatively "new" pathology and MRI is highly important in its diagnosis. Conclusion. MRI not only enables high-quality neuroimaging of CLIPPERS, it also allows avoiding invasive, traumatic diagnostic methods.

Clinical characteristics, management, and outcomes of CLIPPERS: A comprehensive systematic review of 140 patients from 100 studies

INTRODUCTION

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare inflammatory disorder of the central nervous system, characterized by symptoms referable to the brainstem and cerebellum such as, diplopia, gait ataxia and cerebellar dysarthria. The features and outcomes of CLIPPERS remains uncertain. we conducted this comprehensive systematic review to summarize all the existing studies that described CLIPPERS in the literature and to provide a quantitative assessment on the clinical characteristics, management, and outcomes of this rare syndrome.

METHODS

A comprehensive search of PubMed and Web of Science databases was conducted from inception until January 15, 2022, was conducted. We only included the cases that clearly reported probable or definite diagnosis of CLIPPERS based on Taieb et al.'s criteria. The quality of the included studies was assessed using the JBI Critical Appraisal Tool. Descriptive statistics were performed to analyze the studies. Data were expressed as mean and standard deviation (SD) for continuous variables and proportions for categorical variables.

RESULTS

We identified 100 case reports and series including a total of 140 patients with CLIPPERS (mean age: 46±18 years and males were 60%). The average follow-up duration was 32.27±57.8 months. Ataxia was the most common presenting symptom. Sixteen percent of the cases were associated with malignancy, mostly hematologic malignancies. The overall relapse rate was 59.2%, and the duration of steroid therapy was considerably shorter in the relapsed cases than in the non-relapsed (mean 6.19±7.9 vs. 10.14±12.1 days, respectively, P = 0.04). The overall mortality rate was 10%, but mortality in patients with malignancy was 30% and it was 12% in patients with relapses. In the case of steroid dosing (less than 20 mg/d versus greater than 20 mg/d) there was no significant modification in the risk of relapse.

CONCLUSION

CLIPPERS is a rare clinical syndrome that affects mainly middle-aged males. Diagnosis of CLIPPERS is often challenging, and delays in diagnosis and treatment can lead to unfavorable outcomes. Therefore, neurologists should maintain a high index of suspicion for CLIPPERS in any patient presenting with symptoms and signs referrable to the brainstem. These patients should be screened for associated malignancies, especially hematological malignancies. The cases associated with malignancy tend to have worse outcomes. The relapse rate is relatively high. The relapse rate may be associated with worse mortality. Based on our findings, we recommend that CLIPPERS be treated with high-dose steroid therapy for at least ten days during the acute phase with a very slow taper. Prospective studies with a larger sample size are needed to validate our findings and guide the clinical care of these patients.

CLIPPERS: Multiparametric and quantitative MRI features

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare chronic central-nervous-system inflammatory disorder that became known only recently, and the pathogenesis of CLIPPERS remains poorly understood. This report presents clinical and radiological features of a rare case: a young female patient who rapidly died of suspected CLIPPERS. Helpful multiparametric MRI diagnostic criteria are proposed that can help discriminate CLIPPERS from non-CLIPPERS pathologies. We reviewed clinical history, symptoms, quantitative data from brain multiparametric MRI before and after treatment, and histopathological data. Perfusion-weighted imaging revealed a decrease in regional cerebral blood flow by 31% and in cerebral blood volume by 64%, with a moderate increase in transit time and in time to peak by up to 23% in affected pontine and cerebral white matter. As estimated by diffusion tensor imaging, there was elevated density of tracts (n/mm²) and a decrease of fraction anisotropy (×10^-3 mm/s²) in the patient's pons as compared to a healthy control: density of tracts = 13.5 vs 12.4 and fraction anisotropy = 0.32 vs 0.45, respectively. Macromolecular proton fraction values proved to be reduced (15.8% and 14.5% in the control, respectively) in the patient's cerebral peduncles by 3% and in the pons by 4.1% and in a periventricular white matter lesion by 6.4% (11.3% in the normal-looking contralateral hemisphere). Based on our findings, we argue that quantitative MRI techniques may be a valuable source of biomarkers and reliable diagnostic criteria and can shed light on the pathogenesis and exact nosological position of this disorder.

A rare case report of primary Sjögren’s syndrome with clinical characteristics similar to those of CLIPPERS

Background

Primary Sjögren’s syndrome (pSS) is an autoimmune inflammatory disease characterized by dryness of the eyes, mouth and other mucous membranes. Patients with pSS can also present with extraglandular manifestations, such as pulmonary, kidney and nervous system involvement. Central nervous system (CNS) manifestations have rarely been described in pSS.

Case presentation

A 33-year-old man was admitted with a one-month history of dizziness, speech disturbance, and walking instability. His brain enhanced magnetic resonance imaging (MRI) showed symmetrical, enhanced “salt-and-pepper-like” speckled lesions in the brainstem, basal ganglia, and subcortical regions, and his diagnosis was considered possible chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS). Further examination revealed that anti-SSA antibody was positive, and the Schirmer test and labial salivary gland histopathology were abnormal, which supported the diagnosis of pSS.

Conclusion

pSS is a chronic systemic autoimmune disease that involves neurological complications. This case suggests that CNS lesions of pSS can present with clinical and MRI findings similar to those of CLIPPERS.

Rare Etiologies in Immune-Mediated Cerebellar Ataxias: Diagnostic Challenges

The cerebellum is particularly enriched in antigens and represents a vulnerable target to immune attacks. Immune-mediated cerebellar ataxias (IMCAs) have diverse etiologies, such as gluten ataxia (GA), post-infectious cerebellitis (PIC), Miller Fisher syndrome (MFS), paraneoplastic cerebellar degeneration (PCD), opsoclonus myoclonus syndrome (OMS), and anti-GAD ataxia. Apart from these well-established entities, cerebellar ataxia (CA) occurs also in association with autoimmunity against ion channels and related proteins, synaptic adhesion/organizing proteins, transmitter receptors, glial cells, as well as the brainstem antigens. Most of these conditions manifest diverse neurological clinical features, with CAs being one of the main clinical phenotypes. The term primary autoimmune cerebellar ataxia (PACA) refers to ataxic conditions suspected to be autoimmune even in the absence of specific well-characterized pathogenic antibody markers. We review advances in the field of IMCAs and propose a clinical approach for the understanding and diagnosis of IMCAs, focusing on rare etiologies which are likely underdiagnosed. The frontiers of PACA are discussed. The identification of rare immune ataxias is of importance since they are potentially treatable and may lead to a severe clinical syndrome in absence of early therapy.

Adult-Onset Genetic Central Nervous System Disorders Masquerading as Acquired Neuroinflammatory Disorders: A Review

Importance

Adult-onset genetic disorders may present with clinical and magnetic resonance imaging (MRI) features suggestive of acquired inflammatory diseases. An ever-growing number of potentially treatable adult-onset genetic neuroinflammatory disorders have been described in the past few years that need to be rapidly identified.

Observations

Adult-onset acquired neuroinflammatory disorders encompass a large group of central nervous system (CNS) diseases with varying presentation, MRI characteristics, and course, among which the most common is multiple sclerosis. Despite recent progress, including the discovery of specific autoantibodies, a significant number of adult-onset neuroinflammatory disorders with progressive or relapsing course still remain without a definite diagnosis. In addition, some patients with genetic disorders such as leukodystrophies, hemophagocytic lymphohistiocytosis, or genetic vasculopathies can mimic acquired neuroinflammatory disorders. These genetic disorders, initially described in pediatric populations, are increasingly detected in adulthood thanks to recent progress in molecular genetics and the larger availability of high-throughput sequencing technologies.

Conclusions and Relevance

Genetic adult-onset neuroinflammatory diseases are at the border between primary CNS inflammatory diseases and systemic disorders with multiorgan involvement and predominantly neurologic manifestations. Neurologists must be aware of the main clues and red flags so they can confirm a diagnosis early, when some of these genetic disorders can be successfully treated.

Myelin Oligodendrocyte Glycoprotein-Associated Disorders

PURPOSE OF REVIEW

Anti-myelin oligodendrocyte glycoprotein (MOG) autoantibodies have become a recognized cause of a pathophysiologically distinct group of central nervous system (CNS) autoimmune diseases. MOG-associated disorders can easily be confused with other CNS diseases such as multiple sclerosis or neuromyelitis optica, but they have a distinct clinical phenotype and prognosis.

RECENT FINDINGS

Most patients with MOG-associated disorders exhibit optic neuritis, myelitis, or acute disseminated encephalomyelitis (ADEM) alone, sequentially, or in combination; the disease may be either monophasic or relapsing. Recent case reports have continued to expand the clinical spectrum of disease, and increasingly larger cohort studies have helped clarify its pathophysiology and natural history.

SUMMARY

Anti-MOG-associated disorders comprise a substantial subset of patients previously thought to have other seronegative CNS diseases. Accurate diagnosis is important because the relapse patterns and prognosis for MOG-associated disorders are unique. Immunotherapy appears to successfully mitigate the disease, although not all agents are equally effective. The emerging large-scale data describing the clinical spectrum and natural history of MOG-associated disorders will be foundational for future therapeutic trials.

Case 302: Supratentorial Lymphocytic Inflammation with Parenchymal Perivascular Enhancement Responsive to Steroids

HISTORY

Part one of this case appeared 4 months previously and may contain larger images. A 21-year-old immunocompetent man who was a long-term resident of Qatar presented to the emergency department with recurrent episodes of unprovoked generalized tonic-clonic seizures lasting 2-3 minutes that spontaneously resolved and were associated with postictal confusion. The patient also had progressive mild diplopia, intermittent dizziness, and numbness in the left arm over the course of 3 months. The patient did not have any other systemic symptoms or chronic medical diseases. He did not have any history of intake of illicit drugs, supplements, or regular medications; he had not received any recent vaccinations; and he had not undergone any surgical procedures. He had no history of travel. At presentation, vital signs were normal. Neurologic examination showed mild left homonymous hemianopia, normal gait with no cerebellar signs, and preserved sensations, power, tone, and reflexes in all four limbs. An electroencephalogram showed no epileptiform discharges. Chest CT and extensive laboratory work-up, including viral, fungal, bacterial, and parasite work-up, thyroid function tests, and immunologic blood tests yielded normal results. Those included normal complete and differential blood counts and normal serum chemistry. Serum analysis was negative for antinuclear antibody, Sjögren syndrome antigens A and B, cytoplasmic antineutrophil cvtoplasmic antibody, and paraneoplastic profile. Serum evaluation was also negative for human immunodeficiency virus type 1 and type 2 RNA, and Brucella, Schistosoma, and toxoplasma antibodies. Venereal Disease Research Laboratory (VDRL) and rapid plasma regain (RPR) test results were negative. Cerebrospinal fluid (CSF) analysis revealed clear fluid and normal pressure and biochemistry, except for elevated protein concentration (0.48 g/L) (normal range, 0.15-0.45 g/L). There were 43 leukocytes/µL (99% lymphocytes) (normal range, 0-5 leukocytes/µL; lymphocytes range, 40%-80%), with no atypical or malignant cells. CSF Gram staining, acid-fast staining, cryptococcal antigen, varicella-zoster virus polymerase chain reaction (PCR), herpes simplex virus PCR, VDRL, and RPR test results were negative. CSF cultures did not show any evidence of growth of bacteria, fungi, or acid-fast bacillus. CSF flow cytometry did not show a monoclonal lymphoid population. No CSF oligoclonal bands were detected. Conventional brain MRI with intravenous administration of contrast material and perfusion study were performed and included different sequences (Figs 1-3).

Case Report: A Case With MOGAD and Anti-NMDAR Encephalitis Overlapping Syndrome Mimicing Radiological Characteristics of CLIPPERS

Herein, we reported a case of a young man diagnosed with MNOS (anti-myelin oligodendrocyte glycoprotein associated disease (MOGAD) and anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis overlapping syndrome, i.e., MNOS), whose imaging findings in magnetic resonance imaging (MRI) mimicked chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS). We reported a case of refractory anti-NMDAR encephalitis that recurred after standard first-line and second-line treatment. The patient presented with CLIPPERS on imaging at recent hospital admission, and his MOG antibodies were seropositive. After intravenous methylprednisolone (IVMP) treatment, the patient’s symptoms were significantly alleviated. In this case, we demonstrated that MNOS could mimic the radiological characteristics of CLIPPERS. Future studies should focus on the diagnosis and treatment of antibody overlap syndrome.

Autoimmune diseases of the brain, imaging and clinical review

There is an extensive spectrum of autoimmune entities that can involve the central nervous system, which has expanded with the emergence of new imaging modalities and several clinicopathologic entities. Clinical presentation is usually non-specific, and imaging has a critical role in the workup of these diseases. Immune-mediated diseases of the brain are not common in daily practice for radiologists and, except for a few of them such as multiple sclerosis, there is a vague understanding about differentiating them from each other based on the radiological findings. In this review, we aim to provide a practical diagnostic approach based on the unique radiological findings for each disease. We hope our diagnostic approach will help radiologists expand their basic understanding of the discussed disease entities and narrow the differential diagnosis in specific clinical scenarios. An understanding of unique imaging features of these disorders, along with laboratory evaluation, may enable clinicians to decrease the need for tissue biopsy.

Magnetic Resonance Imaging of Autoimmune Demyelinating Diseases as a Diagnostic Challenge for Radiologists: Report of Two Cases and Literature Review

The magnetic resonance characteristics of autoimmune demyelinating diseases are complex and represent a challenge for the radiologist. In this study we presented two different cases of detected autoimmune demyelinating diseases: one case of acute disseminated encephalomyelitis and one case of neuromyelitis optica, respectively. Expected and unexpected findings of magnetic resonance imaging examination for autoimmune demyelinating diseases were reported in order to provide a valuable approach for diagnosis. In particular, we highlight, review and discuss the presence of several uncommon imaging findings which could lead to a misinterpretation. The integration of magnetic resonance imaging findings with clinical and laboratory data is necessary to provide a valuable diagnosis.

Branch-like enhancement on contrast enhanced MRI is a specific finding of cerebellar lymphoma compared with other pathologies

Branch-like enhancement (BLE) on contrast-enhanced (CE) magnetic resonance imaging (MRI) was found to be effective in differentiating primary central nervous system lymphoma (PCNSL) from high-grade glioma (HGG) in the cerebellum. However, whether it can be applied to assessments of secondary central nervous system lymphoma (SCNSL), or other cerebellar lesions is unknown. Hence, we retrospectively reviewed cerebellar masses to investigate the use of BLE in differentiating cerebellar lymphoma (CL), both primary and secondary, from other lesions. Two reviewers qualitatively evaluated the presence and degree of BLE on CE-T1 weighted imaging (T1WI). If multiple views were available, we determined the view in which BLE was the most visible. Seventy-five patients with the following pathologies were identified:17 patients with CL, 30 patients with metastasis, 12 patients with hemangioblastoma, 9 patients with HGG, and 7 patients with others. Twelve patients presented with PCNSL and five with SCNSL. Of 17 patients with CL, 15 (88%) had BLE, whereas three (5%) out of 58 patients in the non-CL group showed BLE. In patients who underwent three-dimensional-CE-T1WI, BLE was the most visible on the sagittal image. In conclusion, BLE is a highly specific finding for CL and the sagittal image is important in evaluating this finding.

Brain biopsy in patients with CLIPPERS syndrome: why and when

CLIPPERS (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids) is an inflammatory disorder of the central nervous system (CNS), predominantly involving the brainstem with a characteristic magnetic resonance imaging (MRI) appearance and clinical and radiological responsiveness to glucocorticosteroids. Yet diagnostic biomarkers are missing and other immune-mediated, (para-) infectious and malignant causes mimic CLIPPERS-like MRI presentations. We report the case of a 51-year-old male patient with CLIPPERS who repeatedly responded well to high-dose corticosteroids. After 7 months, however, treatment failed, and he had a biopsy-confirmed diagnosis of a CNS B-cell lymphoma. Clinical and MRI signs of CLIPPERS include a wide spectrum of differential diagnoses which often arise only later during the course of disease. Similar to the case presented here, delayed diagnosis and specific therapy may contribute to an unfavorable outcome. Hence, we propose that in the absence of other diagnostic markers, brain biopsy should be performed as early as possible in CLIPPERS patients.

Chronic Lymphocytic Inflammation With Pontine Perivascular Enhancement Responsive to Steroids: An Acute Presentation

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare disease with an unknown etiology which most commonly results in subacute diplopia and ataxia. Diagnosis is achieved through a triad of the following findings: lymphocytic pleocytosis with increased CD4+ T cells on cerebrospinal fluid (CSF) analysis; perivascular punctate and curvilinear hemorrhages in the pons, medulla, or cerebellum on magnetic resonance imaging (MRI) with contrast; and the cessation of symptoms after the initiation of corticosteroids. Here, we report the case of a 23-year-old male who presented with non-specific signs and symptoms, including diffuse weakness in all limbs, ataxia, and slurred speech. The diagnosis was achieved through a contrast MRI of the brain, suggestive of brainstem encephalitis, and a CSF analysis, which revealed elevated glucose and protein levels. Intravenous methylprednisolone was administered for five days and resulted in acute improvement of the patient’s clinical status. Repeat CSF analysis and MRI of the brain with contrast two weeks later showed resolution of previous findings. CLIPPERS syndrome is a newly identified disease thought to cause a predominantly inflammatory reaction in the pons, medulla, cerebellum, and supratentorial region. MRI with contrast tends to reveal a “salt and pepper appearance” in a punctate and curvilinear fashion. The hallmark of treatment is corticosteroid therapy, and discontinuation of therapy should be done with caution as relapse of the syndrome with corticosteroid withdrawal has been documented.

Autoimmune glial fibrillary acidic protein astrocytopathy resembling isolated central nervous system lymphomatoid granulomatosis

We report two patients with meningoencephalomyelitis without evidence of extra central nervous system (CNS) involvement. Brain MRI showed linear perivascular radial gadolinium enhancement patterns and spinal cord MRI showed longitudinal extensive T2-hyperintensity lesions. Pathological findings from brain biopsies were angiocentric T-cell predominant lymphoid infiltrates that lacked Epstein-Barr virus-positive atypical B cells. The patients were initially suspected to have isolated CNS-lymphomatoid granulomatosis (LYG). Thereafter, glial fibrillary acidic protein (GFAP)-immunoglobulin G were detected in their cerebrospinal fluid. This finding suggested autoimmune GFAP astrocytopathy. We speculate there is a link between isolated CNS-LYG and autoimmune GFAP astrocytopathy.

Autoimmune Meningitis and Encephalitis

Meningitis and encephalitis are inflammatory syndromes of the meninges and brain parenchyma, respectively, and may be identified either by finding definitive evidence of inflammation on tissue pathology or by cerebrocpinal fluid (CSF) analysis showing pleocytosis or intrathecal antibody synthesis. Clinicians evaluating undifferentiated meningitis or encephalitis should simultaneously consider autoimmune, infectious, and neoplastic causes, using patient risk factors, clinical syndrome, and diagnostic results including CSF and MRI findings to narrow the differential diagnosis. If an autoimmune cause is favored, an important early diagnostic question is whether a specific neural autoantibody is likely to be identified.

MRI Patterns in Pediatric CNS Hemophagocytic Lymphohistiocytosis

BACKGROUND AND PURPOSE

Neuroimaging has an important role in detecting CNS involvement in children with systemic or CNS isolated hemophagocytic lymphohistiocytosis. We characterized a cohort of pediatric patients with CNS hemophagocytic lymphohistiocytosis focusing on neuroradiologic features and assessed whether distinct MR imaging patterns and genotype correlations can be recognized.

MATERIALS AND METHODS

We retrospectively enrolled consecutive pediatric patients diagnosed with hemophagocytic lymphohistiocytosis with CNS involvement treated at 2 pediatric neurology centers between 2010 and 2018. Clinical and MR imaging data were analyzed.

RESULTS

Fifty-seven children (40 primary, 70%) with a median age of 36 months (interquartile range, 5.5-80.8 months) were included. One hundred twenty-three MR imaging studies were assessed, and 2 broad imaging patterns were identified. Pattern 1 (significant parenchymal disease, 32/57, 56%) was seen in older children (P = .004) with worse clinical profiles. It had 3 onset subpatterns: multifocal white matter lesions (21/32, 66%), brainstem predominant disease (5, 15%), and cerebellitis (6, 19%). All patients with the brainstem pattern failed to meet the radiologic criteria for chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids. An attenuated imaging phenotype (pattern 2) was seen in 25 patients (44%, 30 studies) and was associated with younger age.

CONCLUSIONS

Distinct MR imaging patterns correlating with clinical phenotypes and possible genetic underpinnings were recognized in this cohort of pediatric CNS hemophagocytic lymphohistiocytosis. Disruptive mutations and missense mutations with absent protein expression correlate with a younger onset age. Children with brainstem and cerebellitis patterns and a negative etiologic work-up require directed assessment for CNS hemophagocytic lymphohistiocytosis.

Isolated central nervous system familial hemophagocytic lymphohistiocytosis (fHLH) presenting as a mimic of demyelination in children

Isolated central nervous system (CNS) presentations of haemophagocytic lymphohistiocytosis (HLH), traditionally a systemic inflammatory condition, have been reported in adults and children. We identified nine patients with a diagnosis of isolated CNS familial hemophagocytic lymphohistiocytosis (fHLH) with symptom onset <18 years of age, and one asymptomatic sibling. Children with atypical chronic/recurrent CNS inflammation should be considered for immunological and genetic panel testing for fHLH even in the absence of any systemic inflammatory features. Despite haematopoietic stem cell transplantation (HSCT) being a mainstay of treatment, treatment failure and high morbidity and mortality post-HSCT suggest that alternative immune therapies may be worth considering.

Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids May Extend above and below Pons and Is Associated with Other Autoimmune Diseases

Many autoimmune diseases can affect the central nervous system, and their varying clinical presentations often confound a straightforward diagnosis. In this report, we describe a unique presentation of CLIPPERS syndrome. To our knowledge, this is the first case to demonstrate significant supratentorial involvement with symmetric and non-confluent lesions in the medial orbitofrontal cortex; additionally, this is the second case to describe an association between diagnoses of hypothyroidism and CLIPPERS.

CLIPPERS, chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids: A challenge in neurological practice, clinical landmarks (Review)

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a relatively newly discovered and characterized condition affecting the central nervous system (CNS) that involves the brainstem almost ubiquitously and that focuses primarily on the pons. Characteristically, CLIPPERS represents a combination of clinical symptoms related to the pathology of the brainstem in particular and has a characteristic appearance on magnetic resonance imaging (MRI), with punctate and curvilinear gadolinium enhancement 'peppering' the pons. The lesions can be viewed via neuroimaging with a predominance in the pons and adjacent rhombencephalic structures, such as the cerebellar peduncles, cerebellum, medulla, and middle brain. These lesions may also spread and appear in other areas of the brain such as the thalamus or white matter. As the name suggests, this clinical syndrome responds to immunosuppressive treatment based on glucocorticosteroids (GCSs), expressed as both clinical and radiological improvements. Support for this treatment is required for a long period, since exacerbations may occur without. Thus, the diagnosis of CLIPPERS has garnered increased attention from clinicians and the active exclusion of differential alternative diagnoses is needed. A specific biomarker of serum or cerebrospinal fluid (CSF) for this condition has not been discovered. The pathophysiology of this condition is not fully elucidated, and it is not yet clear whether CLIPPERS is a disease in its own right or is the culmination of several already known syndromes. Clinicians and radiologists should pay close attention to this condition as it is relatively easy to treat and patients can benefit from the early introduction of GCSs, which can produce significant results through long-term immunosuppression. Taking into account previous reports in the literature, which currently include over 50 cases reported as CLIPPERS, this analysis addressed the clinical features, and paraclinical and differential diagnoses of cases described in the literature.

Supratentorial lymphocytic inflammation with parenchymal perivascular enhancement responsive to steroids: A case report and literature review

Background:

Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids is a rare disorder that presents with subacute brainstem symptoms such as ataxia, facial paresthesias, and episodic diplopia, thought to be due to a T-cell medicated perivascular inflammatory process. A supratentorial variant, Supratentorial Lymphocytic Inflammation with Parenchymal Perivascular Enhancement Responsive to Steroids (SLIPPERS), has been described in only three patients.

Case Description:

A 71-year-old male presented with word-finding difficulties, confusion, and left leg weakness. Radiographic workup demonstrated multiple supratentorial ring-enhancing lesions. PET/CT demonstrated hypermetabolism and susceptibility-weighted imaging demonstrated a hemorrhagic component. Frozen pathology revealed a predominately T-cell and monocyte inflammatory infiltrate. He demonstrated interval improvement to dexamethasone therapy, but then demonstrated worsening of his symptoms following discontinuation.

Conclusion:

Given his dramatic response to corticosteroids, he was diagnosed with SLIPPERS. SLIPPERS is an underrecognized diagnostic entity to consider in patients with ring-enhancing lesions and can present with hypermetabolic lesions on PET/CT.

CLIPPERS associated with hypersensitivity pneumonitis: a case report

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare and poorly understood pathology. In this case report we present a 51-year-old male that presented with neurological deficits with recent hypersensitivity pneumonitis. Imaging studies showed multiple punctate enhancing lesions involving the brainstem. After initiation of corticosteroids his symptoms improved, with a decrease in size of his lesions 6-months after his initial presentation. Due to its misdiagnosis, we propose the use of diagnostic criteria, described on this case report, for prompt treatment to avoid neurological sequelae.