Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS) with Limbic Encephalitis

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.

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.

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.

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.

[A case of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) without relapse after early steroid treatment]

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a brainstem predominant lymphocytic inflammatory disease, which often relapses without oral immunosuppressants. This report describes a 37-year-old male case of CLIPPERS without relapse for 1 year after early steroid treatment. He was admitted to our hospital because of sensory disturbance in the left side of his body and ataxic gait. Gadolinium-enhanced T₁-weighted MRI revealed multiple punctate and curvilinear enhancements in the pons and right middle cerebellar peduncle. We started treatment with high-dose intravenous methylprednisolone (IVMP) therapy on the 20th day of the illness. His neurological symptoms dramatically improved. Follow-up MRI showed that the enhancing lesions disappeared. We diagnosed him with CLIPPERS based on the clinical course, radiological findings, and steroid response. He did not take any oral immunosuppressant after discharge. However, there was no clinical and radiological relapse for 1 year after the IVMP therapy. Although this case requires careful follow-up because of recurrence risk, early steroid treatment was possibly related to 1-year remission.

Case report with review of literature for the dilemma of diagnosis of CLIPPERS

CLIPPER is a chronic inflammatory disorder in the CNS, which is characterized by MRI appearance of punctate and curvilinear gadolinium enhancement that involve the pons and the cerebellum and exquisite response to steroid. We report a patient presented with clinical and radiological features suggestive of CLIPPERS. However, despite the initial response to steroid, there were dramatic changes in the course of his disease that were conducive to considering another diagnosis. We searched PubMed using word (CLIPPERS) till December 2018. The pathogenesis, clinical manifestations, imaging features, treatment and prognosis of this disorder are summarized. A review of the literature for cases of CLIPPERS demonstrated a subset of patients who later discovered to have an alternative pathology. Indeed, clinicians should be scrupulous to diagnose this disease based solely on the clinical and radiological findings and they should have a lower threshold of having a brain biopsy.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) in limited cutaneous sclerosis: a rare disease combination

A 26-year-old patient of limited cutaneous sclerosis presented to us with insidious-onset posterior fossa symptoms of headache, vomiting, vertigo and gait imbalance, progressing over a period of 3 weeks. A diagnosis of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids was made by combining the clinical features with radiological evidence showing punctate infiltration of the pons, brainstem and cerebellum. Relevant differentials in the form of neurosarcoid, infections, central nervous system (CNS) lymphoma and Neuro-Behcet's disease were ruled out by history and investigations. The patient responded dramatically to steroid therapy, and had no neurological deficits after 18 months of follow-up. This case highlights the rare association of a not-so-common immunological disease with a rare neurological disease.