Primary and secondary central nervous system vasculitis

Pediatric neuroinflammatory diseases in the intensive care unit

Inflammatory disorders of the central nervous system (CNS) include a wide spectrum of autoimmune, autoinflammatory, and paraneoplastic diseases. While many affected patients require acute hospital admission, a subset may present with severe neurological symptoms requiring intensive care unit (ICU) escalation due to disordered consciousness, respiratory failure, status epilepticus, intracranial hypertension, and/or severe autonomic dysregulation.

Imaging of Childhood Cerebral Vasculitis

Childhood cerebral vasculitis is a condition that affects the blood vessels in the brain of children and is rare but life-threatening. Imaging plays a crucial role in the diagnosis and monitoring of the disease. This article describes the classification, diagnostic algorithm, and various imaging modalities used in the evaluation of childhood cerebral vasculitis and the imaging findings associated with primary and secondary vasculitis. Understanding the imaging features of this condition can assist in early diagnosis, effective treatment, and improve outcomes.

Neuropsychiatric involvement in juvenile-onset systemic lupus erythematosus (jSLE)

Systemic lupus erythematosus (SLE) is a rare autoimmune/inflammatory disease with significant morbidity and mortality. Approximately 15-20% of SLE patients develop the disease during childhood or adolescence (juvenile-onset SLE/jSLE). Patients with jSLE exhibit more variable and severe disease when compared to patients with disease-onset during adulthood. Neuropsychiatric (NP) involvement is a clinically heterogenous and potentially severe complication. Published reports on the incidence and prevalence of NP-jSLE are scarce, and the exact pathophysiology is poorly understood.This manuscript provides a review of the existing literature, suggesting NP involvement in 13.5-51% of jSLE patients. Among patients with NP-jSLE affecting the CNS, we propose two main subgroups: (i) a chronic progressive, predominantly type 1 interferon-driven form that poorly responds to currently used treatments, and (ii) an acutely aggressive form that usually presents early during the disease that may be primarily mediated by auto-reactive effector lymphocytes. While this hypothesis requires to be tested in large collaborative international cohort studies, it may offer future patient stratification and individualised care.

Childhood Cerebral Vasculitis : A Multidisciplinary Approach

Cerebral vasculitis is increasingly recognized as a common cause of pediatric arterial stroke. It can present with focal neurological deficits, psychiatric manifestations, seizures, and encephalopathy. The etiopathogenesis of childhood cerebral vasculitis (CCV) is multifactorial, making an inclusive classification challenging. In this review, we describe the common and uncommon CCV with a comprehensive discussion of etiopathogenesis, the role of various imaging modalities, and advanced techniques in diagnosing CCV. We also highlight the implications of relevant clinical, laboratory, and genetic findings to reach the final diagnosis. Based on the clinicoradiological findings, a stepwise diagnostic approach is proposed to facilitate CCV diagnosis and rule out potential mimics. Identification of key clinical manifestations, pertinent blood and cerebrospinal fluid results, and evaluation of central nervous system vessels for common and disease-specific findings will be emphasized. We discuss the role of magnetic resonance imaging, MR angiography, and vessel wall imaging as the imaging investigation of choice, and reservation of catheter angiography as a problem-solving tool. We emphasize the utility of brain and leptomeningeal biopsy for diagnosis and exclusion of imitators and masqueraders.

Inpatient Management of Encephalopathy

Unexplained encephalopathy is a common occurrence in tertiary care centers and neurologic disorders should be considered after ruling out the infectious, toxic and metabolic etiologies. Neuroimaging combined with a thorough history and examination is often helpful in ruling out stroke and fulminant demyelinating encephalopathies. Autoimmune encephalopathy should be suspected in any patient with unexplained acute or subacute onset encephalopathy or rapidly progressing dementia. Anti-N-methyl-D-aspartate receptor (NMDA-R) encephalitis is the most studied form and Hashimoto encephalitis is the most controversial form of autoimmune encephalopathies. Obtaining a combined serum and Cerebrospinal fluid (CSF) autoantibody testing will increase the diagnostic yield of autoimmune and paraneoplastic encephalitis. When diagnosing NMDA receptor antibodies CSF is always more sensitive than serum and in contrast, voltage-gated potassium channel (VGKC) complex antibodies are more readily detectable in serum than in CSF. Neural-specific antibody tests frequently result after several weeks and treatment should be administered without a significant delay to prevent brain damage. Autoimmune encephalitis is often treatment responsive when immunotherapy (glucocorticoids, intravenous immune globulin, plasma exchange) is used in various combinations. The absence of inflammatory markers and autoantibodies in the serum or CSF may not rule out the possibility of paraneoplastic encephalopathies.

Inflammatory Diseases of the Central Nervous System

Pediatric neuroinflammatory conditions are a complex group of disorders with a wide range of clinical presentations. Patients can present with a combination of focal neurologic deficits, encephalopathy, seizures, movement disorders, or psychiatric manifestations. There are several ways that pediatric neuroinflammatory conditions can be classified, including clinical presentation, pathophysiologic mechanism, and imaging and laboratory findings. In this article, we group these conditions into acquired demyelinating diseases, immune-mediated epilepsies/encephalopathies, primary rheumatologic conditions with central nervous system (CNS) manifestations, CNS vasculitis, and neurodegenerative/genetic conditions with immune-mediated pathophysiology and discuss epidemiology, pathophysiology, clinical presentation, treatment, and prognosis of each disorder.

Clinical Perspective on Primary Angiitis of the Central Nervous System in Childhood (cPACNS)

Non-arteriosclerotic arteriopathies have emerged as important underlying pathomechanism in pediatric arterial ischemic stroke (AIS). The pathogenesis and classification of cerebral arteriopathies in childhood are heterogeneous. Different classifications base on (i) the anatomic site; (ii) the distribution and size of the affected vessel; (iii) the time course, for example, transient vs. progressive, monophasic vs. recurrent; (iv) the putative pathogenesis; (v) the magnetic resonance imaging morphology of the vasculopathies. Inflammation affecting the cerebral vessels is increasingly recognized as common cause of pediatric AIS. Primary cerebral vasculitis or primary angiitis of the central nervous system (CNS) in childhood (cPACNS) is an important differential diagnosis in pediatric AIS. Primary angiitis of the CNS is a rare disorder, and the pathogenesis is poorly understood so far. The current classification of cPACNS is based on the affected cerebral vessel size, the disease course, and angiographic pattern. Two large subtypes are currently recognized comprising large- and medium-sized vessel CNS vasculitis referred to as angiography-positive cPACNS and angiography-negative small vessel cPACNS. As the clinical manifestations of cPACNS are rather diverse, precise diagnosis can be challenging for the treating pediatrician because of the lack of vital laboratory tests or imaging features. Initial misdiagnosis is common because of overlapping phenotypes and pediatric AIS mimics. As untreated cPACNS is associated with a high morbidity and mortality, timely diagnosis, and induction of immunomodulatory and symptomatic therapy are essential. Survival and neurological outcome depend on early diagnosis and prompt therapy. Primary angiitis of the central nervous system in childhood differs in several aspects from primary cerebral angiitis in adults. The aim of this article is to give a brief comprehensive summary on pediatric primary cerebral vasculitis focusing on the clinical perspective regarding the classification, the putative pathogenesis, the disease course, the diagnostic tools, and emerging treatment options. A modified terminology for clinical practice is discussed.

A Closer Look at Angiitis of the central nervous system

Angiitis of the central nervous system (ACNS) is a rather new disease entity that is defined as vascular inflammation limited to the central nervous system and was formally nominated in 1959. Etiologically, it can be divided into primary and secondary ACNS. However, the potential pathogenesis of ACNS remains unclear. The clinical presentation is variable, and there is no consensus concerning its diagnosis and management. Although the incidence is relatively low, ACNS is still a life-threatening condition. It is essential to get a comprehensive and updated understanding of the disease. In this paper, we reviewed the history, definition, classification, pathogenesis, and clinical manifestations of ACNS. In addition, we focused on the latest investigations and viewpoints regarding the diagnosis and treatment of ACNS.

Strategies for treatment of childhood primary angiitis of the central nervous system

Objective

Childhood primary angiitis of the CNS (cPACNS) is a devastating neurologic disease. No standardized treatment protocols exist, and evidence is limited to open-label cohort studies and case reports. The aim of this review is to summarize the literature and provide informed treatment recommendations.

Methods

A scoping review of cPACNS literature from January 2000 to December 2018 was conducted using Ovid, MEDLINE, PubMed, Embase, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Vasculitis Foundation, European Vasculitis Society, CanVasc, Google Scholar, and Web of Science. Potentially relevant articles were selected for full-text review using the STROBE checklist if they met the following inclusion criteria: (1) reported treatment, (2) addressed pediatrics, (3) focused on the disease of interest, (4) included ≥5 patients, (5) original research, and (6) full-length articles. Reviews, expert opinions, editorials, case reports with <5 patients, articles lacking treatment information, or non-English articles were excluded. A standardized assessment tool measured study quality. Treatment and outcomes were summarized.

Results

Of 2,597 articles screened, 7 studies were deemed high quality. No trials were available so no meta-analysis was possible. Overall, treatment strategies recommended are induction with acute antithrombotic therapy subsequently followed by high-dose oral prednisone taper over 3–12 months and long-term platelet therapy. In angiography-positive progressive–cPACNS and angiography-negative–cPACNS, we also recommend 6 months of IV cyclophosphamide therapy, with trimethoprim/sulfamethoxazole as part of induction, and maintenance therapy with mycophenolate mofetil/mycophenolic acid.

Conclusion

No grade-A evidence exists; however, this review provides recommendations for treatment of cPACNS.

Recurrent arterial ischemic stroke with good response to mycophenolate mofetil

BACKGROUND

Arterial ischemic stroke is rare in childhood. Often, the diagnosis is made after considerable delay. A thorough workup to pinpoint the underlying etiology is necessary, as a correct diagnosis is the determining factor in treatment decision. In case of primary angiitis of the central nervous system, treatment with corticosteroids and immunosuppressive agents is indicated.

CASE STUDY

We described an eleven-year-old boy who presented at the age of six years with left hemiparesis and hemianopia. Cerebral imaging showed acute ischemia in the right posterior cerebral artery territory. Extensive workup was negative. In the following eight months, he had recurrent strokes on three separate occasions due to progressive arteriopathy involving multiple large- and medium-sized vessels. A presumed diagnosis of primary angiitis of the central nervous system was made. Pulse intravenous methylprednisolone therapy was started followed by oral prednisolone. After the fourth stroke, a six-month treatment with cyclophosphamide was given which was followed by maintenance treatment with azathioprine. Shortly after cessation of corticosteroids and cyclophosphamide the subject relapsed. Cyclophosphamide was restarted in combination with corticosteroids and subsequently replaced by mycophenolate mofetil. Under mycophenolate mofetil maintenance treatment combined with low-dose corticosteroids, the patient achieved disease control with a relapse-free period of more than four years.

CONCLUSION

A guideline for current treatment of relapsing central nervous system angiitis in childhood is missing in the literature. We describe a subject with multiple relapses despite treatment with corticosteroids and immunosuppressive agents, and stabilization of his clinical condition and of the radiological signs under mycophenolate mofetil treatment.

Vasculitis in Juvenile-Onset Systemic Lupus Erythematosus

Juvenile-onset systemic lupus erythematosus (JSLE) is a rare, heterogeneous multisystem autoimmune disease that can affect any organ, and present with diverse clinical and serological manifestations. Vasculitis can be a feature of JSLE. It more commonly presents as cutaneous vasculitis than visceral vasculitis, which can affect the central nervous system, peripheral nervous system, lungs, gut, kidneys, heart, and large vessels. The incidence and prevalence of vasculitis in JSLE has not been well described to date. Symptoms of vasculitis can be non-specific and overlap with other features of JSLE, requiring careful consideration for the diagnosis to be achieved and promptly treated. Biopsies are often required to make a definitive diagnosis and differentiate JSLE related vasculitis from other manifestations of JSLE, vasculopathies, and JSLE related antiphospholipid syndrome. Visceral vasculitis can be life threatening, and its presence at the time of JSLE diagnosis is associated with permanent organ damage, which further highlights the importance of prompt recognition and treatment. This review will focus on the presentation, diagnosis, management and outcomes of vasculitis in JSLE, highlighting gaps in the current evidence base.

Imaging of Childhood Inflammatory Brain Diseases

Brain has been considered as an immune-privileged site for centuries owing to the presence of blood-brain barrier, absent lymphatic drainage, and antigen-presenting cells. However, the present prevailing concept is of immune surveillance where brain is continuously surveyed by immune cells. However, the presence of immune cells in central nervous system (CNS) brings the risk of inflammation and autoimmunity involving both T and B cell mediated pathways. These mechanisms form the underlying pathology in a wide spectrum of pediatric CNS diseases manifesting as acquired neurological deficits. Overlapping, heterogenous, and ambiguous clinical features often delays the diagnosis. Although not always pathognomonic, magnetic resonance imaging can be an important biomarker leading to early diagnosis, prognostication, and systematic follow-up pf these diseases. This review describes the spectrum of different pediatric inflammatory disorders and their pertinent imaging features illustrated with clinical examples.

Central nervous system vasculitis in adults and children

Primary angiitis of the central nervous system (PACNS) is an inflammatory brain disease targeting the cerebral blood vessels, leading to a wide spectrum of signs and symptoms, including neurologic deficits, cognitive dysfunction, and psychiatric symptoms. The inflammation could be reversible if diagnosed and treated early. The diagnosis requires the careful consideration and rapid evaluation of systemic underlying conditions and disease mimics. The differential diagnosis is distinctly different for angiography-positive and -negative PACNS subtypes and differs depending on age, so there is childhood PACNS or adult PACNS. Distinct disease subtypes have been described, with characteristic disease course, neuroimaging findings, and histopathologic features. Novel and traditional biomarkers, including von Willebrand factor antigen and cytokine levels, can help diagnose, and define subtype and disease activity. Treatment of PACNS should be tailored to the disease subtypes and clinical symptoms. Beyond immunosuppression it should include medications to control symptoms in order to support and enhance the child's or adult's ability to actively participate in rehabilitation. The mortality of PACNS has decreased; studies determining the morbidity and its determinants are urgently needed.

Primary angiitis of the central nervous system: A rare and reversible cause of childhood stroke

Childhood primary angiitis of the central nervous system (cPACNS) is a rare and a potentially fatal cause of childhood stroke. The disease poses a diagnostic dilemma for the clinicians due to overlapping and varied clinical manifestations such as headache, focal acute neurological deficits, cognitive impairment, or encephalopathy. We report a young boy who presented with low-grade fever and headache but rapidly progressed to develop acute encephalopathy and quadriparesis with multiple cranial nerve palsies, masquerading as acute disseminated encephalomyelitis. The neuroimaging was suggestive of vasculitis. He was diagnosed as cPACNS and recovered with immunosuppressive therapy.

Primary angiitis of the central nervous system in adults and children

Primary angiitis of the central nervous system (PACNS) is a rare disease, although it is increasingly recognized both in adults and children. Little is known about pathogenesis, but efforts at classification into subtypes are being made, and the distinction of PACNS from reversible cerebral vasoconstriction syndrome has been a major advance. The prognosis for improvement, or at least stabilization, of neurologic function is good with prompt and aggressive treatment, but the diagnosis continues to be challenging. Refinement of treatment strategies is needed. Multicenter collaboration may be crucial to make additional progress via randomized trials.

Imaging of systemic vasculitis in childhood

The term "systemic vasculitis" encompasses a diverse set of diseases linked by the presence of blood-vessel inflammation that are often associated with critical complications. These diseases are uncommon in childhood and are frequently subjected to a delayed diagnosis. Although the diagnosis and treatment may be similar for adult and childhood systemic vasculitides, the prevalence and classification vary according to the age group under investigation. For example, Kawasaki disease affects children while it is rarely encountered in adults. In 2006, the European League Against Rheumatism (EULAR) and the Pediatric Rheumatology European Society (PReS) proposed a classification system for childhood vasculitis adopting the system devised in the Chapel Hill Consensus Conference in 1993, which categorizes vasculitides according to the predominant size of the involved blood vessels into small, medium and large vessel diseases. Currently, medical imaging has a pivotal role in the diagnosis of vasculitis given recent developments in the imaging of blood vessels. For example, early diagnosis of coronary artery aneurysms, a serious complication of Kawasaki disease, is now possible by magnetic resonance imaging (MRI) of the heart and multidetector computed tomography (MDCT); positron emission tomography/CT (PET/CT) helps to assess active vascular inflammation in Takayasu arteritis. Our review offers a unique approach using the integration of the proposed classification criteria for common systemic childhood vasculitides with their most frequent imaging findings, along with differential diagnoses and an algorithm for diagnosis based on common findings. It should help radiologists and clinicians reach an early diagnosis, therefore facilitating the ultimate goal of proper management of affected children.

Childhood inflammatory brain diseases: pathogenesis, diagnosis and therapy

Inflammatory brain diseases (IBrainDs) are a leading cause of devastating neurological deficits or neuropsychiatric syndromes in previously healthy children. The spectrum is expanding rapidly and new disease entities have been discovered in the last decade. IBrainD can occur as a primary disease or may occur secondary to an underlying cause. This review focuses on the clinical presentation, diagnostic features, pathology and histology characteristics and treatment of the primary childhood IBrainDs.

Development, maintenance and disruption of the blood-brain barrier

The interface between the blood circulation and the neural tissue features unique characteristics that are encompassed by the term 'blood-brain barrier' (BBB). The main functions of this barrier, namely maintenance of brain homeostasis, regulation of influx and efflux transport, and protection from harm, are determined by its specialized multicellular structure. Every constituent cell type makes an indispensable contribution to the BBB's integrity. But if one member of the BBB fails, and as a result the barrier breaks down, there can be dramatic consequences and neuroinflammation and neurodegeneration can occur. In this Review, we highlight recently gained mechanistic insights into the development and maintenance of the BBB. We then discuss how BBB disruption can cause or contribute to neurological disease. Finally, we examine how this knowledge can be used to explore new possibilities for BBB repair.