Diagnostic Yield and Safety of Brain Biopsy for Suspected Primary Central Nervous System Angiitis

European Stroke Organisation (ESO) guidelines on Primary Angiitis of the Central Nervous System (PACNS)

The European Stroke Organisation (ESO) guideline on Primary Angiitis of the Central Nervous System (PACNS), developed according to ESO standard operating procedures (SOP) and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology, was elaborated to assist clinicians in the diagnostic and treatment pathway of patients with PACNS in their decision making. A working group involving vascular neurologists, neuroradiologists, rheumatologists, a neuropathologist and a methodologist identified 17 relevant clinical questions; these were addressed according to the patient/population, intervention, comparison and outcomes (PICO) framework and systematic literature reviews were performed. Notably, each PICO was addressed with respect to large vessel (LV)-PACNS and small vessel (SV)-PACNS. Data to answer many questions were scarce or lacking and the quality of evidence was very low overall, so, for some PICOs, the recommendations reflect the ongoing uncertainty. When the absence of sufficient evidence precluded recommendations, Expert Consensus Statements were formulated. In some cases, this applied to interventions in the diagnosis and treatment of PACNS which are embedded widely in clinical practice, for example patterns of cerebrospinal fluid (CSF) and Magnetic Resonance Imaging (MRI) abnormalities. CSF analysis for hyperproteinorrachia and pleocytosis does not have evidence supporting their use as diagnostic tools. The working group recommended that caution is employed in the interpretation of non-invasive vascular imaging due to lack of validation and the different sensitivities in comparison with digital subtraction angiography (DSA) and histopathological analyses. Moreover, there is not a neuroimaging pattern specific for PACNS and neurovascular issues are largely underreported in PACNS patients. The group's recommendations on induction and maintenance of treatment and for primary or secondary prevention of vascular events also reflect uncertainty due to lack of evidence. Being uncertain the role and practical usefulness of current diagnostic criteria and being not comparable the main treatment strategies, it is suggested to have a multidisciplinary team approach in an expert center during both work up and management of patients with suspected PACNS. Highlighting the limitations of the currently accepted diagnostic criteria, we hope to facilitate the design of multicenter, prospective clinical studies and trials. A standardization of neuroimaging techniques and reporting to improve the level of evidence underpinning interventions employed in the diagnosis and management of PACNS. We anticipate that this guideline, the first comprehensive European guideline on PACNS management using GRADE methodology, will assist clinicians to choose the most effective management strategy for PACNS.

Central Nervous System Vasculitis: Primary Angiitis of the Central Nervous System and Central Nervous System Manifestations of Systemic Vasculitis

Central nervous system vasculitis (CNSV) is a group of disorders leading to inflammatory vasculopathy within the brain, spinal cord, and leptomeninges. CNSV is divided into primary angiitis of the central nervous system (PACNS) and secondary CNSV based on the underlying etiology. PACNS is a rare inflammatory disorder with poorly understood pathophysiology and heterogeneous and highly variable clinical features. The diagnosis depends on a combination of clinical and laboratory variables, multimodal imaging, and histopathological examination as well as exclusion of mimics. Several systemic vasculitides, infectious etiologies and connective tissue disorders have been shown to cause secondary CNSV and require prompt recognition.

Vessel Wall Imaging in Cryptogenic Stroke

Cryptogenic strokes are symptomatic cerebral ischemic infarcts without a clear etiology identified following standard diagnostic evaluation and currently account for 10% to 40% of stroke cases. Continued research is needed to identify and bridge gaps in knowledge of this stroke grouping. Vessel wall imaging has increasingly shown its utility in the diagnosis and characterization of various vasculopathies. Initial promising evidence suggests rational use of vessel wall imaging in stroke workup may unravel pathologies that otherwise would have been occult and further improve our understanding of underlying disease processes that can translate into improved patient outcomes and secondary stroke prevention.

Primary central nervous system vasculitis: a diagnostic and therapeutic challenge. A series of 7 patients

INTRODUCTION

Primary central nervous system vasculitis (PCNSV) is a rare disease affecting medium- and small-calibre blood vessels of the central nervous system.

OBJECTIVE

The aim of this study was to analyse clinical findings and diagnostic aspects, with special attention to histopathological findings, as well as the treatments used and treatment response in patients diagnosed with PCNSV at our hospital.

PATIENTS AND METHODS

We conducted a retrospective descriptive analysis of patients with a diagnosis of PCNSV at discharge from our centre and meeting the 1988 Calabrese criteria. To this end, we analysed the hospital discharge records of Hospital General Universitario de Castellón between January 2000 and May 2020.

RESULTS

We analysed a series of 7 patients who were admitted with transient focal alterations and other less specific symptoms such as headache or dizziness; diagnosis was based on histological findings in 5 cases and on suggestive arteriographic findings in the remaining 2. Neuroimaging results were pathological in all cases, and CSF analysis detected alterations in 3 of the 5 patients who underwent lumbar puncture. All patients received initial treatment with megadoses of corticosteroids followed by immunosuppressive treatment. Progression was unfavorable in 6 cases, with fatal outcomes in 4.

CONCLUSIONS

Despite the diagnostic challenge of PCNSV, it is essential to attempt to reach a definitive diagnosis using such tools as histopathology and/or arteriography studies, in order to promptly establish appropriate treatment and thus reduce the morbidity and mortality of this condition.

Adult and childhood vasculitis

Vasculitis refers to heterogeneous clinicopathologic disorders that share the histopathology of inflammation of blood vessels. Unrecognized and therefore untreated, vasculitis of the nervous system leads to pervasive injury and disability, making this a disorder of paramount importance to all clinicians. There has been remarkable progress in the pathogenesis, diagnosis, and treatment of primary CNS and PNS vasculitides, predicated on achievement in primary systemic forms. Primary neurological vasculitides can be diagnosed with assurance after intensive evaluation that incudes tissue confirmation whenever possible. Clinicians must choose from among the available immune modulating, suppressive, and targeted immunotherapies to induce and maintain remission status and prevent relapse, unfortunately without the benefit of RCTs, and tempered by the recognition of anticipated medication side effects. It may be said that efforts to define a disease are attempts to understand the very concept of the disease. This has been especially evident in systemic and neurological disorders associated with vasculitis. For the past 100 years, since the first description of granulomatous angiitis of the brain, the CNS vasculitides have captured the attention of generations of clinical investigators around the globe to reach a better understanding of vasculitides involving the central and peripheral nervous system. Since that time it has become increasingly evident that this will necessitate an international collaborative effort.

Diagnostic and therapeutic approach to adult central nervous system vasculitis

The clinical manifestations of central nervous system (CNS) vasculitis are highly variable. In the absence of a positive CNS biopsy, CNS vasculitis is particularly suspected when markers of both vascular disease and inflammation are present. To facilitate the clinical and therapeutic approach to this rare condition, CNS vasculitis can be classified according to the size of the involved vessels. Vascular imaging is used to identify medium vessel disease. Small vessel disease can only be diagnosed with a CNS biopsy. Medium vessel vasculitis usually presents with focal neurological signs, while small vessel vasculitis more often leads to cognitive deficits, altered level of consciousness and seizures. Markers of CNS inflammation include cerebrospinal fluid pleocytosis or elevated protein levels, and vessel wall, parenchymal or leptomeningeal enhancement. The broad range of differential diagnoses of CNS vasculitis can be narrowed based on the disease subtype. Common mimickers of medium vessel vasculitis include intracranial atherosclerosis and reversible cerebral vasoconstriction syndrome. The diagnostic workup aims to answer two questions: is the neurological presentation secondary to a vasculitic process, and if so, is the vasculitis primary (i.e., primary angiitis of the CNS) or secondary (e.g., to a systemic vasculitis, connective tissue disorder, infection, malignancy or drug use)? In primary angiitis of the CNS, glucocorticoids and cyclophosphamide are most often used for induction therapy, but rituximab may be an alternative. Based on the available evidence, all patients should receive maintenance immunosuppression. A multidisciplinary approach is necessary to ensure an accurate and timely diagnosis and to improve outcomes for patients with this potentially devastating condition.

Central and Peripheral Nervous System Complications of Vasculitis Syndromes From Pathology to Bedside: Part 1-Central Nervous System

PURPOSE OF REVIEW

The aim of this review is to provide a comprehensive update on the clinical assessment, diagnosis, complications, and treatment of primary central nervous system vasculitis (PCNSV).

RECENT FINDINGS

The developments in neuroimaging, molecular testing, and cerebral biopsy have enhanced clinical assessment and decision making, providing novel insights to prevent misdiagnosis increasing diagnostic certainty. Advances in imaging techniques visualizing the wall of intracranial vessels have improved the possibility to distinguish inflammatory from non-inflammatory vascular lesions. Large recent studies have revealed a more varied histopathological pictures and disclosed an association with amyloid angiopathy. Unfortunately, therapy remains largely empiric. PCNSV is a heterogeneous group of disorders encompassing different clinical subsets that may differ in terms of prognosis and therapy. Recent evidence has described a more benign course, with good response to therapy. New diagnostic techniques will play soon a pivotal role in the appropriate diagnosis and prompt management of PCNSV.

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.

Primary Angiitis of the CNS: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

To facilitate and improve the diagnostic and therapeutic process by systematically reviewing studies on patients with primary angiitis of the CNS (PACNS).

METHODS

We searched PubMed, looking at the period between 1988 and February 2020. Studies with adult patients with PACNS were included. We extracted and pooled proportions using fixed-effects models. Main outcomes were proportions of patients with certain clinical, imaging, and laboratory characteristics and neurologic outcomes.

RESULTS

We identified 46 cohort studies including a total of 911 patients (41% biopsy confirmed, 43% angiogram confirmed, and 16% without clear assignment to the diagnostic procedure). The most frequent onset symptoms were focal neurologic signs (63%), headache (51%), and cognitive impairment (41%). Biopsy- compared with angiogram-confirmed cases had higher occurrences of cognitive impairment (55% vs 39%) and seizures (36% vs 16%), whereas focal neurologic signs occurred less often (56% vs 95%). CSF abnormalities were present in 75% vs 65% and MRI abnormalities in 97% vs 98% of patients. Digital subtraction angiography was positive in 33% of biopsy confirmed, and biopsy was positive in 8% of angiogram-confirmed cases. In 2 large cohorts, mortality was 23% and 8%, and the relapse rate was 30% and 34%, during a median follow-up of 19 and 57 months, respectively. There are no randomized trials on the treatment of PACNS. The initial treatment usually includes glucocorticoids and cyclophosphamide.

DISCUSSION

PACNS is associated with disabling symptoms, frequent relapses, and significant mortality. Differences in symptoms and neuroimaging results and low overlap between biopsy and angiogram suggest that biopsy- and angiogram-confirmed cases represent different histopathologic types of PACNS. The optimal treatment is unknown.

Fused 18F-Choline PET/MRI: A potential non-invasive biomarker imaging tool in cerebral vasculitis

Primary CNS vasculitis is an inflammatory brain disease commonly misdiagnosed affecting the medium and small vessels of the CNS. Due to its broad and non-specific clinical and radiological manifestations; Its diagnosis remains challenging. New diagnostic tools and biomarkers which increase specificity and facilitate the diagnosis for patients with suspected vasculitis are highly desirable to enable physicians to start therapy that can alter its potential aggressive course like immunosuppressant.

This case report highlights the potential role of ¹⁸F-choline PET/MRI as a novel imaging tool that might help in the right clinical scenario in the diagnosis of this disease.

Furthermore, it speculates on its secondary role in monitoring the response to immunosuppressant therapy.

Current Clinical Applications of Intracranial Vessel Wall MR Imaging

Intracranial vessel wall MR imaging (VWI) is increasingly being used as a valuable adjunct to conventional angiographic imaging techniques. This article will provide an updated review on intracranial VWI protocols and image interpretation. We review VWI technical considerations, describe common VWI imaging features of different intracranial vasculopathies and show illustrative cases. We review the role of VWI for differentiating among steno-occlusive vasculopathies, such as intracranial atherosclerotic plaque, dissections and Moyamoya disease. We also highlight how VWI may be used for the diagnostic work-up and surveillance of patients with vasculitis of the central nervous system and cerebral aneurysms.

Diagnosis and follow-up evaluation of central nervous system vasculitis: an evaluation of vessel-wall MRI findings

Objective

To approach the clinical value of MRI with vessel wall imaging (VWI) in patients with central nervous system vasculitis (CNSV), we analyzed patterns of VWI findings both at the time of initial presentation and during follow-up.

Methods

Stenoocclusive lesions, vessel-wall contrast enhancement (VW-CE) and diffusion-restricted lesions were analyzed in patients with a diagnosis of CNSV. On available VWI follow-up, progression, regression or stability of VW-CE were evaluated and correlated with the clinical status.

Results

Of the 45 patients included, 28 exhibited stenoses visible on MR angiography (MRA-positive) while 17 had no stenosis (MRA-negative). VW-CE was found in 2/17 MRA-negative and all MRA-positive patients (p < 0.05). 79.1% (53/67) of stenoses showed VW-CE. VW-CE was concentric in 88.3% and eccentric in 11.7% of cases. Diffusion-restricted lesions were found more frequently in relation to stenoses with VW-CE than without VW-CE (p < 0.05). 48 VW-CE lesions in 23 patients were followed over a median time of 239.5 days. 13 VW-CE lesions (27.1%) resolved completely, 14 (29.2%) showed partial regression, 17 (35.4%) remained stable and 4 (8.3%) progressed. 22/23 patients received immunosuppressive therapy for the duration of follow-up. Patients with stable or progressive VW-CE were more likely (p < 0.05) to have a relapse (14/30 cases) than patients with partial or complete regression of VW-CE (5/25 cases).

Conclusion

Concentric VW-CE is a common finding in medium/large-sized vessel CNSV. VW-CE might represent active inflammation in certain situations. However, follow-up VWI findings proved ambiguous as persisting VW-CE despite immunosuppressive therapy and clinical remission was a frequent finding.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10683-7.

Novel method using DW-MRI and ADC images to guide stereotactic biopsy for the diagnosis small primary angiitis of the central nervous system: a case report

Objective

To determine the role of diffusion-weighted magnetic resonance imaging (DW-MRI) and apparent diffusion coefficient (ADC) imaging to guide stereotactic biopsy for the diagnosis of intracranial angiitis.

Case presentation

In a 28-year-old woman who had experienced inactive headache and right limbs numbness for 4 days, preoperative magnetic resonance (MR) scanning, enhanced scanning, diffusion tensor imaging, magnetic resonance spectroscopy, diffusion-weighted imaging (DWI), and ADC image scanning were performed. Stereotactic biopsy was performed in one target where the area of edema detected with MR FLAIR, and two targets where the area shown as a high-value and a lower value area in the DWI/ADC image. Pathological examinations together with computed tomographic and enhanced MRI scans were conducted after surgery. A preoperative enhanced MRI scan showed a uniform low-intensity lesion in the patient’s left centrum semiovale, with a volume of 3.1 cm³. The DWI and ADC images showed uneven high-intensity signals and different ADC values in the lesion area, respectively. During surgery, tissues around the lesion and the lesion center were sampled at the three selected targets. The postoperative pathological diagnosis was primary angiitis of the central nervous system, and the patient was given anti-inflammatory medication and hormone therapy. The 3-year follow-up confirmed that the patient had recovered well, with a Glasgow Outcome Scale score of five.

Conclusion

DW-MRI and ADC images can be reliably used to determine the location of small intracranial lesions, and guide stereotactic biopsy to facilitate the diagnosis of primary vasculitis of the central nervous system.

Extended stereotactic brain biopsy in suspected primary central nervous system angiitis: good diagnostic accuracy and high safety

OBJECTIVE

To evaluate the diagnostic accuracy and safety of extended stereotactic brain biopsy (ESBB) in a single center cohort with suspected primary angiitis of the central nervous system (PACNS).

METHODS

A standardized stereotactic biopsy targeting MRI-positive lesions and collecting samples from the meninges and the cortex as well as from the white matter was performed in 23 patients with clinically suspected PACNS between 2010 and 2017. The relationship between biopsy yield and clinical characteristics, cerebrospinal fluid parameters, MR-imaging, time point of biopsy and exact localization of biopsy as well as number of tissue samples were examined.

RESULTS

PACNS was confirmed in 7 of 23 patients (30.4%). Alternative diagnoses were identified in 7 patients (30%). A shorter time period between the onset or worsening of symptoms (p = 0.018) and ESBB significantly increased the diagnostic yield. We observed only minor and transient postoperative complications in 3 patients (13.0%). ESBB led to a direct change of the therapeutic regime in 13 of 23 patients (56.5%). Careful neuropathological analysis furthermore revealed that cortical samples were crucial in obtaining a diagnosis.

CONCLUSION

ESBB is a safe approach with good feasibility, even in critically ill patients, and high diagnostic accuracy in patients with suspected PACNS changing future therapies in 13 of 23 patients (56.5%). Early biopsy after symptom onset/worsening is crucial and (sub)acute MRI-lesions should be targeted with a particular need for biopsy samples from the cortical layer.

Primary CNS vasculitis: A systematic review on clinical characteristics associated with abnormal biopsy and angiography

BACKGROUND

Primary Central Nervous System Vasculitis (PCNSV) remains a diagnostic challenge due to its variable and non-specific clinical manifestations. In part, the clinical heterogeneity of PCNSV may be a consequence of the modalities used for diagnosis; accordingly, there may be different subtypes of PCNSV based on whether the diagnosis was attained by biopsy or cerebral angiography.

OBJECTIVE

To examine the frequency of symptoms, laboratory, and radiological features associated with PCNSV, and to identify distinct clinical features between biopsy and angiography defined PCNSV.

METHODS

We conducted a systematic review of articles published in the English language from 1991 to 2019 that met all diagnostic criteria of PCNSV.

RESULTS

We identified 55 studies, reporting on 907 PCNSV cases. Median age was 45 (IQR 50-36), and 53% were women. Biopsy compared to angiography defined PCNSV had a higher percentage of cognitive impairment, and seizures on initial presentation, and were more likely to have a subacute or progressive onset, abnormal CSF profile, small vessel involvement on angiography, and tumor-like lesions and gadolinium enhancement on MRI. Angiography defined PCNSV were more likely to have an acute onset, focal weakness and visual impairment on initial presentation, medium vessel involvement on angiography, and infarcts on MRI. Brain biopsy was diagnostic of PCNSV in 71% of cases, and demonstrated an alternative diagnosis in 37% of cases, the most common being infection (19%) and lymphoproliferative disease (18%).

CONCLUSIONS

This study provides further evidence that there are distinct clinical features between biopsy and angiography defined PCNSV, which may aid in selecting patients for appropriate invasive tests.

Retrospective Analysis of 28 Cases Confirmed for Primary Angiitis of the Central Nervous System by Biopsy

OBJECTIVE

The present study aimed to summarize the clinical characteristics, therapeutic effects, and long-term prognosis of cases confirmed with primary angiitis of the central nervous system (PACNS) by biopsy, analyze the risk factors, and provide clinical guidance for the diagnosis and treatment of the disease.

METHODS

Retrospective analysis was performed on 28 cases of PACNS confirmed by biopsy, and the age, gender, pathological results, course of the disease, imaging manifestations, treatment, and prognosis of the patients were analyzed and summarized.

RESULTS

The cohort (age 16-60 years) comprised of 16 males. The average time from the visit to diagnosis was 6 months. The first symptom was chronic headache in 18 patients. The pathological results were accompanied by demyelination in 10 cases and glial hyperplasia in 6 cases. A total of 27 patients received treatments including glucocorticoid+cyclophosphamide; of these, 3 cases of craniotomy were improved. Among the 28 patients, 15 patients improved after the treatment, 12 patients had no significant improvement, and 1 patient was deceased. Patients with a long course of the disease before diagnosis, a Karnofsky performance status (KPS) score <60 at the time of diagnosis, a behavioral, cognitive abnormality before treatment, and a short-term relapse (0.3-1 month) have a poor outcome.

CONCLUSIONS

PACNS patients are prone to misdiagnosis and mistreatment, with unknown etiology and poor prognosis due to delayed treatment. Therefore, early biopsy, pathological diagnosis, and timely treatment with glucocorticoid shock are recommended, and patients with obvious mass effect should be treated by surgical resection.

Concordance of angiography and cerebral biopsy results for suspected primary central nervous system vasculitis: A multi-center retrospective review

OBJECTIVE

Primary CNS Vasculitis (PCNSV) is a rare disease that is often challenging to diagnose. Cerebral angiography and biopsy have been utilized in the diagnostic workup for several decades but limited literature reports on the concordance of findings of angiography and biopsy. The primary objective of this work was to examine how cerebral angiography corresponded with biopsy findings in patients with suspected PCNSV.

PATIENTS AND METHODS

A total of 128 patients who underwent workup for PCNSV between years 2005-2016 were identified by query of existing neurological surgery and angiography databases at University Hospitals Cleveland Medical Center (UHCMC) and the Cleveland Clinic Foundation (CCF). The primary outcome was to examine the concordance of results between angiography and cerebral biopsy. Secondary outcomes included examining concordance between results of biopsy and other commonly performed tests for diagnosis of PCNSV including Magnetic Resonance Imaging (MRI), cerebrospinal fluid white blood cell count (CSF WBC), Erythrocyte Sedimentation Rate (ESR), C-reactive protein (CRP).

RESULTS

128 patients underwent cerebral biopsy for diagnosis of suspected PCNSV. 93 (73%) of these patients also underwent angiography. Of the 34 patients with positive biopsy findings, only 5 also had positive angiography. Positive angiography was not found to be correlated with positive biopsy in our analysis. The only test that was significantly associated with biopsy proven vasculitis was increased CSF WBC count (P = 0.0114).

CONCLUSIONS

PCNSV is a rare disease and often requires multiple tests or procedures to obtain definitive diagnosis. These results suggest that cerebral angiography findings are not associated with biopsy findings and should be used cautiously in the diagnostic work-up of PCNSV.

The diagnostic quality of needle brain biopsy specimens obtained with different sampling methods - Experimental study

The aim is to examine whether brain tissue samples obtained through needle biopsy are better for histopathological evaluation when obtained with defined vacuum pressure, a novel needle rotation method, and using different needle type - Laitinen or Nashold. Moreover the paper aims to answer the question: Does vacuum and mechanical injury resulting from different sampling methods damage the tissue specimen challenging the diagnosis?. Eight hundred biopsy specimens from fresh swine brains were obtained using Nashold and Laitinen brain biopsy needles through inner cannula cutting or needle rotation sampling at vacuum pressure, from 0 to 0.06 MPa. The specimen weight and tissue quality for microscopic assessment were evaluated using the Mair score. Rising aspiration pressure increased the biopsy sample weight. Needle rotation delivered larger biopsy samples than the standard method. Laitinen provided larger samples than the Nashold needle, with the same sampling method or vacuum pressure. A higher histopathological diagnostic quality of tissue was obtained with the Laitinen needle than with Nashold, with higher vacuum pressure than lower pressure and finally with needle rotation than the standard method. No tissue damage caused by higher suction pressure or method of tissue separation was documented. Brain tissue samples obtained through needle biopsy are better for histopathological evaluation when obtained with higher vacuum pressure, a novel needle rotation method and with Laitinen needle. Higher suction pressure and sampling methods did not cause tissue damage.

Treatment of Vasculitis of the Nervous System

The diagnosis of primary central and peripheral nerve vasculitides should be established with certainty if suspected before commencing potent immunosuppressive therapy. The aim of induction therapy is to rapidly control the underlying inflammatory response and stabilize the blood-brain and blood-nerve barriers, followed by maintenance immunosuppression tailored to the likeliest humoral and cell-mediated autoimmune inflammatory vasculitic processes.

Autoimmune Encephalitides

Autoimmune encephalitis is a severe inflammatory disorder of the brain with diverse causes and a complex differential diagnosis. Recent advances in the past decade have led to the identification of new syndromes and biological markers of limbic encephalitis, the commonest presentation of autoimmune encephalitis. The successful use of serum and intrathecal antibodies to diagnose affected patients has resulted in few biopsy and postmortem examinations. In those available, there can be variable infiltrating inflammatory T cells with cytotoxic granules in close apposition to neurons, consistent with an inflammatory autoimmune basis, but true vasculitis is rarely seen. The exception is Hashimoto encephalopathy.

High-resolution Intracranial Vessel Wall Imaging in Monitoring Treatment Response in Primary CNS Angiitis

INTRODUCTION

High-resolution vessel wall imaging (HR-VWI) is emerging as a tool of notable utility in the diagnosis of intracranial vessel pathology. Its role in monitoring vessel wall disease response to treatment, however, is less well-established.

CASE REPORT

We report the case of a 45-year-old man with left middle and anterior cerebral artery infarcts and an National Institute of Health Stroke Scale (NIHSS) score of 2. Time-of-flight magnetic resonance angiography and digital subtraction angiography showed multifocal intracranial vessel pathology without extracranial vessel involvement. Comprehensive investigation with echocardiography and 24 hours Holter electrocardiography was unrevealing and the coagulation and routine autoimmune panel results were within normal limits. Cerebrospinal fluid showed mildly elevated protein and a diagnosis of probable primary central nervous system (PCNS) angiitis was made. The diagnosis was corroborated by intracranial HR-VWI, which showed homogenous, concentric enhancement of the left supraclinoid internal carotid artery (ICA) wall. The patient received high-dose IV methylprednisolone and cyclophosphamide. Repeat brain magnetic resonance imaging with HR-VWI at 3 and 9 months showed reduction and final resolution of vessel wall enhancement without recurrent infarcts. He has since remained clinically stable with an NIHSS score of 0 on low-dose oral glucocorticoids.

CONCLUSIONS

Our report illustrates the utility of HR-VWI in diagnosing a case of PCNS angiitis through the demonstration of a vasculitic pattern of mural enhancement. Furthermore, it has provided evidence of disease response to treatment, assisting us in modifying treatment accordingly. Tracking disease activity and response to treatment in cases of central nervous system vasculitis can be another important use of HR-VWI in clinical practice besides assisting in establishing the diagnosis.

Primary angiitis of the CNS and reversible cerebral vasoconstriction syndrome

Objectives

To further improve the distinction between primary angiitis of the CNS (PACNS) and reversible cerebral vasoconstriction syndrome (RCVS).

Methods

We compared 2 large French cohorts of patients with PACNS (n = 110, retrospectively and prospectively enrolled) and RCVS (n = 173, prospectively enrolled).

Results

Patients with RCVS were predominantly female (p < 0.0001), with migraines (p < 0.0001), and were more often exposed to vasoactive substances (p < 0.0001) or postpartum (p = 0.002) than patients with PACNS. Headache, especially thunderclap headache, was more frequent in RCVS (both p < 0.0001). Thunderclap headache was absent in only 6% of patients with RCVS and was mainly recurrent (87%) and provoked (77%) mostly by sexual intercourse, exertion, or emotion. All other neurologic symptoms (motor deficit, seizure, cognitive disorder, or vigilance impairment, all p < 0.0001) were more frequent in PACNS. At admission, brain CT or MRI was abnormal in all patients with PACNS and in 31% of patients with RCVS (p < 0.0001). Acute ischemic stroke was more frequent in PACNS than in RCVS (p < 0.0001). Although intracerebral hemorrhage was more frequent in PACNS (p = 0.006), subarachnoid hemorrhage and vasogenic edema predominated in RCVS (p = 0.04 and p = 0.01, respectively). Multiple small deep infarcts, extensive deep white matter lesions, tumor-like lesions, or multiple gadolinium-enhanced lesions were observed only in PACNS, whereas cervical artery dissection was found only in RCVS.

Conclusions

Our study confirms that careful analysis of clinical context, headache features, and patterns of brain lesions can distinguish PACNS and RCVS within the first few days of admission in most cases. However, diagnosis remains challenging in a few cases.

Primary angiitis of the central nervous system: diagnosis and treatment

Primary angiitis of the central nervous system (PACNS) represents a rare inflammatory disease affecting the brain and spinal cord. Stroke, encephalopathy, headache and seizures are major clinical manifestations. The diagnosis of PACNS is based on the combination of clinical presentation, imaging findings (magnetic resonance imaging and angiography), brain biopsy, and laboratory and cerebral spinal fluid (CSF) values. PACNS can either be confirmed by magnetic resonance angiography (MRA)/conventional angiography or tissue biopsy showing the presence of typical histopathological patterns. Identification of PACNS mimics is often challenging in clinical practice, but crucial to avoid far-reaching treatment decisions. In view of the severity of the disease, with considerable morbidity and mortality, early recognition and treatment initiation is necessary. Due to the rareness and heterogeneity of the disease, there is a lack of randomized data on treatment strategies. Retrospective studies suggest the combined administration of cyclophosphamide and glucocorticoids as induction therapy. Immunosuppressants such as azathioprine, methotrexate or mycophenolate mofetil are often applied for maintenance therapy. In addition, the beneficial effects of two biological agents (anti-CD20 monoclonal antibody rituximab and tumour necrosis factor-α blocker) have been reported. Nevertheless, diagnosis and treatment is still a clinical challenge, and further insights into the immunopathogenesis of PACNS are required to improve the diagnosis and management of patients. The present review provides a comprehensive overview of diagnostics, differential diagnoses, and therapeutic approaches of adult PACNS.

Cerebrospinal Fluid Concentrations of Neuronal Proteins Are Reduced in Primary Angiitis of the Central Nervous System

Primary angiitis of the central nervous system (PACNS) is a rare autoimmune vasculitis limited to the CNS often causing substantial disability. Understanding of this disease is impaired by the lack of available biomaterial. Here, we collected cerebrospinal fluid (CSF) from patients with PACNS and matched controls and performed unbiased proteomics profiling using ion mobility mass spectrometry to identify novel disease mechanisms and candidate biomarkers. We identified 14 candidate proteins, including amyloid-beta A4 protein (APP), with reduced abundance in the CSF of PACNS patients and validated APP by Enzyme-linked Immunosorbent Assay (ELISA) in an extended cohort of patients with PACNS. Subsequent functional annotation surprisingly suggested neuronal pathology rather than immune activation in PACNS. Our study is the first to employ mass spectrometry to local immune reactions in PACNS and it identifies candidates such as APP with pathogenic relevance in PACNS to improve patient care in the future.

The first case of bacillus Calmette-Guérin-induced small-vessel central nervous system vasculitis

To present an unrecognized vascular complication of bacillus Calmette-Guérin (BCG) therapy administered for superficial bladder carcinoma. We also review the potential mimickers for primary angiitis of the central nervous system (PACNS) as well as complications of intravesical BCG therapy. An 89-year-old Caucasian man with a history of relapsing high-grade bladder carcinoma treated with intravesical BCG presented with recurring episodes of right upper limb paresthesia with clumsiness and dysarthria. Magnetic resonance imaging of the head revealed multiple predominantly left-sided frontotemporal micronodular peri-vascular lesions. Left frontal lobe biopsy showed non-necrotizing granulomatous vasculitis. Ziehl staining was negative. Initially, he was treated for PACNS but his symptoms relapsed during every attempt to taper the corticosteroids. Six months later, he developed bilateral mycobacterial endophthalmitis, caused by Mycobacterium bovis. Brain biopsy was reviewed and confirmed the presence of perivascular mycobacteria. A retrospective diagnosis of BCG-induced central nervous system vasculitis was made and he was treated with high-dose corticosteroids, moxifloxacin, isoniazid, ethambutol, and rifampicin. BCG is a live attenuated form of Mycobacterium bovis widely used as tuberculosis vaccination and intravesical therapy for superficial forms of bladder cancer. Systemic complications affect roughly 5% of patients and can manifest months or years after the last instillation. Cases of endophthalmitis, meningitis, aortitis, or mycotic aneurysms have been described, but no reports of CNS vasculitis have been found. In disseminated forms of BCG infections, referred to as BCGitis, histopathology usually reveals granulomatous inflammation. Mycobacterial cultures are often negative, making this a diagnostic challenge. This is the first documented case of BCG-induced small-vessel CNS vasculitis. Mycobacterium bovis infection is rare and findings are often nonspecific, making the diagnosis very difficult. Other infectious and non-infectious causes must be ruled out appropriately before considering this entity.

New onset refractory status epilepticus due to primary angiitis of the central nervous system

Primary Angiitis of the central nervous system is a rare and poorly understood variant of vasculitis. We narrate a case of a 46-year-old male who presented with new onset refractory status epilepticus mimicking autoimmune encephalitis. In this case we are reporting clues that could be useful for diagnosis and extensive literature review on the topic.

Added Value of Vessel Wall Magnetic Resonance Imaging for Differentiation of Nonocclusive Intracranial Vasculopathies

BACKGROUND AND PURPOSE

Our goal is to determine the added value of intracranial vessel wall magnetic resonance imaging (IVWI) in differentiating nonocclusive vasculopathies compared with luminal imaging alone.

METHODS

We retrospectively reviewed images from patients with both luminal and IVWI to identify cases with clinically defined intracranial vasculopathies: atherosclerosis (intracranial atherosclerotic disease), reversible cerebral vasoconstriction syndrome, and inflammatory vasculopathy. Two neuroradiologists blinded to clinical data reviewed the luminal imaging of defined luminal stenoses/irregularities and evaluated the pattern of involvement to make a presumed diagnosis with diagnostic confidence. Six weeks later, the 2 raters rereviewed the luminal imaging in addition to IVWI for the pattern of wall involvement, presence and pattern of postcontrast enhancement, and presumed diagnosis and confidence. Analysis was performed on per-lesion and per-patient bases.

RESULTS

Thirty intracranial atherosclerotic disease, 12 inflammatory vasculopathies, and 12 reversible cerebral vasoconstriction syndrome patients with 201 lesions (90 intracranial atherosclerotic disease, 64 reversible cerebral vasoconstriction syndrome, and 47 inflammatory vasculopathy lesions) were included. For both per-lesion and per-patient analyses, there was significant diagnostic accuracy improvement with luminal imaging+IVWI when compared with luminal imaging alone (per-lesion: 88.8% versus 36.1%; P<0.001 and per-patient: 96.3% versus 43.5%; P<0.001, respectively). There was substantial interrater diagnostic agreement for luminal imaging+IVWI (κ=0.72) and only slight agreement for luminal imaging (κ=0.04). Although there was a significant correlation for both luminal and IVWI pattern of wall involvement with diagnosis, there was a stronger correlation for IVWI finding of lesion eccentricity and intracranial atherosclerotic disease diagnosis than for luminal imaging (κ=0.69 versus 0.18; P<0.001).

CONCLUSIONS

IVWI can significantly improve the differentiation of nonocclusive intracranial vasculopathies when combined with traditional luminal imaging modalities.

Maintenance therapy is associated with better long-term outcomes in adult patients with primary angiitis of the central nervous system

Objective

We aimed to analyse the effect of maintenance therapy after induction on the outcomes of adult patients with primary angiitis of the CNS (PACNS).

Methods

We analysed long-term outcomes (relapse, survival and functional status) of patients enrolled in the French multicentre PACNS cohort who achieved remission after induction treatment and with ⩾12 months' follow-up, according to whether or not they received maintenance therapy. Good outcome was defined as relapse-free survival and good functional status (modified Rankin scale ⩽ 2) at last follow-up.

Results

Ninety-seven patients [46 (47%) female, median age: 46 (18-78) years at diagnosis] were followed up for a median of 55 (5-198) months. Induction treatment consisted of glucocorticoids in 95 (98%) patients, combined with an immunosuppressant in 80 (83%) patients, mostly CYC. Maintenance therapy was prescribed in 48 (49%) patients, following CYC in 42 of them. Maintenance therapy was started 4 (3-18) months after glucocorticoid initiation. At last follow-up, good outcomes were observed in 32 (67%) patients who had received maintenance therapy vs 10 (20%) who had not (P < 0.0001). Thirty-two (33%) patients experienced relapse [10 (22%) had received maintenance therapy while 22 (45%) had not, P = 0.01]; four subsequently died from relapse. In the multivariate analysis, maintenance therapy was the only independent predictor of good outcome [odds ratio (OR) = 7.8 (95% CI: 3.21, 20.36), P < 0.0001].

Conclusion

The results of this long-term follow-up study suggest that maintenance therapy in adults with PACNS is associated with better functional outcomes and lower relapse rates. Further studies are needed to confirm these findings.

Neuroradiologic Characteristics of Primary Angiitis of the Central Nervous System According to the Affected Vessel Size

INTRODUCTION

Magnetic resonance imaging (MRI) has an important impact in diagnosing primary angiitis of the central nervous system (PACNS). However, neuroradiologic findings may vary immensely, making an easy and definite diagnosis challenging.

METHODS

In this retrospective, single center study, we analyzed neuroradiologic findings of patients with PACNS diagnosed at our hospital between 2009 and 2014. Furthermore, we classified patients according to the affected vessel size and compared imaging characteristics between the subgroups.

RESULTS

Thirty-three patients were included (mean age 43 [±15.3] years, 17 females) in this study. Patients with positive angiographic findings were classified as either medium or large vessel PACNS and presented more ischemic lesions (p < 0.001) and vessel wall enhancement (p = 0.017) compared to patients with small vessel PACNS. No significant differences were detected for the distribution of contrast-enhancing lesions (parenchymal or leptomeningeal), hemorrhages, or lesions with mass effect. Twenty-five patients underwent brain biopsy. Patients with medium or large vessel PACNS were less likely to have positive biopsy results.

DISCUSSION

It is essential to differentiate between small and medium/large vessel PACNS since results in MRI, digital subtraction angiography and brain biopsy may differ immensely. Since image quality of MR scanners improves gradually and brain biopsy may often be nonspecific or negative, our results emphasize the importance of MRI/MRA in the diagnosis process of PACNS.

Subtypes of primary angiitis of the CNS identified by MRI patterns reflect the size of affected vessels

OBJECTIVE

To describe patterns of diagnostic findings, and identify subgroups of primary angiitis of the central nervous system (PACNS).

METHODS

We retrospectively analysed 31 patients with PACNS. Cases were selected by predetermined diagnostic criteria and stratified into biopsy-proven and imaging-based PACNS. We compared clinical characteristics, cerebrospinal fluid (CSF) findings and imaging results including high-resolution vessel wall MRI between groups.

RESULTS

There were 31 cases of PACNS (mean age 45.6 years, 58.1% female), of whom 17 (55%) were biopsy-proven, 14 (45%) were based on imaging findings. Patients with a positive biopsy had fewer infarcts (29.4% vs 85.7%, p=0.003), were more likely to have meningeal and parenchymal contrast enhancement (76.5% vs 28.6%, p=0.012), were less likely to have abnormal MR angiography (11.8% vs 100%, p<0.001) and did not show vessel wall enhancement at the time of diagnosis (0% vs 76.9%, p<0.001). In contrast, patients with imaging-based diagnosis showed more frequently multiple infarcts and vessel abnormalities, with vessel wall enhancement in most of the cases. Clinical characteristics and CSF analysis did not reveal marked differences between groups.

INTERPRETATION

Multi-parametric MRI distinguishes two subtypes of PACNS that most likely differ concerning the affected vessel size. Biopsy-proven PACNS primarily involves smaller vessels beyond the resolution of vascular imaging, while imaging-based PACNS affects predominantly medium-sized vessels leading to false-negative biopsy results. Using distinct MRI patterns may be helpful for selecting patients for appropriate invasive diagnostic modalities.

Adult primary angiitis of the central nervous system: isolated small-vessel vasculitis represents distinct disease pattern

Objectives

We aimed to identify whether presentations and outcomes in adult patients with isolated small-vessel primary angiitis of the CNS (PACNS) would differ from other patients with large/medium-vessel involvement.

Methods

In the French PACNS cohort, we compared the characteristics, treatments and outcomes of patients with isolated small-vessel disease (normal CT, MR and/or conventional angiograms, brain biopsy positive for vasculitis) with other patients who had large/medium-vessel involvement (vessel abnormalities on CT, MR or conventional angiograms). A good functional outcome was defined as a modified Rankin scale ⩽2 at last follow-up, regardless of the occurrence of relapse.

Results

Among the 102 patients in the cohort, 26 (25%) had isolated small-vessel PACNS, whereas the 76 others demonstrated large/medium-vessel involvement. Patients with isolated small-vessel PACNS had more seizures (P < 0.0001), cognitive (P = 0.02) or consciousness impairment (P = 0.03) and more dyskinesias (P = 0.002) but less focal deficits (P = 0.0002) than other PACNS patients. They also had more abnormal cerebrospinal fluid analysis (P = 0.008) and gadolinium enhancements on MRI (P = 0.001) but less frequent acute ischaemic lesions (P < 0.0001) than patients with large/medium-vessel involvement. Treatments and modified Rankin scale at last follow-up did not differ between groups. Thirty-two (31%) patients relapsed; 14 (54%) with isolated small-vessel PACNS vs 18 (24%) with large/medium-vessel involvement (P = 0.004). Eight patients died, with no difference between the groups (P = 0.97).

Conclusion

In our cohort, adult patients with isolated small-vessel PACNS presented some distinct disease features and relapsed more often than other PACNS patients who had large/medium-vessel involvement. Functional outcomes and mortality did not differ.

Primary Angiitis of the Central Nervous System

Background and Purpose—

Primary angiitis of the central nervous system remains challenging. To report an overview and pictorial review of brain magnetic resonance imaging findings in adult primary angiitis of the central nervous system and to determine the distribution of parenchymal, meningeal, and vascular lesions in a large multicentric cohort.

Methods—

Adult patients from the French COVAC cohort (Cohort of Patients With Primary Vasculitis of the Central Nervous System), with biopsy or angiographically proven primary angiitis of the central nervous system and brain magnetic resonance imaging available at the time of diagnosis were included. A systematic imaging review was performed blinded to clinical data.

Results—

Sixty patients met inclusion criteria. Mean age was 45 years (±12.9). Patients initially presented focal deficit(s) (83%), headaches (53%), cognitive disorder (40%), and seizures (38.3%). The most common magnetic resonance imaging finding observed in 42% of patients was multiterritorial, bilateral, distal acute stroke lesions after small to medium artery distribution, with a predominant carotid circulation distribution. Hemorrhagic infarctions and parenchymal hemorrhages were also frequently found in the cohort (55%). Acute convexity subarachnoid hemorrhage was found in 26% of patients and 42% demonstrated pre-eminent leptomeningeal enhancement, which is found to be significantly more prevalent in biopsy-proven patients (60% versus 28%; P =0.04). Seven patients had tumor-like presentations. Seventy-seven percent of magnetic resonance angiographic studies were abnormal, revealing proximal/distal stenoses in 57% and 61% of patients, respectively.

Conclusions—

Adult primary angiitis of the central nervous system is a heterogenous disease, with multiterritorial, distal, and bilateral acute stroke being the most common pattern of parenchymal lesions found on magnetic resonance imaging. Our findings suggest a higher than previously thought prevalence of hemorrhagic transformation and other hemorrhagic manifestations.