7 Tesla MRI of Balo's concentric sclerosis versus multiple sclerosis lesions

Central intra-lesional iron deposits as a possible novel imaging marker at 7 Tesla MRI in Susac Syndrome - an exploratory study

BACKGROUND

Susac syndrome (SuS) is a rare autoimmune disease that leads to hearing impairment, visual field deficits, and encephalopathy due to an occlusion of precapillary arterioles in the brain, retina, and inner ear. Given the potentially disastrous outcome and difficulties in distinguishing SuS from its differential diagnoses, such as multiple sclerosis (MS), our exploratory study aimed at identifying potential new SuS-specific neuroimaging markers.

METHODS

Seven patients with a definite diagnosis of SuS underwent magnetic resonance imaging (MRI) at 7 Tesla (7T), including T2* weighted and quantitative susceptibility mapping (QSM) sequences. T2 weighted hyperintense lesions were analyzed with regard to number, volume, localization, central vein sign, T1 hypointensity, and focal iron deposits in the center of SuS lesions ("iron dots"). Seven T MRI datasets from the same institute, comprising 75 patients with, among others, MS, served as controls.

RESULTS

The "iron dot" sign was present in 71.4% (5/7) of the SuS patients, compared to 0% in our control cohort. Thus, sensitivity was 71.4% and specificity 100%. A central vein sign was only incidentally detected.

CONCLUSION

We are the first to demonstrate this type of "iron dot" lesions on highly resolving 7T T2*w and QSM images in vivo as a promising neuroimaging marker of SuS, corroborating previous histopathological ex vivo findings.

Knowledge and awareness on Balo's disease among dental students: A survey

Balo's disease is an uncommon central nervous system disorder causing demyelination and is a form of multiple sclerosis. Concentric sclerosis, leukoencephalitis periaxialis concentrica, is also known as Balo's disease. Concentric sclerosis signalizes the bands of intact myelin and alternating rings of myelin loss present in several parts of the brainstem and brain. The present study aimed to assess and create awareness about Balo's disease among dental undergraduates. The study included an online survey about the knowledge and awareness of Balo's disease among dental students. A questionnaire was prepared, uploaded, and distributed in an online portal. The latest software version of SPSS was used to analyze the collected data. Descriptive statistical analysis and Chi-square test were done, and the P value was calculated. The survey showed that 54.55% of males and 45.45% of females participated in this survey. Most of the respondents (87.88%) knew about Balo's disease, whereas only 12.12% of participants were not aware of the disease. It was found that most of dental students are aware of Balo's disease. The study also showed that male respondents are more aware than the females.

Case Report: Baló's Concentric Sclerosis-Like Lesion in a Patient With Relapsing-Remitting Multiple Sclerosis Treated With Dimethyl Fumarate

Baló's concentric sclerosis (BCS) is a rare demyelinating disorder characterized by acute or subacute neurological symptoms associated with characteristic lesions of concentric onion skin appearance on MRI images and in pathology. The connection between BCS and classic MS is still a subject of debates. Our report presents a case of a patient who developed a symptomatic Baló-like lesion following several years of classical relapsing-remitting multiple sclerosis treated with dimethyl fumarate.

New Prospects for Ultra-High-Field Magnetic Resonance Imaging in Multiple Sclerosis

ABSTRACT

There is growing interest in imaging multiple sclerosis (MS) through the ultra-high-field (UHF) lens, which currently means a static magnetic field strength of 7 T or higher. Because of higher signal-to-noise ratio and enhanced susceptibility effects, UHF magnetic resonance imaging improves conspicuity of MS pathological hallmarks, among them cortical demyelination and the central vein sign. This could, in turn, improve confidence in MS diagnosis and might also facilitate therapeutic monitoring of MS patients. Furthermore, UHF imaging offers unique insight into iron-related pathology, leptomeningeal inflammation, and spinal cord pathologies in neuroinflammation. Yet, limitations such as the longer scanning times to achieve improved resolution and incipient safety data on implanted medical devices need to be considered. In this review, we discuss applications of UHF imaging in MS, its advantages and limitations, and practical aspects of UHF in the clinical setting.

Imaging cortical multiple sclerosis lesions with ultra-high field MRI

BACKGROUND

Cortical lesions are abundant in multiple sclerosis (MS), yet difficult to visualize in vivo. Ultra-high field (UHF) MRI at 7 T and above provides technological advances suited to optimize the detection of cortical lesions in MS.

PURPOSE

To provide a narrative and quantitative systematic review of the literature on UHF MRI of cortical lesions in MS.

METHODS

A systematic search of all literature on UHF MRI of cortical lesions in MS published before September 2020. Quantitative outcome measures included cortical lesion numbers reported using 3 T and 7 T MRI and between 7 T MRI sequences, along with sensitivity of UHF MRI towards cortical lesions verified by histopathology.

RESULTS

7 T MRI detected on average 52 ± 26% (mean ± 95% confidence interval) more cortical lesions than the best performing image contrast at 3 T, with the largest increase in type II-IV intracortical lesion detection. Across all studies, the mean cortical lesion number was 17 ± 6 per patient. In progressive MS cohorts, approximately four times more cortical lesions were reported than in CIS/early RRMS, and RRMS. Yet, there was no difference in lesion type ratio between these MS subtypes. Furthermore, superiority of one MRI sequence over another could not be established from available data. Post-mortem lesion detection with UHF MRI agreed only modestly with pathological examinations. Mean pro- and retrospective sensitivity was 33 ± 6% and 71 ± 10%, respectively, with the highest sensitivity towards type I and type IV lesions.

CONCLUSION

UHF MRI improves cortical lesion detection in MS considerably compared to 3 T MRI, particularly for type II-IV lesions. Despite modest sensitivity, 7 T MRI is still capable of visualizing all aspects of cortical lesion pathology and could potentially aid clinicians in diagnosing and monitoring MS, and progressive MS in particular. However, standardization of acquisition and segmentation protocols is needed.

Magnetic Resonance Characteristics of Baló Concentric Sclerosis in Children

BACKGROUND

Baló concentric sclerosis is a rare demyelinating disease with characteristic magnetic resonance appearance of multilayered ringlike lesions of demyelination. This disease is extremely rare in children. We present the clinical data, radiological appearance, and development of lesions in eight children.

METHODS

We analyzed the clinical information of eight patients diagnosed between 2012 and 2020. Magnetic resonance brain and spinal cord examinations with contrast medium administration were performed using a 1.5-T scanner.

RESULTS

All patients presented at least one typical Baló lesion on brain imaging. Four patients additionally had typical multiple sclerosis plaques. All primary Baló lesions had a characteristic appearance of concentric hyperintense rings on T2-weighted imaging and were round or ovoid. Cerebrospinal fluid analysis was performed in all patients. Oligoclonal bands were present in seven patients, and four of them had multiple sclerosis plaques on baseline brain magnetic resonance imaging.

CONCLUSION

Baló concentric sclerosis in children is characterized by acute and severe onset with hemiparesis as a predominant symptom. The size, contrast enhancement, and restricted diffusion depend on the phase of the disease.

Baló's concentric sclerosis - A rare entity within the spectrum of demyelinating diseases

Baló's concentric sclerosis (BCS) is a rare, inflammatory demyelinating disease of the central nervous system (CNS). Historically, BCS was thought to be uniformly fatal and diagnosis was based on postmortem findings. With advances in modern neuroimaging, BCS is currently defined by the presence of concentric layered patterns composed of alternating rings of varying intensity. They are best appreciated on gadolinium-enhanced T1-weighted sequences and predominantly occur in the supratentorial cerebral white matter with sparing of cortical U-fibers. The lamellar pattern of the lesions likely reflects bands of demyelination and relative myelin preservation with minimal axonal loss. While BCS falls within the spectrum of atypical demyelinating diseases, there is ongoing debate over whether BCS is a phenotypical variant of multiple sclerosis (MS) or a separate entity. Corticosteroids comprise first-line therapy but there is ongoing controversy regarding appropriate maintenance therapy. First-line MS disease-modifying therapies such as interferon beta-1a are appropriate for patients who fulfill diagnostic criteria for relapsing-remitting MS. Fingolimod should likely be avoided as Baló-like lesions have been reported during its administration or after withdrawal. Monoclonal antibodies such as natalizumab and rituximab are potentially effective at reducing BCS relapses, but alemtuzumab may be relatively ineffective because humoral immunity does not play a central role in BCS pathogenesis.

Balo's Concentric Sclerosis Mimicking Tumor on Magnetic Resonance Imaging in a Young Patient

Balo’s concentric sclerosis (BCS) is a rare demyelinating disease known as Multiple Sclerosis (MS) lesion type III. It is a disease of the white matter of the brain characterized by a round lesion with variable concentric myelinated and demyelinated layers, appearing as “onion bulb.” We present a case of BCS and discuss the imaging findings and management strategies of this disease. A 26-y-old male developed headache, weakness, and numbness of limbs. Magnetic resonance imaging (MRI) showed concentric lamellar like demyelinating lesions at the subcortical regions. The patient’s neurological symptoms were consistent with the MRI findings.

From Baló's concentric sclerosis to multiple sclerosis: a series of 6 patients

INTRODUCTION

Baló's concentric sclerosis (BCS) is a rare CNS disorder characterized by alternating bands of demyelination on MRI. One of the main issues is its relationship with multiple sclerosis (MS).

OBJECTIVES

To describe 6 BCS patients. To review the risk of developing MS in BCS patients.

METHODS

We retrospectively recorded clinical and radiological findings of 6 BCS patients and performed a review of the literature.

RESULTS

Six patients (5 women) with a mean age of 25 years old were included. Main symptoms were hemiparesis/hemihypoesthesia. On MRI, two patients had a single BCS lesion and four had additional MS-like lesions. Alternating bands were usually more visible on DWI. A patient had reduced central perfusion and SWI hypointensity suggestive of a central vein. Oligoclonal bands were identified in 5/6 patients. After 7 years of follow-up, all patients achieved MS criteria with mild disability (mean EDSS 1.75; 0-4). Our literature review included 65 BCS patients from 30 studies: although CSF oligoclonal bands and the presence of additional MS lesions were associated with subsequent relapses, this was not significant.

DISCUSSION/CONCLUSION

Our series allows a detailed MRI description in BCS and gives a new insight into BCS evolution and its strong relationship with MS.

Antibody signatures in patients with histopathologically defined multiple sclerosis patterns

Early active multiple sclerosis (MS) lesions can be classified histologically into three main immunopathological patterns of demyelination (patterns I–III), which suggest pathogenic heterogeneity and may predict therapy response. Patterns I and II show signs of immune-mediated demyelination, but only pattern II is associated with antibody/complement deposition. In pattern III lesions, which include Baló’s concentric sclerosis, primary oligodendrocyte damage was proposed. Serum antibody reactivities could reflect disease pathogenesis and thus distinguish histopathologically defined MS patterns. We established a customized microarray with more than 700 peptides that represent human and viral antigens potentially relevant for inflammatory demyelinating CNS diseases, and tested sera from 66 patients (pattern I n = 12; II n = 29; III n = 25, including 8 with Baló’s), healthy controls, patients with Sjögren’s syndrome and stroke patients. Cell-based assays were performed for aquaporin 1 (AQP1) and AQP4 antibody detection. No single peptide showed differential binding among study cohorts. Because antibodies can react with different peptides from one protein, we also analyzed groups of peptides. Patients with pattern II showed significantly higher reactivities to Nogo-A peptides as compared to patterns I (p = 0.02) and III (p = 0.02). Pattern III patients showed higher reactivities to AQP1 (compared to pattern I p = 0.002, pattern II p = 0.001) and varicella zoster virus (VZV, compared to pattern II p = 0.05). In patients with Baló’s, AQP1 reactivity was also significantly higher compared to patients without Baló’s (p = 0.04), and the former revealed distinct antibody signatures. Histologically, Baló’s patients showed loss of AQP1 and AQP4 in demyelinating lesions, but no antibodies binding conformational AQP1 or AQP4 were detected. In summary, higher reactivities to Nogo-A peptides in pattern II patients could be relevant for enhanced axonal repair and remyelination. Higher reactivities to AQP1 peptides in pattern III patients and its subgroup of Baló’s patients possibly reflect astrocytic damage. Finally, latent VZV infection may cause peripheral immune activation.