scholarly journals A “kissing lesion”: In-vivo 7T evidence of meningeal inflammation in early multiple sclerosis

2017 ◽  
Vol 23 (8) ◽  
pp. 1167-1169 ◽  
Author(s):  
Pierre Kolber ◽  
Amgad Droby ◽  
Alard Roebroeck ◽  
Rainer Goebel ◽  
Vinzenz Fleischer ◽  
...  

Background: The role of cortical lesions (CLs) in disease progression and clinical deficits is increasingly recognized in multiple sclerosis (MS); however the origin of CLs in MS still remains unclear. Objective: Here, we report a para-sulcal CL detected two years after diagnosis in a relapsing-remitting MS (RRMS) patient without manifestation of clinical deficit. Methods: Ultra-high field (7T) MR imaging using magnetization-prepared 2 rapid acquisition gradient echoes (MP2RAGE) sequence was performed. Results: A para-sulcal CL was detected which showed hypointense rim and iso- to hyperintense core. This was detected in the proximity of the leptomeninges in the left precentral gyrus extending to the adjacent postcentral gyrus. Conclusion: This finding indicates that inflammatory infiltration into the cortex through the meninges underlies cortical pathology already in the early stage of disease and in mild disease course.

2020 ◽  
Author(s):  
Lynn van Olst ◽  
Carla Rodriguez-Mogeda ◽  
Carmen Picon-Munoz ◽  
Svenja Kiljan ◽  
Rachel E. James ◽  
...  

AbstractMeningeal inflammation strongly associates with demyelination and neuronal loss in the underlying cortex of progressive MS patients, contributing to clinical disability. However, the pathological mechanisms of meningeal inflammation-induced cortical pathology are still largely elusive. Using extensive analysis of human post-mortem tissue, we identified two distinct microglial phenotypes, termed MS1 and MS2, in the cortex of progressive MS patients. These phenotypes differed in morphology and protein expression, but both associated with inflammation of the overlying meninges. We could replicate the MS-specific microglial phenotypes in a novel in vivo rat model for progressive MS-like meningeal inflammation, with microglia present at 1 month post-induction resembling MS1 microglia whereas those at 2 months acquired an MS2-like phenotype. Interestingly, MS1 microglia were involved in presynaptic displacement and phagocytosis and associated with a relative sparing of neurons in the MS and animal cortex. In contrast, the presence of MS2 microglia coincided with substantial neuronal loss. Taken together, we uncovered that in response to meningeal inflammation, microglia acquire two distinct phenotypes that differentially associate with neurodegeneration in the progressive MS cortex. Our data suggests that these phenotypes occur sequentially and that microglia may lose their protective properties over time, contributing to neuronal loss.


2021 ◽  
Vol 11 (5) ◽  
pp. 431
Author(s):  
Sabine Hofer ◽  
Norbert Hofstätter ◽  
Albert Duschl ◽  
Martin Himly

COVID-19, predominantly a mild disease, is associated with more severe clinical manifestation upon pulmonary involvement. Virion-laden aerosols and droplets target different anatomical sites for deposition. Compared to droplets, aerosols more readily advance into the peripheral lung. We performed in silico modeling to confirm the secondary pulmonary lobules as the primary site of disease initiation. By taking different anatomical aerosol origins into consideration and reflecting aerosols from exhalation maneuvers breathing and vocalization, the physicochemical properties of generated respiratory aerosol particles were defined upon conversion to droplet nuclei by evaporation at ambient air. To provide detailed, spatially-resolved information on particle deposition in the thoracic region of the lung, a top-down refinement approach was employed. Our study presents evidence for hot spots of aerosol deposition in lung generations beyond the terminal bronchiole, with a maximum in the secondary pulmonary lobules and a high preference to the lower lobes of both lungs. In vivo, initial chest CT anomalies, the ground glass opacities, resulting from partial alveolar filling and interstitial thickening in the secondary pulmonary lobules, are likewise localized in these lung generations, with the highest frequency in both lower lobes and in the early stage of disease. Hence, our results suggest a disease initiation right there upon inhalation of virion-laden respiratory aerosols, linking the aerosol transmission route to pathogenesis associated with higher disease burden and identifying aerosol transmission as a new independent risk factor for developing a pulmonary phase with a severe outcome.


2021 ◽  
Vol 141 (4) ◽  
pp. 585-604 ◽  
Author(s):  
Carmen Picon ◽  
Anusha Jayaraman ◽  
Rachel James ◽  
Catriona Beck ◽  
Patricia Gallego ◽  
...  

AbstractSustained exposure to pro-inflammatory cytokines in the leptomeninges is thought to play a major role in the pathogenetic mechanisms leading to cortical pathology in multiple sclerosis (MS). Although the molecular mechanisms underlying neurodegeneration in the grey matter remain unclear, several lines of evidence suggest a prominent role for tumour necrosis factor (TNF). Using cortical grey matter tissue blocks from post-mortem brains from 28 secondary progressive MS subjects and ten non-neurological controls, we describe an increase in expression of multiple steps in the TNF/TNF receptor 1 signaling pathway leading to necroptosis, including the key proteins TNFR1, FADD, RIPK1, RIPK3 and MLKL. Activation of this pathway was indicated by the phosphorylation of RIPK3 and MLKL and the formation of protein oligomers characteristic of necrosomes. In contrast, caspase-8 dependent apoptotic signaling was decreased. Upregulation of necroptotic signaling occurred predominantly in macroneurons in cortical layers II–III, with little expression in other cell types. The presence of activated necroptotic proteins in neurons was increased in MS cases with prominent meningeal inflammation, with a 30-fold increase in phosphoMLKL+ neurons in layers I–III. The density of phosphoMLKL+ neurons correlated inversely with age at death, age at progression and disease duration. In vivo induction of chronically elevated TNF and INFγ levels in the CSF in a rat model via lentiviral transduction in the meninges, triggered inflammation and neurodegeneration in the underlying cortical grey matter that was associated with increased neuronal expression of TNFR1 and activated necroptotic signaling proteins. Exposure of cultured primary rat cortical neurons to TNF induced necroptosis when apoptosis was inhibited. Our data suggest that neurons in the MS cortex are dying via TNF/TNFR1 stimulated necroptosis rather than apoptosis, possibly initiated in part by chronic meningeal inflammation. Neuronal necroptosis represents a pathogenetic mechanism that is amenable to therapeutic intervention at several points in the signaling pathway.


2014 ◽  
Vol 20 (10) ◽  
pp. 1322-1330 ◽  
Author(s):  
Rebecca S Samson ◽  
Manuel J Cardoso ◽  
Nils Muhlert ◽  
Varun Sethi ◽  
Claudia AM Wheeler-Kingshott ◽  
...  

Background: Pathological abnormalities including demyelination and neuronal loss are reported in the outer cortex in multiple sclerosis (MS). Objective: We investigated for in vivo evidence of outer cortical abnormalities by measuring the magnetisation transfer ratio (MTR) in MS patients of different subgroups. Methods: Forty-four relapsing–remitting (RR) (mean age 41.9 years, median Expanded Disability Status Scale (EDSS) 2.0), 25 secondary progressive (SP) (54.1 years, EDSS 6.5) and 19 primary progressive (PP) (53.1 years, EDSS 6.0) MS patients and 35 healthy control subjects (mean age 39.2 years) were studied. Three-dimensional (3D) 1×1×1mm3 T1-weighted images and MTR data were acquired. The cortex was segmented, then subdivided into outer and inner bands, and MTR values were calculated for each band. Results: In a pairwise analysis, mean outer cortical MTR was lower than mean inner cortical MTR in all MS groups and controls ( p<0.001). Compared with controls, outer cortical MTR was decreased in SPMS ( p<0.001) and RRMS ( p<0.01), but not PPMS. Outer cortical MTR was lower in SPMS than PPMS ( p<0.01) and RRMS ( p<0.01). Conclusions: Lower outer than inner cortical MTR in healthy controls may reflect differences in myelin content. The lowest outer cortical MTR was seen in SPMS and is consistent with more extensive outer cortical (including subpial) pathology, such as demyelination and neuronal loss, as observed in post-mortem studies of SPMS patients.


2009 ◽  
Vol 15 (7) ◽  
pp. 789-794 ◽  
Author(s):  
B Benedetti ◽  
M Rovaris ◽  
MA Rocca ◽  
D Caputo ◽  
M Zaffaroni ◽  
...  

Objective The term benign multiple sclerosis (BMS) is referred to patients who have a mild or absent disability several years after disease clinical onset. Axonal damage can be measured in vivo using proton MR spectroscopy (1H-MRS). In this study, we quantified the severity of “global” axonal damage in BMS and early relapsing–remitting (RR) MS patients, using whole brain N-acetylaspartate (WBNAA) 1H-MRS, to better elucidate the structural correlates of a non-disabling disease evolution. Methods WBNAA concentration was measured in 37 patients with BMS (mean disease duration 22.3 years) and 17 patients with early RRMS (mean disease duration 4.0 years), using an unlocalized 1H-MRS sequence. Dual echo and T1-weighted scans were also obtained to measure T2-hyperintense lesion volume (TLV) and normalized brain volume (NBV). Results TLV was higher in BMS (mean TLV = 13.1 mL) than in early RRMS patients (mean TLV = 7.2 mL) ( P = 0.018), whereas neither NBV (mean NBV: 1491.0 mL in BMS vs 1520.3 mL in RRMS) nor WBNAA concentration (mean WBNAA: 10.5 mmol in BMS vs 11.4 mmol in RRMS) significantly differed between the two groups. In MS patients, no correlation was found between WBNAA concentration and Expanded Disability Status Scale (EDSS), TLV and NBV. Conclusions The similar WBNAA concentrations seen in BMS and early RRMS patients fit with the notion that a non-disabling long-term evolution of MS may be due, at least in part, to non-progression of pathology. Such a condition seems to be independent from MRI-visible lesions burden.


2004 ◽  
Vol 10 (6) ◽  
pp. 630-635 ◽  
Author(s):  
C Espejo ◽  
L Brieva ◽  
G Ruggiero ◽  
J Río ◽  
X Montalban ◽  
...  

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system probably mediated by Th1 lymphocytes. IFN-b is an established therapy for relapsing MS patients, although the mechanisms underlying its efficacy are yet to be well characterized. We determined IL-2 production, CD25 expression and T-cell proliferation from relapsing -remitting MS patients before and three months after starting therapy. A decrease in the percentage of CD80-induced IL-2-producing cells was observed after in vivo IFN-b treatment. These data support that one of the immunomodulatory effects of IFN-b treatment in MS may be a limitation of the autoimmune response modifying the CD80:CD28/CTLA-4 pathway.


2021 ◽  
Author(s):  
Koy Chong Ng Kee Kwong ◽  
Daisy Mollison ◽  
Rozanna Meijboom ◽  
Elizabeth N. York ◽  
Agniete Kampaite ◽  
...  

Abstract Purpose Rim lesions, characterised by a paramagnetic rim on susceptibility-based MRI, have been suggested to reflect chronic inflammatory demyelination in multiple sclerosis (MS) patients. Here, we assess, through susceptibility-weighted imaging (SWI), the prevalence, longitudinal volume evolution and clinical associations of rim lesions in subjects with early relapsing–remitting MS (RRMS). Methods Subjects (n = 44) with recently diagnosed RRMS underwent 3 T MRI at baseline (M0) and 1 year (M12) as part of a multi-centre study. SWI was acquired at M12 using a 3D segmented gradient-echo echo-planar imaging sequence. Rim lesions identified on SWI were manually segmented on FLAIR images at both time points for volumetric analysis. Results Twelve subjects (27%) had at least one rim lesion at M12. A linear mixed-effects model, with ‘subject’ as a random factor, revealed mixed evidence for the difference in longitudinal volume change between rim lesions and non-rim lesions (p = 0.0350 and p = 0.0556 for subjects with and without rim lesions, respectively). All 25 rim lesions identified showed T1-weighted hypointense signal. Subjects with and without rim lesions did not differ significantly with respect to age, disease duration or clinical measures of disability (p > 0.05). Conclusion We demonstrate that rim lesions are detectable in early-stage RRMS on 3 T MRI across multiple centres, although their relationship to lesion enlargement is equivocal in this small cohort. Identification of SWI rims was subjective. Agreed criteria for defining rim lesions and their further validation as a biomarker of chronic inflammation are required for translation of SWI into routine MS clinical practice.


Brain ◽  
2021 ◽  
Author(s):  
Matteo Pardini ◽  
J William L Brown ◽  
Roberta Magliozzi ◽  
Richard Reynolds ◽  
Declan T Chard

Abstract While multiple sclerosis can affect any part of the CNS, it does not do so evenly. In white matter it has long been recognized that lesions tend to occur around the ventricles, and grey matter lesions mainly accrue in the outermost (subpial) cortex. In cortical grey matter, neuronal loss is greater in the outermost layers. This cortical gradient has been replicated in vivo with magnetization transfer ratio and similar gradients in grey and white matter magnetization transfer ratio are seen around the ventricles, with the most severe abnormalities abutting the ventricular surface. The cause of these gradients remains uncertain, though soluble factors released from meningeal inflammation into the CSF has the most supporting evidence. In this Update, we review this ‘surface-in’ spatial distribution of multiple sclerosis abnormalities and consider the implications for understanding pathogenic mechanisms and treatments designed to slow or stop them.


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