Neuronal Damage In T1-HypoIntense Multiple Sclerosis Lesions Demonstrated In Vivo Using Proton Magnetic Resonance Spectroscopy
van Walderveen MA, Barkhof F, Pouwels PJ, van Schijndel RA, Polman CH, Castelijns JA
Ann Neurol 1999 Jul;46(1):79-87
Univ Hospital Vrije Universiteit, MR Centre for MS Research and Dept of Radiology, Amsterdam, The Netherlands
PMID# 10401783; UI# 99328210
HypoIntense T1 lesions in Multiple Sclerosis patients correlate with Axonal loss at autopsy and biopsy.
We evaluated the chemical substrate of HypoIntense T1 lesions by using in vivo Proton Magnetic Resonance Spectroscopy, and analyzed the Spectroscopic correlate of increased T1-relaxation time measurements.
Localized Proton Magnetic Resonance Spectroscopy and T1-relaxation time measurements were performed in Lesions.
Selected on T1-weighted Spin-Echo Magnetic Resonance Images according to degree of HypoIntensity, in Normal-Appearing White Matter (NAWM) and in normal White Matter of controls.
In NAWM, prolongation of T1-relaxation time and a decrease in N-AcetylAspartate (NAA) were present, compared with normal White Matter.
Severely HypoIntense lesions showed a lower concentration of NAA and Creatine compared with NAWM and a lower concentration of NAA compared with IsoIntense to mildly HypoIntense lesions.
NAA concentration correlated with degree of HypoIntensity of lesions and with T1-relaxation time within the Spectroscopic Voxel.
Our results provide the first in vivo evidence of Axonal Damage in severely HypoIntense T1 lesions in Multiple Sclerosis patients.
T1-relaxation time correlates with the concentration of NAA in both Multiple Sclerosis Lesions and NAWM, indicating that this parameter deserves further evaluation to monitor disease progression.
Axonal Damage In Multiple Sclerosis Plaques: A Combined Magnetic Resonance Imaging And 1H-Magnetic Resonance Spectroscopy Study
Simone IL, Tortorella C, Federico F, Liguori M, Lucivero V, Giannini P, Carrara D, Bellacosa A, Livrea P
J Neurol Sci 2001 Jan 1;182(2):143-150
Univ of Bari, Dept of Neurological and Psychiatric Sciences, Piazza Giulio Cesare, 70124, Bari, Italy
The purpose of this study was to compare Magnetic Resonance Imaging (MRI) features and Proton MR Spectroscopy (1H-MRS) patterns of Multiple Sclerosis (MS) plaques in order to define the metabolic substrate in different lesion subtypes.
Combined MRI and single-Voxel 1H-MRS investigation was performed in 54 MS patients:
- 47 Relapsing/Remitting (RR)
- 07 Secondary/Progressive (SP)
From sixty-seven Gadolinium (Gd) enhancing MS lesions, on pre-contrast T1-weighted scans:
- Thirty-seven lesions were
- On thirty Gd unenhancing T1-weighted scans, pre- and post-contrast:
Choline (Cho), Creatine (Cr), N-AcetylAspartate (NAA) and Lactate were evaluated in 1H Spectra acquired from MS plaques and from Normal White Matter (NWM) of 22 Neurological controls.
MS lesions of RR patients were characterized by a significant increase of Cho/Cr and decrease of NAA/Cr and NAA/Cho ratios.
No significant metabolite changes were found in lesions of SP patients. Gd enhancing plaques showed Lactate signal with higher frequency (37.8%) than Gd unenhancing plaques (16.7%) (p=0.04).
A significant increase of Cho/Cr was found in Gd enhancing Lesions when compared to controls (p<0.01), and to Gd unenhancing lesions (p<0.05).
In particular, there was evidence of a significant increase of Cho/Cr in pre-contrast T1 HypoIntense Gd enhancing lesions (p<0.01 vs. controls).
The Gd unenhancing lesions (p<0.01), in particular the T1 HypoIntense group (p<0.05), showed a significant decrease of NAA/Cr only when compared to controls.
These data confirm that in vivo MRS indicates key pathological features of MS plaques. The increased Cho/Cr ratio found in Gd-enhancing plaques, in particular in the T1 HypoIntense lesions, may reflect increased membrane cell turnover.
The T1 HypoIntense Gd unenhancing Plaques better reflect Axonal Damage, as suggested by the decrease of NAA/Cr.
Nevertheless, the lack of statistical differences in NAA/Cr between plaque subgroups suggests that Axonal impairment might occur even in the early stages.
Axonal Damage Induced By CerebroSpinal Fluid From Patients With Relapsing/Remitting Multiple Sclerosis
Alcazar A, Regidor I, Masjuan J, Salinas M, Alvarez-Cermeno JC
J NeuroImmunol 2000 Apr 3;104(1):58-67
Servicio Bioquimica-Investigacion, Hospital Ramon y Cajal, Ctra. Colmenar Km 9, 28034, Madrid, Spain
PMID# 10683515; UI# 20184261
The importance of Axonal damage in Multiple Sclerosis (MS) has been recently stressed in Proton Magnetic Resonance Spectroscopy and Pathological studies, but the exact mechanism producing this damage is unknown.
The aim of our study was to ascertain whether soluble mediators present in the CerebroSpinal Fluid (CSF) of patients with Relapsing/Remitting MS could induce Neuron injury in culture.
Different biochemical and CytoChemical parameters were determined in Primary embryonal rat Neuron cultures following 8 days of exposure to CSF. CytoToxic activity was evaluated with a blue formazan production colorimetric assay.
Morphological and ImmunoCytoChemical studies performed with AntiBodies against beta-Tubulin revealed Neuritic fragmentation, Axonal damage and cellular shrinkage indicating Apoptosis.
Detection of Apoptosis was carried out using the fluorescent DNA-binding dye Hoechst 33342, as well as by a Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick End-Labeling assay.
We observed that soluble factors in CSF from patients with "aggressive" MS i.e, those with poor recovery after relapses, induced Neurite breakdown and Neuronal Apoptosis in cultures. Neuron injury is not related with Blood-Brain Barrier dysfunction nor with Ig G index.
Interestingly, CSF from patients with "non-aggressive" MS i.e., Relapsing/Remitting patients with a good recovery after relapses, did not induce any damage.
In conclusion, we report that CSF from patients with aggressive MS bears soluble mediators that induce Axonal damage and Apoptosis of Neurons in culture.
These mediators can be present during the first attack of the disease, and the Neuronal Damage caused could be related to the functional deficit of these MS patients.
Evidence Of Axonal Damage In The Early Stages Of Multiple Sclerosis And Its Relevance To Disability
De Stefano N, Narayanan S, Francis GS, Arnaoutelis R, Tartaglia MC, Antel JP, Matthews PM, Arnold DL
Arch Neurol 2001 Jan;58(1):65-70
Institute of Neurological Science, Viale Bracci 2, 53100, Siena, Italy
To assess Axonal damage and its contribution to disability at different stages of Multiple Sclerosis (MS).
Recent in vivo imaging and in situ pathologic studies have demonstrated that substantial Axonal damage accompanies the inflammatory lesions of MS.
However, the relation of Axonal Damage to the duration of MS and its contribution to disability at different stages of the disease remain poorly defined.
We performed Proton Magnetic Resonance Spectroscopic Imaging in 88 patients with a wide range of clinical disability and disease duration.
To measure N-AcetylAspartate (NAA), an index of Axonal integrity, relative to Creatine (Cr) in a large Central Brain Volume that included mostly Normal-Appearing White Matter on Magnetic Resonance Imaging.
We observed that the NAA/Cr values were abnormally low in the early stages of MS, even before significant disability (measured using the Expanded Disability Status Scale [EDSS]) was evident clinically, and declined more rapidly with respect to EDSS at lower than at higher EDSS scores (P<.001).
The correlation of NAA/Cr values with EDSS score was significantly (P<.03) stronger in patients with mild Disability (EDSS score <5, Spearman rank order correlation = -0.54, P<.001) than in patients with more severe Disability (EDSSscore >/=5, Spearman rank order correlation = -0.1, P<.9).
When similar analyzes were performed in patients with MS grouped for duration of disease, the subgroup with early disease duration (<5 years) also showed central Brain NAA/Cr resonance intensity ratios significantly lower than healthy controls (P<.001).
Cerebral Axonal damage begins and contributes to disability from the earliest stages of the disease.
PlasMinogen Activators In Multiple Sclerosis Lesions: Implications For The Inflammatory Response And Axonal Damage
Gveric D, Hanemaaijer R, Newcombe J, van Lent NA, Sier CF, Cuzner ML
Brain 2001 Oct;124(Pt 10):1978-88
Univ, College London, Institute of Neurology, Dept of NeuroChemistry, London, UK; Gaubius Laboratory, TNO-PG, Leiden, The Netherlands; and DIBIT, San Raffaele Scientific Institute, Dept of Molecular Medicine, Milan, Italy
PMID# 11571216; UI# 21455218
Components of the PlasMinogen Activator (PA) and Matrix MetalloProtease (MMP) cascade have been characterized in Multiple Sclerosis lesions.
By ImmunoHistoChemistry, Enzyme-linked ImmunoSorbent assay and Enzyme activity assays in order to establish a functional role for the Enzyme sequence in Lesion development.
Highly significant quantitative increases in Urokinase PA (uPA), Urokinase Receptor (uPAR) and PlasMinogen Activator Inhibitor-1 were detected.
In acute Multiple Sclerosis lesions (P < 0.0001) and in uPAR in Normal-Appearing White Matter (P < 0.0001) compared with control tissue.
All three proteins were Immunolocalized to MonoNuclear Cells in PeriVascular Cuffs and to Macrophages in the Lesion Parenchyma.
MMP-9 and the Tissue Inhibitor of MetalloProteinase-1 also increased during lesion development but the Enzyme was present largely in the inactive pro-form.
In contrast to uPA, the concentration and activity of tissue PA (tPA), the most abundant PlasMinogen Activator in normal control Brain, were reduced in Multiple Sclerosis specimens.
In acute lesions tPA co-localized with Fibrin (Ogen) on large diameter Axons also stained with SMI-32, an ImmunoHistoChemical marker of Axonal Damage
The uPA-uPAR complex, concentrated on inflammatory cells in the PeriVascular zone of the evolving lesion, may facilitate cellular infiltration into the CNS which is amplified by MMP- mediated degradation of blood vessel Matrix.
tPA localization on injured Axons may be a marker of Axonal Damage or represent a protective mechanism aimed at removal of Fibrin deposits and restoration of Axonal function.
Acute Axonal Damage In Multiple Sclerosis Is Most Extensive In Early Disease Stages And Decreases Over Time
Kuhlmann T, Lingfeld G, Bitsch A, Schuchardt J, Bruck W
Brain 2002 Oct;125(Pt 10):2202-12
Humboldt-Universitat, Department of Neuropathology, Charite, Berlin; and Ruppiner Kliniken GmbH, Department of Neurology, Neuruppin, Germany
PMID# 12244078; UI# 22229078
Multiple Sclerosis is characterized Morphologically by the key features: DeMyelination, Inflammation, Gliosis and Axonal damage.
In recent years, it has become more evident that Axonal damage is the major Morphological substrate of permanent clinical disability.
In our study, we investigated the occurrence of acute Axonal damage determined by ImmunoCytoChemistry for Amyloid Precursor Protein (APP) which is produced in Neurons and accumulates at sites of recent Axon transection or damage.
The numbers of APP-positive Axons in Multiple Sclerosis lesions were correlated with the disease duration and course.
Most APP-positive Axons were detected within the first year after disease onset, but acute Axonal damage was also detected to a minor degree in Lesions of patients with a disease duration of 10 years and more.
This effect was not due to the lack of active DeMyelinating lesions in the chronic disease stage. Late ReMyelinated lesions (so-called shadow plaques) did not show signs of Axon destruction.
The number of inflammatory cells showed a decrease over time similar to that of the number of APP-positive Axons.
There was a significant correlation between the extent of Axon Damage and the numbers of CD8+ CytoToxic T-Cells and Macrophages/Microglia.
Our results indicate that a putative Axon-protective treatment should start as early as possible and include strategies preventing T-Cell/Macrophage-mediated Axon destruction and leading to ReMyelination of Axons.
Multiple Sclerosis And Chronic AutoImmune Encephalomyelitis: A Comparative Quantitative Study Of Axonal Injury In Active, Inactive, And ReMyelinated Lesions
Kornek B, Storch MK, Weissert R, Wallstroem E, Stefferl A, Olsson T, Linington C, Schmidbauer M, Lassmann H
Am J Pathol 2000 Jul;157(1):267-76
University of Vienna, Brain Research Institute, Division of NeuroImmunology, Austria
Recent Magnetic Resonance (MR) studies of Multiple Sclerosis lesions indicate that Axonal injury is a major correlate of permanent clinical deficit. In the present study we systematically quantified acute Axonal injury.
Defined by ImmunoReactivity for ß-Amyloid-Precursor-Protein in dystrophic Neurites, in the Central Nervous System of 22 Multiple Sclerosis patients and 18 rats with Myelin-Oligodendrocyte Glycoprotein (MOG)-induced chronic Autoimmune Encephalomyelitis (EAE).
The highest incidence of acute Axonal injury was found during active DeMyelination, which was associated with Axonal damage in PeriPlaque and in the Normal-Appearing White Matter of actively DeMyelinating cases.
In addition, low but significant Axonal injury was also observed in inactive DeMyelinated plaques. In contrast, no significant Axonal damage was found in ReMyelinated shadow plaques.
The patterns of Axonal pathology in chronic active EAE were qualitatively and quantitatively similar to those found in Multiple Sclerosis.
Our studies confirm previous observations of Axonal destruction in Multiple Sclerosis lesions during active DeMyelination, but also indicate that ongoing Axonal damage in inactive lesions may significantly contribute to the clinical progression of the disease.
The results further emphasize that MOG-induced EAE may serve as a suitable model for testing Axon-protective therapies in Inflammatory DeMyelinating conditions.