Axonal Loss Is Progressive And Partly Dissociated From Lesion Load In Early Multiple Sclerosis
Pascual AM, Martínez-Bisbal MC, Boscá I, Valero C, Coret F, Martínez-Granados B, Marti-Bonmati L, Mir A, Celda B, Casanova B
Neurology 2007 Jul 3;69(1):63-7
Hospital Universitario La Fe, Department of Neurology, Avda. Campanar 21, at Valencia. E. 46009, Valencia, Spain
To assess the relationship between the Spectroscopically measured Axonal Damage in the Normal-Appearing White Matter of the BrainStem.
The total Brain T2-HyperIntense Lesion Volume (T2LV), and disability in patients with early Relapsing/Remitting Multiple Sclerosis (RRMS).
Forty-three RRMS patients and 10 sex- and age-matched healthy controls were prospectively studied for 2 years.
T2-weighted Magnetic Resonance (MR) images and Proton MR Spectroscopy were acquired at the time of recruitment and at year 2.
BrainStem was considered, where large tracts join together, as a suitable region to detect early Axonal Damage.
The T2LV was calculated with a semiautomatic program.
N-AcetylAspartate (NAA), Creatine (Cr), and Choline (Cho) resonances areas were integrated with the jMRUI program, and the ratios were calculated for the sum of the Volume Elements represented at BrainStem.
The basal NAA/Cho ratio was significantly decreased in patients compared with controls.
After 2-year follow-up, there was a decrease in the NAA/Cho (-9%; p = 0.002) and NAA/Cr (-13%; p = 0.001) ratios.
And, an increase in the T2LV (19%; p = 0.043) in Multiple Sclerosis patients, whereas control subjects had no significant metabolic changes.
Significant NAA/Cr ratio decreases were observed in both patients, with and without relapses, whereas T2LV only increased in patients with relapses.
The final Expanded Disability Status Scale (EDSS) score correlated with T2LV at baseline.
But, no significant correlations were found between metabolic values, T2LV change, or EDSS score over the study period.
Our data reveal an early and progressive Axonal Damage in Relapsing/Remitting Multiple Sclerosis.
Axonal loss and T2 lesion volume seem to be at least partly dissociated processes in early stages of the disease.
Can Imaging Techniques Measure NeuroProtection And ReMyelination In Multiple Sclerosis?
Neurology 2007 May 29;68(22 Suppl 3):S72-82; discussion S91-6
Buffalo Neuroimaging Analysis Center, The Jacobs Neurological Institute, Department of Neurology, SUNY Buffalo, Buffalo, NY 14203, USA
MRI is the most important paraclinical measure for assessing and monitoring the pathologic changes implicated in the onset and progression of Multiple Sclerosis (MS)
Conventional MRI sequences, such as T1-weighted Gadolinium-enhanced and Spin-Echo
T2-weighted imaging, are unable to provide full details about the degree of inflammation and underlying NeuroDegenerative changes.
Newer nonconventional MRI techniques have the potential to detect clinical impairment, disease progression, accumulation of disability, and the NeuroProtective effects of treatment.
Unenhanced T1-weighted imaging can reveal HypoIntense black holes, a measure of chronic NeuroDegeneration.
Two- and Three-dimensional Fluid-Attenuated Inversion Recovery sequences allow better identification of Cortical lesions.
Ultrahigh-field strength MRI has the potential to detect Subpial Cortical and deep Gray Matter lesions.
Magnetization Transfer Imaging is increasingly used to characterize the evolution of MS lesions and Normal-Appearing Brain Tissue.
Evidence suggests that the dynamics of Magnetization Transfer changes correlate with the extent of DeMyelination and ReMyelination.
Magnetic Resonance Spectroscopy, which provides details on tissue BioChemistry, metabolism, and function, also has the capacity to reveal NeuroProtective mechanisms.
By measuring the motion of water, Diffusion Imaging can provide information about the orientation, size, and geometry of tissue damage in white and Gray Matter.
Functional MRI may help clarify the Brain's plasticity-dependent compensatory mechanisms in patients with MS.
High-resolution MicroAutoRadiography and new contrast agents are proving to be sensitive means for characterizing molecular markers of disease activity, such as activated Microglia and Macrophages.
Optical Coherence Tomography, a new research technique, makes it possible to investigate relevant physiologic systems that provide accurate measures of tissue changes secondary to the MS disease process.
Although detecting the status of Neuronal integrity using MRI techniques continues to improve, a "gold standard" model remains to be established.
Onset And Underpinnings Of White Matter Atrophy At The Very Early Stage Of Multiple Sclerosis--A Two-Year Longitudinal MRI/MRSI Study Of Corpus Callosum
Audoin B, Ibarrola D, Malikova I, Soulier E, Confort-Gouny S, Duong MV, Reuter F, Viout P, Ali-Chérif A, Cozzone PJ, Pelletier J, Ranjeva JP
Mult Scler 2007 Jan;13(1):41-51
Université de la Méditerranée, Faculté de Médecine, Centre de Résonance Magnétique Biologique et Médicale, UMR CNRS 6612, 27 Boulevard Jean Moulin, Marseille 13385, 05. France
Atrophy of Corpus Callosum (CC), a White Matter structure linking the two Hemispheres, is commonly observed in Multiple Sclerosis (MS).
However, the occurrence and processes leading to this alteration are not yet determined.
Goal And Methods
To better characterize the onset and progression of CC Atrophy from the early stage of MS.
We performed a two-year follow-up Magnetic Resonance Imaging/Magnetic Resonance Spectroscopic Imaging (MRI/MRSI) exploration of CC in 24 patients with Clinically Isolated Syndrome.
These patients were explored using the same protocol at month (M)6, M12 and M24.
MRI/MRSI techniques were applied to measure CC volume, and relative concentrations of N-AcetylAspartate (NAA), Creatine/PhosphoCreatine (Cr) and Choline-containing compounds (Cho).
A group of matched controls was also explored.
Atrophy of CC, not present at baseline, was observed at M12 and progressed over the second year (M24).
At baseline, a decrease in relative NAA level was observed in the Anterior and Posterior Body of CC, with normalization during the follow-up period.
In the Anterior Body, an increase in relative Cho level was observed, with normalization at M6.
Normal relative Cr levels were observed at all time points in all sub-regions.
The rate of CC Atrophy was correlated with the change in the Expanded Disability Status Scale (EDSS) during the follow-up period.
These results suggest that CC Atrophy appears over a period of one year after the first acute inflammatory episode, and that this Atrophy is accompanied, especially in the Anterior Body of CC.
By a normalization of the relative Cho levels, marker of acute inflammation, and NAA levels, marker of Neuronal Dysfunction and/or Loss.