Proton MRS of Gadolinium‐enhancing MS Plaques and Metabolic Changes in Normal‐Appearing White Matter

Abstract

Localized short echo time (TE = 20 ms), stimulated echo acquisition mode, and double spin echo (TE = 135 ms) proton spectroscopy were performed in clearly defined, acute Gadolinium (Gd)-enhancing multiple sclerosis (MS) plaques of 22 patients with clinically definite MS. The resonances of N-acetylated metabolites (NA), creatine/phosphocreatine (Cr), choline-containing compounds (Cho), glycine/myo-inositol (Ino), and lactate were evaluated. The ratios of NA/Cr and NA/Cho were significantly decreased, Cho/Cr increased, and Ino/Cr remained unchanged. No marker peaks or elevated lactate levels were found. The measured metabolic changes were practically independent of the relative plaque size within the volume of interest (8 ml). Thus, the spectral changes measured with 1H MRS in acute Gd-enhancing MS plaques originate not only from the lesion as depicted by MRI, but also from the surrounding normal-appearing white matter.

Digitized image analysis reveals diffuse abnormalities in normal‐appearing white matter during acute experimental autoimmune encephalomyelitis

“…Using proton magnetic resonance spectroscopy (MRS) in combination with magnetic resonance imaging (MRI), several groups have shown decreased levels of the neuronal marker N-acetyl aspartate in otherwise NAWM indicating that axonal damage or loss occurs in MS in tissue distant from lesion areas (Peters et al, 1995;Roser et al, 1995;Matthews et al, 1996;Pan et al, 1996;Tourbah et al, 1996;De Stefano et al, 1997;Narayanan et al, 1997;Rooney et al, 1997;Schiepers et al, 1997;Sarchielli et al, 1998), a finding consistent with recent reports showing increased CNS staining for amyloid precursor protein (Ferguson et al, 1997) and nonphosphorylated neurofilaments (Trapp et al, 1998) in MS tissue. Thus, autoimmune inflammation and demyelination may result in loss of myelin and axonal damage in areas that either receive projections from or send projections to sites of manifest inflammation.…”

“…Recent studies indicate that abnormalities of NAWM may actually precede the appearance of visible enhancing lesions in MS. Several MRI/MRS-based studies have shown decreased choline levels in NAWM of MS patients suggesting increased microdemyelination or membrane turnover in tissue areas showing no overt signs of lesion activity (Roser et al, 1995;Pan et al, 1996;Tourbah et al, 1996). Most recently, retrospective analysis of coregistered images of monthly scans have shown that prior to the appearance of enhancement, NAWM of MS patients shows increased magnetization transfer ratios consistent with microdemyelination and altered vascular permeability (Goodkiin et al 1998;Comi et al, 1998).…”

Localized 1 H magnetic resonance spectroscopy in mainly cortical gray matter of patients with multiple sclerosis

“…The most relevant findings in MS concern the reduction in the N-acetylaspartate (NAA) peak which is more consistent, but partially reversible, in large acute lesions. This reduction is present and maintained in chronic lesions and has also been detected in NAWM [1,2,3,13,14,15,17,20,22,24,27,30,32,33,34,35,36,40,42,43,46,47,50,53]. The decrease in the values of this neural marker has been interpreted either as an index of loss of neural viability and therefore of potential neural recovery, particularly in acute lesions, or as an index, when persisting, of neural loss and therefore accumulation of irreversible disease, especially in chronic demyelinating lesions and s Abstract The brain water fraction (R), the brain water transverse relaxation time (T2), the atrophy index (α) and the absolute concentration of the principal brain metabolites (NAA, Cho and Cr) were measured by localized proton magnetic resonance spectroscopy in the occipito-parietal cortex (mainly gray matter) of 15 relapsing-remitting (R-R) multiple sclerosis (MS) patients, 15 secondary progressive (SP) MS patients and 8 healthy subjects.…”

Neurometabolite Markers of Cerebral Injury in the Antiphospholipid Antibody Syndrome of Systemic Lupus Erythematosus

“…30,32,33 Cho/Cre was increased in normal-appearing tissues even when other clinical factors were included, suggesting exaggerated injury to normal-appearing tissue in patients with SLE-aPLS consistent with widespread microinfarction. 5,6,28,34 The effect of aPLS remained significant even after adjusting for all clinical factors ( Table 5).…”