Cognitive Dysfunction Lateralizes With NAA in Multiple Sclerosis

Abstract

Recent studies have demonstrated the utility of magnetic resonance (MR) spectroscopic imaging to evaluate axonal integrity in patients with multiple sclerosis (MS). Patient status in MS is frequently assessed by the Expanded Disability Status Scale, which emphasizes ambulation but underestimates the contribution of cognitive factors. Yet, cognitive functions of memory and processing are known to be impaired in MS. We used quantitative MR spectroscopy to determine this relation between cognitive function and N-acetyl aspartate (NAA) levels. We find a significant correlation (r = .63, p < .005) for the left periventricular (PV) NAA concentrations with performance on the verbal Selective Reminding Test. Right PVNAA was significantly (p < .02) correlated with the Tower of Hanoi performance, with r = .58.

MRI in Multiple Sclerosis: What’s Inside the Toolbox?

“…Such measures show relatively stronger correlations with clinical measures of disability (i.e., cognitive dysfunction and physical disability) than do conventional MRI measures. [71][72][73][74][75][76][77][78] Longitudinal studies suggest that MRS measures hold promise in predicting the development of disability. [71][72] MRS is just beginning to be applied to the study of the spinal cord in patients with MS (e.g., see section on "Spinal cord imaging" as follows for details).…”

Primary Progressive Multiple Sclerosis

“…As of the time of writing (July 2001), we found 12 different studies that used some form of 1 H-MRS or 1 H-MRSI to study patients with PPMS [13,[31][32][33][34][35][36][37][38][39][40][41]. Of these 12 studies, only 7 were articles published in peer-reviewed journals [13,31,32,34,35,37,41], the other 5 being abstracts published as part of the conference proceedings of the International Society for Magnetic Resonance in Medicine [33,36,38,39] or the American Academy of Neurology [40].…”

“…Of these 12 studies, only 7 were articles published in peer-reviewed journals [13,31,32,34,35,37,41], the other 5 being abstracts published as part of the conference proceedings of the International Society for Magnetic Resonance in Medicine [33,36,38,39] or the American Academy of Neurology [40]. Information regarding the general methodology used in each of these studies is presented in Table 1.…”

“…The remaining 11 studies [13,[32][33][34][35][36][37][38][39][40][41] all used an in vivo approach to study patients with PPMS as well as patients with other forms of MS, normal controls, or both. Unfortunately, two of the abstracts [36,38] did not present 1 H-MRS data from the different MS subgroups separately and, thus, findings in patients with PPMS could not be compared to those in patients with other forms of the disease.…”

Imaging of multiple sclerosis: Role in neurotherapeutics

“…Some evidence supports a disproportionate increase in Cr in patients with PP MS compared with those with RR MS, 115 possibly reflecting more widespread gliosis in the former. Reductions in NAA and increased signal from lipids are also found in PP MS in a manner that is consistent with findings of widespread neuronal dysfunction in RR MS. 116 Regional reductions in NAA correlate with cognitive dysfunction, 117 and the extent of adaptive cortical reorganization for motor movements shown by functional imaging has been correlated with altered NAA/Cr ratios in the centrum semiovale. 118 Reductions in NAA are associated with total T2 BOD, the extent of global tissue loss or atrophy, and the extent of tissue damage reflected by cerebral T1-hypointense lesion load.…”