Magnetic Resonance Spectroscopy of Memory and Frontal Brain Region in Early Multiple Sclerosis

Abstract

In vivo proton magnetic resonance spectroscopy (1H-MRS) has been used to assess biochemical changes that occur in demyelinating lesions and in normal appearing white matter (NAWM) in multiple sclerosis (MS) patients. N-acetylaspartate (NAA) levels in MS patients may indicate neural viability. In early stages of MS, patients may suffer from slight cognitive impairment. The objective of this study was to investigate memory function in relation to biochemical properties of frontal brain areas of MS patients. Twenty-one patients with relapsing-remitting MS and 21 healthy comparison subjects were examined psychometrically using the Wechsler Memory Scale (WMS) and the Multiple Sclerosis Functional Composite (MSFC) scale, and (1H-MRS) was used to examine frontal deep white matter (left hemisphere) and the frontal cingulate gyrus (Brodmann areas 24/32, bihemispheric). A significant reduction of the NAA/Creatine (Cr) ratio in the frontal cingulate gyrus among the MS patient group was detected when compared to healthy subjects. A significant decrease in the NAA/Cr ratio was also found in volumes of cerebral deep white matter, including plaques, in the MS patients. No NAA/Cr ratio changes were found in NAWM. Differences in MSFC results did not reach statistical significance, but the WMS general memory score showed a significant statistical difference between the patient group and healthy subjects. Regression analysis showed the gray matter NAA/Cr ratio of the frontal cingulate gyrus to be significantly related to distinct memory functions. The authors conclude that (1H-MRS) of gray matter in early stages of MS may be pertinent in the detections of early metabolic disturbances, particularly in subjects with or without minor neurological impairment. Findings suggest a general relationship between the metabolic status of the frontal cortices and memory function.

Quantifying the Metabolic Signature of Multiple Sclerosis by in vivo Proton Magnetic Resonance Spectroscopy: Current Challenges and Future Outlook in the Translation From Proton Signal to Diagnostic Biomarker

“…Creatine-referenced N-acetyl aspartate has shown reductions relative to control in mixed or unspecified multiple sclerosis lesions (22–35), white matter (36), normal-appearing white matter (22, 24, 25, 30, 34, 37–46), and mixed tissue (47); in relapsing-remitting multiple sclerosis lesions (48–56), white matter (36, 54, 57–64), normal-appearing white matter (48, 50–52, 65–70), gray matter (54, 70), mixed tissue (54, 58, 63, 71–75), and spine (76); and in progressive multiple sclerosis lesions (50, 52, 77–79), white matter (36, 60, 62, 80), normal-appearing white matter (45, 46, 50, 52, 66, 69, 78, 79, 81, 82), gray matter (83), and mixed tissue (71, 73, 84–89). In addition, N-acetyl aspartate quantified as institutional units or relative to non-creatine references like water or phantom acquisitions has been shown to decrease in mixed or unspecified multiple sclerosis lesions (22, 29, 90–96), white matter (97, 98), normal-appearing white matter (22, 91, 94, 99–105), gray matter (94, 100, 103, 104, 106), mixed tissue (107, 108), spine (109–112), and whole-brain measures (113, 114); in relapsing-remitting lesions (50, 53, 96, 115–…”

A quantitative comparison of metabolite signals as detected by in vivo MRS with ex vivo1H HR‐MAS for childhood brain tumours

“…In vivo 1 H MRS is a powerful non-invasive method for measuring the concentration of biochemicals in a pre-selected volume of interest. The biochemical profiles measured by 1 H MRS have been used to diagnose and characterise a variety of diseases (1)(2)(3)(4)(5)(6)(7). Non-invasive methods are of particular clinical importance in the study of childhood brain tumours, and 1 H MRS has been shown to provide information on tumour type, grade and prognosis (7)(8)(9) as well as being a promising tool for treatment monitoring.…”

Análisis crítico de los estudios de neuroimagen en relación con el rendimiento cognitivo en pacientes con esclerosis múltiple

“…Finalmente, otros autores han comprobado que la información cuantitativa aportada por las técni-cas de espectroscopía, como la disminución de los niveles del metabolito N-acetil aspartato (NAA) -que aparece predominantemente en placas crónicas y refleja destrucción neuronal-, puede ser también un buen predictor del rendimiento cognitivo en pacientes con EM [54,55]. Utilizando esta técnica, se muestran correlaciones significativas entre tests neuro psicológicos de aprendizaje verbal y planificación y disminuciones del NAA en zonas de la sustancia blanca periventricular [56], y un menor rendimiento en pruebas de memoria y disminución del NAA asociada al cingulado anterior [57]. Por otra parte, se ha asociado la peor ejecución en tests atencionales de escucha dicótica en pacientes con EM, con disminuciones en el NAA en la zona del sistema atencional activador del locus coeruleus [58].…”