Advances in High-Field Magnetic Resonance Spectroscopy in Alzheimer’s Disease

Abstract

Alzheimer’s disease (AD) affects several important molecules in brain metabolism. The resulting neurochemical changes can be quantified non-invasively in localized brain regions using in vivo single-voxel proton magnetic resonance spectroscopy (SV 1H MRS). Although the often heralded diagnostic potential of MRS in AD largely remains unfulfilled, more recent use of high magnetic fields has led to significantly improved signal-to-noise ratios and spectral resolutions, thereby allowing clinical applications with increased measurement reliability. The present article provides a comprehensive review of SV 1H MRS studies on AD at high magnetic fields (3.0 Tesla and above). This review suggests that patterned regional differences and longitudinal alterations in several neurometabolites are associated with clinically established AD. Changes in multiple metabolites are identifiable even at early stages of AD development. By combining information of neurochemicals in different brain regions revealing either pathological or compensatory changes, high field MRS can be evaluated in AD diagnosis and in the detection of treatment effects. To achieve this, standardization of data acquisition and analytical approaches is needed.

Human Neural Stem Cell Transplantation Rescues Cognitive Defects in APP/PS1 Model of Alzheimer’s Disease by Enhancing Neuronal Connectivity and Metabolic Activity

“…mI is associated with the activation or proliferation of astrocytes, often used as a featured marker of glial cells (Oz et al, 2014). While Cho was shown to increase due to disrupted cell membrane in AD brains, mI was to be elevated because of reactive astrocyte proliferation (Zhang N. et al, 2014). In this study, we showed that Cho and mI were both increased in the frontal cortex and hippocampus of AD mice but only increased mI reached significance.…”

“…Despite much progress in the pathogenesis, no curative measures have been developed to improve the poor prognosis of patients with AD. Currently, the widely-used therapies including cholinesterase inhibitors and N-methyl D-aspartic acid (NMDA) receptor antagonists are symptomatic (Fereshtehnejad et al, 2014), which have diminished efficacy with long-term medication and always bring considerable side effects (Zhang N. et al, 2014). …”

“…Magnetic resonance spectroscopy (MRS) provides a non-invasive measure to quantitate brain metabolism and it is becoming widely used in researches of AD (Chen et al, 2012). The metabolites characteristic of AD include N-acetylaspartate (NAA), choline (Cho), glutamate (Glu), myo-inositol (mI) and creatine (Cr; Ackl et al, 2005; Zhang N. et al, 2014). While NAA and Glu were found to decrease in AD, mI exhibited an early increase (Zhang N. et al, 2014).…”

“…The metabolites characteristic of AD include N-acetylaspartate (NAA), choline (Cho), glutamate (Glu), myo-inositol (mI) and creatine (Cr; Ackl et al, 2005; Zhang N. et al, 2014). While NAA and Glu were found to decrease in AD, mI exhibited an early increase (Zhang N. et al, 2014). Thus, MRS offers a sensitive and reliable tool to detect brain metabolic changes, which can be used to assess the effects of NSC transplantation on AD (Arturo et al, 2004).…”

Quantitativein vivoneurochemical profiling in humans: where are we now?

“…These MRS studies report valuable observations about a variety of CNS disorders, but the range of detectable metabolites is almost completely limited only to NAA, tCr and tCho. Some recent publications of interest include reviews on Alzheimer disease and mild cognitive impairments, 51,52 common dementias, 53 psychiatric disorders, 54 autism spectrum disorders 55 and alcohol abuse disorders. 56 Recently, the MRS 63 Potential of in vivo neurochemical profiling in epidemiology…”