Longitudinal 1H MRS changes in mild cognitive impairment and Alzheimer's disease

Abstract

Magnetic Resonance (MR)-based volume measurements of atrophy are potential markers of disease progression in patients with amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD). Longitudinal changes in 1 H MR spectroscopy ( 1 H MRS) metabolite markers have not been characterized in aMCI subjects. Our objective was to determine the longitudinal 1 H MRS metabolite changes in patients with aMCI, and AD, and to compare 1 H MRS metabolite ratios and ventricular volumes in tracking clinical disease progression in AD. The neuronal integrity marker Nacetylaspartate/Creatine ratio declined in aMCI and AD patients compared to cognitively normal elderly. The changein 1 H MRS metabolite ratios correlated with clinical progression about as strongly as the rate of ventricular expansion, suggesting that 1 H MRS metabolite ratios may be useful markers for the progression of AD. Choline/Creatine ratio declined in stable aMCI, compared to converter aMCI patients and cognitively normal elderly, which may be related to a compensatory mechanism in aMCI patients who did not to progress to AD.

On the early diagnosis of Alzheimer's Disease from multimodal signals: A survey

“…Some studies have reported lower NAA/Cr [153][154][155][156][157] and higher Cho/Cr [158] levels in several brain regions in MCI patients who developed dementia than stable MCI subjects. Nevertheless, some disagree with these findings [159,160] so further research is needed to verify MRSI's predictability from MCI to AD. Some researches have also affirmed the potential of MRSI to help in distinguishing different types of dementia from AD, such as FTD [161] or subcortical ischemic VD [162,163].…”

“…AD patients have shown metabolite abnormalities like decreased NAA or NAA/Cr levels [143][144][145][146][147][148][149], elevated mI/Cr ratio [144,147], increased or decreased Cho/Cr ratio levels depending on the stage of the disease [150] and decreased Glu levels [147][148][149] in the gray matter (GM). NAA/mI ratio has been found to be useful for distinguishing between AD patients and healthy subjects.…”

The neurochemical profile quantified by in vivo 1H NMR spectroscopy

“…Jessen et al, 2009;Kantarci et al, 2007;Watanabe et al, 2010). Furthermore, NAA decrease has been suggested to correlate with cognitive decline from light dementia to AD (e.g.…”

Mild Cognitive Impairment: A Systematic Review

“…These data confirmed previous evidence suggesting that decreased NAA/Cr levels predict future conversion to AD in subjects with MCI [26,86]. It was recently reported that while there were no differences in NAA/Cr, Cho/Cr and mI/Cr at baseline between stable MCI and MCI who converted to AD after a median follow-up period of thirteen months, the annualized rate of change in Cho/Cr ratio was greater in stable MCI compared to converter MCI and cognitively normal controls, suggesting a possible compensatory mechanism in stable MCI [61].…”