It is unclear whether alterations in cerebral pH underlie Alzheimer's disease (AD) and other dementias. We performed proton spectroscopy after oral administration of histidine in healthy young and elderly persons and in patients with mild cognitive impairment and dementia (total N = 147). We measured cerebral tissue pH and ratios of common brain metabolites in relation to phosphocreatine and creatine (Cr) in spectra acquired from the hippocampus, the white matter (WM) of the centrum semiovale, and the cerebellum. Hippocampal pH was inversely associated with age in healthy participants but did not differ between patients and controls. WM pH was low in AD and, to a lesser extent, mild cognitive impairment but not in frontotemporal dementia spectrum disorders and pure vascular dementia. Furthermore, WM pH provided incremental diagnostic value in addition to N-acetylaspartate to Cr ratio. Our study suggests that in vivo assessment of pH may be a useful marker for the differentiation between AD and other types of dementia.

中文翻译：

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正常的大脑衰老和阿尔茨海默病与较低的大脑 pH 值有关：体内组氨酸 1H-MR 光谱研究

目前尚不清楚大脑 pH 值的改变是否是阿尔茨海默病 (AD) 和其他痴呆症的原因。我们在健康的年轻人和老年人以及轻度认知障碍和痴呆患者（总 N = 147）中口服组氨酸后进行了质子光谱分析。我们测量了从海马、半卵圆中心的白质 (WM) 和小脑获得的光谱中与磷酸肌酸和肌酸 (Cr) 相关的脑组织 pH 值和常见脑代谢物的比率。健康参与者的海马 pH 值与年龄呈负相关，但在患者和对照组之间没有差异。WM pH 在 AD 和轻度认知障碍中较低，但在额颞叶痴呆谱系障碍和纯血管性痴呆中没有。此外，除了 N-乙酰天冬氨酸与 Cr 的比率外，WM pH 值还提供了增量诊断价值。我们的研究表明，体内 pH 值评估可能是区分 AD 和其他类型痴呆症的有用标记。