皮质下缺血性脑血管病的磁共振波谱研究

目的:检测皮质下缺血性脑血管病(SIVD)患者和正常对照组不同脑区脑组织的代谢水平,探讨其与认知功能损害的关系。方法:采用多体素磁共振波谱(1 H-MRS)技术评测SIVD患者(SIVD组,n=32例)和体检健康人(对照组,n=21)额叶及顶叶皮质、白质的代谢物N-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr);计算有关比值NAA/Cr、Cho/Cr,分析有无认知功能损害SIVD患者上述比值的变化。结果:(1)SIVD组额叶皮质、白质及顶叶皮质、白质各体素NAA/Cr比值明显低于对照组(P0.01);(2)SIVD组顶叶皮质及白质的Cho/Cr比值明显高于对照组(P0.01);(3)SIVD组有认知功能损害患者的额叶皮质和顶叶皮质、白质NAA/Cr比值显著低于无认知功能损害者(P值分别0.01、0.01、0.05),Cho/Cr比值的两者间差异无统计学意义(P0.05)。结论:SIVD患者脑组织存在NAA/Cr、Cho/Cr比值改变,且额叶皮质和顶叶皮质、白质NAA/Cr的下降与认知损害有关。     

首发抑郁症患者海马质子磁共振波谱成像研究

目的:探讨首发抑郁症患者海马的磁共振质子波谱(1HMRS)特点.方法:应用1HMRS成像技术检测21例未用药首发抑郁症患者和14例健康志愿者海马N-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)3种代谢物,计算NAA/Cr和Cho/Cr比值.结果:首发抑郁症患者组双侧海马NAA/Cr比值低于对照组,差异有统计学意义(右侧:0.88±0.29/1.37±0.51,P=0.004;左侧:0.76±0.33/1.40±0.99,P=0.034);Cho/Cr比值两组间无统计学差异(P＞0.05);双侧海马NAA/Cr和Cho/Cr与抑郁严重度无相关性(P＞0.05).结论:首发抑郁症患者可能存在双侧海马神经元活力和功能下降.     

首发精神分裂症患者脑磁共振质子波谱的对照研究

目的研究首发精神分裂症患者脑磁共振质子波谱(1HMRS)的变化。方法对26例首发精神分裂症患者和12例正常人分别进行MRI常规扫描和1HMRS检查,1HMRS采用定点分辨率波谱序列(TR2000毫秒,TE135毫秒),所测定的代谢产物包括N-乙酰基天门冬氨酸(NAA)、肌酸复合物(Cr)、胆碱复合物(Cho)、肌醇(MI)、乳酸(Lac)、谷氨酸及谷氨酰胺(Glu-Gln)。结果精神分裂症患者前额叶背外侧回中NAA/Cr值和NAA/Cho值显著低于对照组前额叶背外侧回(1.83±0.15/2.42±0.13,t=3.202,P<0.01,2.37±0.16/2.06±0.24,t=2.453,P<0.05);患者组海马区中NAA/Cr值(1.65±0.19)和NAA/Cho值(1.12±0.21)显著低于对照组海马中的NAA/Cr值(1.83±0.27,t=2.532,P<0.05)和NAA/Cho值(1.34±0.12,t=2.641,P<0.05);且NAA/Cr的水平与简明精神障碍评定量表阴性症状总分呈负相关(r=-0.416,P<0.05);而丘脑、颞叶颞横回、枕叶脑区的NAA/Cr和NAA/Cho两组无显著性差异(P>0.05)。结论精神分裂症患者的1HMRS与正常人存在显著差异,提示精神分裂症存在神经元功能的异常,其前额叶背外侧回和海马两处脑区功能低下。     

磁共振波谱分析在颅脑胶质瘤分级中的应用研究

目的分析脑胶质瘤的氢质子磁共振波谱(proton magnetic resonance spectroscopy,~1H-MRS)表现及其临床意义;探讨脑胶质瘤的1H-MRS特点与其病理级别相关性。方法搜集经临床手术、病理证实的脑胶质瘤病例49例,按照WHO诊断标准分成两组:低级别脑胶质瘤组、高级别脑胶质瘤组。所有患者在术前行~1H-MRS检查,均在MR非增强成像的基础上获得。使用Philips Achieva 1.5T超导磁共振扫描仪,单体素或多体素扫描,点分辨法,检测不同区域代谢物变化。结果脑胶质瘤的~1H-MRS表现:肌酸(Cr)轻度下降,N-乙酰天门冬氨酸(NAA)显著下降,胆碱(Cho)显著增高。低、高级别脑胶质瘤的肿瘤组织与对侧正常脑组织的NAA、Cho、NAA/Cr、NAA/Cho值存在显著性差异(P0.05);低级别和高级别脑胶质瘤的肿瘤组织的NAA/Cr、NAA/Cho值存在显著性差异(P0.05)。脑胶质瘤的NAA/Cho、Cho/Cr、NAA/Cr值与病理级别相关,其中NAA/Cho和NAA/Cr值反映肿瘤级别较稳定;NAA/Cr、NAA/Cho值呈负相关关系,Cho/Cr值呈正相关关系。结论 :~1H-MRS结合MRI能提高脑胶质瘤术前诊断的准确性。~1H-MRS能对胶质瘤进行分级,反映胶质瘤代谢特性以及肿瘤生长潜能。     

颞叶癫癎磁共振波谱研究

目的 :探讨磁共振波谱 (magneticresonancespectrum ,MRS)检查对颞叶癫患者致灶的定位价值。方法 :对 36例颞叶癫患者进行MRS检查 ,主要分析波谱的三个峰 :N—乙酰天门冬氨酸 (NAA)峰位于 2 0 ppm ,总肌酸 (Cr)峰位于 3 0 ppm ,胆碱类物质 (Cho)峰位于 3 2ppm) ,根据波峰曲线下的绝对面积计算出NAA/ (Cr Cho)的比值 ,以NAA(Cr Cho) <0 6 8作为判断异常的标准。结果 :36例病人中 34例NAA/ (Cr Cho)比值 <0 6 8,其中双侧异常 2 1例 ,单侧异常 13例。结论 :MRS能准确反映体内NAA、Cho、Cr等代谢产物的变化 ,对颞叶癫的致灶有定位价值。     

阿尔茨海默病大鼠氢质子磁共振波谱研究

目的:探讨海马注射β-淀粉样肽(Aβ1-42)诱发阿尔茨海默病(AD)大鼠模型的病理学变化及氢质子磁共振波谱(~1H MRS)特性。方法:健康SD大鼠40只,实验随机分为假伤组(Sham组)、阿尔茨海默病模型(AD组)。采用大鼠海马注射Aβ_(1-42)复制AD模型。苏木精-伊红染色法染色观察海马CA1区神经元形态,免疫化学染色观察Aβ的沉积,采用Morris水迷宫法进行大鼠记忆功能的测定。~1H MRS检测AD鼠脑中的N-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)和乳酸(Lac)水平。结果:与Sham组比较,AD组游全程时间延长,错误次数增加,差异显著(均P0.01)。与Sham组比较,AD组双侧海马CA1区神经元数目减少,核固缩增加;且与注射对侧比较,Aβ_(1-42)注射侧大鼠海马CA1区神经元数目显著减少,核固缩显著增加。免疫化学染色Sham组呈阴性;AD组双侧抗Aβ1-42呈阳性,且与注射对侧比较,注射侧阳性显著增加。~1H MRS结果Sham组双侧半球无显著性差异。与Sham组比较,AD组双侧~1H MRS海马NAA/Cr明显降低、Cho/Cr增加、Lac/Cr增加;在AD组,与注射对侧半球比较,注射侧半球海马NAA/Cr明显降低(P0.05)、Cho/Cr显著增加(P0.01)、Lac/Cr显著增加(P0.01)。结论:Aβ1-42能引起大鼠海马CA1区神经元损伤,记忆功能下降,注射Aβ后4周NAA/Cr已有明显改变,与免疫组化发现Aβ1-42表达增强结果一致,提示利用~1H MRS检测NAA/Cr改变,可能有助于AD早期临床诊断。     

帕金森病大鼠模型额叶皮质的代谢及形态改变

目的：探讨帕金森病中大脑额叶皮质的形态及代谢改变。方法：大鼠实验组于6-OHDA毁损后用BIOSPEC47／30磁共振波谱仪(4．7T)，采用点分辨波谱法对双侧额叶皮质行H-MRS检测，分析该区N-乙酰天门冬氨酸／肌酸(NAA／Cr)和胆碱／肌酸(Cho／Cr)比值的变化，并用电镜观察该区神经元及突触的形态变化。结果：实验组大鼠损毁侧额叶皮质．NA．A／Cr比值显著低于对侧，对照组两侧无显著差别；Cho／Cr比值在两组的两侧相比均无显著差别。电镜观察显示：损毁侧额叶皮质的突触数量较对侧减少，突触前、后膜和突触小泡结构异常，典型突触结构消失，树突棘出现大片低电子密度区，细胞器消失。结论：帕金森病大鼠模型损毁侧额叶皮质内存在神经元缺失或突触数量的减少，突触结构异常及功能异常。     

弥散加权成像联合磁共振波谱分析在脑梗死中的应用研究

目的探讨脑梗死弥散加权成像(DWI)和磁共振波谱分析(MRS)的特点和影响因素,及二者对评估脑梗死的临床价值。方法采用Philips Achieva 1.5T双梯度超导磁共振扫描仪,对72例临床疑是脑梗死患者行常规T1WI、T2WI、FLAIR、DWI、MRS检查,在工作站上测定梗死核心区、内缘区、外缘区、周围区和镜像区的ADC值和代谢物Lac、NAA、Cr、Cho、NAA/Cr、Lac/Cr、Lac/NAA值。结果 DWI显示的梗死灶范围较常规MRI像更加准确、清晰;超急性期、急性期、亚急性期和慢性期梗死核心区的Lac/Cr值和Lac/NAA值高于对侧镜像区,ADC值和NAA/Cr值低于对侧镜像区,存在统计学差异(P<0.05);DWI的影响因素有b值、扩散系数、T2穿透效应和各向异性等,MRS的影响因素有磁场均匀性、压水压脂性能、体素、TE与TR、组织代谢物浓度和波谱采集链等。结论 DWI结合MRS能更加全面地评估缺血半暗带,更精确地对脑梗死进行分期和定位。     

难治性抑郁症患者rTMS治疗前后双侧前额叶质子磁共振波谱定量研究

目的:探讨难治性抑郁症患者与正常对照之间神经生化代谢分布的差异,探索rTMS治疗前后难治性抑郁症局部脑代谢物的特异性.方法:应用1H-MRS检测34例难治性抑郁症患者双侧前额叶N-乙酰天门冬氨酸(NAA)、谷氨酸(Glx)、胆碱复合物(cho)、肌醇(ml)及肌酸(cr)5种代谢物,分别计算NAA、Glx、Cho、mI与Cr的比值,并与28名健康对照者比较.对34例难治性抑郁症患者进行4周共20次高频rTMS治疗.治疗前后分别评定汉密尔顿抑郁量表(HAMD).治疗后再次应用1H-MRS检测34例难治性抑郁症患者双侧前额叶代谢物分布特征.结果:①rTMS治疗前难治性抑郁症组患者左侧前额叶皮质mI/Cr比值明显低于健康对照组(P＜0.001).rTMS治疗组治疗有效患者mI/Cr比值增高,与健康对照比较无显著性差异.(②在控制年龄、病程的影响后,rTMS治疗组左侧前额叶mI/Cr改变与HAMD减分率成正相关(r=0.86,P=0.000).结论:难治性抑郁症患者可能存在前额叶胶质细胞代谢异常,有效的rTMS治疗可改善神经胶质细胞功能.     

基于纤维束的空间统计方式的复发缓解型多发性硬化患者磁共振扩散张量成像与正常人对照

目的:利用基于纤维束的空间统计(TBSS)方式结合磁共振扩散张量成像技术(DTI)综合评价DTI对复发缓解型多发性硬化(RRMS)患者全脑白质微结构改变与正常人的对比,并探讨其应用价值。方法:实验组和对照组均进行全脑轴位常规扫描及DTI扫描,数据进行TBSS后处理,生成三维平均各向异性系数纤维骨架并进行非参数统计比较。结果:RRMS患者全脑双侧额叶、颞叶、顶叶及枕叶脑白质区域纤维素呈广泛性各向异性系数值减低、平均扩散率值升高,差异有统计学意义(P0.05)。结论:RRMS患者双侧额叶、颞叶、顶叶及枕叶脑白质区存在广泛的脑白质损伤,TBSS后处理方法能较为准确地定位和定量监测、评估及发现RRMS病灶。     

二维磁共振波谱分析在评价颅内胶质瘤中的临床应用

目的探讨脑胶质瘤二维磁共振波谱分析(2D 1H-MRS)表现及其主要代谢物含量变化。方法选择120例幕上脑胶质瘤行常规MRI及2D-1H-MRS检查并定量检测其主要代谢物N-乙酰天门冬胺酸(NAA)、含胆碱化合物(Cho)、肌酸(Cr)、乳酸(Lac)和脂质(Lip)含量。采用t检验进一步探讨各级别胶质瘤代谢物含量的差异。结果120例接受常规MRI和2D-1H-MRS检查的病例按术后病理结果分为三组:星形细胞瘤(AS)40例,间变性星形细胞瘤(AA)40例,胶质母细胞瘤(GM)40例。随胶质瘤恶性程度的增加,NAA呈下降趋势,Cho呈上升趋势,Cr变化不明显或轻度下降,Lip-Lac呈升高趋势。在AS与AA、AS与GM、AA与GM间NAA含量差异显著(p<0.01)。在AS与GM间Cr含量差异显著(P<0.05),在AS与AA、GM间Cho含量差异显著(p<0.01)。在AS与AA、AS与GM、AA与GM间Cho/cr比值差异显著(p<0.01);在AS与AA、GM间及AA与GM间NAA/Cho比值差异显著(p<0.01,P<0.05);在AS与AA、GM间Lip/lac比值差异显著(p<0.01)。结论胶质瘤2D1H-MRS表现及其代谢物定量研究有助于胶质瘤临床诊断与肿瘤恶性度分级。     

Proton magnetic resonance spectroscopy in children with spastic diplegia

The objective of this prospective study was the application of proton magnetic resonance spectroscopy in children with spastic diplegia (SD) to determine the metabolite profile of SD children in the left basal ganglia, and to assess the relationship of this profile with motor and mental development. Patients with SD showed reduced ratios of N-acetylaspartate (NAA)/creatine (Cr), NAA/choline (Cho), NAA/myo-inositol (mI), Cho/NAA, Cho/Cr and Cho/mI in the basal ganglia compared to a well-matched control group. On the other hand, we noted increased Cr/NAA, Cr/Cho and mI/NAA ratios in the SD patients as compared with controls. NAA/mI ratios were positively correlated with the severity scale of cerebral palsy in SD children. There was also a significant correlation between Cr/NAA and mental retardation. Increased Cr/NAA, Cr/Cho and mI/NAA ratios in SD children may suggest the existence of the compensatory mechanisms in these patients. The NAA/mI ratio could be used as an additional marker of SD severity and Cr/NAA as a marker of the mental retardation.     

MRI and 1H-MRS detects volumetric and metabolic abnormalities of hippocampal sclerosis in temporal lobe epilepsy

Objective:To further investigate the ability of MRI and 1H-MRS techniques for presurgical evaluation of hippocampal sclerosis. Methods:MRI and 1H-MRS were performed on 30 healthy subjects to determine the confidence levels. Eight patients who were pathologically confirmed hippocampal sclerosis were then studied using the same protocols. The difference of hippocampal formation (DHF) was used to determine atrophy of hippocampus. Areas under the peak of N-acetylaspartate(NAA) ,Creatine(Cr) and Choline (Cho) were measured, and the ratios of NAA/Cr, Cho/Cr, and NAA/Cr+Cho were calculated. NAA/Cr+Cho value was applied to localize the seizure focus. Results:Two patients showed hippocampal atrophy according to DHF value. NAA/Cr ratio decreased significantly in ipsilateral hippocampus compared to that in contralateral hippocampus and control subjects(P＜0.01). Cho/Cr value increased in both ipsi-and contralateral hippocampus in comparison with that in control subjects(P＜0.01). NAA/Cr+Cho ratio, however, significantly reduced in both ipsi-and contralateral hippocampus(P＜0.01) with lowest NAA/Cr+Cho ratio in seizure foci. Six patients could be lateralized by reduced and/or asymmetric NAA/Cr+Cho value. Conclusion:1H-MRS should be a promising diagnostic tool to detect neuron abnormality.1H-MRS and MRI complement each other hi presurgical lateralization of epileptogenic lesion in epilepsy patients.     

Comparisons of brain metabolites observed by HRMAS 1H NMR of intact tissue and solution 1H NMR of tissue extracts in SIV-infected macaques

The objective of this study was to compare ex vivo proton high-resolution magic angle spinning magnetic resonance spectra of intact tissue with those spectra obtained by solution (1)H NMR of brain extracts of the same sample. Sixteen brain tissue samples from simian immunodeficiency virus-infected rhesus macaques from both frontal cortex and putamen were evaluated by comparing brain metabolite quantities of N-acetylaspartate (NAA), choline-containing compounds (Cho), myo-inositol (MI), creatine (Cr), lactate (Lac), glutamate (Glu) and acetate (Ace). The ratios of the individual NMR peak areas of all metabolites relative to the creatine peak area were calculated. Linear regression analysis revealed significant correlations between measurements using the two methods. The strength of the correlations varied depending on the metabolite studied. We found highly significant correlations for NAA/Cr (r2 = 0.77; p < 0.0001), NAA + Ace/Cr (r2 = 0.73; p < 0.0001) and MI/Cr (r2 = 0.75; p < 0.0001). We observed somewhat less strong correlations for Glu/Cr (r2 = 0.54; p < 0.002) and Lac/Cr (r2 = 0.54; p < 0.002). There was a substantially weaker correlation for Cho/Cr (r2 = 0.32; p = 0.02). When plotting the metabolite ratios obtained by 1H HRMAS NMR of the intact tissue sample on the ordinate vs 1H NMR of the tissue extract on the abscissa, most metabolites exhibited a slope close to unity, and a positive intercept probably due to macromolecular contributions to the MAS spectra. The slope for Cho/Cr was substantially less than unity. Generally, samples from the frontal cortex showed a better correlation between intact and extracted tissue samples than putamen. This is most prominent in the cases of NAA/Cr and Cho/Cr. We conclude that both methods provide substantially the same information for most major brain metabolites, with the exception of the Cho resonance.     

Aerobic Fitness and the Brain: Increased N-Acetyl-Aspartate and Choline Concentrations in Endurance-Trained Middle-Aged Adults

Engagement in regular aerobic exercise is associated with cognitive benefits, but information on the mechanisms governing these changes in humans is limited. The goal of the current study was to compare neurometabolite concentrations relating to cellular metabolism, structure, and viability in endurance-trained and sedentary middle-aged adults. Twenty-eight endurance-trained and 27 sedentary adults, aged 40–65 years, underwent general health assessment, cardiorespiratory fitness measurement, neuropsychological testing, and proton magnetic resonance spectroscopy (¹H MRS). ¹H MRS was used to examine N-acetyl-aspartate (NAA), creatine (Cr), myo-inositol (mI), choline (Cho), and glutamate (Glu) concentrations in frontal and occipitoparietal grey matter. Group differences in concentrations of NAA, Cho, mI, and Glu, calculated as ratios over Cr, were explored using ANOVA. There were no significant differences in global cognitive function, memory, and executive function performance between the groups. In comparison to sedentary adults, the endurance-trained group displayed significantly higher NAA/Cr in the frontal grey matter (F(1, 53) = 5.367, p = 0.024) and higher Cho/Cr in the occipitoparietal grey matter (F(1, 53) = 5.138, p = 0.028). Within our middle-aged sample, endurance-trained adults demonstrated higher levels of NAA/Cr in the frontal grey matter and higher Cho/Cr in the occipitoparietal grey matter. Higher levels of NAA may indicate greater neuronal integrity and higher cerebral metabolic efficiency in association with cardiorespiratory fitness, whereas increased Cho may represent increased phospholipid levels secondary to neural plasticity.     

Metabolic alterations in the visual pathway of retinitis pigmentosa rats: A longitudinal multimodal magnetic resonance imaging study with histopathological validation

Because retinitis pigmentosa (RP) has been shown to cause degenerative changes in the entire visual pathway, there is an urgent need to perform longitudinal assessments of RP-induced degeneration and identify imaging protocols to detect this degeneration as early as possible. In this study, we assessed a transgenic rat model of RP by using complementary noninvasive magnetic resonance imaging techniques, namely, proton magnetic resonance spectroscopy (¹H-MRS), to investigate the metabolic changes in RP. Our study demonstrated decreased concentrations and ratios to creatine (Cr) of N-acetylaspartate (NAA), glutamate (Glu), γ-aminobutyric acid (GABA), and taurine (Tau), whereas myo-inositol (Ins) and choline (Cho) were increased in the visual cortex of Royal College of Surgeons (RCS) rats compared with control rats (p < 0.05). Furthermore, with the progression of RP, the concentrations of NAA, Glu, GABA, and Tau, and the ratios of GABA/Cr and Tau/Cr significantly decreased over time, whereas the concentrations of Ins and Cho and the ratio of Ins/Cr significantly increased over time (p < 0.05). In addition, in RCS rats, NAA/Cr decreased significantly from 3 to 4 months postnatal (p < 0.001), and Cho/Cr increased significantly from 4 to 5 months postnatal (p = 0.005). Meanwhile, the ¹H-MRS indicators in 5-month postnatal RCS rats could be confirmed by immunohistochemical staining. In conclusion, with the progression of RP, the metabolic alterations in the visual cortex indicated progressive reprogramming with the decrease of neurons and axons, accompanied by the proliferation of gliocytes.     

2D ~1H-MRS与PWI技术相结合在评价胶质瘤中的应用

目的探讨胶质瘤内含胆碱化合物(Cho),肌酸(Cr)、脂质(Lip)、乳酸(Lac)含量与肿瘤相对性脑血流容积(rCBV)间的相关性,间接评价胶质瘤细胞增殖、缺氧与坏死及血管生成情况。方法采用二维质子磁共振波谱分析技术(2D ~1H-MRS)与灌注成像技术(PWI),分别定量测量40例胶质瘤代谢物(Cho/Cr、Lac、Lip)与rCBV,并采用统计学分析探讨不同级别胶质瘤代谢物含量变化及代谢物含量与rCBV的相关性。结果经MRI影像诊断的40例胶质瘤术后病理证实为星形细胞瘤20例,间变性星形细胞瘤12例,胶质母细胞瘤8例。t检验表明,rCBV、Cho/Cr、Lip-Lac在低级别组(星形细胞瘤20例)和高级别组(包括间变性星形细胞瘤12例和胶质母细胞瘤8例)间均有非常显著的差异(t=3.29,p<0.01;t=6.73,p<0.01;t=28.9,p<0.01)。相关性分析表明,rCBV与Cho/Cr具有非常显著的正相关(r=0.635,p<0.01),rCBV与Lip-Lac具有显著正相关(r=0.554,p<0.05)。结论2D ~1H-MRS与PWI技术相结合可用于胶质瘤恶性度分级,对胶质瘤临床诊断和治疗方案选择具有一定的指导作用。     

Brainstem proton magnetic resonance spectroscopy in idopathic REM sleep behavior disorder

STUDY OBJECTIVES: Rapid-eye-movement (REM) sleep behavior disorder (RBD) is thought to result from a dysfunction of the brainstem structures that regulate physiologic REM sleep muscle atonia. Proton magnetic resonance spectroscopy (1H-MRS) is a noninvasive method that allows detection of in vivo neuronal dysfunction in localized brain areas. The aim of our study was to investigate whether 1H-MRS can detect brainstem abnormalities in patients with idiopathic RBD. DESIGN: 1H-MRS centered on the midbrain and the pontine tegmentum was acquired in 15 patients with idiopathic RBD and 15 control subjects matched for age and sex. SETTING: University hospital sleep laboratory center. PARTICIPANTS: Fifteen untreated patients with chronic RBD diagnosed by history and video-polysomnography, normal neurologic examination, and normal cranial MRI. Fifteen healthy controls with no sleep complaints and normal polysomnography and brain MRI. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: The metabolic peaks detectable with 1H-MRS, N-acetylaspartate (NAA), creatine-phosphocreatine (Cr), choline-containing compounds (Cho) and myoinositol (mI), and the ratios of NAA, Cho and ml to Cr were evaluated both in the midbrain and pontine tegmentum. No significant differences in N-acetylaspartate/creatine, choline/creatine and myoinosito/creatine ratios were found between patients and controls. CONCLUSIONS: The results do not suggest that marked mesopontine neuronal loss or 1H-MRS detectable metabolic disturbances occur in idiopathic RBD.