肌萎缩侧索硬化症病人大脑中央前回运动区磁共振波谱分析

目的 :1H MRS是否可确定ALS病人大脑皮质运动区神经元受损 ,是否适用于监测ALS病情。方法 :病例组包括 9例ALS病人。对照组包括 5例健康人 ,同时测定大脑皮质运动区的NAA、Cho、Cr。结果 :ALS病例组中NAA/Cr显著低于对照组 (P <0 0 5 ) ,Cho/Cr显著高于对照组 (P <0 0 1)。结论 :NAA/Cr下降和Cho/Cr升高 ,提示ALS病人大脑皮质运动区存在神经元破坏和鞘膜功能的异常     

Proton spectroscopy in medication-free pediatric attention-deficit/hyperactivity disorder.

BACKGROUND: The frontal-striatal pathway has been previously implicated in the neuropathology of attention-deficit/hyperactivity disorder (ADHD). Hence, we used proton magnetic resonance spectroscopy (1H-MRS) to examine metabolite levels in the prefrontal cortex of children with ADHD. METHODS: Nine age- and gender-matched case-control pairs were examined, ages 7 to 16 years. A long-echo 1H-MRS scan was acquired from the right prefrontal cortex and left striatum in all subjects. Compounds that can be visualized with 1H-MRS include N-acetyl-aspartate (NAA), glutamate/glutamine/gamma-aminobutyric acid (Glx), creatine/phosphocreatine (Cr), and choline compounds (Cho). RESULTS: Frontal-striatal glutamatergic resonances were elevated in the children with ADHD as compared to healthy control subjects. No differences were noted in NAA, Cho, or Cr metabolite ratios. CONCLUSIONS: These findings suggest that frontal-striatal Glx resonances may be increased in children with ADHD in comparison with healthy control subjects.     

Proton magnetic resonance spectroscopy study of dyskinesia patients.

Oral dyskinesias may occur spontaneously or be induced by medications such as antipsychotics and antidepressants. In this study, single voxel proton magnetic resonance spectroscopy was used to compare metabolite levels in the striatum for (1) 12 patients with drug-induced tardive dyskinesia (TD), (2) 12 patients with spontaneous oral dyskinesia (SOD), (3) 8 antidepressant-treated patients without TD, and (4) 8 control subjects. Statistically significant reductions in the choline/creatine (Cho/Cr) ratio were measured for the drug-treated patients with TD (-13%, P = 0.020) and SOD patients (-12%, P = 0.034) relative to control subjects. In comparison with antidepressant-treated patients without TD, drug-treated patients with TD showed a non statistically significant reduction in Cho/Cr (-11%, P = 0.079). All other metabolite ratios (N-acetylaspartate (NAA)/Cr, myo-inositol (mI)/Cr, glutamine + glutamate (Glx)/Cr, macromolecule + lipid (MM+Lip)/Cr, NAA/Cho) were unaffected by either type of dyskinesia. The observed Cho/Cr reduction in dyskinesia patients suggests decreased membrane phosphatidylcholine turnover, which provides free choline as precursor of molecules responsible for cellular signal transduction.     

Proton magnetic resonance spectroscopy of the motor cortex in 70 patients with amyotrophic lateral sclerosis

OBJECTIVE: To evaluate proton magnetic resonance spectroscopy for detection and monitoring of upper motoneuron degeneration in patients with amyotrophic lateral sclerosis. METHODS: Seventy patients with amyotrophic lateral sclerosis according to the El Escorial criteria were compared with 48 healthy control subjects. Single-volume proton magnetic resonance spectroscopy (echo time, 272 milliseconds; repetition time, 2000 milliseconds) was performed in both motor cortices for detection of N-acetylaspartate (NAA), phosphocreatine + creatine ([P]Cr), and choline-containing compounds (Cho) to calculate the metabolite ratios NAA/Cho, NAA/(P)Cr, and Cho/(P)Cr. In addition, absolute metabolite concentrations of NAA, (P)Cr, and Cho were obtained in 30 patients and 15 controls with the unsuppressed water signal used as an internal reference. RESULTS: Absolute concentrations of NAA (P<.001) and (P)Cr (P<.05) were reduced in motor cortices of patients, whereas Cho concentrations remained unchanged. The NAA/Cho and NAA/(P)Cr ratios were reduced in all El Escorial subgroups (P<.001). The Cho/(P)Cr ratio was elevated in patients with definite amyotrophic lateral sclerosis (P<.05). Metabolite ratio changes corresponded to the lateralization of clinical symptoms and were weakly correlated with disease duration and disease severity. In follow-up observations of 16 patients during a mean (+/-SD) of 12.1 +/- 8.7 months, NAA/Cho dropped by 9.1% (P<.01), and Cho/(P)Cr increased by 7.0% (P<.01). Changes of metabolite ratios were significantly correlated with progression of disease severity. CONCLUSIONS: Measurement of NAA concentrations and NAA/Cho ratios appear to be most suitable for detection of motor cortex degeneration by single-volume proton magnetic resonance spectroscopy. Reduced NAA/Cho ratios correspond to aspects of the clinical presentation and reflect disease progression in follow-up measurements.     

磁共振波谱检测肌萎缩侧索硬化的上运动神经元损害

目的探讨质子磁共振波谱(proton magnetic resonance spectroscopy,1 H-MRS)检测肌萎缩侧索硬化(amyotrophic lateral sclerosis,ALS)的上运动神经元损害(upper motor neuron,UMN)的特点和诊断准确性。方法收集ALS患者31例和健康对照32名,采用1 H-MRS检测脑中央前回皮质下、内囊后肢和大脑脚感兴趣区代谢产物N-乙酰天冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)的水平,计算NAA/Cr、NAA/(Cho+Cr)、Cho/Cr比值,采用受试者工作特征(receiver operating characteristic,ROC)曲线分析1 H-MRS对ALS患者UMN损害的诊断价值。结果 ALS患者各锥体束走行部位和部位组合的NAA/Cr和NAA/(Cho+Cr)较对照组显著降低(P0.05)。NAA比值预测ALS的UMN损害的ROC曲线下面积(area under the curve,AUC)为0.67~0.91,其中内囊后肢、大脑脚两部位的平均NAA/(Cho+Cr)和三部位的平均NAA/(Cho+Cr)的AUC、灵敏度、特异度分别为0.91、0.828、0.906和0.90、0.769、0.875。结论 1 H-MRS可检出ALS患者锥体束走行的生化代谢异常,是评估ALS的UMN损害的客观影像学指标,其诊断准确性中等,多水平检测和综合指标的选择有助于提高其诊断效力。     

Reduced NAA in motor and non-motor brain regions in amyotrophic lateral sclerosis: a cross-sectional and longitudinal study.

OBJECTIVES: After replication of previous findings we aimed to: 1) determine if previously reported (1)H MRSI differences between ALS patients and control subjects are limited to the motor cortex; and 2) determine the longitudinal metabolic changes corresponding to varying levels of diagnostic certainty. METHODS: Twenty-one patients with possible/suspected ALS, 24 patients with probable/definite ALS and 17 control subjects underwent multislice (1)H MRSI co-registered with tissue-segmented MRI to obtain concentrations of the brain metabolites N-acetylaspartate (NAA), creatine, and choline in the left and right motor cortex and in gray matter and white matter of non-motor regions in the brain. RESULTS: In the more affected hemisphere, reductions in the ratios, NAA/Cho and NAA/Cre+Cho were observed both within (12.6% and 9.5% respectively) and outside (9.2% and 7.3% respectively) the motor cortex in probable/definite ALS. However, these reductions were significantly greater within the motor cortex (P<0.05 for NAA/Cho and P<0.005 for NAA/Cre+Cho). Longitudinal changes in NAA were observed at three months within the motor cortex of both possible/suspected ALS patients (P<0.005) and at nine months outside the motor cortex of probable/definite patients (P<0.005). However, there was no clear pattern of progressive change over time. CONCLUSIONS: NAA ratios are reduced in the motor cortex and outside the motor cortex in ALS, suggesting widespread neuronal injury. Longitudinal changes of NAA are not reliable, suggesting that NAA may not be a useful surrogate marker for treatment trials.     

Proton magnetic resonance spectroscopy of the brain in three cases of Rett syndrome: comparison with autism and normal controls

Rett syndrome (RS) is a clinically defined disorder characterized by autistic behavior, and cognitive and motor skill loss early in life. We performed ¹H-MRS of the brain in 3 cases of RS in comparison with in autism and controls. The older patient with RS demonstrated decreased N-acetylaspartate (NAA)/choline (Cho) and NAA/creatine (Cr) ratios when compared with the autism and control groups, whereas the younger patients did not demonstrate these decreased metabolite ratios. The Cho/Cr ratio did not differ among Rett syndrome, autism and controls. Since the clinical stage did not differ among the 3 cases of RS, it was suggested that NAA was decreased with increasing age and was not related with the clinical stage of RS. The NAA/Cho, NAA/Cr and Cho/Cr ratios did not differ between autism and controls. The present data suggest that there may be a secondary degenerative process of late onset in RS, which pathophysiologically differs from autism.     

Brain metabolites in definite amyotrophic lateral sclerosis

Abstract Biomarkers beyond clinical assessment are needed in patients who suffer from amyotrophic lateral sclerosis (ALS). Here, single-voxel proton magnetic resonance spectroscopy (¹H MRS) of the gray matter of the motor cortex and the white matter including the pyramidal tracts was used to investigate concentrations of N-acetylaspartate (NAA), creatine (Cr), choline (Cho), myoinositol, glutamate, and glutamine in patients with definite ALS in a longitudinal design (three measurements at study inclusion, after 3 and 6 months). A volume-corrected analysis of gray and white matter fractions within the volumes of interest (VOI) was performed for the identification of the absolute metabolite concentrations. The patient group showed a significant decline of the compound NAA over time in the motor cortex areas both of the clinically more and less affected hemisphere between first measurement and month 6 and for the less affected side additionally between first measurement and month 3. For the NAA/(Cr + Cho) ratio, significant decline in the less affected hemisphere was observed from the first measurement to month 3 and to month 6 as well as from month 3 to month 6. In contrast, neither NAA nor the NAA/(Cr + Cho) ratios in the white matter areas showed any significant alterations. All other compounds showed no significant changes over time. In summary, the longitudinal changes of cortical metabolite concentrations in the course of ALS could be assessed by optimized ¹H MRS techniques at group level, so that ¹H MRS parameters, in particular volume-corrected values of NAA in the clinically less affected hemisphere, seem to have the potential to serve as a surrogate marker for monitoring ALS disease progression.     

Early detection and longitudinal changes in amyotrophic lateral sclerosis by (1)H MRSI

OBJECTIVE: To determine 1) the reproducibility of metabolite measurements by (1)H MRS in the motor cortex; 2) the extent to which (1)H MRS imaging (MRSI) detects abnormal concentrations of N-acetylaspartate (NAA)-, choline (Cho)-, and creatine (Cre)-containing compounds in early stages of ALS; and 3) the metabolite changes over time in ALS. METHODS: Sixteen patients with definite or probable ALS, 12 with possible or suspected ALS, and 12 healthy controls underwent structural MRI and multislice (1)H MRSI. (1)H MRSI data were coregistered with tissue-segmented MRI data to obtain concentrations of NAA, Cre, and Cho in the left and right motor cortex and in gray matter and white matter of nonmotor regions in the brain. RESULTS: The interclass correlation coefficient of NAA was 0.53 in the motor cortex tissue and 0.83 in nonmotor cortex tissue. When cross-sectional data for patients were compared with those for controls, the NAA/(Cre + Cho) ratio in the motor cortex region was significantly reduced, primarily due to increases in Cre and Cho and a decrease in NAA concentrations. A similar, although not significant, trend of increased Cho and Cre and reduced NAA levels was also observed for patients with possible or suspected ALS. Furthermore, in longitudinal studies, decreases in NAA, Cre, and Cho concentrations were detected in motor cortex but not in nonmotor regions in ALS. CONCLUSION: Metabolite changes measured by (1)H MRSI may provide a surrogate marker of ALS that can aid detection of early disease and monitor progression and treatment response.     

Metabolic changes in 37 newly diagnosed Wilson's disease patients assessed by magnetic resonance spectroscopy

Wilson's Disease (WD) is a rare autosomal recessive disorder. The literature about proton MR spectroscopy (MRS) in WD is based mostly on data derived from patients undergoing treatment. The aim of this study was to identify brain metabolic changes in newly diagnosed WD patients using MRS to elucidate the pathomechanism of the cerebral pathology of WD. The globus pallidus and thalamus of 37 patients with WD were examined bilaterally with MRS. The calculations were performed for: myoinositol (mI), choline (Cho), creatine (Cr), N-acetyl-aspartate (NAA), lipid (Lip), glutamine, and glutamate (Glx). In all WD patients a significantly decreased mI/Cr and NAA/Cr ratio levels and an increased Lip/Cr ratio in the pallidum were observed. Analysis revealed a significantly increased Glx/Cr and Lip/Cr ratio in the thalamus. In the pallidum of neurologically impaired patients, Cho/Cr, Glx/Cr and Lip/Cr ratios were higher than in control subjects, and the NAA/Cr was significantly lower. In hepatic patients, the mI/Cr, Cho/Cr and NAA/Cr ratio levels were lower than in controls. The Cho/Cr and Lip/Cr ratios were higher in the thalami of neurologically impaired patients, and Lip/Cr ratios were higher than controls' in hepatic patients. Both findings were statistically significant. Compared to the thalamus, the basal ganglia are more sensitive to ongoing degenerative changes and portal-systemic encephalopathy in WD. The NAA/Cr reduction in hepatic and neurologically impaired patients could indicate that neurodegeneration is associated with all presentations of WD. In hepatic patients a mI and Cho decrease and in neurological Glx increase can be caused by porto-systemic shunting.     

Longitudinal metabolic and cognitive changes in mild cognitive impairment patients

Advancements in clinical therapies have identified the need for biomarkers of early Alzheimer disease that distinguish the earliest stages of pathology and target those patients who are likely to gain the most benefit. The aim of this study was to characterize the longitudinal metabolic changes measured by 1H magnetic resonance spectroscopy in correlation to neuropsychologic indices of episodic memory, attention and mental processing speed, language facility, and executive function in subjects with mild cognitive impairment (MCI). Quantitative 1H magnetic resonance spectroscopy of the posterior cingulate gyrus was performed and repeated at 11.56+/-4.3 months. N-acetyl aspartate (NAA), total choline (Cho), total creatine (Cr), myo-inositol (mI), and glutamate/glutamine (Glx) metabolite levels were measured, corrected for cerebrospinal fluid dilution, and ratios calculated in MCI and cognitively normal subjects. In the first study, MCI subjects showed lower NAA levels, NAA/Cho, and NAA/mI ratios and increased Cho/Cr and mI/Cr compared with controls. In the follow-up study, 36% of the MCI subjects [atypical MCI (atMCI)] showed interval increases in NAA, Cr, and Glx levels compared with 64% of MCI subjects (typical MCI) who showed an interval decrease in NAA, Cr, and Glx. Both MCI subgroups had higher Clinical Dementia Rating scores and lower scores on episodic memory, phonemic, and semantic word fluency tasks, compared with controls. The annualized rate of change in metabolic and cognitive status did not differ between normal aging and MCI subjects. atMCI subjects showed significant negative correlations between metabolite levels and executive function task scores, with NAA/mI showing a significant positive correlation with phonemic and semantic word fluency. There were no significant correlations between metabolite levels and cognitive performance in tMCI subjects; however, NAA/mI and mI/Cr were negatively correlated with executive function tasks. These results indicate 2 distinct evolving metabolite profiles that correlate with changes in executive function and can be used to differentiate MCI from normal aging.     

Detection of cerebral degeneration in amyotrophic lateral sclerosis using high-field magnetic resonance spectroscopy

BACKGROUND: Clinical assessment is insensitive to the degree of cerebral involvement in amyotrophic lateral sclerosis (ALS). Regional brain concentrations N-acetylaspartylglutamate (NAA) plus myo-inositol (Ins), as measured by magnetic resonance spectroscopy, are respectively decreased and increased, suggesting that these compounds may provide a biomarker of the degree of cerebral involvement in ALS. OBJECTIVE: To test the hypothesis that the NAA/Ins ratio may provide an index of cerebral involvement in patients with ALS. DESIGN: High-field (3.0-T) magnetic resonance spectroscopy was performed to determine the NAA/creatine plus phosphocreatine (NAA/Cr), NAA/choline (NAA/Cho), Ins/Cr, and NAA/Ins ratios in the motor cortex. PARTICIPANTS: Seventeen patients with ALS and 15 healthy control subjects were studied. RESULTS: In patients with ALS, the greatest abnormality was a 22% decrease in NAA/Ins (71% sensitivity and 93% specificity, P = .001); Ins/Cr was increased 18% (88% sensitivity and 53% specificity, P = .04), NAA/Cr was decreased 10% (88% sensitivity and 47% specificity, P = .04), and NAA/Cho was decreased 14% (53% sensitivity and 87% specificity, P = .047). Correlation of the ALS Functional Rating Scale with NAA/Ins approached statistical significance (R = 0.43, P = .07). CONCLUSION: The NAA/Ins ratio may provide a meaningful biomarker in ALS given its optimal sensitivity and specificity profile.     

In vivo measurements of glutamine + glutamate (Glx) and N-acetyl aspartate (NAA) levels in human partial epilepsy

OBJECTIVE: To investigate whether cerebral levels of N-acetyl aspartate (NAA), and glutamine + glutamate (Glx), are interictally altered in the epileptogenic regions of patients with partial seizures. MATERIAL AND METHODS: NAA, Glx, creatine (Cr), choline (Cho) and myo-inositol (mI) was measured in 28 patients with partial epilepsy and 10 healthy controls using localized 1H magnetic resonance spectroscopy. According to the multimethodological consensus, the epileptogenic region was mesial temporal in 18 and neocortical in 10 patients. RESULTS: The Glx/NAA and Glx/Cr ratios in epileptogenic regions were higher, and the NAA/Cr ratios lower than in the homologous regions (P=0.013, P=0.002 and P<0.0001). Applying the 95% confidence interval of controls, 17 of the 20 mesial temporal epileptogenic regions were correctly identified by an increased Glx/NAA and 15 of 20 by a decreased NAA/Cr ratio. Among patients with neocortical epilepsy the Glx/NAA ratio was increased in 8 of the 10 epileptogenic regions, whereas the NAA/Cr ratio was decreased in three. CONCLUSION: Both Glx and NAA are useful to identify the epileptogenic zone. The Glx/NAA ratios may be particularly useful to indentify neocortical epileptogenic regions.     

Progressive cerebral injury in the setting of chronic HIV infection and antiretroviral therapy

Emerging evidence suggests that CNS injury and neurocognitive impairment persist in the setting of chronic HIV infection and combination antiretroviral therapy (CART). Yet, whether neurological injury can progress in this setting remains uncertain. Magnetic resonance spectroscopy and neurocognitive and clinical assessments were performed over 2 years in 226 HIV-infected individuals on stable CART, including 138 individuals who were neurocognitively asymptomatic (NA). Concentrations of N-acetylaspartate (NAA), creatine (Cr), choline (Cho), myoinositol, and glutamate/glutamine (Glx) were measured in the midfrontal cortex (MFC), frontal white matter (FWM), and basal ganglia (BG). Longitudinal changes in metabolite levels were determined using linear mixed effect models, as were metabolite changes in relation to global neurocognitive function. HIV-infected subjects showed significant annual decreases in brain metabolite levels in all regions examined, including NAA (2.95 %) and Cho (2.61 %) in the FWM; NAA (1.89 %), Cr (1.84 %), Cho (2.19 %), and Glx (6.05 %) in the MFC; and Glx (2.80 %) in the BG. Similar metabolite decreases were observed in the NA and subclinically impaired subgroups, including subjects with virologic suppression in plasma and CSF. Neurocognitive decline was associated with longitudinal decreases in Glx in the FWM and the BG, and in NAA in the BG. Widespread progressive changes in the brain, including neuronal injury, occur in chronically HIV-infected persons despite stable antiretroviral treatment and virologic suppression and can lead to neurocognitive declines. The basis for these findings is poorly understood and warrants further study.     

Choline in the aging brain

Proton magnetic resonance spectroscopy has been increasingly utilized in brain research to monitor non-invasively metabolites such as N-acetyl aspartate (NAA), creatine (Cr) and choline (Cho). We present here studies of the effect of aging on the ratios of these metabolites measured in the rat brain in vivo and on choline transport and lipid synthesis in rat brain slices, in vitro. The in vivo studies indicated that the ratios of Cho/NAA and Cho/Cr increased in the aged hippocampus, whereas the ratio of Cr/NAA was similar in the aged and adult hippocampus. These three ratios remained similar in the cortex of adult and aged rats. The in vitro studies revealed that in the aged cortex and the aged hippocampus the activity of the low-affinity choline uptake increased, possibly compensating for a decrease in the high-affinity uptake activity and the rate of choline diffusion. The incorporation of choline into phospholipids exhibited high and low affinity kinetics which were not modified by aging.     

Reduced brain creatine in gyrate atrophy of the choroid and retina with hyperornithinemia.

OBJECTIVE: To analyze in vivo brain creatine (Cr) content in gyrate atrophy of the choroid and retina with hyperornithinemia (GA). BACKGROUND: GA is caused by inherited deficiency of ornithine-delta-aminotransferase activity. Patients lose their vision by middle age and develop selective atrophy of type II skeletal muscle fibers. As demonstrated by MRS, the patients' skeletal muscles have diminished stores of high-energy Cr phosphate. Minor structural and electrophysiologic abnormalities in the brain of these patients also imply that the CNS may be affected. METHODS: The authors acquired proton MR spectra of the basal ganglia of 22 healthy control subjects and 20 GA patients. Nine patients received supplementary Cr or its precursors, and one child was on an arginine-restricted diet to normalize plasma ornithine concentration. The ratios of N-acetylaspartate (NAA) to Cr, NAA to choline (Cho), and Cho to Cr, and the ratios of NAA, Cho, and Cr to tissue water were calculated. RESULTS: NAA/Cr (Cho/Cr) in the untreated and treated patients and control subjects were (mean +/- SD) 3.3+/-0.4, 2.0+/-0.4, and 1.5+/-0.7 (1.9+/-0.3, 1.3+/-0.4, and 0.9+/-0.2), indicating that Cr content in untreated GA patients was proportionally and markedly diminished, and partially corrected by therapy (p < 0.0001). NAA/Cho was similar in all three groups. Cr/water in the untreated patients was only 46%, and increased to 75% of the control ratios in the treated patients (p < 0.0001). CONCLUSIONS: Hyperornithinemia-associated Cr deficiency in GA also affects the CNS, further supporting the possibility that Cr deficiency also has a pathogenetic role in the retina. The deficiency was partially corrected by Cr supplementation and an arginine-restricted diet.     

正常人半卵圆中心质子磁共振波谱研究

目的运用质子磁共振波谱（^1H-MRS）研究年龄对正常人半卵圆中心脑组织代谢物浓度的影响。方法对80例健康成人双侧半卵圆中心进行^1H-MRS检测,对比分析不同年龄组的半卵圆中心N-乙酰基天门冬氨酸（NAA）/肌酸复合物（Cr）和含胆碱化合物（Cho）/Cr比值的变化。结果随着年龄的增长,在≤50岁年龄段半卵圆中心的NAA/Cr和Cho/Cr比值无明显改变,但在〉50岁年龄段半卵圆中心的NAA/Cr比值逐渐降低、Cho/Cr比值逐渐增高。结论^1H-MRS是可以为正常人半卵圆中心与年龄相关的代谢物浓度的改变提供有价值的信息的一种无创技术。     

The involvement of distinct neural systems in patients with obsessive-compulsive disorder with autogenous and reactive obsessions

Besiroglu L, Sozen M, Ozbebit Ö, Avcu S, Selvi Y, Bora A, Atli A, Unal O, Bulut MD. The involvement of distinct neural systems in patients with obsessive–compulsive disorder (OCD) with autogenous and reactive obsessions. Objective: To investigate the regional metabolite abnormalities and changes after treatment in patients with OCD with autogenous and reactive obsessions. Method: We assessed right anterior cingulate cortex (ACC) and amygdala–hippocampal region (Am + Hpp) N‐acetyl‐aspartate (NAA), choline (Cho) and creatine (Cr) concentrations and NAA/Cr and Cho/Cr ratios using single‐voxel proton magnetic resonance spectroscopy in 15 patients with autogenous obsessions (OCD‐A), 15 patients with reactive obsessions (OCD‐R) and 15 healthy controls (HC). Measurements were repeated after 16 weeks of fluoxetine treatment. Results: Baseline ACC NAA/Cr ratios of both OCD groups were significantly lower than HC. OCD‐A group had significantly lower baseline NAA/Cr ratios in the Am + Hpp than other groups. These differences were more likely to be explained by higher Cr levels in ACC. We found no significant differences and changes for Cho levels and Cho/Cr ratios between groups and within groups. Significant increase in NAA/Cr ratios of OCD‐A group found in the Am + Hpp was more likely to be explained by increased NAA levels. No significant changes were found in ACC NAA/Cr ratios. Conclusion: While disturbed energy metabolism in ACC might reflect a common pathology in patients with OCD regardless of symptom dimension, alterations in mesiotemporal lobe are more likely for autogenous obsessions.     

3T磁共振波谱分析在轻微型肝性脑病诊断中的应用

目的研究3T场强磁共振MRS对轻微型肝性脑病（MHE）患者的诊断价值。方法对33例MHE患者和46例无轻微型肝性脑病的肝硬化患者采用单体素点分辨自旋回波波谱序列进行扣带回和右侧前额叶的MRS扫描。计算N-乙酰天门冬氨酸（NAA）、肌酐（Cr）、胆碱（Cho）、肌醇（MI）和谷氨酰胺复合物（Glx）的峰下面积,计算NAA／Cr、Cho／Cr、MI／Cr、Glx／Cr,并与30例健康体检者（正常对照组）比较。33例MHE患者在MRS检查前后1周内进行了静脉血氨水平测定。结果与正常对照组相比,MHE患者扣带回和右侧前额叶的Cho／Cr、MI／Cr显著降低（P值分别〈0．01和〈0．001）,Glx／Cr比值显著升高（P〈0．005）。与无MHE的肝硬化患者间Glx／Cr与Cho／Cr有显著性差异（P〈0．01,P〈0．005）,无MHE的肝硬化患者与正常对照组比较MI／Cr有显著性差异（P〈0．001）。扣带回与右侧额叶的Glx／Cr比值与血氨浓度呈正相关,Cho／Cr和MI／Cr的比值与血氨浓度呈负相关。结论3T场强磁共振MRS检查显示MHE患者扣带回和右侧前额叶Cho、MI水平降低,Glx水平升高;扣带回与右侧额叶的MRS指标与血氨之间存在相关关系,3T场强磁共振MRS对MHE的诊断有显著价值;扣带回与右侧前额叶可作为检测肝硬化患者脑改变的敏感部位。     

Quantitative proton magnetic resonance spectroscopy detects abnormalities in dorsolateral prefrontal cortex and motor cortex of patients with frontotemporal lobar degeneration

Frontotemporal lobar degeneration (FTLD) is a neurodegenerative disease of the frontal and temporal neocortex. The single most common pathology underlying FTLD is neuronal degeneration with ubiquitin-positive but tau-negative inclusions consisting of Tar DNA binding proteins (TDP-43). Inclusions containing TDP-43 in neurons are also the most common pathology underlying motor neuron disease (MND). The present study tested the hypothesis that abnormal metabolite patterns within the dorsolateral prefrontal cortex (DLPFC) as well as the motor cortex (MC) may be observed in FTLD patients without motor disorders, using proton magnetic resonance spectroscopy (¹H MRS). Twenty-six FTLD patients with cognitive damage and ten controls underwent multivoxel ¹H MRS. Absolute concentrations of N-acetyl aspartate (NAA), creatine (Cr), choline (Cho) and myo-inositol (mI) were measured from the DLPFC, the MC and the parietal cortex (PC, an internal control). Statistical analyses were performed for group differences between FTLD patients and controls. Comparisons were also made across brain regions (PC and DLPFC; PC and MC) within FTLD patients. Significant reductions in NAA and Cr along with increased Cho and mI were observed in the DLPFC of FTLD patients compared to controls. Significantly lower NAA and higher Cho were also observed in the MCs of patients as compared to controls. Within the FTLD patients, both the MC and the DLPFC exhibited significantly decreased NAA and elevated Cho compared to the PC. However, only the DLPFC had significantly lower Cr and higher mI. Abnormal metabolite pattern from the MC supports the hypothesis that FTLD and MND may be closely linked.