Reduced cortical gamma-aminobutyric acid levels in depressed patients determined by proton magnetic resonance spectroscopy

BACKGROUND: Several lines of emerging evidence suggest that dysfunction of gamma-aminobutyric acid (GABA) systems is associated with major depression. However, investigation of this hypothesis is limited by difficulty obtaining noninvasive in vivo measures of brain GABA levels. In this study we used in vivo proton magnetic resonance spectroscopy to investigate the hypothesis that abnormalities in the GABA neurotransmitter system are associated with the neurobiologic processes of depression. METHODS: The GABA levels were measured in the occipital cortex of medication-free depressed patients meeting DSM-IV criteria (n = 14) and healthy control subjects with no history of mental illness (n = 18) using a localized difference editing proton magnetic resonance spectroscopy protocol. An analysis of covariance was employed to examine the effects of depression, sex, and age. RESULTS: The depressed patients demonstrated a highly significant (52%) reduction in occipital cortex GABA levels compared with the group of healthy subjects. While there were significant age and sex effects, there was no interaction of diagnosis with either age or sex. CONCLUSION: This study provides the first evidence of abnormally low cortical GABA concentrations in the brains of depressed patients.     

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。     

Antidepressant effect detected on proton magnetic resonance spectroscopy in drug-naïve female patients with first-episode major depression

Aim:  Recent neuroimaging studies support functional and structural alterations in the dorsolateral prefrontal cortex (DLPFC), particularly on the left side in patients with major depressive disorders (MDD). The aim of the present study was to examine the biochemical characteristics of left DLPFC as measured on proton (¹H) magnetic resonance spectroscopy (MRS) in patients with drug-naïve first-episode MDD and a healthy control group. A second aim was to assess the effect of antidepressant treatment on the metabolites of DLPFC.
Methods:  Short-echo single-voxel ¹H-MRS was done for the left DLPFC in 17 female drug-free MDD patients (mean age ± SD, 30.9 ± 6.9 years) and 13 matched control subjects (mean age ± SD, 29.1 ± 6.2 years) and was repeated at 8 weeks following antidepressant treatment.
Results:  Comparison of baseline values indicated that there were no significant differences in any of the metabolite ratios ( N -acetyl aspartate/creatine [NAA/Cr], myoinositol [Ino]/Cr, and choline [Cho]/Cr) between patients and controls. Significant differences were detected between pre- and post-treatment Ino/Cr ratios (0.67 ± 0.13, 0.58 ± 0.22, P  = 0.032, respectively), although there was no difference in NAA/Cr and Cho/Cr ratios.
Conclusion:  Although no significant metabolic alterations exist in female patients with drug-naïve first-episode MDD as evaluated on ¹H-MRS, an increase in Ino/Cr was observed following 8-week antidepressant treatment. These findings give rise to the possibility that non-neuronal cells, particularly glial cells that are probably damaged, play a role in the action of antidepressant treatment.     

Attenuated prefrontal activation during a verbal fluency task in remitted major depression

The aim of the present study was to investigate whether a functional abnormality in the left prefrontal cortex observed in patients with major depression performing a verbal fluency task is present after remission of depression. Functional magnetic resonance imaging was used to study changes in cerebral blood oxygenation in eight remitted patients with major depression and 10 healthy control subjects during a verbal fluency task. Compared to the control subjects, the patients had a reduced response in the left prefrontal cortex (middle frontal gyrus, Brodmann area 10). These findings suggest the presence of dysfunction in the left prefrontal cortex during remission in major depression.     

Decreased N-acetyl-aspartate levels in anterior cingulate and hippocampus in subjects with post-traumatic stress disorder: a proton magnetic resonance spectroscopy study

The purpose of this study was to investigate the concentration of N-acetyl-aspartate (NAA) in the brain and its relationship with clinical characteristics in patients with post-traumatic stress disorder (PTSD). Proton magnetic resonance spectroscopy was performed in order to measure NAA concentrations in the anterior cingulate cortex (ACC) and bilateral hippocampus in 26 subjects with fire-related PTSD, who were survivors of a subway fire in South Korea, and 25 age- and sex-matched healthy comparison subjects. There were decreased NAA levels in the ACC (t = -3.88, d.f. = 49, P < 0.001) and bilateral hippocampus (right, t = -3.88, d.f. = 49, P < 0.001; left, t = -3.62, d.f. = 49, P < 0.001) in the PTSD group relative to the healthy comparison group. Also, NAA levels of the ACC (r = -0.43, n = 26, P = 0.027) and bilateral hippocampus (right, r = -0.48, n = 26, P = 0.013; left, r = -0.40, n = 26, P = 0.04) were negatively correlated with re-experience symptom scores in subjects with PTSD. In conclusion, our findings suggest that subjects with PTSD had decreased neuronal viabilities in the ACC and bilateral hippocampus, and that these deficits may play an important role in the pathophysiology of PTSD, especially regarding the re-experiencing of traumatic events.     

Reduced prefrontal glutamate/glutamine and gamma-aminobutyric acid levels in major depression determined using proton magnetic resonance spectroscopy

CONTEXT: Increasing evidence indicates that major depressive disorder (MDD) is associated with altered function of the major excitatory and inhibitory neurotransmitters glutamate and gamma-aminobutyric acid (GABA), respectively. A recently developed magnetic resonance spectroscopy method allows for reliable measurement of glutamate/glutamine (Glx) and GABA concentrations in prefrontal brain regions that have been implicated in the pathophysiologic mechanisms of MDD by studies using other neuroimaging and postmortem techniques. OBJECTIVE: To measure Glx and GABA levels in 2 regions of the prefrontal brain tissue in unmedicated adults with MDD. DESIGN: Cross-sectional study for association. SETTING: Psychiatric outpatient clinic. PARTICIPANTS: Twenty unmedicated, depressed patients with MDD and 20 age- and sex-matched controls. Intervention Participants underwent scanning using a 3-T whole-body scanner with a transmit-receive head coil, providing a homogeneous radiofrequency field and the capability of obtaining spectroscopic measurements in a dorsomedial/dorsal anterolateral prefrontal region of interest (ROI) and a ventromedial prefrontal ROI. MAIN OUTCOME MEASURES: Glx and GABA levels derived from magnetic resonance spectroscopy signals. RESULTS: Depressed patients had reduced Glx levels in both ROIs. The GABA levels were reduced in the dorsomedial/dorsal anterolateral prefrontal ROI. Levels of GABA and Glx were positively correlated in both ROIs. CONCLUSIONS: For the first time, GABA and Glx concentrations were compared between unmedicated depressed adults and controls in prefrontal ROIs. The abnormal reductions in Glx and GABA concentrations found in the MDD sample were compatible with findings from postmortem histopathologic studies, indicating that glial cell density is reduced in the same areas in MDD.     

Association between dorsolateral prefrontal N-acetyl aspartate and depression in chronic back pain: an in vivo proton magnetic resonance spectroscopy study

Most studies of pain, including chronic pain, agree that depression and pain are interrelated, although the neurobiology of this relationship remains unknown. Neuroimaging studies suggest a specific role of the prefrontal brain regions in the mechanisms of mood disorders and chronic pain. The present study examines the interrelationships between regional brain N-Acetyl aspartate (NAA) levels (as identified by in vivo proton magnetic resonance spectroscopy in the right and left dorsolateral prefrontal cortex [DLPFC], orbitofrontal cortex, cingulate and thalamus), depression (as measured by the Beck Depression Inventory), and pain (as measured by short form of the McGill Pain Questionnaire) in 10 chronic back pain (CBP) patients with depression, and compared to the relationship between regional brain NAA levels and depression in 10 normal subjects (sex and age-matched). Reduction of NAA levels was demonstrated in the right DLPFC of CBP patients with depression, as compared to the normal controls (p < 0.02, two-tailed t-test). The depression levels in CBP patients were highly correlated with NAA levels in the right DLPFC (r = -0.99, p < 0.0001), and were unrelated to the other studied regional NAA in both groups, including the right DLPFC in normal subjects (p < 10(-6); comparing the difference between r values in the right DLPFC between the two groups). The pain levels in CBP patients were also associated with the right DLPFC (r = -0.62, p < 0.05), although these relationships were much weaker as compared to depression-NAA correlations (p < 0.0001; comparing the difference between r values). The interrelationships between NAA across brain regions were examined using correlation analysis, which detected different connectivity patterns between CBP patients with depression and normal subjects. These findings provide evidence for a stronger association of prefrontal NAA to depression than to pain in CBP, which may reflect the common neurobiological substrate underlying these conditions in CBP patients. Spectroscopic brain mapping of NAA, the marker of neuronal density and function, to the depression and pain measures might be used for segregation of their circuitries in the chronic pain brain.     

抑郁症患者前扣带回谷氨酸多体素^1H-MRS研究

目的：探索抑郁症患者前扣带回谷氨酸相对含量的变化。方法：对13例未服药的抑郁症患者及13位健康志愿者前扣带回行多体素磁共振氢质子波谱（^1H-MRS）扫描,抑郁症患者经6周抗抑郁治疗后再次作1H-MRS扫描,测定谷氨酸（Glu）和肌酸（Cr）。结果：抑郁症患者双侧前扣带回皮质和白质的Glu/Cr值低于正常对照组;抗抑郁治疗后Glu/Cr值升高不明显。结论：前扣带回Glu的改变参与了抑郁症的发生。     

Neurochemical metabolites in the medial prefrontal cortex in bipolar disorder A proton magnetic resonance spectroscopy study

The aim of this study was to investigate proton magnetic resonance spectroscopy metabolite values in the medial prefrontal cortex of individuals with euthymic bipolar disorder. The subjects consisted of 15 patients with euthymic bipolar disorder type Ⅰ and 15 healthy controls. We performed proton magnetic resonance spectroscopy of the bilateral medial prefrontal cortex and measured levels of N-acetyl aspartate, choline and creatine. Levels of these three metabolites in the medial prefrontal cortex were found to be lower in patients with bipolar disorder compared with healthy controls. A positive correlation was found between illness duration and choline levels in the right medial prefrontal cortex. Our study suggests that during the euthymic period, there are abnormalities in cellular energy and membrane phospholipid metabolism in the medial prefrontal cortex, and that this may impair neuronal activity and integrity.     

Decreased GABA concentrations in left prefrontal cortex of methamphetamine dependent patients: A proton magnetic resonance spectroscopy study

Increasing evidence suggested the dorsolateral prefrontal cortex (DLPFC) is implicated in the pathogenesis of methamphetamine use disorder. Metabolites changes of DLPFC may mediate the progression of addiction. We used proton magnetic resonance spectroscopy (¹H-MRS) to examine the changes of metabolites in the left DLPFC in individuals with methamphetamine dependence compared to healthy controls. Fifty patients and twenty age-matched healthy controls participated in this study. The ¹H MRS data were automatically fit with linear combination model for quantification of metabolite levels of γ-aminobutyric acid (GABA), glutamate + glutamine (Glx) and other metabolites across groups. The GABA and Glx levels were calculated with the unsuppressed water signal as reference. Methamphetamine users showed reduced GABA and GABA/Glx in left DLPFC than healthy controls. Furthermore, the concentration of GSH, GPC, Ins, NAA, GPC + PCh, NAA + NAAG, Cr + PCr were lower in individuals with methamphetamine dependence compared with controls. The patients group's relative GABA and Glx metabolite concentrations were significantly correlated with age and duration of withdrawal. Our preliminary findings provide the first report of abnormal levels of GABA in left DLPFC of patients with methamphetamine use disorder, indicating that dysregulation of the GABAergic neurotransmitter system may be an important neurobiological mechanism in the pathogenesis of methamphetamine dependence.     

Reduction in occipital cortex gamma-aminobutyric acid concentrations in medication-free recovered unipolar depressed and bipolar subjects.

BACKGROUND: Studies using proton magnetic resonance spectroscopy (MRS) have indicated that unmedicated, acutely depressed patients have decreased levels of gamma-aminobutyric acid (GABA) in occipital cortex. Cortical levels of glutamate (Glu) may be increased, although these data are less consistent. The aim of this study was to use MRS to determine whether changes in GABA and Glu levels were present in patients with mood disorders who had recovered and were no longer taking medication. METHODS: An [1H]-MRS was used to measure levels of GABA, of the combined concentration of Glu and glutamine (Gln), and of N-acetylaspartate (NAA) in occipital cortex in medication-free, fully recovered subjects with a history of recurrent unipolar depression (n = 15), bipolar disorder (n = 16), and a group of healthy controls (n = 18). RESULTS: Occipital levels of GABA and NAA were significantly lower in recovered depressed and bipolar subjects than in healthy controls, whereas Glu +Gln concentrations were higher. CONCLUSIONS: Our data suggest that recovered unmedicated subjects with a history of mood disorder have changes in cortical concentrations of GABA, NAA, and Glu +Gln. These biochemical abnormalities may be markers of a trait vulnerability to mood disorder, rather than neurochemical correlates of an abnormal mood state.     

Metabolite changes with age measured by proton magnetic resonance spectroscopy in normal subjects

Abstract  To determine whether there are metabolite changes in the left medial temporal and frontal lobes with aging, we performed proton magnetic resonance spectroscopy in 36 normal subjects. The N-acetylaspartate/creatine-phosphocreatine ratio in the medial temporal lobe tended to be decreased in subjects over 60 years of age. The ratio decrease in the frontal lobe related to aging was lower than that in the medial temporal lobe. There were no significant differences in the metabolite ratios between males and females. These findings suggest that structures in the medial temporal lobe may be more susceptible to neuronal dysfunction associated with aging than those in the frontal lobe.     

Metabolic changes of prefrontal cerebral lobe ,white matter and cerebellum in patients with post-stroke depression A proton magnetic resonance spectroscopy study

BACKGROUND:Proton magnetic resonance spectroscopy(1H-MRS)non-invasively detects changes in chemical substances in the brain,which reflects the pathological metabolism.OBJECTIVE:To investigate changes in N-acetyl-aspartate(NAA),choline(Cho),creatine(Cr),and myoinositol(MI)in the gray and white matter of cerebral prefrontal lobe and cerebellum of patients with differential degrees of post-stroke depression(PSD)using 1H-MRS.DESIGN:A case control study.SETTING:The First Affiliated Hospital of the Dalian Medical University.PARTICIPANTS:A total of 38 patients with stroke(28 male and 10 female patients,aged 40 to 79 years)were selected from the Department of Neurology,1st Atfiliated Hospital,Dalian Medical University,from February to October in 2004.All subjects met the DSM-IV criteria for cerebrovascular disease and depression.The degree of depression was defined according to Hamilton criteria.38 patients with PSD were divided into two groups according to the time after ischemia,20 patients in the acute group with less than 10 days after ischemic attack(mild:16 patients,moderate/severe:4 patients)and 18 patients in the chronic group with more than 11 days after ischemic attack(mild:15 patients,moderate/severe:3 patients).Seventeen healthy volunteers with matching age from 41 to 80 years were examined as a control group.The study was approved by the Medical Ethics Committee of the University Medical Center Utrecht,and each participant signed an informed consent form.METHODS:Spectra were acquired by multi-voxel point-resolved spectroscopy(PRESS)sequence with GE signal.ST MP-di,localized in prefrontal cerebral lobe and cerebellum.Values of NAA,Cho,MI,and Cr ere compared between different graded PSD patients and control subjects with one-way analysis of variance in software SPSS11.5.MAIN OUTCOME MEASURES:Metabolite concentration in different brain regions of interest.Difference in metabolites between distinctly graded PSD patients and control subjects.Exclusion of age-effects on metabolites. RESULTS:Metabolite concentrations of different brain regions:A significant rise in the Cho/Cr ratio was detected in the acute and chronic group compared to the control group.The ratio change was more significant in the acute group(P＜0.05).There was no significant difference between these three groups for other metabolites detected by 1H-MRS in the right frontal white matter,bilateral frontal grey matter,and cerebellum(P＞0.05).Comparison of metabolite levels among differently graded PSD patients and control subjects:a significant increase in the Cho/Cr ratio was detected in the left frontal white matter compared to the control group(P＜0.05).There was no significant difference in age between patients in the stroke groups and the control group(P＞0.05),and similarly,there was no significant correlation between age and absolute or relative values in the control group(P＞0.05).CONCLUSION:Abnormalities of frontal lobe in PSD were located in the white matter.There was early abnormality of metabolic substance in PSD.     

磁共振质子波谱分析对多发性硬化的诊断价值

目的研究磁共振质子波谱分析(1HMRS)对多发性硬化(MS)的诊断价值。方法对29例MS患者(MS组)和26例正常志愿者(正常对照组)进行头颅MRI及1HMRS检查;计算其峰下面积,对脑部代谢产物氮-乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)的浓度进行定量,比较两组间NAA/Cr、Cho/Cr比值的差异。用扩展的功能障碍分级法(EDSS)对MS患者进行评分,分析MS组患者的NAA/Cr、Cho/Cr比值与EDSS评分之间的相关性。结果MS组的NAA/Cr、Cho/Cr比值分别为1.38±0.43、1.99±0.84,正常对照组为1.89±0.49、1.48±0.36。MS组的NAA/Cr比值显著低于正常对照组(P<0·05),Cho/Cr比值显著高于正常对照组(P<0·05)。MS组的NAA/Cr比值与EDSS评分之间呈负相关(r=-0.588,P<0·05),Cho/Cr比值与EDSS评分之间不相关(r=0·012,P>0·05)。结论MS患者的1HMRS检查有明显异常改变,NAA/Cr比值可反映MS患者临床神经功能障碍的程度。     

Metabolic changes of prefrontal cerebral lobe, white matter and cerebellum in patients with post-stroke depression*☆ A proton magnetic resonance spectroscopy study

BACKGROUND： Proton magnetic resonance spectroscopy （IH-MRS） non-invasively detects changes in chemical substances in the brain, which reflects the pathological metabolism.
OBJECTIVE： To investigate changes in N-acetyl-aspartate （NAA）, choline （Cho）, creatine （Cr）, and myoinositol （MI） in the gray and white matter of cerebral prefrontal lobe and cerebellum of patients with differential degrees of post-stroke depression （PSD） using ^1H-MRS.
DESIGN： A case control study.
SETTING： The First Affiliated Hospital of the Dalian Medical University.
PARTICIPANTS： A total of 38 patients with stroke （28 male and l0 female patients, aged 40 to 79 years） were selected from the Department of Neurology, 1st Affiliated Hospital, Dalian Medical University, from February to October in 2004. All subjects met the DSM-IV criteria for cerebrovascular disease and depression. The degree of depression was defined according to Hamilton criteria. 38 patients with PSD were divided into two groups according to the time after ischemia, 20 patients in the acute group with less than 10 days after ischemic attack （mild： 16 patients, moderate/severe： 4 patients） and 18 patients in the chronic group with more than l l days after ischemic attack （mild： 15 patients, moderate/severe： 3 patients）. Seventeen healthy volunteers with matching age from 41 to 80 years were examined as a control group. The study was approved by the Medical Ethics Committee of the University Medical Center Utrecht, and each participant signed an informed consent form.
METHODS： Spectra were acquired by multi-voxel point-resolved spectroscopy （PRESS） sequence with GE signal.5T MR/i, localized in prefrontal cerebral lobe and cerebellum. Values of NAA, Cho, MI, and Cr ere compared between different graded PSD patients and control subjects with one-way analysis of variance in software SPSS 11.5.
MAIN OUTCOME MEASURES： Metabolite concentration in different brain regions of interest. Difference in metabolites b     

Influence of work shift on glutamic acid and gamma-aminobutyric acid (GABA): Evaluation with proton magnetic resonance spectroscopy at 3T

Working conditions such as shift work constitute a well-known risk factor for insomnia and excessive daytime sleepiness complaints. We compared brain gamma-aminobutyric acid (GABA), glutamic acid (Glu), glutamine (Gln), and Glx (Glu+Gln) levels in day-shift versus alternate-shift workers with proton magnetic resonance spectroscopy (¹H-MRS) at 3T. The study population consisted of 32 healthy adult volunteers (16 day-shift and 16 alternate-shift workers). Each subject underwent MRS conducted using a MEGA-PRESS sequence in the early morning and early evening on the same day. Spectroscopy voxels (3.0 cm × 3.0 cm × 3.0 cm) were placed in the frontal lobe and parieto-occipital lobe. The GABA/Cr ratio in the frontal lobe was significantly lower for the alternate-shift group than for the day-shift group in the early evening (1.885 vs. 0.875). For the other metabolite ratios (Gln/Cr and Glx/Cr), there were no significant differences between the two groups regardless of morning or evening schedule. Our preliminary finding represents a possible alteration of GABA content in the brain related to an irregular work schedule.     

磁共振波谱分析对轻微型肝性脑病患者的诊断价值

目的研究磁共振波谱分析(MRS)对轻微型肝性脑病(MHE)患者的诊断价值。方法应用3.0MR机对26例MHE患者进行扣带回和额叶的单体素点分辨自旋回波波谱序列扫描。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的值,并与正常对照组比较。结果与正常对照组相比,MHE组扣带回和额叶的Cho/Cr、mI/Cr显著降低(P<0.01～0.001),Glx/Cr值显著升高(均P<0.005),NAA/Cr值差异无统计学意义(均P>0.05)。结论MHE患者MRS检查显示扣带回和额叶Cho、mI水平降低,Glx水平升高,MRS对MHE的诊断有显著价值。     

Cortical gamma-aminobutyric acid concentrations in depressed patients receiving cognitive behavioral therapy.

BACKGROUND: Reduced gamma-aminobutyric acid (GABA) concentrations have been reported in plasma, cerebrospinal fluid, and cortex of depressed subjects. Treatment with both electroconvulsive therapy (ECT) and selective serotonin reuptake inhibitors (SSRI) increased occipital cortex GABA concentrations in prior studies. The purpose of this study was to determine whether treatment of major depression with cognitive behavioral therapy (CBT) produces similar changes in cortical GABA concentrations. METHODS: Occipital cortex GABA concentrations were measured in eight subjects with Major Depressive Disorder prior to and after a course of CBT using proton magnetic resonance spectroscopy. RESULTS: The effect of CBT on occipital cortex GABA content was different than that seen for ECT and SSRI medication treatment of depressed patients. CONCLUSIONS: This preliminary finding suggests CBT has a less robust effect on cortical GABA content than ECT and SSRI treatments and might indicate a difference between the mechanisms of antidepressant action.     

MRI和磁共振波谱在肝性脑病的应用价值

目的探讨MRI和磁共振波谱(1H-MRS)在肝性脑病中的应用价值。方法对6例肝性脑病患者行MRI和1H-MRS检查,检测基底节MRS的N-乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)、谷氨酰胺复合物(Glx)、肌醇(mI)的峰值,计算Cho、mI、NAA与Cr的比值,并与5名正常对照者比较。结果 MRI检查显示,6例肝性脑病患者双侧基底节T1WI均出现高信号,其中1例累及内囊、2例累及尾状核、1例累及中脑被盖;5例患者T2WI未见明显异常信号,1例患者因并发弥漫性脑水肿T2WI出现广泛高信号影。1H-MRS显示,肝性脑病组双侧基底节Cho峰、mI峰、Cho/Cr和mI/Cr显著低于正常对照组,Glx峰显著高于正常对照组(P<0.01～0.005);两组NAA/Cr比较差异无统计学意义。结论 MRI显示双侧基底节T1WI高信号是肝性脑病特征性改变。1H-MRS能准确地反映其脑代谢物质水平的变化。     

Reduced anterior cingulate glutamate in pediatric major depression: a magnetic resonance spectroscopy study.

BACKGROUND: Anterior cingulate cortex has been implicated in the pathogenesis of major depressive disorder (MDD). With single voxel proton magnetic resonance spectroscopy, we reported reductions in anterior cingulate glutamatergic concentrations (grouped value of glutamate and glutamine) in 14 pediatric MDD patients versus 14 case-matched healthy control subjects. These changes might reflect a change in glutamate, glutamine, or their combination. METHODS: Fitting to individually quantify anterior cingulate glutamate and glutamine was performed in these subjects with a new basis set created from data acquired on a 1.5 Tesla General Electric Signa (GE Healthcare, Waukesha, Wisconsin) magnetic resonance imaging scanner with LCModel (Version 6.1-0; Max-Planck-Institute, Gottingen, Germany). RESULTS: Reduced anterior cingulate glutamate was observed in MDD patients versus control subjects (8.79 +/- 1.68 vs. 11.46 +/- 1.55, respectively, p = .0002; 23% decrease). Anterior cingulate glutamine did not differ significantly between patients with MDD and control subjects. CONCLUSIONS: These findings provide confirmatory evidence of anterior cingulate glutamate alterations in pediatric MDD.