磁共振质子波谱分析对颞叶癫(癇)定侧的研究

目的探讨在磁共振质子波谱分析(1HMRS)对颞叶癫疒间的定侧作用及其影响因素。方法用1.5T场强的MR成像系统1HMRS,对40例不同病程的颞叶癫疒间患者和20名正常对照者分别进行双颞叶内侧N乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)浓度测定,根据颞叶癫疒间患者两侧NAA/(Cho Cr)值进行定侧。结果NAA/(Cho Cr)值正常对照组为0.58±0.09,癫疒间组病灶侧为0.45±0.12,病灶对侧为0.51±0.10,癫疒间组两侧显著小于正常对照组(均P<0.05);24例患者1HMRS癫疒间灶定侧与EEG一致,符合率63%;病灶侧内、中、外各亚区NAA/(Cho Cr)值较正常对照组低,差异有显著性(均P<0.05);病灶侧NAA/(Cho Cr)值下降程度与单或双侧NAA/(Cho Cr)值下降及发作频率无关(P>0.05);双侧NAA/(Cho Cr)值异常者两侧EEG异常率高于单侧异常者(P<0.05);病灶侧NAA/(Cho Cr)值与病程呈负相关(r=-0.361,P<0.05)。结论癫疒间患者脑代谢异常弥散;1HMRS在颞叶癫疒间有定侧作用;NAA/(Cho Cr)值与病程呈负相关。     

In vivo proton magnetic resonance spectroscopy of the temporal lobe in Alzheimer's disease

PURPOSE: Prior proton magnetic resonance spectroscopy (MRS) studies have consistently reported decreased brain n-acetyl aspartate (NAA) levels and increased myo-inositol (mI) levels in subjects with Alzheimer's disease (AD) relative to healthy comparison subjects. These studies have usually been conducted in small and homogeneous populations of patients with established Alzheimer's disease. Few studies have tested the usefulness of this finding in a general population seeking evaluation for memory loss and other cognitive declines. We designed a study to evaluate the significance of single-voxel proton MRS findings in these patients with memory loss and other cognitive declines. GENERAL METHOD: Thirty-five subjects with a primary complaint of memory loss and other cognitive declines were consecutively referred over a period of 13 months to a specialty clinic. Patients with a diagnosis of mild to moderate probable Alzheimer's disease (N = 22), non-Alzheimer's dementia (depression, multiinfarct dementia, Parkinson's Disease, Korsakoff's Psychosis, and bipolar disorder; N = 13), and healthy comparison subjects (N = 18) were examined with respect to possible differences in metabolites using proton MRS in a 3.4-ml anterior temporal lobe voxel. FINDINGS: The Alzheimer's disease group had 10.7% lower NAA/creatine (Cr) ratios relative to the healthy comparison group and 9.4% lower NAA/creatine relative to the non-Alzheimer's dementia group (15.0% lower NAA/creatine relative to the depression subgroup of the non-Alzheimer's dementia group). There were no significant differences in choline (Cho) or myo-inositol ratios among the groups. There were significant correlations between NAA/creatine ratios and mini-mental status exam (MMSE) scores in subjects with Alzheimer's disease (t = 2.41, p = 0.032) but not in subjects with non-Alzheimer's dementia or in its depression subgroup. CONCLUSIONS: This study found a reduction in the neuronal marker NAA in the anterior temporal lobe of patients diagnosed with probable Alzheimer's disease, using a short add-on proton MRS exam. This change was not observed in patients whose memory loss and other cognitive declines were not attributed to Alzheimer's disease, suggesting that it may aid in the diagnosis or detection of Alzheimer's disease.     

Frontal lobe N-acetylaspartate correlates with psychopathology in schizophrenia: a proton magnetic resonance spectroscopy study

INTRODUCTION: Clinical, neuropsychological and functional neuroimaging studies in schizophrenia suggest impaired frontal lobe function, especially of the dorsolateral prefrontal region (DLPFR). This dysfunction has in particular been associated with negative or "deficit" symptoms. Despite these findings, morphological studies have failed to show consistent structural abnormalities in the frontal lobe. This may be because existing techniques are not sensitive enough to detect structural abnormalities or that dysfunction in the frontal lobe is caused by lesions elsewhere. We used volume-localised proton magnetic resonance spectroscopy (1H-MRS) to measure N-acetylaspartate (NAA), a neuronal marker, to evaluate the neuronal integrity of the dorsolateral prefrontal region in schizophrenic patients with persistent negative symptoms and in healthy comparison subjects. METHOD: Twenty-five patients who fulfilled DSM-IV criteria for schizophrenia and met the criteria for the Deficit syndrome were compared to 26 healthy controls matched for age and gender. Bilateral proton MR spectra were collected from a 2-cm(3) volume in the dorsolateral prefrontal region and the absolute concentrations of N-acetylaspartate, choline (Cho) and creatine+phosphocreatine (Cr+PCr) were measured. RESULTS: There was a significant negative correlation between severity of symptoms and NAA concentration in the schizophrenic patients. This was more marked for positive symptoms and for general psychopathology than for negative symptoms. There was also a significant correlation between NAA concentration and social functioning within the schizophrenic group. There were no significant differences between the two groups for the three metabolites. CONCLUSIONS: The negative association between severity of symptoms and NAA in schizophrenic patients and an association of NAA with social functioning suggest that NAA may be an indicator of disease severity. The lack of significant mean difference in NAA between the two groups suggests that there is no marked neuronal loss in the dorsolateral prefrontal region in schizophrenia.     

Seizure frequency and bilateral temporal abnormalities: a proton magnetic resonance spectroscopy of temporal lobe epilepsy.

Proton magnetic resonance spectroscopy ((1)H-MRS) was performed in seven healthy volunteers and 17 patients with temporal lobe epilepsy (TLE) to clarify the correlation of the severity of epilepsy with bilateral temporal changes in N-acetylaspartate (NAA), choline-containing compounds (Cho) and creatine + phosphocreatine (Cr). Despite unilateral EEG focus, bilateral temporal reduction in NAA /(Cho + Cr) was revealed in patients with intractable seizures. The potential for seizure generation correlated with the NAA /(Cho + Cr) reduction not only on the ipsilateral side but also on the contralateral side. Proton MRS proved to be a useful measurement for obtaining important information about the neuronal changes as well as the lateralization of the epileptogenic focus in TLE patients.     

Proton magnetic resonance spectroscopy in children with temporal lobe epilepsy

We performed proton magnetic resonance spectroscopy of the mesial temporal regions in 20 children with intractable temporal lobe epilepsy and compared results with those from 13 normal subjects. Abnormalities of the ratio of N-acetylaspartate to choline plus creatine (NAAI[Cho+Cr]) were seen in 15 patients (75%). The ratio NAA/(Cho+Cr) was correctly lateralizing in 55% and incorrectly lateralizing in none. Bilateral abnormalities were seen in 45%. Overall there was a unilateral decrease in N-acetylaspartate on the side ipsilateral to the seizure focus (mean 19% decrease vs normals, with 5% decrease on the contralateral side), suggesting neuronal loss or dysfunction. There was also a bilateral increase in creatine and choline (mean l8%), consistent with reactive astrocytosis. We conclude that proton magnetic resonance spectroscopy can contribute to lateralization of the seizure focus, and by detection of bilateral abnormalities, can contribute to the understanding of the underlying pathophysiology in temporal lobe epilepsy.     

精神分裂症患者前额叶和丘脑的质子磁共振波谱研究

Objective To identify the metabolite levels in prefrontal lobe and thalamus in patients with schizophrenia by proton magnetic resonance spectroscopy (1H-MRS). Methods Thirty-eighty schizophrenics and 38 normal controls were involved in this study. A multi-voxel 1H-MRS was given to all the subjects on prefrontal lobe and thalamus within 24 hours they got in hospital. The N-acetylaspartate (NAA), choline-congtaining compounds (Cho), and creatine compounds (Cr) were measured and the ratios of NAA/Cr, Cho/Cr and NAA/( Cho + Cr) were determined Results In left prefrontal lobe and bilateral thalamus, the NAA/Cr ratio in patients demonstrated lower than that in normal controls ( all P <0. 05). In left prefrontal lobe, the NAA/(Cho + Cr) ratio in patients showed lower than that in normal controls (0. 64 ±0. 13 vs. 0. 74±0. 22,t =2. 26, P<0. 05). Both in patients and in normal controls, there were no significant differences in NAA/Cr, Cho/Cr and NAA/(Cho + Cr) between the two sides (all P >0. 05). Conclusious Abnormalities in neuronal function and/or integrity are present in schizophrenics.There is no significantly lateralized asymmetry for metabolite levels such as NAA, Cho and Cr in either the schizophrenics or the controls.     

Thalamic abnormalities in patients with schizophrenia revealed by proton magnetic resonance spectroscopy

Recent investigations suggest that thalamic abnormalities may underlie symptom formation in schizophrenia. We previously demonstrated reduced concentrations of N-acetylaspartate (NAA) in tissue from the thalamus of schizophrenic patients using in vitro proton magnetic resonance spectroscopy (1H-MRS). In the present study, in vivo 1H-MR spectra of the left thalamus and frontal lobe were investigated in 20 patients with schizophrenia and 16 age-matched control subjects to replicate our previous postmortem findings and support the hypothesis of thalamic abnormality in schizophrenia. Schizophrenic patients showed significantly lower NAA/total creatine (Cr) and choline-containing compounds (Cho)/Cr ratios in the thalamus than control subjects, while no significant difference was found in the frontal lobe. There was no significant correlation in the schizophrenic patients between the NAA/Cr or Cho/Cr ratio and other clinical data including clinical symptoms or neuroleptic dosage. These findings may further support other studies suggesting decreased thalamic volume or neuronal number and/or thalamic dysfunction, and reduction in size of white matter tracts adjacent to the thalamus in schizophrenia, as well as our previous postmortem MRS study.     

Relationships among hippocampal volumetry, proton magnetic resonance spectroscopy, and verbal memory in temporal lobe epilepsy

PURPOSE: To examine the relationship between hippocampal volumes, 1H magnetic resonance spectroscopy (MRS)-identified hippocampal metabolic function, and verbal memory in patients with unilateral mesial temporal lobe epilepsy (MTLE). METHODS: Hippocampal volumes, 1H MRS-derived hippocampal creatine to N-acetylaspartate (Cr/NAA), and verbal memory assessment were obtained preoperatively in 22 patients (six right, 16 left) with EEG-defined unilateral MTLE. RESULTS: Left hippocampal volume correlated significantly with left hippocampal Cr/NAA (r=-0.549, p < 0.01), whereas right volume correlated significantly with right Cr/NAA (r=-0.478, p < 0.05). Verbal memory correlated significantly with left hippocampal Cr/NAA (r=-0.594, p < 0.01), but not with left hippocampal volume or right hippocampal measures. CONCLUSIONS: Hippocampal volumes and 1H MRS-derived metabolite ratios are statistically related, but share only a small percentage of variance, suggesting separate but related pathophysiologic processes. Left hippocampal Cr/NAA appears to be more sensitive to verbal memory function than volumes.     

青少年首次发病精神分裂症患者前额叶和海马磁共振质子波谱成像的研究

目的探讨青少年首次发病（以下简称首发）精神分裂症患者前额叶、海马的磁共振质子波谱（^1H—MRS）变化特点。方法对21例青少年（13—17岁）首发精神分裂症患者（患者组）和20名（14～17岁）年龄、性别、受教育时间均匹配的正常对照者（对照组），应用^1H—MRS成像技术检测两组前额叶、海乌N-乙酰天门冬氨酸（NAA）、肌碱（Cho）、肌酸（Cr）3种代谢物，计算NAA／Cr和Cho／Cr比值。采用t检验进行分析。结果（1）患者组左侧前额叶NAA／Cr（1．56±0．81）低于对照组（2．09±0．81），右侧前额叶NAA／Cr（1．84±0．42）低于对照组（2．58±0．83），右侧前额叶Cho／Cr（1．25±0．17）也低于对照组（1．51±0．38），差异有统计学意义（P〈0．05和P〈0．01）。（2）患者组左侧海马NAA／Cr（1．33±0．34）低于对照组（1．64±0．56），差异有统计学意义（P〈0．05）。结论青少年首发精神分裂症患者存在双侧前额叶、左侧海弓神经元完整性和功能障碍，同时可能提示右侧前额叶神经厄能黾需要降低及神经胶质细胞的密度或功能完整性受损。     

Postictal stability of proton magnetic resonance spectroscopy imaging (1H-MRSI) ratios in temporal lobe epilepsy

Interictal proton (1H) MRS is increasingly used for seizure lateralization in patients with temporal lobe epilepsy (TLE). Studies reporting postictal 1H-MRS metabolite changes in patients with TLE are few and contradictory. The authors prospectively performed interictal and postictal proton magnetic resonance spectroscopy imaging (1H-MRSI) studies in seven patients with TLE. The authors found no consistent changes in metabolite peak area ratios between studies, suggesting that 1H-MRS ratios remain stable between interictal and postictal state in TLE.     

Ictal fear in temporal lobe epilepsy: surgical outcome and focal hippocampal changes revealed by proton magnetic resonance spectroscopy imaging

BACKGROUND: Ictal fear (IF) is most frequently associated with epileptic discharges from mesial temporal areas. OBJECTIVES: To determine whether patients with IF were more likely to become seizure free after anteromesial temporal lobe resection compared with those without IF and whether they show more anteriorly pronounced metabolic changes assessed by means of multivoxel magnetic resonance spectroscopy (MRS) along the hippocampal axis. METHODS: Surgical outcome was assessed in 33 consecutive patients with temporal lobe epilepsy after a mean follow-up of 25 months (range, 12-38 months). Proton multivoxel MRS of the hippocampal formation was applied to detect regional differences along the axis of the hippocampus in patients with and without IF. Magnetic resonance tomography showed typical features of hippocampal sclerosis in all patients. RESULTS: Twelve (36%) of the 33 patients reported fear at the beginning of their habitual seizures. Eleven of these patients were seizure free postoperatively. In contrast, only 11 of 21 patients without IF had a favorable outcome. Results of MRS revealed significantly higher pathologic N-acetylaspartate-choline ratios in the anterior portion of the hippocampal formation in patients with than in those without IF, indicating focal metabolic and/or morphologic changes in the head of the hippocampus. CONCLUSIONS: These results indicate the importance of diagnosing auras with IF to provide a more detailed prognosis of the surgical outcome. In addition, our data emphasize that multivoxel MRS is a valuable tool in the presurgical evaluation, as it may reveal different topographical patterns of hippocampal sclerosis.     

不同性别首发精神分裂症患者前额叶和丘脑质子波谱的比较研究

目的探讨首发精神分裂症患者前额叶和丘脑神经生化代谢物质的特点及其性别差异。方法纳入首发精神分裂症患者男性33例、女性31例以及男性正常对照30名、女性正常对照22名,采用多体素磁共振质子波谱(proton magnetic resonance spectroscopy,1H-MRS)检测前额叶和丘脑N-乙酰基天门冬氨酸(NAA)、胆碱复合物(Cho)与肌酸复合物(Cr),完成NAA/Cr值、Cho/Cr值的计算。患者在抗精神病药物治疗8周末复查1H-MRS,治疗前后采用阳性与阴性症状量表(positive and negative syndrome scale,PANSS)评定临床症状和疗效。结果治疗前,男性患者组、女性患者组左侧前额叶NAA/Cr值[(1.38±0.33)、(1.37±0.35)]、左侧丘脑NAA/Cr值[(1.47±0.35)、(1.45±0.38)]均分别低于同性别正常对照组[(1.61±0.38)、(1.63±0.37)和(1.71±0.38)、(1.72±0.39)],差异均有统计学意义(P0.05)。治疗前与治疗后,男性与女性患者组之间1H-MRS各代谢指标的差异均无统计学意义(P0.05),两组中NAA/Cr值、Cho/Cr值的治疗前后自身比较均无明显差异(P0.05)。男性患者组治疗前后左侧前额叶NAA/Cr变化值分别与PANSS总分及阴性症状因子分的变化值呈负相关(r=-0.39,P0.05;r=-0.43,P0.05)。结论未发现首发精神分裂症患者前额叶和丘脑代谢物存在明显的性别差异,但男性左侧前额叶NAA浓度的变化与阴性症状的变化可能有关。     

Prognostic significance of metabolic changes detected by proton magnetic resonance spectroscopy in ischaemic stroke

Proton magnetic resonance spectroscopy has proved to be useful for monitoring a number of metabolites in cerebral infarction. Combined magnetic resonance imaging and spectroscopy investigations were carried out in 14 patients with a recent ischaemic stroke (< 1 week); follow-up examinations were performed from day 28 to day 252 after stroke. The aim of this study was to assess the correlation between the changes ofN-acetyl-aspartate, choline, creatine-phosphocreatine, lactate and clinical evolution measured by the Scandinavian Neurological Scale (SNS). Initially the lactate magnetic resonance signal was present in all patients and the other metabolite contents were significantly reduced (P < 0.001; unpairedt-test) as compared with those on the contralateral side. Spearman's rank correlation test showed a positive correlation between the initial reduction ofN-acetyl-aspartate content and the SNS (P < 0.05), and between the finalN-acetyl-aspartate content and the SNS (P < 0.001). Our results suggest that serial examination in stroke patients may provide further prognostic information and encourage controlled clinical studies.     

Neuron loss localizes human temporal lobe epilepsy by in vivo proton magnetic resonance spectroscopic imaging

Temporal lobe epileptogenic foci were blindly localized in 8 patients with medically refractory unilateral complex partial seizures using noninvasive in vivo proton magnetic resonance spectroscopic imaging (¹H-MRSI) with 4-ml effective voxel size. The brain proton metabolite signals in 8 matched normal controls were bilaterally symmetrical within ± 10%. The hippocampal seizure foci had 21 ± 5% less N-acetyl aspartate signal than the contralateral hippocampal formations (p < 0.01). The focal N-acetyl aspartate reductions were consistent with pathology findings of mesial temporal sclerosis with selective neuron loss and gliosis in the surgically resected epileptogenic foci. Proton MRSI correctly localized the seizure focus in all 8 cases. By comparison, MR imaging correctly localized 7 of 8 cases and single photon emission computed tomography correctly localized 2 of 5 cases. No lactate was detected in these interictal studies. No significant changes in choline or creatine were observed. In conclusion, ¹H-MRSI is a useful tool for the noninvasive clinical assessment of intractable focal epilepsy. These preliminary results suggest that ¹H-MRSI can accurately localize temporal lobe epileptogenic foci.     

31Phosphorus magnetic resonance spectroscopy of the temporal lobes in schizophrenia.

Eleven schizophrenic patients and nine normal controls were studied using in vivo 31Phosphorous magnetic resonance spectroscopy (31P MRS) to test the hypothesis of metabolic asymmetry in the temporal lobes in schizophrenia. The controls did not demonstrate any asymmetry of phosphorous metabolite ratios, percentage of phosphorous metabolites, or pH. In the schizophrenics, however, phosphocreatine/beta-adenosine triphosphate (PCr/beta-ATP) and phosphocreatine/inorganic phosphate (PCr/Pi) effects appeared to primarily reflect higher ratios on the right side, while the percentage of beta-ATP appeared to primarily reflect higher relative concentrations in the left temporal lobe. Moreover, significant negative correlations were noted between total Brief Psychiatric Rating Scale scores and PCr/beta-ATP in both the right and left temporal lobes. These results support the hypothesis of an asymmetric distribution of 31P metabolites in the temporal lobe of schizophrenic patients, and also show an association between temporal lobe phosphorous metabolism and the severity of psychiatric symptomatology.     

Metabolic and pathological effects of temporal lobe epilepsy in rat brain detected by proton spectroscopy and imaging

The goal of these experiments was to test the hypothesis that in an animal model of temporal lobe epilepsy (TLE), magnetic resonance spectroscopic measurement of N-acetylaspartate (NAA) and other metabolites, together with magnetic resonance imaging, provides a sensitive in vivo method to localize and monitor the progression of neuronal cell death and gliosis. Seizures were induced in rats by unilateral hippocampal injection of kainate. Magnetic resonance measurements were made from 1 to 84 days using proton spectroscopic imaging (¹H-MRSI), T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI). The results were compared with findings on histological sections. Decreased NAA and creatine levels and increased apparent diffusion coefficient of water were found in the ipsilateral hippocampus after 14 days where neuronal loss and gliosis were observed. In the contralateral hippocampus a significant increase of choline level was observed. These results suggest that ¹H-MRSI is a useful in vivo method for localizing neuronal loss and may also indicate additional pathological and metabolic alterations. In addition, DWI may be a useful method for in vivo detection of tissue alterations due to TLE.     

磁共振多体素波谱技术对颞叶癫痫的定位研究

目的评价磁共振多体素波谱扫描技术对颞叶癫痫的定位诊断价值。方法选择具有明显颞叶癫痫表现,并经脑电图检查定位诊断明确的单侧颞叶癫痫患者30例作为研究对象;排除M R I检查存在颅脑肿瘤、脑血管畸形等症状性癫痫患者。患者均行常规M RI及双侧海马区多体素波谱扫描,完成检查后将以代谢物峰值含量为灰阶的伪彩图与倾斜冠状重度T2W I图像进行融合,测量双侧海马区N-乙酰天冬氨酸、胆碱峰值含量和胆碱/N-酰天冬氨酸比值,并直观分析双侧海马区两代谢物的分布情乙况。结果患侧N-乙酰天冬氨酸峰值含量为(13587.61±3913.99)M R units,健侧为(17683.10±5610.61)M R units,患侧低于健侧差异有显著性意义(t=6.728,P<0.001);患侧胆碱/N-乙酰天冬氨酸比值为(1.26±0.11),健侧比值为(1.01±0.14),患侧高于健侧差异亦有显著性意义(t=7.883,P<0.001)。将两代谢物含量及比值伪彩图与常规M RI图像进行融合,可直观发现双侧海马区N-乙酰天冬氨酸峰值含量及胆碱/N-酰天冬氨酸比值存在明显差异。结论磁共振多体素波谱技术不仅可以通过对某些代谢物含量乙的定量分析进行癫痫灶的定位、定侧诊断,还可通过常规M RI图像与多体素磁共振波谱图像的融合图像直观评价代谢物分布状态,描记癫痫灶的大致轮廓,为制定手术方案提供依据。     

Choline-containing compounds detected by proton magnetic resonance spectroscopy in the basal ganglia in bipolar disorder.

Choline-containing compounds (Cho) were examined by proton magnetic resonance spectroscopy (1H-MRS) in the left subcortical region, including basal ganglia, in 19 euthymic patients with bipolar disorder and 19 age-matched normal controls. Ten of the patients were treated with lithium; the remaining 9 were not treated with lithium for at least 30 d. The Cho to creatine + phosphocreatine (Cr) peak ratio in the bipolar patients (0.75 +/- 0.38 [mean +/- SD]) was higher than that in the normal controls (0.52 +/- 0.26, P < 0.05). There was no significant difference in the Cho:Cr peak ratio between patients treated with lithium (0.63 +/- 0.36) and without lithium (0.89 +/- 0.35). These results do not support the hypothesis that lithium increases the brain choline-containing compounds, but rather imply that membrane breakdown may occur in the basal ganglia of patients with bipolar disorder.