Regional metabolism in microsmic patients with schizophrenia.

The cerebral glucose metabolism of eight patients with schizophrenia and an olfactory agnosia was compared with that of eight normosmic patients with schizophrenia and eight normal controls. Since all patients were scanned while on their current medication regimen, the duration and dosage of the medication of the two patient groups were compared. Similarly, duration and dosage were correlated with absolute regional metabolic rates. No significant effects were found in these analyses. The patients with schizophrenia had significantly lower rates of frontal metabolism than the normal controls. However, the patients with schizophrenia and an olfactory agnosia had a lower right basal ganglia and thalamic metabolism than the normosmic patients with schizophrenia.     

老年抑郁症患者的脑正电子发射体层摄影术显像分析

目的 探讨老年抑郁症患者脑^18氟-脱氧葡萄糖（18^F-FDG）正电子发射体层摄影术（PET）显像的特点。方法 分别对6例老年抑郁症患者（GD组）及10名健康体检者（对照组）进行脑^18 F-FDGPET显像，按年龄、简易智力状态检查量表总分和性别构成配对，用统计参数图第2版软件比较两组间脑局部葡萄糖代谢的差别。结果 GD组较对照组在双侧尾状核、额下回、颞上回、额中回，右侧核外、额上回、舌回和左侧扣带回、中央前回等脑区局部葡萄糖代谢减低（均P〈0．005）。GD组无局部脑葡萄糖代谢增加的脑区。结论 老年抑郁症患者存在基底节区、前额叶、颞叶和边缘系统的局部葡萄糖代谢下降。     

Greater left cerebral hemispheric metabolism in bulimia assessed by positron emission tomography

Eight women with bulimia and eight age- and sex-matched normal control subjects were studied with positron emission tomography using [18F]-fluorodeoxyglucose (FDG) as a tracer of brain metabolic rate. Subjects performed a visual vigilance task during FDG uptake. In control subjects, the metabolic rate was higher in the right hemisphere than in the left, but patients with bulimia did not have this normal asymmetry. Lower metabolic rates in the basal ganglia, found in studies of depressed subjects, and higher rates in the basal ganglia, reported in a study of anorexia nervosa, were not found. This is consistent with the suggestion that bulimia is a diagnostic grouping distinct from these disorders.     

Regional cerebral glucose utilization in patients with a range of severities of unipolar depression.

BACKGROUND: Patients with unipolar depression are most often reported to have decreased regional cerebral glucose metabolism (rCMRglu) in dorsal prefrontal and anterior cingulate cortices compared with healthy control subjects, often correlating inversely with severity of depression. METHODS: We measured rCMRglu with fluorine-18 deoxyglucose positron emission tomography (PET) in 38 medication-free patients with unipolar depression and 37 healthy control subjects performing an auditory continuous performance task to further investigate potential prefrontal and anterior paralimbic rCMRglu abnormalities in patients attending to this task. RESULTS: Compared with control subjects, the subgroup of patients with Hamilton depression scores of 22 or greater demonstrated decreased absolute rCMRglu in right prefrontal cortex and paralimbic/amygdala regions as well as bilaterally in the insula and temporoparietal cortex (right > left); they also exhibited increased normalized metabolic activity bilaterally in the cerebellum, lingula/cuneus, and brain stem. Severity of depression negatively correlated with absolute rCMRglu in almost the entire extent of the right cingulate cortex as well as bilaterally in prefrontal cortex, insula, basal ganglia, and temporoparietal cortex (right > left). CONCLUSIONS: Areas of frontal, cingulate, insula, and temporal cortex appear hypometabolic in association with different components of the severity and course of illness in treatment-resistant unipolar depression.     

Selective hypometabolism in the inferior frontal lobe in depressed patients with Parkinson's disease

Depression is a frequent finding in patients with Parkinson's disease (PD). Regional cerebral glucose metabolism was measured in depressed and nondepressed patients with PD and in age-comparable normal control subjects using 2-[18F]-fluoro-2-deoxy-D-glucose and positron emission tomography (PET). Relative metabolic activity in the caudate and orbital-inferior region of the frontal lobe was significantly lower in the depressed patients with PD as compared to both nondepressed patients and control subjects. There was a significant inverse correlation between relative glucose metabolism in the orbital-inferior area of the frontal lobe and depression scores. This study suggests that depression in PD is associated with dysfunction in the caudate and orbital-inferior area of the frontal lobe. This metabolic pattern is unlike that seen in patients with PD who have other behavioral deficits such as dementia, and suggests that disruption of basal ganglia circuits involving the inferior region of the frontal lobe may affect the regulation of mood.     

Neuroanatomic correlates of psychopathologic components of major depressive disorder

BACKGROUND: The Hamilton Depression Rating Scale (HDRS) is widely used to measure the severity of depression in mood disorders. Total HDRS score correlates with brain metabolism as measured by fludeoxyglucose F 18 ([(18)F]-FDG) positron emission tomography. The HDRS comprises distinct symptom clusters that may be associated with different patterns of regional brain glucose metabolism. OBJECTIVE: To examine associations between HDRS component psychopathologic clusters and resting glucose cerebral metabolism assessed by [(18)F]-FDG positron emission tomography.Patients We evaluated 298 drug-free patients who met the DSM-III-R criteria for major depressive disorder. MAIN OUTCOME MEASURES: Five principal components were extracted from the 24-item HDRS for all subjects and ProMax rotated: psychic depression, loss of motivated behavior, psychosis, anxiety, and sleep disturbance. The [(18)F]-FDG scans were acquired in a subgroup of 43 drug-free patients in twelve 5-minute frames. Voxel-level correlation maps were generated with HDRS total and factor scores. RESULTS: Total HDRS score correlated positively with activity in a large bilateral ventral cortical and subcortical region that included limbic, thalamic, and basal ganglia structures. Distinct correlation patterns were found with the 3 individual HDRS factors. Psychic depression correlated positively with metabolism in the cingulate gyrus, thalamus, and basal ganglia. Sleep disturbance correlated positively with metabolism in limbic structures and basal ganglia. Loss of motivated behavior was negatively associated with parietal and superior frontal cortical areas. CONCLUSIONS: Different brain regions correlate with discrete symptom components that compose the overall syndrome of major depression. Future studies should extend knowledge about specific regional networks by identifying responsible neurotransmitters related to specific psychopathologic components of mood disorders.     

The effects of ECT on brain glucose: a pilot FDG PET study

BACKGROUND: Regional brain activity was measured before and after electroconvulsive therapy (ECT) using [18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET). METHODS: 6 patients (4 females) with major depression were free of psychotropic medications for at least 2 weeks prior to baseline FDG scans. Patients were treated with bifrontotemporal ECT, and posttreatment scans were obtained after the last treatment. RESULTS: A region of interest (ROI) analysis of absolute metabolic rate showed a decrease in CMRglu after ECT in all 61 regions examined. In 17 of the 61 regions, the decrease was significant at the p < 0.05 level. In the right parietal lobe, and the right anterior and left posterior frontal lobes, the decrease in CMRglu significantly correlated with the decrease in Hamilton Depression Rating Scale (HDRS) scores (r = 0.83, 0.82, and 0.84, respectively). The analysis of CMRglu normalized to global metabolic rate showed significant increases in 8 of 61 regions, including basal ganglia, upper brainstem, and occipital lobe. DISCUSSION: The decreases in global glucose metabolism and correlation of changes in frontal metabolism with decreases in HDRS are consistent with earlier brain imaging studies of ECT. The relative increases in CMRglu observed in regions with known dopaminergic innervation (caudate and upper brainstem) have not been previously reported.     

Donepezil HCl (E2020) maintains functional brain activity in patients with Alzheimer disease: results of a 24-week, double-blind, placebo-controlled study.

OBJECTIVE: The authors evaluated the effects of donepezil (10 mg/day) versus placebo on brain glucose metabolism. METHODS: This was a randomized, double-blind, parallel-group, 24-week pilot study in 28 patients with mild-to-moderate Alzheimer disease (AD). Functional brain activity was quantified by measuring average glucose metabolism in an axial brain slice and regional brain glucose metabolism using positron emission tomography. RESULTS: At Week 24, relative to the pons metabolic rate, mean brain glucose metabolism in an axial slice at the level of the striatum was maintained within 0.5% of mean baseline levels for donepezil-treated patients, whereas it declined by an average of 10.4% in placebo-treated patients. This observation was confirmed by an analysis of differences in the mean slopes of glucose metabolism in the striatal slice in donepezil- and placebo-treated patients during the 24-week period. Significant treatment differences at Week 24 favoring donepezil for the mean percentage change from baseline in regional brain glucose metabolism were observed in four predefined regions of interest: the right parietal lobe 1, left temporal lobe 2, right frontal lobe 2, and left frontal lobe 2. CONCLUSION: Placebo-treated patients with AD show a decline in functional brain activity, relative to the pons, in several regions, and treatment with donepezil may slow this decline.     

Cerebral metabolic dysfunction and impaired vigilance in recently abstinent methamphetamine abusers.

BACKGROUND: Methamphetamine (MA) abusers have cognitive deficits, abnormal metabolic activity and structural deficits in limbic and paralimbic cortices, and reduced hippocampal volume. The links between cognitive impairment and these cerebral abnormalities are not established. METHODS: We assessed cerebral glucose metabolism with [F-18]fluorodeoxyglucose positron emission tomography in 17 abstinent (4 to 7 days) methamphetamine users and 16 control subjects performing an auditory vigilance task and obtained structural magnetic resonance brain scans. Regional brain radioactivity served as a marker for relative glucose metabolism. Error rates on the task were related to regional radioactivity and hippocampal morphology. RESULTS: Methamphetamine users had higher error rates than control subjects on the vigilance task. The groups showed different relationships between error rates and relative activity in the anterior and middle cingulate gyrus and the insula. Whereas the MA user group showed negative correlations involving these regions, the control group showed positive correlations involving the cingulate cortex. Across groups, hippocampal metabolic and structural measures were negatively correlated with error rates. CONCLUSIONS: Dysfunction in the cingulate and insular cortices of recently abstinent MA abusers contribute to impaired vigilance and other cognitive functions requiring sustained attention. Hippocampal integrity predicts task performance in methamphetamine users as well as control subjects.     

Singing can improve speech function in aphasics associated with intact right basal ganglia and preserve right temporal glucose metabolism: Implications for singing therapy indication

Clinically, we know that some aphasic patients can sing well despite their speech disturbances. Herein, we report 10 patients with non-fluent aphasia, of which half of the patients improved their speech function after singing training. We studied ten patients with non-fluent aphasia complaining of difficulty finding words. All had lesions in the left basal ganglia or temporal lobe. They selected the melodies they knew well, but which they could not sing. We made a new lyric with a familiar melody using words they could not name. The singing training using these new lyrics was performed for 30 minutes once a week for 10 weeks. Before and after the training, their speech functions were assessed by language tests. At baseline, 6 of them received positron emission tomography to evaluate glucose metabolism. Five patients exhibited improvements after intervention; all but one exhibited intact right basal ganglia and left temporal lobes, but all exhibited left basal ganglia lesions. Among them, three subjects exhibited preserved glucose metabolism in the right temporal lobe. We considered that patients who exhibit intact right basal ganglia and left temporal lobes, together with preserved right hemispheric glucose metabolism, might be an indication of the effectiveness of singing therapy.     

Subthalamic nucleus stimulation restores glucose metabolism in associative and limbic cortices and in cerebellum: evidence from a FDG-PET study in advanced Parkinson's disease.

Deep brain stimulation of the subthalamic nucleus (STN-DBS) is a highly effective surgical treatment in patients with advanced Parkinson's disease (PD). Because the STN has been shown to represent an important relay station not only in motor basal ganglia circuits, the modification of brain areas also involved in non-motor functioning can be expected by this intervention. To determine the impact of STN-DBS upon the regional cerebral metabolic rate of glucose (rCMRGlc), we performed positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) in eight patients with advanced PD before surgery as well as in the DBS on- and off-conditions 4 months after electrode implantation and in ten age-matched healthy controls. Before surgery, PD patients showed widespread bilateral reductions of cortical rCMRGlc versus controls but a hypermetabolic state in the left rostral cerebellum. In the STN-DBS on-condition, clusters of significantly increased rCMRGlc were found in both lower thalami reaching down to the midbrain area and remote from the stimulation site in the right frontal cortex, temporal cortex, and parietal cortex, whereas rCMRGlc significantly decreased in the left rostral cerebellum. Therefore, STN-DBS was found to suppress cerebellar hypermetabolism and to partly restore physiologic glucose consumption in limbic and associative projection territories of the basal ganglia. These data suggest an activating effect of DBS upon its target structures and confirm a central role of the STN in motor as well as associative, limbic, and cerebellar basal ganglia circuits.     

Positron emission tomography studies of basal ganglia and somatosensory cortex neuroleptic drug effects: differences between normal controls and schizophrenic patients

Glucose metabolic rate in the basal ganglia, thalamus, and somatosensory cortex was examined in eight patients with schizophrenia before and after receiving neuroleptic medication. Basal ganglia metabolic rates were increased with medication: more on the right than on the left and more in putamen than caudate. The cortical anteroposterior ratio, an index of relative hypofrontality, was not affected by neuroleptics. The brain areas that were found to be altered by neuroleptics were selected for comparison between off-medication schizophrenics and controls. Metabolic rates in the basal ganglia tended to be low in patients with schizophrenia in comparison to 24 age- and sex-matched controls.     

GSM mobile phone radiation suppresses brain glucose metabolism

We investigated the effects of mobile phone radiation on cerebral glucose metabolism using high-resolution positron emission tomography (PET) with the (18)F-deoxyglucose (FDG) tracer. A long half-life (109 minutes) of the (18)F isotope allowed a long, natural exposure condition outside the PET scanner. Thirteen young right-handed male subjects were exposed to a pulse-modulated 902.4 MHz Global System for Mobile Communications signal for 33 minutes, while performing a simple visual vigilance task. Temperature was also measured in the head region (forehead, eyes, cheeks, ear canals) during exposure. (18)F-deoxyglucose PET images acquired after the exposure showed that relative cerebral metabolic rate of glucose was significantly reduced in the temporoparietal junction and anterior temporal lobe of the right hemisphere ipsilateral to the exposure. Temperature rise was also observed on the exposed side of the head, but the magnitude was very small. The exposure did not affect task performance (reaction time, error rate). Our results show that short-term mobile phone exposure can locally suppress brain energy metabolism in humans.     

Mood disturbances and regional cerebral metabolic abnormalities in recently abstinent methamphetamine abusers

BACKGROUND: Mood disturbances in methamphetamine (MA) abusers likely influence drug use, but the neurobiological bases for these problems are poorly understood. OBJECTIVE: To assess regional brain function and its possible relationships with negative affect in newly abstinent MA abusers. DESIGN: Two groups were compared by measures of mood and cerebral glucose metabolism ([18F]fluorodeoxyglucose positron emission tomography) during performance of a vigilance task. SETTING: Participants were recruited from the general community to a research center. PARTICIPANTS: Seventeen abstaining (4-7 days) MA abusers (6 women) were compared with 18 control subjects (8 women). MAIN OUTCOME MEASURES: Self-reports of depressive symptoms and anxiety were measured, as were global and relative glucose metabolism in the orbitofrontal, cingulate, lateral prefrontal, and insular cortices and the amygdala, striatum, and cerebellum. RESULTS: Abusers of MA provided higher self-ratings of depression and anxiety than control subjects and differed significantly in relative regional glucose metabolism: lower in the anterior cingulate and insula and higher in the lateral orbitofrontal area, middle and posterior cingulate, amygdala, ventral striatum, and cerebellum. In MA abusers, self-reports of depressive symptoms covaried positively with relative glucose metabolism in limbic regions (eg, perigenual anterior cingulate gyrus and amygdala) and ratings of state and trait anxiety covaried negatively with relative activity in the anterior cingulate cortex and left insula. Trait anxiety also covaried negatively with relative activity in the orbitofrontal cortex and positively with amygdala activity. CONCLUSIONS: Abusers of MA have abnormalities in brain regions implicated in mood disorders. Relationships between relative glucose metabolism in limbic and paralimbic regions and self-reports of depression and anxiety in MA abusers suggest that these regions are involved in affective dysregulation and may be an important target of intervention for MA dependence.     

Comparison of cerebral glucose metabolism between multiple system atrophy Parkinsonian type and Parkinson's disease

OBJECTIVE: To investigate the difference in the regional cerebral glucose metabolism between multiple system atrophy Parkinsonian type (MSA-P) and Parkinson's disease (PD). MATERIAL AND METHODS: Fifteen patients with MSA-P, 32 patients with PD and eight cases of healthy control underwent positron emission tomography (PET) with (18)F-fluorodeoxyglucose ((18)F-FDG) showing glucose metabolism. Glucose metabolism ratios of various cerebral regions were compared as an indicator of regional cerebral glucose metabolic patterns. RESULTS: The metabolism ratios of frontal lobe/occipital lobe, parietal lobe/occipital lobe, temporal lobe/occipital lobe and corpus striatum/occipital lobe in patients with MSA-P were lower than those in patients with PD and control, respectively (p<0.01). For patients with MSAP, the metabolism ratio in thalamus was higher than those in lenticular nucleus and anterior cortical brain, respectively (p<0.01) and the changes of metabolism ratio in cortex, corpus striatum and thalamus were symmetric. For patients with PD, the metabolism ratio in corpus striatum was higher than that in thalamus and two side of the basal ganglia show asymmetric change of metabolism (p<0.01). CONCLUSION: This study suggests that significant differences exist in the patterns of regional cerebral glucose metabolism between MSA-P and PD. (18)F-FDG PET might be a useful adjunctive method for differential diagnosis between MSA-P and PD.     

Changes in glucose metabolism and metabolites during the epileptogenic process in the lithium-pilocarpine model of epilepsy

Purpose: The metabolic and biochemical changes that occur during epileptogenesis remain to be determined. ¹⁸F‐Fluorodeoxyglucose positron emission tomography (FDG‐PET) and proton magnetic resonance spectroscopy (¹H MRS) are noninvasive techniques that provide indirect information on ongoing pathologic changes. We, therefore, utilized these methods to assess changes in glucose metabolism and metabolites in the rat lithium‐pilocarpine model of epilepsy as markers of epileptogenesis from baseline to chronic spontaneous recurrent seizures (SRS). Methods: PET and MRS were performed at baseline, and during the acute, subacute, silent, and chronic periods after lithium‐pilocarpine induced status epilepticus (SE). Sequential changes in glucose metabolism on ¹⁸F‐FDG PET using SPM2 and the ratios of percent injected dose per gram (%ID)/g of regions of interest (ROIs) in the bilateral amygdala, hippocampus, basal ganglia with the thalamus, cortex, and hypothalamus normalized to the pons were determined. Voxels of interest (VOIs) on ¹H MRS were obtained at the right hippocampus and the basal ganglia. NAA/Cr levels and Cho/Cr at various time points were compared to baseline values. Key Findings: Of 81 male Sprague‐Dawley rats, 30 progressed to SRS. ¹⁸F‐FDG PET showed widespread global hypometabolism during the acute period, returning to baseline level during the subacute period. Glucose metabolism, however, declined in part of the hippocampus during the silent period, with the hypometabolic area progressively expanding to the entire limbic area during the chronic period. ¹H MRS showed that the NAA/Cr levels in the hippocampus and basal ganglia were reduced during the acute period and were not restored subsequently from the subacute to the chronic period without any significant change in the Cho/Cr ratio throughout the entire experiment. Significance: Serial metabolic and biochemical changes in the lithium‐pilocarpine model of epilepsy indirectly represent the process of human epileptogenesis. Following initial irreversible neural damage by SE, global glucose metabolism transiently recovered during the subacute period without neuronal recovery. Progressive glucose hypometabolism in the limbic area during the silent and chronic periods may reflect the important role of the hippocampus in the formation of ongoing epileptic network during epileptogenesis.     

False Lateralization of Temporal Lobe Epilepsy with FDG Positron Emission Tomography

Summary: We report 2 patients in whom visual interpretation of interictal positron emission tomography (PET) with [¹⁸F]fluorodeoxyglucose (FDG) suggested false lateralization of an epileptic focus. PET scans were interpreted as showing diffuse left temporal lobe hypometabolism in 1 patient and lateral temporal hypometabolism in the other. However, seizures began in the right mesial temporal lobe in both patients, and both responded favorably to right temporal lobectomy. In 1 patient, the intra-cranial EEG showed continuous asymptomatic subclinical seizure activity emanating from the right amygdala. These limbic discharges probably caused unrecognized right temporal lobe hypermetabolism. In the other case, quantitative analysis of metabolic rates showed conflicting mesial and lateral metabolic indexes. Frequent mesial interictal discharges might have increased lateral temporal metabolism. We conclude that asymptomatic epileptiform activity may alter temporal lobe metabolism and that quantitative PET analysis helps clarify contradictory visual PET interpretations.     

Increased interictal cerebral glucose metabolism in a cortical-subcortical network in drug naive patients with cryptogenic temporal lobe epilepsy.

Positron emission tomography with [18F]-2-fluoro-2-deoxy-D-glucose ([18F]FDG) has been used to assess the pattern of cerebral metabolism in different types of epilepsies. However, PET with [18F]FDG has never been used to evaluate drug naive patients with cryptogenic temporal lobe epilepsy, in whom the mechanism of origin and diffusion of the epileptic discharge may differ from that underlying other epilepsies. In a group of patients with cryptogenic temporal lobe epilepsy, never treated with antiepileptic drugs, evidence has been found of significant interictal glucose hypermetabolism in a bilateral neural network including the temporal lobes, thalami, basal ganglia, and cingular cortices. The metabolism in these areas and frontal lateral cortex enables the correct classification of all patients with temporal lobe epilepsy and controls by discriminant function analysis. Other cortical areas--namely, frontal basal and lateral, temporal mesial, and cerebellar cortices--had bilateral increases of glucose metabolism ranging from 10 to 15% of normal controls, although lacking stringent statistical significance. This metabolic pattern could represent a pathophysiological state of hyperactivity predisposing to epileptic discharge generation or diffusion, or else a network of inhibitory circuits activated to prevent the diffusion of the epileptic discharge.     

情绪感知障碍型抑郁患者脑区激活的Meta分析

目的：运用基于激活似然评估的Meta分析,定量描绘抑郁患者情绪感知过程中的异常激活脑区分布。 资料来源：计算机检索PscyINFO、Pubmed、CNKI等数据库,检索时限为建库至2010-06。 资料选择：纳入以下研究：○1基于情绪诱导的抑郁患者fMRI研究。○2以Talairach或MNI坐标定位抑郁患者与正常对照间激活差异脑区的研究。利用Icbm2tal软件将MNI坐标转换至Talairach坐标系,使用Ginger-ALE 2.0软件依次行高斯平滑、排列检验和错误发现率评估,最终计算出脑区激活似然评估分布图。 结局评价指标：受试者的脑区激活情况。 结果：共纳入17篇文献,包含抑郁患者261例,健康对照273名,坐标201个。Meta分析表明执行情感任务时,面对负性情绪刺激,抑郁患者前额叶皮质,基底节区主要表现为激活降低,而边缘叶,尤其是杏仁核激活增加。提示以上脑区可能是情绪调控脑功能环路重要节点。 结论：前额叶皮质、基底节区、边缘叶之间联系异常可能是抑郁症的神经病理基础。     

Positron emission tomography in schizophrenic patients with and without neuroleptic medication

Positron emission tomography using [18F]2-fluoro-2-deoxy-D-glucose was performed in nine chronic schizophrenic patients both when medication-free and when medicated with neuroleptics. Total brain cortex, temporal cortex, and basal ganglia glucose use was significantly increased with medication; however, there was no change in anterior/posterior metabolic gradients.