Brain perfusion in Alzheimer's disease with and without apathy: a SPECT study with statistical parametric mapping analysis

Alzheimer's disease (AD) is clinically characterized by cognitive symptoms that, in combination with behavioral disturbances, significantly interfere with activities of daily living. These behavioral disorders contribute to the clinical heterogeneity of the disease and probably express different pathophysiological processes. Apathy is one of the most frequent behavioral disorders in AD. The aim of this study was to evaluate brain perfusion of AD patients with and without apathy (as determined by the Neuropsychiatric Inventory) compared with that in healthy elderly subjects. A total of 15 AD patients without apathy (AD/NA; mean age 76.6) and 15 AD patients with apathy (AD/A; mean age 77.6) were studied. Brain perfusion was measured by 99mTc-labeled bicisate (ECD) single-photon emission tomography (ECD SPECT). The images of the two AD subgroups were compared by means of statistical parametric mapping (SPM 99) to corresponding images of 11 healthy elderly control subjects (obtained from the Society of Nuclear Medicine database). Compared with the healthy elderly subjects, the apathy-free AD subgroup had significantly lower perfusion of inferior temporal regions (left fusiform gyrus, left parahippocampal area) and occipital regions (left gyrus lingualis). The apathy subgroup had significantly decreased perfusion of the left anterior cingulate, the right inferior and medial gyrus frontalis, the left orbitofrontal gyrus and the right gyrus lingualis. The differences in the brain areas with reduced perfusion between the apathy-free subjects (mainly the posterior regions) and the apathetic subjects (mainly the anterior regions) indicate that behavioral disorders such as apathy participate in the heterogeneity of brain perfusion in AD.     

Orbitofrontal dysfunction related to both apathy and disinhibition in frontotemporal dementia

Orbitofrontal metabolic impairment is characteristic of the frontal variant of frontotemporal dementia (fv-FTD), as are early changes in emotional and social conduct. Two main types of behavioral disturbances have been distinguished in fv-FTD patients: apathetic and disinhibited manifestations. In this study, we searched for relationships between brain metabolism and presence of apathetic or disinhibited behavior. Metabolic activity and behavioral data were collected in 41 fv-FTD patients from European PET centers. A conjunction analysis of the PET data showed an expected impairment of metabolic activity in the anterior cingulate, ventromedial and orbital prefrontal cortex, the dorsolateral prefrontal cortex and the left anterior insula in fv-FTD subjects compared to matched controls. A correlation was observed between disinhibition scores on the Neuropsychiatric Inventory scale and a cluster of voxels located in the posterior orbitofrontal cortex (6, 28, -24). Comparison of brain activity between apathetic and nonapathetic fv-FTD patients from two centers also revealed a specific involvement of the posterior orbitofrontal cortex in apathetic subjects (4, 22, -22). The results confirm that the main cerebral metabolic impairment in fv-FTD patients affects areas specializing in emotional evaluation and demonstrate that decreased orbitofrontal activity is related to both disinhibited and apathetic syndromes in fv-FTD.     

Medial temporal hypoperfusion and aggression in Alzheimer disease

BACKGROUND: It is not understood why some patients with Alzheimer disease (AD) display aggression and others do not. OBJECTIVE: To examine the relation between regional brain perfusion and aggression in AD. DESIGN: Single-photon emission computed tomographic scans were coregistered to a standardized template in Talairach space, generating mean ratios of uptake referenced to the cerebellum. PARTICIPANTS: Forty-nine outpatients (25 men and 24 women; mean +/- SD age, 74 +/- 11 years) with probable AD (Mini-Mental State Examination score, 17.7 +/- 5.0; 30 aggressive and 19 nonaggressive), comparable in age, sex, and severity of cognitive impairment. MAIN OUTCOME MEASURES: Regional perfusion ratios were determined for 5 bilateral regions of interest: orbitofrontal, middle medial temporal, inferior medial temporal, hypothalamus/thalamus, and anterior cingulate. RESULTS: Compared with nonaggressive patients, aggressive ones displayed hypoperfusion in the right and left middle medial temporal regions of interest (P = .02 for both), but not the others (all (t tests, unpaired, 2-tailed). On regression analyses, right middle temporal hypoperfusion (P = .001), younger age (P = .002), greater activity disturbances (P = .004), and higher Mini-Mental State Examination scores (P = .04) independently predicted aggression, accounting for 44% of the total variance (F = 8.7; P<.001). Statistical parametric mapping analyses supported right middle medial temporal hypoperfusion in the aggressive group (P = .008). CONCLUSION: In this sample of patients with AD, the right middle medial temporal region emerged as an important neural correlate of aggression.     

Regional cerebral blood flow abnormalities in early-onset obsessive-compulsive disorder: an exploratory SPECT study

OBJECTIVE: Recent epidemiological and clinical data suggest that obsessive-compulsive disorder (OCD) may be subtyped according the age of onset of obsessive-compulsive symptoms. The regional cerebral blood flow (rCBF) single photon emission computed tomography (SPECT) technique was used to investigate whether the pathophysiology of OCD differs between early- and late-onset OCD subjects. METHOD: Resting rCBF was measured in 13 early-onset (<10 years) and 13 late-onset (>12 years) adult OCD subjects and in 22 healthy controls. Voxel-based rCBF comparisons were performed with statistical parametric mapping. RESULTS: Early-onset OCD cases showed decreased rCBF in the right thalamus, left anterior cingulate cortex, and bilateral inferior prefrontal cortex relative to late-onset subjects (p < .0005, uncorrected for multiple comparisons). Relative to controls, early-onset cases had decreased left anterior cingulate and right orbitofrontal rCBF, and increased rCBF in the right cerebellum, whereas late-onset subjects showed reduced right orbitofrontal rCBF and increased rCBF in the left precuneus. In early-onset subjects only, severity of obsessive-compulsive symptoms correlated positively with left orbitofrontal rCBF. CONCLUSIONS: rCBF differences in frontal-subcortical circuits between early-onset and late-onset OCD subjects were found, both in location and direction of changes. These results provide preliminary evidence that brain mechanisms in OCD may differ depending on the age at which symptoms are first expressed.     

Regional cerebral blood flow abnormalities associated with apathy and depression in Alzheimer disease

The aim of this study was to identify brain areas related to apathy or depression in patients with Alzheimer disease (AD). Eighty-one AD patients were enrolled in this prospective study. (99m)Tc-HMPAO single photon emission computed tomography was performed to evaluate regional cerebral blood flow (rCBF). According to the Neuropsychiatric Inventory subscores of apathy and depression, 9 patients were classified as clinically significant (cs) depressed and non-cs-apathetic (D+) groups and 9 were classified as cs-apathetic and non-cs-depressed (A+) groups. In addition, 18 patients were classified as age-matched and Mini-Mental State Examination-matched disease control groups (D-, A-). The significance of rCBF differences between groups and the correlation between rCBF and subscores in 81 AD patients were estimated by SPM (uncorrected P < 0.005) analysis. D+ patients had significantly lower perfusion in the right orbitofrontal and inferior frontal gyri than D- patients, whereas A+ patients had this in the right amygdala, temporal, posterior cingulate, right superior frontal, postcentral, and left superior temporal gyri than A- patients. The negatively correlated areas with depression subscores included the left inferior frontal and the right middle frontal gyri and those with apathy subscores included the right temporal and right medial frontal gyri. We suggest that this finding may indicate that apathy and depression in AD patients involve distinct functional circuits.     

Cerebral blood flow in corticobasal degeneration and progressive supranuclear palsy

To compare brain perfusion between corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP), we investigated regional cerebral blood flow (rCBF) semiquantitatively with single-photon emission computed tomography and [123I]iodoamphetamine in six patients with CBD and five with PSP. Compared with 12 age-matched control subjects, the average of the left and right rCBF values for the CBD patients was significantly reduced in the inferior prefrontal, anterior cingulate, medial premotor, sensorimotor, posterior parietal, and superior temporal cortices as well as in the basal ganglia and thalamus, whereas only the medial premotor cortex was significantly hypoperfused in the PSP patients. Compared with the PSP patients, the CBD patients showed significantly decreased rCBF in the inferior prefrontal, sensorimotor, and posterior parietal cortices, but not in the subcortical regions. Compared with the controls, interhemispheric differences of rCBF were significant in the inferior prefrontal, sensorimotor, and posterior parietal cortices of the CBD patients but in only the medial prefrontal cortex of the PSP patients. These results indicate that rCBF reductions are more extensive and asymmetric in CBD than in PSP, although the two diseases share medial frontal involvement.     

SPECT检测利培酮对精神分裂症患者脑血流灌注的影响

目的探讨利培酮对局部脑血流灌注(rCBF)的影响及疗效与rCBF之间的关系。方法研究组为24例未用过药的精神分裂症患者。男10例,女14例。正常对照组26例,男12例,女14例。用利培酮(3～6mg/d)治疗8周。患者在治疗前后进行基础状态及认知激活状态脑SPECT显像。结果与正常对照组相比,治疗前基础状态时,24例患者左右颞叶后下部血流灌注增加;激活状态时,左额叶外侧中部血流灌注显著下降。治疗后与治疗前相比,右颞叶外侧部、左右颞叶后上部基础状态的血流灌注显著下降;左右额叶中下部、左额叶外侧下部、左额颞上部及左额外侧上部认知激活状态的血流灌注显著增加。PANSS减分率与脑血流灌注的变化有关。结论利培酮治疗精神分裂症后,右颞外侧部、左右颞叶后上部、左右额叶中下部及左额叶外侧上下部的血流灌注变化显著。疗效与血流灌注变化有关。提示脑血流灌注对预测药物疗效具有重要意义。     

Assessment of regional blood flow in cerebral motor and sensory areas in patients with spinal cord injury

We assessed the presence and the degree of alteration of the regional blood flow (rCBF) as visualized by Tc-99m HMPAO brain rest SPECT in the sensory motor cortex and subcortical structure in spinal cord injury (SCI) patients, who suffered from various levels of motor and sensory function loss. Twenty-two patients (mean age: 42.1+/-13.4 years, 18 M, 4 F) and 11 control subjects (mean age: 32.2+/-6.4 years, 8 M, 3 F) participated in this study. The spinal cord injury group was consisted of 2 groups (14 paraplegic and 8 tetraplegic patients). The corticocortical rCBF ratios were calculated by using region of interests obtained from 34 cortical areas on coronal slices. Significantly reduced rCBF were measured from 11 cortical areas in tetraplegic patients and 11 cortical areas in paraplegic patients. Some of these areas were different in each group. In the tetraplegic group, significant reduction was observed in the following rCBF areas: left anterior cingulate gyrus, left medial supplementary motor area, bilateral front and back aspects of posterior cingulate gyrus, right lateral primary motor area, right medial primary sensory area, bilateral putamen, and right cerebellum. In the paraplegic group, reduced rCBF areas were as follows: bilateral anterior cingulate gyrus, right lateral supplementary motor area, left front aspect of posterior cingulate gyrus, left lateral primary motor area, bilateral back aspects of posterior cingulate gyrus, right medial primary sensory area, left lateral primary sensory area and bilateral putamen. In conclusion, in some of the movement-cortical and subcortical areas having significantly reduced blood flow in SCI may be helpful to demonstrate the disrupted areas of rCBF by SPECT. We believe that it may be useful if these findings should be considered during the evaluations related to the reorganization in SCI cases.     

Changes in regional cerebral blood flow following antidepressant treatment in late-life depression

OBJECTIVE: Reversible/irreversible abnormalities of regional cerebral blood flow (rCBF) are seen in patients with depression. However, in late-life depression there is little evidence of a longitudinal change in rCBF through remission. We examined whether the decreased rCBF in individuals with late-life depression resolves following treatment. METHODS: Twenty-five depressed patients older than 55 years completed the Hamilton Rating Scale for Depression and single photon emission computed tomography before and after a mean of 13.7 weeks of pharmacotherapy. Quantitative analyses were performed using the Statistical Parametric Mapping procedure. RESULTS: Patients with depression demonstrated decreased rCBF in the anterior ventral and dorsal medial prefrontal cortex (PFC), including anterior cingulate cortices, bilateral ventrolateral PFC to temporal cortices, and bilateral medial to lateral parieto-occipital lobes relative to healthy controls. No particular areas showed increased rCBF. Following pharmacotherapy, rCBF significantly increased in the left dorsolateral PFC to precentral areas and the right parieto-occipital regions. However, decreased rCBF at baseline in the anterior ventral/dorsal medial PFC, bilateral ventrolateral PFC, bilateral temporal lobes, and bilateral parietal lobes did not show significant improvement after treatment. CONCLUSIONS: Remarkable improvements in rCBF in the left dorsolateral PFC to precentral regions are consistent with the hypothesis that neuronetworks including the left frontal cortex may be functionally and reversibly involved in late-life unipolar major depression (state-dependent). In contrast, neural circuits including bilateral medial, dorsolateral, and parietal areas may reflect underlying and continuous pathognomonic brain dysfunction of depression (trait-dependent).     

State and trait influences on mood regulation in bipolar disorder: blood flow differences with an acute mood challenge.

BACKGROUND: Even in remission, patients with bipolar disorder (BD) remain sensitive to external stressors that can trigger new episodes. Imitating such stressors by the controlled transient exposure to an emotional stimulus may help to identify brain regions modulating this sensitivity. METHODS: Transient sadness was induced in 9 euthymic and in 11 depressed subjects with BD. Regional blood flow (rCBF) changes were measured using (15)O-water positron emission tomography. RESULTS: Common changes in both groups were increased rCBF in anterior insula and cerebellum and decreased rCBF in dorsal-ventral-medial frontal cortex, posterior cingulate, inferior parietal, and temporal cortices. Decreases in dorsal ventral medial frontal cortices occurred in both groups, but subjects in remission showed a greater magnitude of change. Unique to remitted subjects with BD were rCBF increases in dorsal anterior cingulate and in premotor cortex. Lateral prefrontal rCBF decreases were unique to depressed subjects with BD. At baseline, remitted subjects showed a unique increase in dorsal anterior cingulate and orbitofrontal cortex. CONCLUSIONS: Common rCBF changes in remitted and depressed subjects identifies potential sites of disease vulnerability. Unique cingulate and orbitofrontal changes both at baseline and with induced sadness seen in the absence of prefrontal rCBF decreases may identify regional interactions important to the euthymic state in this population.     

Role of serotonergic 1A receptor dysfunction in depression associated with Parkinson's disease

Depression is frequent in Parkinson's disease, but its pathophysiology remains unclear. Two recent studies have investigated the role of serotonergic system at the presynaptic level. The objective of the present study was to use positron emission tomography and [(18)F]MPPF to investigate the role of postsynaptic serotonergic system dysfunction in the pathophysiology of depression in Parkinson's disease. Four parkinsonian patients with depression and 8 parkinsonian patients without depression were enrolled. Each patient underwent a scan using [(18)F]MPPF, a selective serotonin 1A receptor antagonist. Voxel-by-voxel statistical comparison of [(18)F]MPPF uptake of the 2 groups of parkinsonian patients and with 7 matched normal subjects was made using statistical parametric mapping (P uncorrected < .001). Compared with nondepressed parkinsonian patients, depressed patients exhibited reduced tracer uptake in the left hippocampus, the right insula, the left superior temporal cortex, and the orbitofrontal cortex. Compared with controls, nondepressed parkinsonian patients presented reduced [(18)F]MPPF uptake bilaterally in the inferior frontal cortex as well as in the right ventral striatum and insula. Compared with controls, [(18)F]MPPF uptake was decreased in depressed parkinsonian patients in the left dorsal anterior cingulate and orbitofrontal cortices, in the right hippocampic region, and in the temporal cortex. The present imaging study suggests that abnormalities in serotonin 1A receptor neurotransmission in the limbic system may be involved in the neural mechanisms underlying depression in patients with Parkinson's disease.     

Comparison of brain perfusion in corticobasal degeneration and Alzheimer's disease

To compare brain perfusion between corticobasal degeneration (CBD) and Alzheimer's disease (AD), we measured regional cerebral blood flow (rCBF) semiquantitatively with single-photon emission computed tomography in 10 patients with CBD and 16 with AD. There was no significant difference in age or illness duration between the patients with CBD and AD. Mini-Mental State Examination scores were significantly lower in the AD patients than in the CBD patients. All CBD patients showed asymmetric akinetic-rigid syndrome and limb apraxia. Four CBD patients were demented, and 1 AD patient had parkinsonism. Compared with 12 age-matched control subjects, the average of the left and right rCBF values for the CBD patients was significantly reduced in the prefrontal, anterior cingulate (AC), medial premotor, sensorimotor (SM), posterior parietal (PP) and superior temporal (ST) cortices as well as in the basal ganglia (BG) and thalamus (Th), while the prefrontal, PP and ST cortices were significantly hypoperfused in the AD patients. In the CBD patients, rCBF was significantly less in the AC and SM cortices, and in the Th and BG, and significantly greater in the PP cortex than in the AD patients. Interhemispheric differences of rCBF in the inferior prefrontal and SM cortices were significantly greater in the CBD patients than the AD patients. It is concluded that rCBF comparison may aid in differentiating CBD from AD.     

Neuroanatomical correlates of therapeutic efficacy of low-frequency right prefrontal transcranial magnetic stimulation in treatment-resistant depression

Aims: Low‐frequency transcranial magnetic stimulation (TMS) to the right prefrontal cortex has been shown to be effective in treatment‐resistant depression. The aim of the present study was to investigate changes in regional cerebral blood flow (rCBF) after low‐frequency right prefrontal stimulation (LFRS), and neuroanatomical correlates of therapeutic efficacy of LFRS in treatment‐resistant depression. Methods: Twenty‐six patients with treatment‐resistant depression received five 60‐s 1‐Hz trains over the right prefrontal cortex, and 12 treatment sessions were administered during 3 weeks. Brain scans were acquired before and after LFRS using single photon emission computed tomography with ^99mTc‐ethyl cysteinate dimer. Severity of depression was assessed on the Hamilton Depression Rating Scale (HDRS). Results: Significant decreases in rCBF after LFRS were seen in the prefrontal cortex, orbitofrontal cortex, subgenual cingulate cortex, globus pallidus, thalamus, anterior and posterior insula, and midbrain in the right hemisphere. Therapeutic efficacy of LFRS was correlated with decreases in rCBF in the right prefrontal cortex, bilateral orbitofrontal cortex, right subgenual cingulate cortex, right putamen, and right anterior insula. Conclusion: The antidepressant effects of LFRS in treatment‐resistant depression may be associated with decreases in rCBF in the orbitofrontal cortex and the subgenual cingulate cortex via the right prefrontal cortex.     

Blunted prefrontal cortical 18fluorodeoxyglucose positron emission tomography response to meta-chlorophenylpiperazine in impulsive aggression

BACKGROUND: Impulsive aggression is a prevalent problem and yet little is known about its neurobiology. Preclinical and human studies suggest that the orbital frontal cortex and anterior cingulate cortex play an inhibitory role in the regulation of aggression. METHODS: Using positron emission tomography, regional metabolic activity in response to a serotonergic stimulus, meta-chlorophenylpiperazine (m-CPP), was examined in 13 subjects with impulsive aggression and 13 normal controls. The anterior cingulate and medial orbitofrontal regions were hypothesized to respond differentially to m-CPP in patients and controls. In the frontal cortex, regional metabolic glucose response to m-CPP was entered into a group (impulsive aggressive, control) x slice (dorsal, middle, orbital) x position (medial, lateral) x location (anterior, posterior) x hemisphere (right, left) mixed-factorial analysis of variance design. A separate group (impulsive aggressive, controls) x anteroposterior location (Brodmann areas 25, 24, 31, 29) x hemisphere (right, left) analysis of variance was used to examine regional glucose metabolism in the cingulate gyrus. RESULTS: Unlike normal subjects, patients with impulsive aggression did not show activation specifically in the left anteromedial orbital cortex in response to m-CPP. The anterior cingulate, normally activated by m-CPP, was deactivated in patients; in contrast, the posterior cingulate gyrus was activated in patients and deactivated in controls. CONCLUSIONS: The decreased activation of inhibitory regions in patients with impulsive aggression in response to a serotonergic stimulus may contribute to their difficulty in modulating aggressive impulses.     

SPECT study of visual fixation in schizophrenia and comparison subjects.

BACKGROUND: The consistent association of impaired eye movements and schizophrenia suggests a relationship between the neurobiology of the illness and visual pursuit systems. Visual fixation (VF), an eye "movement" task at zero velocity, is the simplest such abnormality in schizophrenia patients and their relatives. METHODS: We used a VF task for a functional imaging study. Six neuroleptic-free schizophrenia patients and eight gender and mean age matched comparison subjects had SPECT scans with 20 mCi of Tc99-HMPAO, during VF on a simple blue line intersection. MEDX data saved in ANALYZE format for SPM 95 was used to generate paired t-test statistical data for display in Talairach space, with rCBF changes given as Z-scores. RESULTS: Patients, compared to controls, had increased rCBF in both the parahippocampal gyrus (bilaterally) and in the right fusiform gyrus. They had decreased rCBF in the left frontal cortex, including medial and superior frontal gyri and anterior cingulate. Overall, compared to controls, patients had medial temporal lobe hyperperfusion along with left prefrontal hypoperfusion. CONCLUSIONS: These findings are consistent with the hypothesized imbalance between the medial temporal and frontal lobes that is postulated for schizophrenia. It was of interest that the relative rCBF differences between schizophrenia patients and controls in this small sample were observable with this cognitively non-demanding visual fixation task.     

A single photon emission computerized tomography (SPECT) study of regional cerebral blood flow in bipolar disorder

Data on functional imaging of bipolar disorder (BD) utilizing single photon emission computerized tomography (SPECT) is limited. This study assessed regional cerebral blood flow (rCBF), using ^99mTc-ECD SPECT, among patients with BD, with mania (N=10) or depression (N=10), compared with 10 patients with unipolar depression and 10 normal controls. Regions of interest were analysed using a semi-automatic brain quantification programme. Compared to controls, patients with mania had significantly reduced perfusion mainly in the left frontal area, also in the left anterior cingulate and parietal cortices; those with bipolar depression had significantly lowered rCBF principally in the anterior temporal regions bilaterally, as well as the left parietal area. Patients with unipolar depression had significantly lowered perfusion than controls in most of the regions examined, chiefly in the anterior temporal and frontal cortices bilaterally; they also had lowered perfusion in the right anterior temporal and frontal areas, as well as the right middle temporal area and the right thalamus, compared to patients with mania. Increased severity of psychotic symptoms was associated with reduced rCBF in patients. These results indicate that altered blood flow in the frontal-subcortical systems characterises patients with BD, as well as those with unipolar depression.     

Regional cerebral blood flow deficits in mild Alzheimer's disease using high resolution single photon emission computerized tomography

In spite of its wide availability, single photon emission computerized tomography (SPECT) scanning is uncommonly used in the assessment of Alzheimer's disease (AD) and related dementias. In light of recent advances in scanning protocols and image analysis, SPECT needs to be re-examined as a tool in the diagnosis of dementia. A total of 18 subjects with early AD and 10 healthy elderly control subjects were examined with high resolution SPECT during the performance of a simple word discrimination task. SPECT images were coregistered with individual magnetic resonance imaging scans, allowing delineation of predetermined neuroanatomical Regions of Interest (ROI). There was a gradation of regional cerebral blood flow (rCBF) values in both groups, with the lowest values being in the hippocampus and the highest in the striatum, thalamus and cerebellum. Compared to healthy controls, AD subjects demonstrated lower relative rCBF in parietal and prefrontal cortices. Analysis of individual ROI demonstrated bilateral reduction of rCBF in prefrontal poles, posterior temporal and anterior parietal cortex, and unilateral reduction of rCBF in left dorsolateral prefrontal cortex, right posterior parietal cortex and the left cingulate body. There were no significant differences for hippocampal, occipital or basal ganglia rCBF. Discriminant function analysis indicated that rCBF in the prefrontal polar regions achieved the best classification of cases. SPECT has utility in the diagnostic assessment of AD if standardized and semiquantitative techniques are used.     

药物过度使用性头痛患者脑白质结构的变化

目的利用磁共振弥散张量成像技术研究药物过度使用性头痛患者脑白质结构的变化。方法药物过度使用性头痛患者(病例组)及年龄、性别相匹配的同期健康体检者(对照组)各80例,收集一般临床资料,进行颅脑磁共振弥散张量成像(diffusion tensor imaging,DTI)检查,测取部分各向异性(fractional anisotropy,FA)值、表观弥散系数(apparent diffusion coefficient,ADC)值,并结合临床特点进行相关性分析。结果 (1)病例组眶额皮质、前后扣带回皮质、胼胝体压部、右侧内囊前肢FA值较对照组明显降低,差异有统计学意义(P0.05);(2)病例组右侧眶额皮质、左侧额下回皮质及前扣带回皮质ADC值较对照组明显升高,差异有统计学意义(P0.05);(3)病例组双侧眶额部皮质以及右侧内囊后肢FA值与患者头痛病程及发作频率呈负相关;左侧内囊后肢FA值与头痛频率呈负相关;(4)病例组左侧眶额皮质ADC值与患者头痛病程及发作频率呈正相关;右侧眶额皮质以及前扣带回皮质ADC值与患者头痛发作频率呈正相关;后扣带回皮质ADC值与患者头痛病程呈正相关。结论药物过度使用性头痛患者双侧额叶皮质及扣带回皮质存在白质微观结构异常变化,FA值与患者头痛病程及发作频率呈负相关,ADC值则呈正相关。     

Quantitative analysis of brain perfusion SPECT in Alzheimer's disease using a fully automated regional cerebral blood flow quantification software, 3DSRT

PURPOSE: The clinical symptoms of Alzheimer's disease (AD) show great diversity depending on the clinical stage. We investigated the correlation of regional cerebral blood flow (rCBF) changes and the clinical severity of AD patients. METHODS: Thirty-nine AD patients and 16 normal subjects participated in this study. AD patients were divided into three subgroups by clinical severity. Quantitative brain perfusion SPECT analyses were performed using a rCBF quantification software, 3DSRT. RESULTS: In mild AD, significant decreases of rCBF were detected in the bilateral parietal, angular gyrus, pericallosal, thalamus, right temporal and left hippocampal regions. Moderate AD patients showed significantly lower blood flow than those with mild AD only to the right hippocampus. Analysis of the severe AD group revealed a nearly diffuse decrease of rCBF throughout the cerebral cortex except for part of the frontal lobe compared with moderate patients. CONCLUSIONS: These results were consistent with previous findings demonstrated by qualitative analysis of CBF. The decreased thalamic blood flow was noteworthy as this finding has rarely been reported. In consideration of the structure and function of the Papez circuit, which connects the medial temporal lobe and thalamus, a remote metabolic effect might be the cause of lower rCBF in the thalamus.     

Regional brain activity during transient self-induced anxiety and anger in healthy adults.

BACKGROUND: Several studies have demonstrated that transient self-induced sadness activates anterior paralimbic structures. To further examine the specificity of these findings and the neural substrates involved in anger and anxiety, we studied the neural correlates of the induction of anxiety and anger in healthy adults. METHODS: We used H2(15)O and positron emission tomography (PET) to measure regional cerebral blood flow (rCBF) in 16 healthy adults during the induction of transient anxiety, anger, and neutral emotions. Subjects achieved differential emotions by recalling prior life events while viewing affect-appropriate faces. RESULTS: Both the anxiety and anger conditions were associated with increased normalized rCBF in left inferior frontal and left temporal pole regions and decreased rCBF in right posterior temporal/parietal and right superior frontal cortex, compared to the neutral induction. Additionally, compared to neutral induction, anxiety was associated with increased rCBF in the left anterior cingulate and cuneus and decreased rCBF in right medial frontal cortex, while the anger induction was uniquely associated with increased rCBF in right temporal pole and thalamus. CONCLUSIONS: Self-generated transient states of anxiety and anger are associated with both overlapping and distinct regional brain activity patterns and provide a template for further dissection of specific components of normal and pathologic emotions.