The Cerebral Cost of Breathing: An fMRI Case-Study in Congenital Central Hypoventilation Syndrome

Certain motor activities - like walking or breathing - present the interesting property of proceeding either automatically or under voluntary control. In the case of breathing, brainstem structures located in the medulla are in charge of the automatic mode, whereas cortico-subcortical brain networks - including various frontal lobe areas - subtend the voluntary mode. We speculated that the involvement of cortical activity during voluntary breathing could impact both on the “resting state” pattern of cortical-subcortical connectivity, and on the recruitment of executive functions mediated by the frontal lobe. In order to test this prediction we explored a patient suffering from central congenital hypoventilation syndrome (CCHS), a very rare developmental condition secondary to brainstem dysfunction. Typically, CCHS patients demonstrate efficient cortically-controlled breathing while awake, but require mechanically-assisted ventilation during sleep to overcome the inability of brainstem structures to mediate automatic breathing. We used simultaneous EEG-fMRI recordings to compare patterns of brain activity between these two types of ventilation during wakefulness. As compared with spontaneous breathing (SB), mechanical ventilation (MV) restored the default mode network (DMN) associated with self-consciousness, mind-wandering, creativity and introspection in healthy subjects. SB on the other hand resulted in a specific increase of functional connectivity between brainstem and frontal lobe. Behaviorally, the patient was more efficient in cognitive tasks requiring executive control during MV than during SB, in agreement with her subjective reports in everyday life. Taken together our results provide insight into the cognitive and neural costs of spontaneous breathing in one CCHS patient, and suggest that MV during waking periods may free up frontal lobe resources, and make them available for cognitive recruitment. More generally, this study reveals how the active maintenance of cortical control over a continuous motor activity impacts on brain functioning and cognition.     

Alien hand syndrome: neural correlates of movements without conscious will

Background

The alien hand syndrome is a striking phenomenon characterized by purposeful and autonomous movements that are not voluntarily initiated. This study aimed to examine neural correlates of this rare neurological disorder in a patient with corticobasal degeneration and alien hand syndrome of the left hand.

Methodology/Principal Findings

We employed functional magnetic resonance imaging to investigate brain responses associated with unwanted movements in a case study. Results revealed that alien hand movements involved a network of brain activations including the primary motor cortex, premotor cortex, precuneus, and right inferior frontal gyrus. Conscious and voluntary movements of the alien hand elicited a similar network of brain responses but lacked an activation of the inferior frontal gyrus. The results demonstrate that alien and unwanted movements may engage similar brain networks than voluntary movements, but also imply different functional contributions of prefrontal areas. Since the inferior frontal gyrus was uniquely activated during alien movements, the results provide further support for a specific role of this brain region in inhibitory control over involuntary motor responses.

Conclusions/Significance

We discuss the outcome of this study as providing evidence for a distributed neural network associated with unwanted movements in alien hand syndrome, including brain regions known to be related to movement execution and planning as well as areas that have been linked to inhibition control (inferior frontal gyrus) and experience of agency (precuneus).     

Unitary activity in the cat motor cortex during a conditioned postural adjustment reflex

Unitary activity in the motor cortex (area 4) during a conditioned postural adjustment reflex was investigated in cats. Responses of the overwhelming majority of neurons connected with conditioned-reflex placing movements were activational in type. They consisted of several components and preceded the movements themselves by 50–600 msec. During realization of incorrect responses to presentation of a differential stimulus and of "spontaneous" interstimulus movements, the unitary responses were similar in direction but differed in their lower intensity and, in most cases, they appeared simultaneously with these movements. In the course of extinction both the conditioned-reflex movements and the corresponding unitary responses disappeared simultaneously. The technique of formation of a conditioned postural adjustment reflex suggested in this paper can be used to from natural, well-coordinated forelimb movements in animals in response to conditioned stimulation which are necessary initial components of more complex behavioral motor responses.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 16, No. 6, pp. 745–753, November–December, 1984.     

A Functional Magnetic Resonance Imaging Study of Pathophysiological Changes Responsible for Mirror Movements in Parkinson’s Disease

Mirror movements correspond to involuntary movements observed in the limb contralateral to the one performing voluntary movement. They can be observed in Parkinson’s disease (PD) but their pathophysiology remains unclear. The present study aims at identifying their neural correlates in PD using functional magnetic resonance imaging. Ten control subjects and 14-off drug patients with asymmetrical right-sided PD were included (8 with left-sided mirror movements during right-hand movements, and 6 without mirror movements). Between-group comparisons of BOLD signal were performed during right-hand movements and at rest (p<0.005 uncorrected). The comparison between PD patients with and without mirror movements showed that mirror movements were associated with an overactivation of the insula, precuneus/posterior cingulate cortex bilaterally and of the left inferior frontal cortex and with a deactivation of the right dorsolateral prefrontal cortex, medial prefrontal cortex, and pre-supplementary motor area and occipital cortex. These data suggest that mirror movements in Parkinson’s disease are promoted by: 1- a deactivation of the non-mirroring inhibitory network (dorsolateral prefrontal cortex, pre-supplementary motor area); 2- an overactivation of prokinetic areas (notably the insula). The concomitant overactivation of a proactive inhibitory network (including the posterior cingulate cortex and precuneus) could reflect a compensatory inhibition of mirror movements.     

Effect of an additional manual motor task on the maintenance of equilibrium in the frontal and sagittal planes in standing subjects

The postural oscillations of a standing subject during an additional manual motor task consisting in holding a movable ball in the center of a flat box were studied. The movements of the center of pressure (CP) in the frontal and sagittal planes were studied when subjects were standing on a stable rigid support and on a movable unstable support. The effect of the additional motor task on the movement of the CP depended on the stability of the support. When the additional task was performed, the sagittal movements of the CP increased in the case a movable support and did not increase when the support was stable. The additional task decreased the frontal movements of CP in the case of a stable support, and it did not change the frontal movements of CP when the support was unstable. Thus, the performance of an additional motor task led to a reduction of the efficiency of the postural control system in maintaining equilibrium on an unstable support. This decrease may be due to a greater cortical influence on the posture control system in subjects standing on a movable support in comparison with this influence in the case of a stable support.     

Driving oscillatory activity in the human cortex enhances motor performance

Voluntary movement is accompanied by changes in the degree to which neurons in the brain synchronize their activity within discrete frequency ranges. Two patterns of movement-related oscillatory activity stand out in human cortical motor areas. Activity in the beta frequency (15-30 Hz) band is prominent during tonic contractions but is attenuated prior to and during voluntary movement. Without such attenuation, movement may be slowed, leading to the suggestion that beta activity promotes postural and tonic contraction, possibly at a cost to the generation of new movements. In contrast, activity in the gamma (60-90 Hz) band increases during movement. The direction of change suggests that gamma activity might facilitate motor processing. In correspondence with this, increased frontal gamma activity is related with reduced reaction times. Yet the possibility remains that these functional correlations reflect an epiphenomenal rather than causal relationship. Here we provide strong evidence that oscillatory activities at the cortical level are mechanistically involved in determining motor behavior and can even improve performance. By driving cortical oscillations using noninvasive electrical stimulation, we show opposing effects at beta and gamma frequencies and interactions with motor task that reveal the potential quantitative importance of oscillations in motor behavior.     

Frontal White Matter Volume Is Associated with Brain Enlargement and Higher Structural Connectivity in Anthropoid Primates

Previous research has indicated the importance of the frontal lobe and its ‘executive’ connections to other brain structures as crucial in explaining primate neocortical adaptations. However, a representative sample of volumetric measurements of frontal connective tissue (white matter) has not been available. In this study, we present new volumetric measurements of white and grey matter in the frontal and non-frontal neocortical lobes from 18 anthropoid species. We analyze this data in the context of existing theories of neocortex, frontal lobe and white versus grey matter hyperscaling. Results indicate that the ‘universal scaling law’ of neocortical white to grey matter applies separately for frontal and non-frontal lobes; that hyperscaling of both neocortex and frontal lobe to rest of brain is mainly due to frontal white matter; and that changes in frontal (but not non-frontal) white matter volume are associated with changes in rest of brain and basal ganglia, a group of subcortical nuclei functionally linked to ‘executive control’. Results suggest a central role for frontal white matter in explaining neocortex and frontal lobe hyperscaling, brain size variation and higher neural structural connectivity in anthropoids.     

Identify Changes of Brain Regional Homogeneity in Bipolar Disorder and Unipolar Depression Using Resting-State fMRI

Background

To identify changes in brain activation patterns in bipolar disorder (BD) and unipolar depression (UD) patients.

Methodology/Principal Findings

Resting-state fMRI scans of 16 healthy controls, 17 BD and 16 UD patients were obtained. T-test of normalized regional homogeneity (ReHo) was performed in a voxel-by-voxel manner. A combined threshold of á = 0.05, minimum cluster volume of V = 10503 mm³ (389 voxels) were used to determine ReHo differences between groups. In UD group, fMRI revealed ReHo increases in the left middle occipital lobe, right inferior parietal lobule, right precuneus and left convolution; and ReHo decreases in the left parahippocampalgyrus, right precentralgyrus, left postcentralgyrus, left precentralgyrus and left cingulated. In BD group, ReHo increases in the right insular cortex, left middle frontal gyrus, left precuneus, left occipital lobe, left parietal, left superior frontal gyrus and left thalamus; and ReHo decreases in the right anterior lobe of cerebellum, pons, right precentralgyrus, left postcentralgyrus, left inferior frontal gyrus, and right cingulate. There were some overlaps in ReHo profiles between UD and BD groups, but a marked difference was seen in the thalamus of BD.

Conclusions/Significance

The resting-state fMRI and ReHo mapping are a promising tool to assist the detection of functional deficits and distinguish clinical and pathophysiological signs of BD and UD.     

Corticospinal Excitability of Trunk Muscles during Different Postural Tasks

Evidence suggests that the primary motor cortex (M1) is involved in both voluntary, goal-directed movements and in postural control. Trunk muscles are involved in both tasks, however, the extent to which M1 controls these muscles in trunk flexion/extension (voluntary movement) and in rapid shoulder flexion (postural control) remains unclear. The purpose of this study was to investigate this question by examining excitability of corticospinal inputs to trunk muscles during voluntary and postural tasks. Twenty healthy adults participated. Transcranial magnetic stimulation was delivered to the M1 to examine motor evoked potentials (MEPs) in the trunk muscles (erector spinae (ES) and rectus abdominis (RA)) during dynamic shoulder flexion (DSF), static shoulder flexion (SSF), and static trunk extension (STE). The level of background muscle activity in the ES muscles was matched across tasks. MEP amplitudes in ES were significantly larger in DSF than in SSF or in STE; however, this was not observed for RA. Further, there were no differences in levels of muscle activity in RA between tasks. Our findings reveal that corticospinal excitability of the ES muscles appears greater during dynamic anticipatory posture-related adjustments than during static tasks requiring postural (SSF) and goal-directed voluntary (STE) activity. These results suggest that task-oriented rehabilitation of trunk muscles should be considered for optimal transfer of therapeutic effect to function.     

Quantitative analysis of MAP2 immunoreactivity in human neocortex of three patients surviving after brain ischemia

Transient global ischemia caused by cardiac arrest results in lesions that involve all brain structures. The aim of this study was to investigate the distribution of MAP2 immunoreactivity in neurons in the brain of patients surviving for various times after an ischemic incident, using confocal laser scanning microscopy. We performed a quantitative analysis of the distribution and density of MAP2-positive structures in human neocortical areas after survival times of 1 week, 3 months, and 1 year after the cardiac arrest. Three important observations were made in the present study: (i) in all human brain areas investigated (motor, temporal, frontal, and visual cortex) a decrease of MAP2 immunoreactivity was found; (ii) in all studied areas the most significant decrease in MAP2 was found in layers II–III, compared with layers V–VII; (iii) the decrease of MAP2 immunoreactivity in layers II–III was related to the duration of the postischemic period. The maximal decrease, by 66.3% (P < .05), in MAP2-positive pyramidal neurons, was observed in layers II–III in the motor cortex after 1 year of survival after cardiac arrest.     

Neural Correlates of Task Cost for Stance Control with an Additional Motor Task: Phase-Locked Electroencephalogram Responses

With appropriate reallocation of central resources, the ability to maintain an erect posture is not necessarily degraded by a concurrent motor task. This study investigated the neural control of a particular postural-suprapostural procedure involving brain mechanisms to solve crosstalk between posture and motor subtasks. Participants completed a single posture task and a dual-task while concurrently conducting force-matching and maintaining a tilted stabilometer stance at a target angle. Stabilometer movements and event-related potentials (ERPs) were recorded. The added force-matching task increased the irregularity of postural response rather than the size of postural response prior to force-matching. In addition, the added force-matching task during stabilometer stance led to marked topographic ERP modulation, with greater P2 positivity in the frontal and sensorimotor-parietal areas of the N1-P2 transitional phase and in the sensorimotor-parietal area of the late P2 phase. The time-frequency distribution of the ERP primary principal component revealed that the dual-task condition manifested more pronounced delta (1–4 Hz) and beta (13–35 Hz) synchronizations but suppressed theta activity (4–8 Hz) before force-matching. The dual-task condition also manifested coherent fronto-parietal delta activity in the P2 period. In addition to a decrease in postural regularity, this study reveals spatio-temporal and temporal-spectral reorganizations of ERPs in the fronto-sensorimotor-parietal network due to the added suprapostural motor task. For a particular set of postural-suprapostural task, the behavior and neural data suggest a facilitatory role of autonomous postural response and central resource expansion with increasing interregional interactions for task-shift and planning the motor-suprapostural task.     

Is There a Role for Combined EMG-fMRI in Exploring the Pathophysiology of Essential Tremor and Improving Functional Neurosurgery?

Background

Functional MRI combined with electromyography (EMG-fMRI) is a new technique to investigate the functional association of movement to brain activations. Thalamic stereotactic surgery is effective in reducing tremor. However, while some patients have satisfying benefit, others have only partial or temporary relief. This could be due to suboptimal targeting in some cases. By identifying tremor-related areas, EMG-fMRI could provide more insight into the pathophysiology of tremor and be potentially useful in refining surgical targeting.

Objective

Aim of the study was to evaluate whether EMG-fMRI could detect blood oxygen level dependent brain activations associated with tremor in patients with Essential Tremor. Second, we explored whether EMG-fMRI could improve the delineation of targets for stereotactic surgery.

Methods

Simultaneous EMG-fMRI was performed in six Essential Tremor patients with unilateral thalamotomy. EMG was recorded from the trembling arm (non-operated side) and from the contralateral arm (operated side). Protocols were designed to study brain activations related to voluntary muscle contractions and postural tremor.

Results

Analysis with the EMG regressor was able to show the association of voluntary movements with activity in the contralateral motor cortex and supplementary motor area, and ipsilateral cerebellum. The EMG tremor frequency regressor showed an association between tremor and activity in the ipsilateral cerebellum and contralateral thalamus. The activation spot in the thalamus varied across patients and did not correspond to the thalamic nucleus ventralis intermedius.

Conclusion

EMG-fMRI is potentially useful in detecting brain activations associated with tremor in patients with Essential Tremor. The technique must be further developed before being useful in supporting targeting for stereotactic surgery.     

Convergence of visual,haltere, and prosternai inputs at neck motor neurons of Calliphora erythrocephala

Summary Neck muscles of Calliphora erythrocephala, situated in the anterior prothorax, are innervated on each side by 8 motor neurons arising in the brain (cervical nerve neurons, CN1–8) and at least 13 motor neurons arising in the prothoracic ganglion (anterior dorsal and frontal nerve neurons, ADN1,2 and FN1-11). Three prominent motor neurons (CN6 and FN1,2) are described in detail with special emphasis on their relationships with giant visual interneurons from the lobula plate, haltere interneurons, and primary afferents from the prosternal organs and halteres. These sensory organs detect head movement and body yaw, respectively. Neuronal relationships indicate that head movement is under multimodal sensory control that includes giant motion-sensitive neurons previously supposed to mediate the optomotor response in flying flies. The described pathways provide anatomical substrates for the control of optokinetic and yaw-incurred head movements that behavioural studies have shown must exist.     

The supplementary motor area is implicated in the coordination between posture and movement in man

The aim of the present experimental series was to investigate the central organization of the coordination between posture and movement in a bimanual load lifting task. The seated subject was instructed to maintain horizontal one forearm (postural arm) which was loaded with a 1 kg weight. The unloading was performed either by the experimenter (imposed unloading) or by a voluntary movement of the other arm (bimanual unloading). With the bimanual unloading, the movement control was accompanied by an anticipatory adjustment of the postural forearm flexors activity, which resulted in the maintenance of the forearm position despite the unloading. No change in the anticipatory postural adjustment was observed in one patient with complete callosal section. It was reduced in 5 patients with lesion of the SMA region, but only when the postural forearm was contralateral to the lesion. It is suggested that the SMA region contralateral to the postural forearm may select the circuits responsible for the phasic postural adjustments which are necessary to ensure postural maintenance, whereas the motor cortex contralateral to the voluntary movement controls both the movement and, via collaterals, the preselected circuits responsible for the associated postural adjustment.     

Role of frontal cortex in the organization of rapid ballistic movements of rats

We have studied the characteristics of rapid ballistic food-procuring movements in nonpedigree albino rats and have established that after ablation of the second area of the frontal cortex contralaterally to the preferred extremity the number of attempts increased, the duration of the movements decreased, and the phase structure of the movements was reorganized. After bilateral ablation of the cortex the animals completely lost their skill at procuring food. Our results indicate involvement of the frontal cortex in the development and achievement of the motor programs produced.N. I. Pirogov Medical Institute. Ukrainian Ministry of Public Health. Translated from Neirofiziologiya, Vol. 24, No. 2, pp. 186–192, February, 1992.     

Are interlimb interactions disturbed in patients with Parkinson’s disease? A study under unloading conditions

During natural human locomotion, neural connections are activated that are typical of regulation of the quadrupedal walking. The interaction between the neural networks generating rhythmic movements of the upper and lower limbs depends on tonic state of each of these networks regulated by motor signals from the brain. Distortion of these signals in patients with Parkinson’s disease (PD) may lead to disruption of the interlimb interactions. We examined the effect of movements of the limbs of one girdle on the parameters of the motor activity of another limb girdle at their joint cyclic movements under the conditions of arm and leg unloading in 17 patients with PD and 16 healthy subjects. We have shown that, in patients, the effect of voluntary and passive movements of arms, as well as the active movement of the distal parts of arms, on the voluntary movement of legs is weak, while in healthy subjects, the effect of arm movements on the parameters of voluntary stepping is significant. The effect of arm movements on the activation of the involuntary stepping by vibrational stimulation of-legs in patients was absent, while in healthy subjects, the motor activity of arms increased the possibility of involuntary rhythmic movements activation. Differences in the effect of leg movements on the rhythmic movements of arms were found in both patients and healthy subjects. The interlimb interaction appeared after drug administration. However, the effect of the drug was not sufficient for the recovery of normal state of the neural networks in patients. In PD patients, neural networks generating stepping rhythm have an increased tonic activity, which prevents the activation and appearance of involuntary rhythmic movements facilitating the effects of arms on legs.     

Using voluntary motor commands to inhibit involuntary arm movements

A hallmark of voluntary motor control is the ability to stop an ongoing movement. Is voluntary motor inhibition a general neural mechanism that can be focused on any movement, including involuntary movements, or is it mere termination of a positive voluntary motor command? The involuntary arm lift, or ‘floating arm trick’, is a distinctive long-lasting reflex of the deltoid muscle. We investigated how a voluntary motor network inhibits this form of involuntary motor control. Transcranial magnetic stimulation of the motor cortex during the floating arm trick produced a silent period in the reflexively contracting deltoid muscle, followed by a rebound of muscle activity. This pattern suggests a persistent generator of involuntary motor commands. Instructions to bring the arm down voluntarily reduced activity of deltoid muscle. When this voluntary effort was withdrawn, the involuntary arm lift resumed. Further, voluntary motor inhibition produced a strange illusion of physical resistance to bringing the arm down, as if ongoing involuntarily generated commands were located in a ‘sensory blind-spot’, inaccessible to conscious perception. Our results suggest that voluntary motor inhibition may be a specific neural function, distinct from absence of positive voluntary motor commands.     

Decreased Functional Connectivity of Homotopic Brain Regions in Chronic Stroke Patients: A Resting State fMRI Study

The recovery of motor functions is accompanied by brain reorganization, and identifying the inter-hemispheric interaction post stroke will conduce to more targeted treatments. However, the alterations of bi-hemispheric coordination pattern between homologous areas in the whole brain for chronic stroke patients were still unclear. The present study focuses on the functional connectivity (FC) of mirror regions of the whole brain to investigate the inter-hemispheric interaction using a new fMRI method named voxel-mirrored homotopic connectivity (VMHC). Thirty left subcortical chronic stroke patients with pure motor deficits and 37 well-matched healthy controls (HCs) underwent resting-state fMRI scans. We employed a VMHC analysis to determine the brain areas showed significant differences between groups in FC between homologous regions, and we explored the relationships between the mean VMHC of each survived area and clinical tests within patient group using Pearson correlation. In addition, the brain areas showed significant correlations between the mean VMHC and clinical tests were defined as the seed regions for whole brain FC analysis. Relative to HCs, patients group displayed lower VMHC in the precentral gyrus, postcentral gyrus, inferior frontal gyrus, middle temporal gyrus, calcarine gyrus, thalamus, cerebellum anterior lobe, and cerebellum posterior lobe (CPL). Moreover, the VMHC of CPL was positively correlated with the Fugl–Meyer Score of hand (FMA-H), while a negative correlation between illness duration and the VMHC of this region was also detected. Furthermore, we found that when compared with HCs, the right CPL exhibited reduced FC with the left precentral gyrus, inferior frontal gyrus, inferior parietal lobule, middle temporal gyrus, thalamus and hippocampus. Our results suggest that the functional coordination across hemispheres is impaired in chronic stroke patients, and increased VMHC of the CPL is significantly associated with higher FMA-H scores. These findings may be helpful in understanding the mechanism of hand deficit after stroke, and the CPL may serve as a target region for hand rehabilitation following stroke.     

Altered Spontaneous Brain Activity in Patients with Acute Spinal Cord Injury Revealed by Resting-State Functional MRI

Background

Previous neuroimaging studies have provided evidence of structural and functional reorganization of brain in patients with chronic spinal cord injury (SCI). However, it remains unknown whether the spontaneous brain activity changes in acute SCI. In this study, we investigated intrinsic brain activity in acute SCI patients using a regional homogeneity (ReHo) analysis based on resting-state functional magnetic resonance imaging.

Methods

A total of 15 patients with acute SCI and 16 healthy controls participated in the study. The ReHo value was used to evaluate spontaneous brain activity, and voxel-wise comparisons of ReHo were performed to identify brain regions with altered spontaneous brain activity between groups. We also assessed the associations between ReHo and the clinical scores in brain regions showing changed spontaneous brain activity.

Results

Compared with the controls, the acute SCI patients showed decreased ReHo in the bilateral primary motor cortex/primary somatosensory cortex, bilateral supplementary motor area/dorsal lateral prefrontal cortex, right inferior frontal gyrus, bilateral dorsal anterior cingulate cortex and bilateral caudate; and increased ReHo in bilateral precuneus, the left inferior parietal lobe, the left brainstem/hippocampus, the left cingulate motor area, bilateral insula, bilateral thalamus and bilateral cerebellum. The average ReHo values of the left thalamus and right insula were negatively correlated with the international standards for the neurological classification of spinal cord injury motor scores.

Conclusion

Our findings indicate that acute distant neuronal damage has an immediate impact on spontaneous brain activity. In acute SCI patients, the ReHo was prominently altered in brain regions involved in motor execution and cognitive control, default mode network, and which are associated with sensorimotor compensatory reorganization. Abnormal ReHo values in the left thalamus and right insula could serve as potential biomarkers for assessment of neuronal damage and the prediction of clinical outcomes in acute SCI.     

抑郁症患者的脑CT灌注成像特征与认知功能的相关性

摘要 目的：探讨抑郁症患者的脑CT灌注成像特征与认知功能的相关性。方法：选取我院2020年1月到2023年1月收治的90例抑郁症患者作为研究对象,将其分为观察组,另选取同期来我院体检的90名健康志愿者作为对照组。收集所有受检者脑CT灌注成像检查数据,分析抑郁症患者的脑CT灌注成像特征,并建立受试者工作特征（ROC）曲线分析脑CT灌注成像对抑郁症的诊断效能。随后对观察组和对照组受检者均进行认知功能评估,其中包括连线检测（TMT）、视觉再生测验（VRT）、言语流畅性测验（VF）、数字广度测验（DST）以及数字符号测验（SDMT）,并分析脑CT灌注成像与抑郁症认知功能的相关性。结果：观察组与对照组受检者rCBV、rCBF、MTT、TIP、右枕叶、左枕叶、右颞叶、左颞叶、右顶叶、左顶叶CT值对比无明显差异（P＞0.05）,观察组与对照组受检者右额叶、左额叶CT值对比差异显著,观察组明显低于对照组（P＜0.05）;90例抑郁症患者经过汉密尔顿抑郁量表（HAMD）评估后分数均＞20分,确定存在抑郁症状,脑CT灌注成像与HAMD评分诊断抑郁症的准确性、灵敏度、特异性、阳性预测值和阴性预测值对比无明显差异（P＞0.05）,脑CT灌注成像的曲线下面积为83.89,最佳诊断着色界限值为82.53%,HAMD评分的曲线下面积为84.26,最佳诊断着色界限值为87.57%;观察组与对照组受检者连线提笔数、连线错误数、视觉再生检测结果对比无明显差异（P＞0.05）,观察组与对照组受检者连线、言语流畅性、数字广度、数字符号检测结果对比差异显著（P＜0.05）;Spearman相关分析结果表明：连线提笔数、连线错误数、视觉再生与脑CT灌注参数均无明显相关性（P＞0.05）,连线、言语流畅性、数字广度、数字符号与rCBV、rCBF、MTT、TIP、右枕叶、左枕叶、右颞叶、左颞叶、右顶叶、左顶叶CT值无明显相关性（P＞0.05）,连线与右额叶、左额叶CT值呈负相关（P＜0.05）,言语流畅性、数字广度、数字符号与右额叶、左额叶CT值呈正相关（P＜0.05）。结论：抑郁症患者的脑CT灌注成像与健康群体呈现差异,其中右额叶、左额叶差异情况最为显著,提示抑郁症患者可能存在大脑额叶功能改变,另外,抑郁症患者的大脑额叶功能与认知功能变化具有明显相关性。