Selected Gray Matter Volumes and Gender but Not Basal Ganglia nor Cerebellum Gyri Discriminate Left Versus Right Cerebral Hemispheres: Multivariate Analyses in human Brains at 3T

Interest in the lateralization of the human brain is evident through a multidisciplinary number of scientific studies. Understanding volumetric brain asymmetries allows the distinction between normal development stages and behavior, as well as brain diseases. We aimed to evaluate volumetric asymmetries in order to select the best gyri able to classify right‐ versus left cerebral hemispheres. A cross‐sectional study performed in 47 right‐handed young‐adults healthy volunteers. SPM‐based software performed brain segmentation, automatic labeling and volumetric analyses for 54 regions involving the cerebral lobes, basal ganglia and cerebellum from each cerebral hemisphere. Multivariate discriminant analysis (DA) allowed the assembling of a predictive model. DA revealed one discriminant function that significantly differentiated left vs. right cerebral hemispheres: Wilks’ λ = 0.008, χ² (9) = 238.837, P < 0.001. The model explained 99.20% of the variation in the grouping variable and depicted an overall predictive accuracy of 98.8%. With the influence of gender; the selected gyri able to discriminate between hemispheres were middle orbital frontal gyrus (g.), angular g., supramarginal g., middle cingulum g., inferior orbital frontal g., calcarine g., inferior parietal lobule and the pars triangularis inferior frontal g. Specific brain gyri are able to accurately classify left vs. right cerebral hemispheres by using a multivariate approach; the selected regions correspond to key brain areas involved in attention, internal thought, vision and language; our findings favored the concept that lateralization has been evolutionary favored by mental processes increasing cognitive efficiency and brain capacity. Anat Rec, 298:1336–1346, 2015. © 2015 Wiley Periodicals, Inc.     

Isolation of the right subclavian artery with subclavian steal in a child with Klippel-Feil anomaly: an example of the subclavian artery supply disruption sequence

We studied a patient with Klippel-Feil anomaly and subclavian steal due to isolation of the right subclavian artery. Other anomalies included hypoplasia of the right clavicle and right vertebral artery, low bifurcation of the left common carotid artery and left choanal atresia. The patient was mentally retarded with corticospinal, cerebellar, and brain stem signs. The entire brain and cervical spinal cord were small; there was no central nervous system malformation, hydrocephalus, or bony impingement on neural structures. Embryologic vascular disorders have been found to be responsible for various congenital systemic and neurologic anomalies such as intestinal atresia and hydranencephaly. Subclavian artery supply disruption sequence has been hypothesized to result in Klippel-Feil, Poland, and M?bius anomalies. In this case the vertebral and facial abnormalities may well be related to anomalous subclavian and carotid supply. An embryonic vascular "steal" has been thought to cause the sirenomelia anomaly. We postulate that the subclavian steal, during the embryonic period, may have been responsible for the small size of this patient's cerebral hemispheres, brain stem, cerebellum, and cervical spinal cord.     

Relationship Between Brain Abnormalities and Cognitive Profile in Williams Syndrome

Previous studies have shown inconsistent results when reporting brain abnormalities in Williams syndrome (WS). This makes an interpretation of clinical and behavioural data uncertain in terms of anatomical localization of brain tissue changes. In this study we employed voxel based morphometry to directly investigate the regional distribution of grey matter (GM) density as a function of individual neuropsychological profiles in individuals with WS. GM maps were regressed against the neuropsychological measures on which WS individuals performed worse than controls. Results showed an association between the regional GM density in the cerebellum, bilaterally, the right Supplementary Motor Area, the right fusiform gyrus, and measures of morpho-syntactic ability. An association was also found between measures of visuo-spatial and visuo-motor abilities and regional GM density in the left cerebellum, left parietal lobule, right superior and left orbital frontal gyri. The study shows the potential to clarify the anatomical substrate underlying specific cognitive deficits in WS.     

20周胎儿标本脑组织MRI显示与三维可视化分析

目的：探讨20周胎儿脑标本MRI显示的发育情况及其三维可视化分析。方法：对8例20周胎儿脑标本行3.0TMR扫描,其中2例加行7.0TMR扫描。选取不同场强、方位的MR图像,分析其发育中的脑结构在MRI上的显示状况。选取1例冠状位7.0TMR图像,应用Amira4.1软件进行分割并三维重建。结果：3.OT与7.0TMRI显示,20周胎儿大部分脑沟雏形已经形成,表现为皮质表面的浅或宽凹陷;皮质层状结构发育典型,呈现为信号不同的堆积条带,以顶枕叶及海马区最为典型;基底核团可以分辨,其间界线与内外囊清晰。7.0TMRI显示脑干与小脑已具备典型成人外观,并可见其内部结构;在其三维重建图像上,可观察到皮质表面幼稚脑沟的深度、长度及所处位置,端脑、脑干与小脑外形及其位置关系都可以得到较好显示。结论：20周时,胎脑已完成初始阶段的发育,并具备成熟脑结构外观,这些结构在3.0T与7.0TMRI上,尤其是7.0TMRI上均得以清晰显示。三维可视化有助于对幼稚脑结构的宏观认识。     

Disseminated Intravascular Coagulation Involving the Brain: A Topographical Study

Histopathological study on 723 brains from routine necropsies was performed. Ten brains (1.38 percent) were found to have histological lesions of disseminated intravascular coagulation (DIC) with multiple fresh fibrin and/or platelet thrombi in the cerebral microcirculation. Among them, premortem diagnosis was made in only one case, and only two cases also showed evidence of visceral involvement. Microthrombi were found most frequently in the cerebral cortex and hypothalamic region and in the cerebral white matter, brain stem, and cerebellum, in descending order. Neurological symptoms and signs, including lethargy, coma and seizure, were detected in all cases. The abnormal body temperature and/or urinary output observed in most patients appeared to be related to the frequent hypothalamic involvement by DIC. The exclusive or predominant involvement of the brain by multiple microthrombi may be considered as a localized form of DIC. It is probably related to cerebral ischemia since severe acute neuronal ischemic changes also were noted in most brains.     

Identification of the cerebral loci processing human swallowing with H2(15)O PET activation

Lesional and electrophysiological data implicate a role for the cerebral cortex in the initiation and modulation of human swallowing, and yet its functional neuroanatomy remains undefined. We therefore conducted a functional study of the cerebral loci processing human volitional swallowing with 15O-labeled water positron emission tomography (PET) activation imaging. Regional cerebral activation was investigated in 8 healthy right handed male volunteers with a randomized 12-scan paradigm of rest and water swallows (5 ml/bolus, continuous infusion) at increasing frequencies of 0.1, 0.2, and 0.3 Hz, which were visually cued and monitored with submental electromyogram (EMG). Group and individual linear covariate analyses were performed with SPM96. In five of eight subjects, the cortical motor representation of pharynx was subsequently mapped with transcranial magnetic stimulation (TMS) in a posthoc manner to substantiate findings of hemispheric differences in sensorimotor cortex activation seen with PET. During swallowing, group PET analysis identified increased regional cerebral blood flow (rCBF) (P < 0.001) within bilateral caudolateral sensorimotor cortex [Brodmann's area (BA) 3, 4, and 6], right anterior insula (BA 16), right orbitofrontal and temporopolar cortex (BA 11 and 38), left mesial premotor cortex (BA 6 and 24), left temporopolar cortex and amygdala (BA 38 and 34), left superiomedial cerebellum, and dorsal brain stem. Decreased rCBF (P < 0.001) was also observed within bilateral posterior parietal cortex (BA 7), right anterior occipital cortex (BA 19), left superior frontal cortex (BA 8), right prefrontal cortex (BA 9), and bilateral superiomedial temporal cortex (BA 41 and 42). Individual PET analysis revealed asymmetric representation within sensorimotor cortex in six of eight subjects, four lateralizing to right hemisphere and two to left hemisphere. TMS mapping in the five subjects identified condordant interhemisphere asymmetries in the motor representation for pharynx, consistent with the PET findings. We conclude that volitional swallowing recruits multiple cerebral regions, in particular sensorimotor cortex, insula, temporopolar cortex, cerebellum, and brain stem, the sensorimotor cortex displaying strong degrees of interhemispheric asymmetry, further substantiated with TMS. Such findings may help explain the variable nature of swallowing disorders after stroke and other focal lesions to the cerebral cortex.     

健康人大脑和小脑空间记忆认知功能的fMRI研究

本研究应用功能磁共振成像(functional magnetic resonance imaging,fMRI)技术,检测了健康人大脑和小脑参与空间记忆的认知过程。通过对10名右利手健康志愿者进行一项短时空间记忆任务作业的同时进行脑功能磁共振扫描,实验采用组块设计,任务与对照任务交替进行,数据采用SPM99软件进行数据分析和脑功能区定位。结果显示:当统计阈值设定为P<0.0001时,大脑皮层和右侧小脑一起被显著激活;大脑皮层所激活的脑区有双侧顶叶的楔前叶、顶上小叶、缘上回(BA7/40,BA:Brodma-nn Area),双侧前额上、中、下回(BA6/9/47),双侧枕叶和枕颞交界处(BA18/19/37),右侧海马回;左侧中脑黑质及被盖部也被激活。上述结果提示:小脑和大脑皮层一起参与了空间记忆的认知过程。     

Anatomical study of the vertebral artery in japanese adults

The aim of the present study was to examine the vertebral arteries. The origins of the right and left vertebral arteries and their entrance points into the cervical transverse foramen were examined in dissections of 515 Japanese cadavers (303 males, 212 females) at Kurume University School of Medicine from 1990 to 2003. There were 515 right vertebral arteries and 514 left vertebral arteries. The right vertebral artery originated from the right subclavian artery in 514 of 515 arteries and one of the arteries arose from the bifurcation of the brachiocephalic trunk. The mean distance between the origin of the right subclavian artery and the right vertebral artery was 20.9 mm. The left vertebral artery originated from the left subclavian artery in 484 of 514 arteries and the mean distance between the origin of the left subclavian artery and the left vertebral artery was 32.1 mm. The remaining 30 arteries (5.8%) originated from the aortic arch between the left common carotid artery and the left subclavian artery and this frequency is similar to previously published data. There was no right-left difference for the entrance point of the vertebral arteries into the cervical transverse foramen and the 6th cervical vertebra (C6) was the most common entrance point. Seventy-eight percent of our cases had right and left vertebral arteries that originated in the subclavian arteries and entered the cervical transverse foramen at C6. Among the 30 left vertebral arteries that originated from the aortic arch, 20 arteries (66.7%) entered a cervical transverse foramen at a level higher than C6. This frequency was higher than that for the left vertebral artery that originated from the subclavian artery.     

Symmetrical and asymmetrical changes in brain tissue with age as measured on CT scans

Age-related changes in mean CT attenuation values of brain tissue were analyzed by an objective, automated technique. Study participants included 64 healthy men ranging in age from 31 to 87 years. Five CT slices from each individual were evaluated: the last ventricular slice and the next four supraventricular slices. Regression analyses indicated that specific regions in the brain change with age. A schematic reconstruction of these regions suggests that several brain regions are selectively altered with age. On the medial aspect of the cerebral hemisphere there was bilaterally symmetrical atrophy of the cingulate gyrus and sulcus, the adjacent interhemispheric frontal gyri, the parietooccipital sulcus, and the marginal branch of the cingulate sulcus. On the convexity of the cerebral hemispheres there was asymmetrical widening of the central and postcentral sulcus on the left, and the intraparietal sulcus on the right.     

DC-potential shifts and regional cerebral blood flow reveal frontal cortex involvement in human visuomotor learning

Summary In the present study, two different physiological parameters were measured to describe brain activity related to visuomotor learning: performance-related DC-potential shifts and regional cerebral blood flow (rCBF) by Tc-99m HMPAO brain SPECT (Single Photon Emission Computerized Tomography). Visuomotor learning was required in a conflicting situation: a visual target moved on a screen and had to be tracked by moving the right hand in an inverted fashion (IT), e.g. movements of the target to the right side required hand movement to the left and vice versa. Compared to a normal, non-inverted control task (T), IT required the development of a novel motor program and the prevention of returning to routine direct pursuit. These additional demands in IT caused a relative hyperperfusion in regions including the middle frontal gyri, frontomedial cortex (including the supplementary motor area, SMA), right basal ganglia (caudate-putamen) and left cerebellum. Correlations of rCBF values between the middle frontal gyrus and basal ganglia may indicate a functional relation between these two brain structures. Visuomotor performance was accompanied by slow negative DC-potential shifts. In frontal and to a lesser degree in central recordings, amplitudes of DC-negativity were larger in IT than they were in T. This additional frontal negativity covaried with the success of learning. Results substantiate, now using a dual approach, previous suggestions that the frontal lobe plays an important role in visuomotor learning.     

Brain Activation Patterns Characterizing Different Phases of Motor Action: Execution,Choice and Ideation

Motor behaviour is controlled by a large set of interacting neural structures, subserving the different components involved in hierarchical motor processes. Few studies have investigated the neural substrate of higher-order motor ideation, i.e. the mental operation of conceiving a movement. The aim of this functional magnetic resonance imaging study was to segregate the neural structures involved in motor ideation from those involved in movement choice and execution. An index finger movement paradigm was adopted, including three different conditions: performing a pre-specified movement, choosing and executing a movement and ideating a movement of choice. The tasks involved either the right or left hand, in separate runs. Neuroimaging results were obtained by comparing the different experimental conditions and computing conjunction maps of the right and left hands for each contrast. Pre-specified movement execution was supported by bilateral fronto-parietal motor regions, the cerebellum and putamen. Choosing and executing finger movement involved mainly left fronto-temporal areas and the anterior cingulate. Motor ideation activated almost exclusively left hemisphere regions, including the inferior, middle and superior frontal regions, middle temporal and middle occipital gyri. These findings show that motor ideation is controlled by a cortical network mainly involved in abstract thinking, cognitive and motor control, semantic and visual imagery processes.     

Serotonin modulation of cerebral glucose metabolism in normal aging

Age-related alterations in serotonin function may increase the vulnerability to psychiatric and neurodegenerative disorders in late life. The neuroendocrine and cerebral metabolic response to the acute administration of the selective serotonin reuptake inhibitor, citalopram (40mg, IV), was measured in 17 normal control subjects using positron emission tomography (PET) to evaluate changes in serotonin function with normal aging. The citalopram-induced change in cerebral metabolism was positively correlated with age in the right precuneus, right paracentral lobule, and left middle temporal gyrus and negatively correlated with age in the left anterior cingulate gyrus, right inferior and middle frontal gyri, right insula, and right inferior parietal lobule. The positive correlations in mainly posterior brain regions indicate that normal aging is associated with an increase in metabolism after citalopram administration, whereas the negative correlations in mainly anterior brain regions indicate that normal aging is associated with a greater decrease in metabolism. These results suggest different compensatory processes in anterior compared to posterior brain regions secondary to the age-related loss of serotonin innervation.     

Responses to rare visual target and distractor stimuli using event-related fMRI

Previous studies have found that the P300 or P3 event-related potential (ERP) component is useful in the diagnosis and treatment of many disorders that influence CNS function. However, the anatomic locations of brain regions involved in this response are not precisely known. In the present event-related functional magnetic resonance imaging (fMRI) study, methods of stimulus presentation, data acquisition, and data analysis were optimized for the detection of brain activity in response to stimuli presented in the three-stimulus oddball task. This paradigm involves the interleaved, pseudorandom presentation of single block-letter target and distractor stimuli that previously were found to generate the P3b and P3a ERP subcomponents, respectively, and frequent standard stimuli. Target stimuli evoked fMRI signal increases in multiple brain regions including the thalamus, the bilateral cerebellum, and the occipital-temporal cortex as well as bilateral superior, medial, inferior frontal, inferior parietal, superior temporal, precentral, postcentral, cingulate, insular, left middle temporal, and right middle frontal gyri. Distractor stimuli evoked an fMRI signal change bilaterally in inferior anterior cingulate, medial frontal, inferior frontal, and right superior frontal gyri, with additional activity in bilateral inferior parietal lobules, lateral cerebellar hemispheres and vermis, and left fusiform, middle occipital, and superior temporal gyri. Significant variation in the amplitude and polarity of distractor-evoked activity was observed across stimulus repetitions. No overlap was observed between target- and distractor-evoked activity. These event-related fMRI results shed light on the anatomy of responses to target and distractor stimuli that have proven useful in many ERP studies of healthy and clinically impaired populations.     

A case of the right aortic arch with the left subclavian artery as its last branch]

A case of the right aortic arch with the left subclavian artery as its last branch was found in an 80-year-old Japanese female cadaver during the 1990 dissection for students. The main findings were as follows. The ascending aorta arose from the left ventricle and ran right and upward to the level of the intervertebral disc between the 2nd and 3rd thoracic vertebrae. It then curved right and backward to form the aortic arch. The aortic arch joined the thoracic aorta that descended along the right side of the vertebral column and crossed obliquely the vertebral column at the level of the 8th thoracic vertebra. Finally it entered the abdomen through the aortic hiatus behind the esophagus. Four branches were given off from the aortic arch in the following order from left to right: the left common carotid, the right common carotid, and the right subclavian and the left subclavian arteries. The left subclavian artery, which had an aortic diverticulum at the origin of the aortic arch, ran left and upward behind the esophagus. The ligamentum arteriosum connected the left pulmonary artery with the aortic diverticulum of the left subclavian artery. The left common carotid artery, which normally had no branches before entering the cranium, gave off an accessory esophageal branch about 20 mm distally from its origin. The right and left vertebral arteries entered the transverse foramen of the 6th cervical vertebra. The left recurrent laryngeal nerve hooked around from the left dorsal to the right ventral part of the ligamentum arteriosum.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prerequisites for structural asymmetry of Broca's motor speech area of the human brain

Structural features of the Broca's speech-motor area in the left and right human cerebral hemispheres were studied. There were some peculiarities in the localization, shape, and structure of the main sulci and gyri of the frontal region in different hemispheres of the human brain. There were differences in the volume of cortical areas 44 and 45 in the left and right hemispheres, as well as in the count of neurons and in the size of pyramidal neurons in cytoarchitectonical layers III and V in the left and right hemispheres of speech-motor areas. It is suggested that left hemispherical asymmetry of Broca's area correlates with the development of human speech functions and oratory.     

NGF在成年猴脑的分布

为了解NGF在成年猴脑的分布,采用免疫组化SP法对成年猴脑多个冠状位切片进行免疫组化反应。结果证明,NGF阳性反应神经元主要分布于大脑皮质Ⅲ、V层,小脑Purkinje细胞,海马,齿状回,纹状体,脑干网状结构等处。此外,在黑质、舌下神经核、迷走神经背核、前庭神经核、三叉神经核、疑核、下橄榄核也出现NGF阳性反应。在大脑和脑干还观察到NGF阳性胶质细胞。本实验结果表明,在成年猴脑的多个脑区有NGF表达,提示NGF可能涉及猴脑某些神经元及胶质细胞的生理过程。     

Complex anomalies of the human aortic arch system: unique case with both vertebral arteries as additional branches of the aortic arch

We describe a case of an aortic arch with five primary branches arising in a sequence that has previously never been reported. From right to left, the brachiocephalic trunk and left common carotid, left vertebral, and subclavian arteries originated from the convexity of the aortic arch. The last branch was the right vertebral artery that arose from the dorsal aspect of the aortic arch opposite the ligamentum arteriosum. Presenting a dilatation at its commencement, the right vertebral ran to the right behind the esophagus and entered the foramen transversarium of the seventh cervical vertebra, whereas the left vertebral passed to the foramen transversarium of the fifth cervical vertebra. The left vertebral artery gave off the left thyroid artery; a thyrocervical trunk was absent on the left side. A thyroidea ima arose from the brachiocephalic trunk. The embryology of this complex anomaly as well as its potential clinical significance are discussed.     

Effect of modafinil on cerebral blood flow in narcolepsy patients

BACKGROUND: To investigate the effects of modafinil on regional cerebral blood flow (rCBF) in narcolepsy, we performed 99mTc-ethylcysteinate dimer single photon emission computed tomography (SPECT) before and after modafinil or placebo medication. METHODS: Brain SPECT was performed twice during the awake state before and after modafinil or placebo administration for 4 weeks in 43 drug-naive narcoleptics with cataplexy (M/F = 23/20, 29.5 +/- 5.8 years). For SPM analysis, all SPECT images were spatially normalized to the standard SPECT template and then smoothed using a 12-mm full width at half-maximum Gaussian kernel. The paired t-test was used to compare pre- and post-modafinil or placebo SPECT images. RESULTS: The mean modafinil dose used was 207.8 +/- 62.3 mg/day. Modafinil significantly reduced Epworth Sleepiness Scale scores from 20.3 +/- 2.1 to 5.2 +/- 3.1 (P < 0.01), while placebo did not. Compared to the off-modafinil condition, the on-modafinil condition showed significantly increased rCBF in the right dorsolateral and bilateral medial prefrontal cortices. Conversely, after modafinil administration, rCBF was decreased in bilateral precentral gyri, left hippocampus, left fusiform gyrus, bilateral lingual gyri, and cerebellum. There was no significant rCBF change after placebo administration. CONCLUSION: By a chronic administration of modafinil in narcoleptic patients, rCBF increased in the bilateral prefrontal cortices, whereas it decreased in left mesio/basal, temporal, bilateral occipital areas, and cerebellum.     

青年人正常颈椎旋转功能的CT研究

目的探讨正常各颈椎的旋转角度及旋转时横突孔移位、寰枢外侧关节活动情况。方法选择16~20岁健康自愿者50例,分别在正位、最大左旋和右旋位行螺旋CT扫描,测量枕骨和各颈椎与水平线所成角度、各横突孔的坐标值、寰椎侧块下关节面总面积及其与枢椎侧块上关节面未重合的面积,计算各颈椎实际旋转角度及占枕骨与第1胸椎间角度的百分比、横突孔在旋转时的实际移位距离及寰枢外侧关节的脱位百分比。结果颈椎向左、右作最大限度旋转时,枕骨相对第1胸椎的旋转角度分别为（69.9°±4.6°）、（69.6°±7.1°）,第1颈椎分别占（60.57±7.64）%、（56.28±10.0）%;第1颈椎左、右侧横突孔分别后移（13.03±4.03）mm、（9.80±3.08）mm,内移（15.74±2.76）mm、（13.97±5.90）mm,对侧分别前移（18.57±3.72）mm、（16.27±2.79）mm,内移（17.72±6.49）mm、（18.47±4.09）mm;左、右侧寰枢外侧关节分别脱位（57.34±7.06）%、（60.28±8.51）%,对侧分别脱位（75.53±8.54）%、（77.49±8.13）%。结论 CT是对活体颈椎旋转功能进行研究的简便、准确的方法,从青年人正常颈椎所测得数值对颈椎退行性变等异常情况下旋转功能的研究具有参考价值。     

Functional magnetic resonance imaging evidence for right-hemisphere involvement in processing unusual semantic relationships

Brain areas active in generating usual (typical) or unusual (atypical) noun-verb relations were examined using functional magnetic resonance imaging. Seven adults generated the 1st verb to come to mind (usual verb) in response to novel and repeated nouns (priming test) and then generated either an unusual verb or the 1st verb to come to mind in response to novel nouns (unusual test). The left inferior prefrontal cortex (LIPC) and right cerebellum were more active when generating usual verbs to novel nouns than to repeated nouns. When participants generated unusual verbs, there was no increased activation in LIPC, but there was increased activity in the right middle and superior frontal gyri, left middle frontal gyrus, and bilateral cerebellum. Results support theories that the right hemisphere is involved in the processing of distant associations that may be useful in creative thought and problem solving.