Immunohistochemical analysis of the arterial supply and mast cells of the trigeminal ganglion

The aim of this study was to quantify the distribution of microvessels and mast cells in all three parts of the trigeminal ganglion (TG). Statistical analyses were applied to investigate possible micromorphological regional differences in their density. Five serially sectioned human TGs were prepared for CD34 and mast cell tryptase immunostaining. The following quantifications were performed in microscopic fields of three parts of the TG: microvessel density (MVD), mast cell density (MCD) and ganglionic cell count. The density of CD34-positive microvessels was not significantly different in any of the three observed parts of the TG. The distribution of neurons showed no significant statistical difference in three parts of the TG. There was no difference in the density of tryptase-positive mast cells within the TG, but there was an abundant presence of mast cells in the periganglionic dural and subdural tissues, a finding hitherto not reported. We can say that there is a homogenous vascular pattern within the TG which excludes local predominance in pathogenesis of trigeminal neuralgia. Second, and more important, the finding of peri-trigeminal mast cells indicates their important role in migraine pain and confirms their degranulation as the main therapeutic goal for this condition.

Longitudinal progression of posterior cortical atrophy over 11 years: Relationship between lesion topology and clinical deficits

Posterior cortical atrophy (PCA) is a rare form of dementia primarily characterized by slowly progressing deterioration of visual processing corresponding to atrophy in the posterior parietal and occipital cortices with less prominent memory loss than are usually seen in other forms of dementia such as Alzheimer's Disease (AD). In the present case report, we describe longitudinal data over a period of 11 years regarding clinical and neuropsychological impairments and their relation to the location and extent of cortical changes related to higher order visual processing in a patient with posterior cortical atrophy. In our patient, visual processing deficits concerning space, motion and object perception emerged at the age of 50 and continued to worsen. By the age of 58, while the perception of contrast, color and figure-ground separation appeared undisturbed the patient exhibited pronounced dorsal- and ventral-related visual deficits, which continued to worsen with age. The patient's MRI scans over the course of the disease revealed increasing circumscribed and bilateral atrophy of the parietal and occipital cortices, with a right-sided predominance. The specific localization of cortical atrophy, the slow progression characterized by visual processing deficits and relatively preserved memory were the main criteria for the diagnosis of posterior cortical atrophy. The case report also highlights the importance of an early extensive neurological and neuropsychological evaluation of visual deficits that occur without the presence of ophthalmological disease.

Analysis of Prognostic Factors and Mortality in Children with Esophageal Atresia

OBJECTIVE

The survival rate in newborns with congenital esophageal atresia (EA) is about 85-90 %, and it raises over 95 % in the developed countries. The survival rate in developing countries is much lower and the authors describe their experience with 60 newborns.

METHODS

Medical records of 60 newborns (40 boys and 20 girls) with congenital EA were reviewed for the prognostic factors and mortality.

RESULTS

The birth weight, mean Apgar score (AS) value, gestational age and birth-operative treatment time had significant influence on the mortality of treated patients (p < 0.05). Thirty five percent newborns had aspirational pneumonia at the moment of hospitalization and 86.7 % of them were operated during the first 48 h. The presence of associated anomalies considerably affected the death rate of treated patients (p < 0.05). The incidence of postoperative complications was similar to those in developed countries but the total mortality was higher (28.3 %); sepsis being the main cause of mortality. The postoperative complications and sepsis significantly influenced the mortality of patients (p < 0.05).

CONCLUSIONS

Total mortality in newborns with EA was high; sepsis being the most frequent cause of death. The high total mortality was also caused by prematurity, delay in diagnosis, increased incidence of the aspiration pneumonia and shortage of qualified nurses.

Cytoarchitectonic mapping of the human dorsal extrastriate cortex

The dorsal visual stream consists of several functionally specialized areas, but most of their cytoarchitectonic correlates have not yet been identified in the human brain. The cortex adjacent to Brodmann area 18/V2 was therefore analyzed in serial sections of ten human post-mortem brains using morphometrical and multivariate statistical analyses for the definition of areal borders. Two previously unknown cytoarchitectonic areas (hOc3d, hOc4d) were detected. They occupy the medial and, to a smaller extent, lateral surface of the occipital lobe. The larger area, hOc3d, is located dorso-lateral to area V2 in the region of superior and transverse occipital, as well as parieto-occipital sulci. Area hOc4d was identified rostral to hOc3d; it differed from the latter by larger pyramidal cells in lower layer III, thinner layers V and VI, and a sharp cortex-white-matter borderline. The delineated areas were superimposed in the anatomical MNI space, and probabilistic maps were calculated. They show a relatively high intersubject variability in volume and position. Based on their location and neighborhood relationship, areas hOc3d and hOc4d are putative anatomical substrates of functionally defined areas V3d and V3a, a hypothesis that can now be tested by comparing probabilistic cytoarchitectonic maps and activation studies of the living human brain.

Pyramidal lobe of the human thyroid gland: an anatomical study with clinical implications

The presence, position, extent, relationships to neighboring structures and size of the human pyramidal lobe were investigated in 58 human post-mortem specimens in order to determine the variability of this structure. The pyramidal lobe is found in 55.2% of cases as a single conical extension of the thyroid gland. It was present more often in male (53.1%) than in female (46.9%) specimens and located slightly more often on the left side of the midsagittal plane (53.1%). According to the origin and location of its base, we defined five types of pyramidal lobe, with the left-sided types (Types III and IV) being predominant. The pyramidal lobe was 22.6 mm long, 11.2 mm wide and 3.6 mm thick (mean values). The means of all measured parameters were higher in female than in male specimens (pyramidal lobe was 2.3 mm longer, 1.6 mm wider and 0.4 mm thicker in female specimens) but these differences were not significant. In addition, we found that the size of the pyramidal lobe was dependent on the presence of a fibrous or muscular band that may represent a fibrous remnant of the thyroglossal duct or the levator glandulae thyroideae muscle. The pyramidal lobe was four times longer and its base was two and a half times wider and three times thicker when it was associated with this band. We believe that our data can be used to perform safer and more effective partial thyroidectomy in order to preserve thyroid function after surgical treatment.

Asymmetries in numerical density of pyramidal neurons in the fifth layer of the human posterior parietal cortex

Background/Aim. Both superior parietal lobule (SPL) of dorsolateral hemispheric surface and precuneus (PEC) of medial surface are the parts of posterior parietal cortex. The aim of this study was to determine the numerical density (NV) of pyramidal neurons in the layer V of SPL and PEC and their potential differences. Methods. From 20 (40 hemispheres) formaline fixed human brains (both sexes; 27- 65 years) tissue blocks from SPL and PEC from the left and right hemisphere were used. According to their size the brains were divided into two groups, the group I with the larger left (15 brains) and the group II with the larger right hemisphere (5 brains). Serial Nissl sections (5 ?m) of the left and right SPL and PEC were used for stereological estimation of NV of the layer V pyramidal neurons. Results. NV of pyramidal neurons in the layer V in the left SPL of brains with larger left hemispheres was significantly higher than in the left SPL of brains with larger right hemisphere. Comparing sides in brains with larger left hemisphere, the left SPL had higher NV than the right one, and then the left PEC, and the right SPL had significantly higher NV than the right PEC. Comparing sides in brains with the larger right hemisphere, the left SPL had significantly higher NV than left PEC, but the right SPL had significantly higher NV than left SPL and the right PEC. Conclusion. Generally, there is an inverse relationship of NV between the medial and lateral areas of the human posterior parietal cortex. The obtained values were different between the brains with larger left and right hemispheres, as well as between the SPL and PEC. In all the comparisons the left SPL had the highest values of NV of pyramidal neurons in the layer V (4771.80 mm-3), except in brains with the larger right hemisphere.

Omental Morgagni-Larrey hernia: an anatomical pictorial essay

This paper reports on a case of an omental diaphragmatic hernia revealed during routine anatomical dissection of an obese 85-year-old male with plethoric appearance of the upper body. The hernial mass, with a size of 12 cm x 9 cm, was detected in the anterior mediastinum. It had a long peduncle originating from the transverse colon and passing through the right sternocostal diaphragmatic opening of Morgagni-Larrey. The whole greater omentum was tightly packed and tumid within the serous hernial sac, but without signs of torquation. To our knowledge, this is the first systematic analysis of the omental hernial anatomy by a step-by-step iconography.

Gender-specific left-right asymmetries in human visual cortex

The structural correlates of gender differences in visuospatial processing are essentially unknown. Our quantitative analysis of the cytoarchitecture of the human primary visual cortex [V1/Brodmann area 17 (BA17)], neighboring area V2 (BA18), and the cytoarchitectonic correlate of the motion-sensitive complex (V5/MT+/hOc5) shows that the visual areas are sexually dimorphic and that the type of dimorphism differs among the areas. Gender differences exist in the interhemispheric asymmetry of hOc5 volumes and in the right-hemispheric volumetric ratio of hOc5 to BA17, an area that projects to V5/MT+/hOc5. Asymmetry was also observed in the surface area of hOc5 but not in its cortical thickness. The differences give males potentially more space in which to process additional information, a finding consistent with superior male processing in particular visuospatial tasks, such as mental rotation. Gender differences in hOc5 exist with similar volume fractions of cell bodies, implying that, overall, the visual neural circuitry is similar in males and females.

Pattern reversal visual evoked responses of V1/V2 and V5/MT as revealed by MEG combined with probabilistic cytoarchitectonic maps

Pattern reversal stimulation provides an established tool for assessing the integrity of the visual pathway and for studying early visual processing. Numerous magnetoencephalographic (MEG) and electroencephalographic (EEG) studies have revealed a three-phasic waveform of the averaged pattern reversal visual evoked potential/magnetic field, with components N75(m), P100(m), and N145(m). However, the anatomical assignment of these components to distinct cortical generators is still a matter of debate, which has inter alia connected with considerable interindividual variations of the human striate and extrastriate cortex. The anatomical variability can be compensated for by means of probabilistic cytoarchitectonic maps, which are three-dimensional maps obtained by an observer-independent statistical mapping in a sample of ten postmortem brains. Transformed onto a subject's brain under consideration, these maps provide the probability with which a given voxel of the subject's brain belongs to a particular cytoarchitectonic area. We optimize the spatial selectivity of the probability maps for V1 and V2 with a probability threshold which optimizes the self- vs. cross-overlap in the population of postmortem brains used for deriving the probabilistic cytoarchitectonic maps. For the first time, we use probabilistic cytoarchitectonic maps of visual cortical areas in order to anatomically identify active cortical generators underlying pattern reversal visual evoked magnetic fields as revealed by MEG. The generators are determined with magnetic field tomography (MFT), which reconstructs the current source density in each voxel. In all seven subjects, our approach reveals generators in V1/V2 (with a greater overlap with V1) and in V5 unilaterally (right V5 in three subjects, left V5 in four subjects) and consistent time courses of their stimulus-locked activations, with three peak activations in V1/V2 (contributing to C1m/N75m, P100m, and N145m) and two peak activations in V5 (contributing to P100m and N145m). The reverberating V1/V2 and V5 activations demonstrate the effect of recurrent activation mechanisms including V1 and extrastriate areas and/or corticofugal feedback loops. Our results demonstrate that the combined investigation of MEG signals with MFT and probabilistic cytoarchitectonic maps significantly improves the anatomical identification of active brain areas.

Cytoarchitectonic Analysis of the Human Extrastriate Cortex in the Region of V5/MT+: A Probabilistic, Stereotaxic Map of Area hOc5

Functional imaging studies identified a motion-sensitive area (V5/MT+) in the vicinity of the posterior branch of the inferior temporal sulcus that has no correlate in any classical cytoarchitectonic map. The aim of the present study was to identify a cytoarchitectonic correlate of this region in 10 human postmortem brains and to provide a probability map of this area. Observer-independent mapping revealed an area, hOc5 (h for human, Oc for occipital lobe), that has a broad layer III, a high cell density in layer II/III, and a low one in layer V. Most of area hOc5 is found in the depths of the anterior occipital sulcus and the anterior parts of either the inferior lateral occipital or the inferior occipital sulcus. After 3-dimensional reconstruction and registration to a standard reference space, a probability map of the area measured the individual variability of its size and location. The mean spatial locations of area hOc5 are -43, -73, 10 (left) and 49, -70, 11 (right). The locations and their relationships to sulci strongly suggest that hOc5 is the cytoarchitectonic correlate of human V5/MT+. This hypothesis was supported by comparing the cytoarchitectonic probabilistic map with results from a functional imaging study.

Human V5/MT+: comparison of functional and cytoarchitectonic data

To date, the delineation of the human visual "motion area" still relies on functional paradigms originally devised to identify monkey area MT. Using fMRI, we have identified putative human area V5/MT+ in normals by modelling the BOLD responses to alternating radially moving and stationary dot patterns. Functional activations were compared with cytoarchitectonic probability maps of its putative correlate area hOc5, which was calculated based upon data from histological sections of ten human post-mortem brains. Bilateral visual cortex activations were seen in the single subject dynamic versus stationary contrasts and in the group random-effects analysis. Comparison of group data with area hOc5 revealed that 19.0%/39.5% of the right/left functional activation was assigned to the right/left hOc5. Conversely, 83.2%/53.5% of the right/left hOc5 was functionally activated. Comparison of functional probability maps (fPM) with area hOc5 showed that 28.6%/18.1% of the fPM was assigned to hOc5. In turn, 84.9%/41.5% of the area hOc5 was covered by the respective fPM. Thus, random-effects data and fPMs yielded similar results. The present study shows for the first time the correspondence between the functionally defined human V5/MT+ and the post-mortem cytoarchitectonic area hOc5.

Perceptual segregation of overlapping shapes activates posterior extrastriate visual cortex in man

Objects in natural scenes are rarely seen in isolation, but are usually overlapping or partially occluding other objects. To recognize individual objects, the visual system must be able to segregate overlapping objects from one another. Evidence from lesions in humans and monkeys suggest that perceptual segregation of occluded or overlapping objects involves extrastriate visual cortex. In monkeys, area V4 has been shown to play an important role in recognizing occluded or poorly salient shapes. In humans, a retinotopic homologue of ventral V4 (V4v) has been described, but it is not known whether this area is also functionally homologous to area V4 in monkeys. In this study, we tried to localize the visual cortical regions involved in perceptual segregation of overlapping shapes using positron emission tomography (PET). Regional cerebral blood flow (rCBF) was measured in seven subjects while they discriminated the relative areas of simultaneously presented rectangular shapes. In the control condition, the shapes were displayed without overlaps; in a second condition, the shapes overlapped each other partially. In a third condition, the shapes did not overlap but had been reduced in salience by adding random noise to the stimuli. Contrasting the overlapping shape condition with the control condition identified a single region in the left posterior lateral occipital cortex. The rCBF in this region also increased, though more weakly, during discrimination of shapes embedded in noise, relative to the control condition. The region activated by segregation of overlapping shapes was located in the posterior occipital cortex close to the anterior border of area V2, near the average location of human V4v as determined by retinotopic mapping studies. The activation of this region of extrastriate visual cortex by a task that involved segregation of overlapping shapes is consistent with monkey V4 and human V4v being functionally homologous. We conclude that discrimination of overlapping shapes involves in particular a region of extrastriate visual cortex located in the left lateral occipital cortex and that this region may correspond to human V4v.

Types of neurons and some dendritic patterns of basolateral amygdala in humans--a golgi study

Classification of the neurons in the human basolateral amygdala is performed on preparations impregnated by the Golgi technique. Three different neuronal types are found in the nuclei of the basolateral amygdala: Type I--Pyramidal cells, with numerous dendritic spines and two subtypes (slender and squat); Type II--Modified pyramidal cells, sparsely spinous with rare dendritic spines and two subtypes (single apical and double apical) and; Type III--Non-pyramidal cells, with few dendritic spines and three subtypes (bipolar, multipolar and gliaform). The analysis of the primary dendritic branches pointed out the occasional presence of dendritic bundles (fascicular dendritic arrangement) with their predomination in the parvicellular division of the basal nucleus and paralaminar nucleus. Additionally, the presence of dendrodendritic contacts, indicated by light microscopy, was also found in the parvicellular division of the basal nucleus and especially in the paralaminar nucleus.

Brodmann's areas 17 and 18 brought into stereotaxic space-where and how variable?

Studies on structural-functional associations in the visual system require precise information on the location and variability of Brodmann's areas 17 and 18. Usually, these studies are based on the Talairach atlas, which does not rely on cytoarchitectonic observations, but on comparisons of macroscopic features in the Talairach brain and Brodmann's drawing. In addition, in this atlas are found only the approximate positions of cytoarchitectonic areas and not the exact borders. We have cytoarchitectonically mapped both areas in 10 human brains and marked their borders in corresponding computerized images. Borders were defined on the basis of quantitative cytoarchitecture and multivariate statistics. In addition to borders of areas 17 and 18, subparcellations within both areas were found. The cytoarchitectonically defined areas were 3-D reconstructed and transferred into the stereotaxic space of the standard reference brain. Surface rendering of the brains revealed high individual variability in size and shape of the areas and in the relationship to the free surface and sulci. Ranges and centers of gravity of both areas were calculated in Talairach coordinates. The positions of areas 17 and 18 in the stereotaxic space differed between the hemispheres. Both areas reached significantly more caudal and medial positions on the left than on the right. Probability maps were created in which the degree of overlap in each stereotaxic position was quantified. These maps of areas 17 and 18 are the first of their kind and contain precise stereotaxic information on both interhemispheric and interindividual differences.

Neuronal correlates of real and illusory contour perception: functional anatomy with PET

Illusory contours provide a striking example of the visual system's ability to extract a meaningful representation of the surroundings from fragmented visual stimuli. Psychophysical and neurophysiological data suggest that illusory contours are processed in early visual cortical areas, and neuroimaging studies in humans have shown that Kanizsa-type illusory contours activate early retinotopic visual areas that are also activated by real contours. It is not known whether other types of illusory contours are processed by the same mechanisms, nor is it clear to what extent attentional effects may have influenced these results, as no attempt was made to match the salience of real and illusory stimuli in previous imaging studies. It therefore remains an open question whether there are any brain regions specifically involved in the perception of illusory contours. To address these questions, we have used 15O-butanol positron emission tomography (PET) and a novel kind of illusory contour stimulus that is induced only by aligned line ends. By employing a form discrimination task that was matched for attention and stimulus salience across conditions we were able to directly contrast perception of real and illusory contours. We found that the regions activated by illusory contour perception were the same as those activated by real contours. Only one region, located in the right fusiform gyrus, was significantly more strongly activated by perception of illusory contours than by real contours. In addition, a principal component analysis suggested that illusory contour perception is associated with a change in the correlation between V1 and V2. We conclude that different kinds of illusory contours are processed by the same cortical regions and that these regions overlap extensively with those involved in processing of real contours. At the regional level, perception of illusory contours thus appears to differ from perception of real contours by the degree of involvement of higher visual areas as well as by the nature of interaction between early visual areas.