Kinking, coiling and diameters of vertebral artery first segment and their relationships to sex and side.

INTRODUCTION: Recent information on tortuosity in the prevertebral (V1) segment of the vertebral artery is based on case reports rather than systematic data on its presence, types, diameters, and sex- or left-right differences.

Immunolocalization of different neuropeptides in human interthalamic adhaesion indicates its functionality.

BACKGROUND/AIM: The interthalamic adhaesion (IA), gray matter connecting both thalami, is absent in about a quarter of human brains. Controversies are present about the nature and functional significance of the human IA. METHODS: In six adult human brains we investigated the expression of different neuropeptides: somatosatin (SOM), neuropeptide Y (NPY), ghrelin, neurotensin (NT), adrenocorticotropic hormone (ACTH), substance P (SP) and L-enkephalin (L-Enk) in neurons and/or neuropil of the IA, using immunohistochemistry (streptavidin-biotin technique). RESULTS: In neurons, as well as in fibers, we found immunoreactivity for ghrelin, SOM, L-Enk and NT. However, reactivity for NPY, SP and ACTH was present only in fibers within the IA. Fusiform neurons were immunoreactive for SOM, Ghrelin, L-Enk, and NT, neurons with oval perikaryon for SOM, and L-Enk, triangular neurons showed immunoreactivity mainly for NT and multipolar neurons for NT and L-Enk. CONCLUSION: These findings can contribute to the understanding of the function of interthalamic adhaesion, and to resolving the question whether it is a vestigial structure. No mather if the interthalamic adhaesion is vestigial structure or not, its presence or absence could be a marker for other, genetic or functional differences between human brains. Our findings indicate the presence of certain neuronal organization in the human interthalamic adhaesion which could have functional significance, and do not support its vestigial nature.

Morphology and digitally aided morphometry of the human paracentral lobule.

The human paracentral lobule, the junction of the precentral and postcentral gyri at the medial hemispheric surface, contains several important functional regions, and its variable morphology requires exact morphological and quantitativedata. In order to obtain precise data we investigated the morphology of the paracentral lobule and quantified its visible (extrasulcal) surface. This surface corresponds to commonly used magnetic resonance imaging scout images. We studied 84 hemispheres of adult persons (42 brains; 26 males and 16 females; 20-65 years) fixed in neutral formalin for at least 4 weeks. The medial hemispheric surface was photographed at standard distance and each digital photo was calibrated. Using the intercommissural line system (commissura anterior-commissura posterior or CA-CP line), we performed standardised measurements of the paracentral lobule. Exact determination of its boundaries and morphological types was followed by digital morphometry of its extrasulcal surface using AutoCAD software. We found two distinct morphological types of the human paracentral lobule: continuous type, which was predominant (95.2%), and rare segmented type (4.8%). In hemispheres with segmented cingulate sulcus we also found the short transitional lobulo-limbic gyrus (13.1%). The mean extrasulcal surface of the left paracentral lobule was significantly larger, both in males (left 6.79 cm2 vs. right 5.76 cm2) and in females (left 6.05 cm2 vs. right 5.16 cm2). However, even larger average surfaces in males were not significantly different than the same in females. Reported morphological and quantitative data will be useful during diagnostics and treatment of pathologies affecting the human paracentral lobule, and in further studies of its cytoarchitectonic and functional parcellations.

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 microm) 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.

Occipital sulci of the human brain: variability and morphometry.

The external morphology of the occipital lobe was investigated in 15 human post-mortem brains (30 hemispheres) fixed in formalin. We identified, described and measured the lengths of nine major human occipital sulci and five variable ones, comparing both types between individuals and hemispheres. Morphological variability of human occipital sulci is related to interindividual and interhemispheric differences in their presence, origin, type, segmentation, intersection and length. The major occipital sulci, particularly the parieto-occipital, the calcarine, the inferior lateral occipital and the anterior occipital sulci, as well as two points of their intersections (cuneal point and intersection of the transverse occipital and superior occipital sulcus) may be used as reliable anatomical landmarks for the location of architectonically and functionally defined human visual areas (V1, V2, V3, V3A, V5/MT+, LO1 and LO2) and during less invasive neurosurgical procedures in the cases of focal lesions within the occipital lobe. Two lateral occipital sulci (inferior and superior) were defined on the lateral surface of the occipital lobe. The variable lunate sulcus was studied and combining our results with those from histological and functional imaging studies, we suggest that the lunate sulci of human and nonhuman primates are not homologous.

Morphological variability of the subcallosal area of man.

BACKGROUND: Knowledge of morphology of human anterior cingulate and medial frontal cortex related to the knee of corpus callosum is important in the diagnostics and neurosurgical treatment. Neuroimaging studies did not provide a clear picture of this region, what is also caused by terminological inconsistencies. It is not always clear what is actually defined under the terms subcallosal area, subcallosal cingulate gyrus, subcallosal gyrus, subcallosal region, or subgenual prefrontal gyrus. Our study of subcallosal area provides morphological data useful for recent imaging studies. METHODS: Digital photographs (42 formaline fixed brains: 26 males, 16 females) were used in morphometry (surfaces and lengths) of subcallosal area. We defined all its boundaries: superoanterior, anterior, posterior, and inferior one. If anterior subcallosal sulcus, as anterior delineation of subcallosal area was absent, we used intercommissural line system. RESULTS: Anterior subcallosal sulcus we found in 86.9% of cases. Its variations were classified into four types: Type 1-vertical or slightly oblique sulcus (most often type on right hemispheres-30.1%), Type 2-in form of letter C or inverted letter C (most often type on left hemispheres-42.9%), Type 3-sulcus in form of letter S or inverted letter S, and Type 4-sulcus not belonging to any previous type. Mean surface of subcallosal area was in males 2.65 cm(2) (right hemispheres), and on left 2.70 cm(2). In females on right it was 2.56 cm(2), and on left 2.55 cm(2). All measured values were not significantly different (left/right; males/females). CONCLUSIONS: Accurate neuroanatomical localization requires exact determination of boundaries of subcallosal area. Therefore, standardized criteria were proposed for definition of subcallosal area.

[Digital morphometric study of the extrasulcal surface of the cingulate gyrus in man].

INTRODUCTION: The frequency of different morphological types and extrasulcal (visible) surface area of the cingulate gyrus, were measured and analysed in order to obtain more precise data about morphology, right/left and sex differences in the human brain. MATERIAL AND METHODS: The study included 42 brains (84 hemispheres) from persons of both sexes and of different age (26 males, 16 females, 20-65 years old), without neuropathological changes. After fixation in 10% formaline (3-4 weeks) and removal of meninges the brains were photographed under standard conditions by digital camera. Following determination of morphological type, regions of interest of cingulate gyrus were determined in stereotactic system system of coordinates and the extrasulcal surface was measured by digital AutoCAD planimetry. RESULTS AND DISCUSSION: Three basic morphological types of cingulate gyrus were found: the continuous type (34.5%), segmented type (35.7%) and double paralel type (29.8%). There was no statistically significant difference in the frequency of morphological types related to the side (right/left) or sex (p 0.05). The area of extrasulcal cortex of cingulate gyrus was statistically significantly (p < 0.05) larger on the left hemispheres (for 1.13 cm) than on the right (left: 14.58 cm; right: 13.45 cnm. 7he extrasulcal surface of the left cingulate gyrus was significantly larger (p 0 .05) in males (males 15.9 cm; females - 13.6 cm), while for the right cingulate gyrus this difference was not significant. CONCLUSION: Morphometry indicated sex and right/left differences of extrasulcal surface area of the human cingulate gyrus. However, the morphological analysis itself did not indicate corresponding differences, suggesting complexity of the problem of sex dimorphism and of right/left asymmetries in the domain of limbic cortex.

[Asymmetry and sexual dimorphism of the medial frontal gyrus visible surface in humans].

BACKGROUND/AIM: Studies of visible (extrasulcal) surface of the brain hemispheres are not feasible for measurements of the brain size, but are valuable for analysis and quantification of sexual dimorphism and/or asymmetries of the human brain. Morphological and morphometric investigations of the brain may contribute in genetic studies of the human nervous system. The aim of this study was to determine and to quantify sexual dimorphism and the right/left morphological asymmetry of the visible surface of medial frontal gyms (gyrus frontalis medialis - GFM). METHODS: Measurements and analysis of the visible surface of GFM were done on 84 hemispheres (42 brains from the persons of both sexes: 26 males and 16 females, 20-65 years of age). After fixation in 10% formalin and dissection, digital morphometric measurements were performed. We studied these in relation to the side of the hemisphere and the person's sex. Standardized digital AutoCAD planimetry of the visible surface of GFM was enabled by the use of coordinate system of intercommissural line. RESULTS: In the whole sample, the visible surface of the right GFM (21.39 cm2) was statistically significantly greater (p < 0.05) than the left GFM (18.35 cm2) indicating the right/left asymmetry of the visible surface of GFM. Also, the visible surface of the right GFM in the males (22.66 cm2) was significantly greater (p < 0.05) than in the females (19.35 cm2), while the difference in size of the left GFM between the males and the females was not significant (p > 0.05). CONCLUSION: Morphological analysis of visible surface of GFM performed by digital planimetry showed sexual dimorphism of the visible surface and the presence of right/left asymmetry of GFM.

Longitudinal striae of the human fornix: shape, relations and variations.

BACKGROUND: Two pairs of sagittal longitudinal striae, medial and lateral, are slender bundles of fibers located on the dorsal surface of corpus callosum, situated deeply in the longitudinal fissure of telencephalon. Imbedded in the structure of tiny gyrus, indusium griseum, they are, in fact, supracallosal fibers of the fornix, previously called fornix longus. METHODS: Longitudinal striae were investigated in 25 fixed human brains obtained from autopsies. Macrodissection and morphometric methods were used in order to find out and analyze the appearance and gross morphological variability of longitudinal striae, as well as their inter-individual relations. RESULTS: Lateral longitudinal striae were located along the sulci of corpus callosum. Medial striae were positioned along the sagittal midline and they were mostly individual. However, they were at times connected, spanned or duplicated. Longitudinal striae make a characteristic pattern on the dorsal surface of corpus callosum. A classification of striae is made on the basis of their appearance. CONCLUSIONS: Although similar at first sight the striae, especially medial ones, have some individual features which make the pattern variable. Medial striae are more variable than the lateral ones. Perhaps functional neuroimaging and DT MRI will disclose the enigma of these striae.

Vocal fold mucosa "blue lines" observed on contact telescopy at Reinke's edema.

Reinke's space is a highly specific structure critical for the function of the vocal fold, involved in a majority of pathological changes of the larynx. The aim of the study was to contribute to the understanding of edematous areas of vocal fold mucosa in patients with Reinke's edema using contact telescopy (ConTel). The edematous tissue which could be identified grossly by microlaryngoscopy under general anesthesia was stained topically with methylene blue and then examined using ConTel. The observed changes on contact images were further correlated with corresponding histological sections of biopsied edematous tissue. In patients with Reinke's edema examined using ConTel, we observed longitudinal arranged mucosal "blue lines" (BL). In the histological sections of edematous tissue showing the BL on ConTel, we almost regularly observed well-developed hollow spaces in subepithelia. Also, they were regularly oriented from the middle of the membranous portion of the vocal fold toward the arcuate line distributed almost parallel to the free edge of the vocal fold. BL were a specific feature of Reinke's edema as they were not found in control groups with normal vocal fold mucosa and with vocal fold polyps. For the first time we are describing a new superficial morphological feature of Reinke's edema. The BL could present epithelial ConTel markers of the area between two enlarged neighboring subepithelial crevices of Reinke's space, as indicated on histological sections. Further characterization of BL is required for the understanding of their role in Reinke's edema.

[Morphological and laminar distribution of cholecystokinin-immunoreactive neurons in cortex of human inferior parietal lobe and their clinical significance].

INTRODUCTION: Cholecystocinine is a neuropeptide whose function in the cortex has not yet been clarified, although its relation with some psychic disorders has been noticed. Previous studies have not provided detailed data about types, or arrangement of neurons that contain those neuropeptide in the cortex of human inferior parietal lobe. The aim of this study was to examine precisely the morphology and typography of neurons containing cholecytocinine in the human cortex of inferior parietal lobule. MATERIAL AND METHODS: There were five human brains on which we did the immunocystochemical research of the shape and laminar distribution of cholecystocinine immunoreactive neurons on serial sections of supramarginal gyrus and angular gyrus. The morphological analysis of cholecystocinine-immunoreactive neurons was done on frozen sections using avidin-biotin technique, by antibody to cholecystocinine diluted in the proportion 1:6000 using diamine-benzedine. RESULTS: Cholecystocinine immunoreactive neurons were found in the first three layers of the cortex of inferior parietal lobule, and their densest concentration was in the 2nd and 3rd layer. The following types of neurons were found: bipolar neurons, then its fusiform subtype, Cajal-Retzius neurons (in the 1st layer), reverse pyramidal (triangular) and unipolar neurons. The diameters of some types of neurons were from 15 to 35 microm, and the diameters of dendritic arborization were from 85-207 microm. A special emphasis is put on the finding of Cajal-Retzius neurons that are immunoreactive to cholecystocinine, which demands further research. CONCLUSION: Bearing in mind numerous clinical studies pointing out the role of cholecystokinine in the pathogenesis of schizophrenia, the presence of a great number of cholecystokinine immunoreactive neurons in the cortex of inferior parietal lobule suggests their role in the pathogenesis of schizophrenia.

[Characteristics of galanin and vasoactive intestinal peptide immunoreactivity in the rat amygdala complex].

INTRODUCTION: Morphological features and morphometric parameters of galanin (GAL) and vasoactive intestinal peptide (VIP) immunoreactive neurons and neuronal fibres were studied in all nuclei of adult male rat amygdala. MATERIAL AND METHODS: After perfusion and fixation, rat brains were immunohistochemically stained with antibodies against GAL and VIP and then visualized by avidin-biotin-peroxidase complex. RESULTS AND DISCUSSION: The greatest number of galanin-immunoreactive neurons were identified in the medial part of the central nucleus and in the dorsal part of the medial nucleus. In the first case, most neurons were bipolar (37%), and in the second, they were ovoid (45%). GAL-immunoreactive fibers were identified in the medial nucleus, "bed nucleus" of the accessory olfactory tract, fiontal cortical nucleus, amygdalo-hippocampal area and basolateral nucleus. VIP-immunoreactive neurons were diffusely distributed in more nuclei than the previous, mostly in the lateral, basolateral, and basomedial nucleus. They were mostly ovoid (40%). VIP-immunoreactive fibers were observed in the lateral part oJ'the central nucleus, while long and radially oriented fibers were present in the frontal and dorsal cortical nucleus. CONCLUSION: By distribution analysis of GAL and VIP immunoreactive neurons and fibers, and according to literature data, it can be assumed that the medial part of the central nucleus receives VIP fibers from other parts of the amygdaloid body, and then sends GAL fibers to the medial nucleus.

Contact telescopy reveals blood vessel alterations of vocal fold mucosa in Reinke's edema.

AIM: To evaluate contact telescopy findings for estimation of blood vessel changes in vocal fold mucosa in patients with Reinke's edema. Histological features significant for diagnosis of microvascular vocal fold alteration were correlated with clinical findings. METHODS: In 80 patients with Reinke's edema, laryngoscopy and video-telescopy image analysis of vocal folds were performed. Vocal fold mucosa biopsies were histologically analyzed and compared with contact telescopy findings. An interesting aspect of vocal fold microcirculation found both by contact telescopy imiging and by histological specimens was described. RESULTS: Contact telescopy in vivo revealed different forms of pathological blood vessel networks with unusual appearance of loops or branching. Some dilated varicose vascular channels had very thin walls, and within atypical capillaries, partial erythrocyte accumulation was found. Details of blood flow are also visible, showing multidirectional and discontinuous blood flow in neighboring vessels. CONCLUSION: The noninvasive contact telescope technique is very useful as an additional diagnostic tool for defining a condition of a subepithelial Reinke's space in a very short period of time. The great advantage of contact telescopy is systematic in vivo and in situ observation of microvascular details in the vocal folds. The contact technique allows dynamic follow-up of the microcirculation in Reinke's edema as well as simultaneous consultation of a pathologist in the operating theater.

[Sexual dimorphism of the human corpus callosum--digital morphometric study].

BACKGROUND/AIM: Changes in the morphology and the size of the corpus callosum, are related to various pathological conditions. An analysis of these changes requires data about sexual dimorphism of the corpus callosum, which we tried to obtain in our study. We also investigated the method of digital morphometry and compared the obtained results with the results of other authors obtained by magnetic resonance imaging or by planimetry. METHODS: A morphological research included 34 human brains (cadavers of both sexes--19 female and 15 male aged 26-72 years). By digital morphometry using an AutoCAD software we performed measurements in the corpus callosum: the length (L), width in the half of its length (WW'), length of its cortical margin (LCM), area and perimeter of the anterior and posterior callosal segments, as well as the area and perimeter of the corpus callosum section area. The investigated parameters were analyzed and compared between the females and males. RESULTS: There was not a statistically significant difference between the males and females in the investigated parameters of the corpus callosum (t test; p > 0.05), including the mean values of the two most important parameters, the surface of its mid-sagittal section area (males 654.11 mm2; females 677.40 mm2) and of its perimeter (males 19.61 cm; females 19.72 cm). The results obtained by digital morphometry were in the range of the results of other authors obtained by magnetic resonance and by planimetry. However, the value of Pearson coefficient of linear correlation between the section surface area and perimeter of the corpus callosum in the males was highly significant (rxy = 0.6943, p < 0.01), while in the females this value was statistically insignificant. CONCLUSION: Digital morphometry is accurate method in encephalometric investigations. Our results suggest that the problem of sexual dimorphism of the corpus callosum is very complex, because the identical variables (section surface area or its perimeter) do not exhibit the same behavior in males and in females, implicating that these variables even cannot be simply compared between the sexes.

[Morphometric variability of precuneus in relation to gender and the hemisphere of human brain]. / Morfometrijska varijabilnost prekuneusa u odnosu na pol i hemisferu mozga covenka.

Precuneus, a quadrangular gyms of the medial surface of the human parietal lobe, is bound by three primary brain sulci and by superior hemispheric border. Precise encephalometric data about precuneus are important in the studies of brain lateralization, sex dimorphism, and brain functions in general. In this study, total and visible (exstrasulcal) surface area of the precuneus were measured on 50 brains of the adult persons (31 male, and 29 female), together with the investigation of its relationship to the side (left/right) and gender (sex dimorphism). The average total surface area of the precuneus was 16.07 cm2 on the right (males 16.44 cm2, females 15.27 cm2), and 15.44 cm2 on the left (males 15.67 cm2, females 14.62 cm2). The average visible (extrasulcal) surface area of cortex of precuneus was 9.97 cm2 on the left (males 10.75 cm2, females 8.91 cm2), and 9.38 cm2 on the right (males 10.25 cm2, females 8.19 cm2). Exstrasulcal surface area of the left precuneus was larger, by 0.59 cm on the average, which was not statistically significant. Total surface area of precuneus of males was significantly larger on the right (16.44 cm2) (p<0.01) than on the left (15.67 cm2). In females it was also larger on the right (15.27 cm2) than on the left (14.62 cm2), but with no statistical significance. Visible (exstrasulcal) surface area of both, (left and right precuneus of males), was highly significantly larger in comparison with the females (p<0.001). The obtained results and other facts suggested that sex dimorphism of human brain, including precuneus, was present, but not always easily observable, studied or proven in all the details.

Endoscopic anatomic features of the triangular recess.

OBJECTIVE: To describe the morphological and topographic features of the triangular recess (TR) in the anterior wall of the third ventricle and the pathological conditions that allow its observation during ventricular endoscopic neuronavigation. METHODS: A systematic review of records and operative videotapes for 145 patients who underwent endoscopic third ventriculostomy was performed. RESULTS: The TR could be recognized in five cases of hydrocephalus, each caused by a different underlying pathological condition. The approach was precoronal in four cases and suboccipital in one. The morphological and topographic features of the TR and adjacent structures varied among the different cases. CONCLUSION: Although it is seldom reported in neuroanatomy handbooks and is not readily accessible under normal conditions, the TR is a characteristic structure of the third ventricle, which might become apparent in several conditions that produce hydrocephalus. Neurosurgeons who perform neuroendoscopy should be aware of this structure and of the situations that cause its deformation and allow its observation during endoscopic neuronavigation.