Convolutional Pattern Research Articles

Primary cortical folding in the human newborn: an early marker of later functional development

In the human brain, the morphology of cortical gyri and sulci is complex and variable among individuals, and it may reflect pathological functioning with specific abnormalities observed in certain developmental and neuropsychiatric disorders. Since cortical folding occurs early during brain development, these structural abnormalities might be present long before the appearance of functional symptoms. So far, the precise mechanisms responsible for such alteration in the convolution pattern during intra-uterine or post-natal development are still poorly understood. Here we compared anatomical and functional brain development in vivo among 45 premature newborns who experienced different intra-uterine environments: 22 normal singletons, 12 twins and 11 newborns with intrauterine growth restriction (IUGR). Using magnetic resonance imaging (MRI) and dedicated post-processing tools, we investigated early disturbances in cortical formation at birth, over the developmental period critical for the emergence of convolutions (26-36 weeks of gestational age), and defined early 'endophenotypes' of sulcal development. We demonstrated that twins have a delayed but harmonious maturation, with reduced surface and sulcation index compared to singletons, whereas the gyrification of IUGR newborns is discordant to the normal developmental trajectory, with a more pronounced reduction of surface in relation to the sulcation index compared to normal newborns. Furthermore, we showed that these structural measurements of the brain at birth are predictors of infants' outcome at term equivalent age, for MRI-based cerebral volumes and neurobehavioural development evaluated with the assessment of preterm infant's behaviour (APIB).

Automatic curvilinear reformatting of three-dimensional MRI data of the cerebral cortex

Curvilinear reformatting of three-dimensional (3D) MRI data of the cerebral cortex is a well-established tool which improves the display of the gyral structure, permits a precise localization of lesions, and helps to identify subtle abnormalities difficult to detect in planar slices due to the brain's complex convolutional pattern. However, the method is time consuming because it requires interactive manual delineation of the brain surface contour. Therefore, a novel technique for automatic curvilinear reformatting is presented. A T1-weighted MRI volume data set is normalized using SPM2. Due to the normalization to a common stereotactic space, predefined masks can be applied to cover skull and outer brain regions in different depths from the brain surface. Thereby, the outer brain regions are subsequently removed in 2-mm layers parallel to the brain surface like ‘peeling an onion’. The serial convex planes enclosing the residual inner part of the brain are presented 3-dimensionally. If necessary (e.g., for intraoperative navigation), the normalized data can be transferred to native space by inverse normalization. Compared to cross-sectional images, curvilinear reformatting offers a markedly superior visualization of topographic relations between lesions and cortical structures, helps to detect subtle cortical malformations and to assess the spatial extent of lesions, thus allowing a better planning of neurosurgical procedures. Compared to alternative methods, it is largely based on freely available software and does not require observer-dependent manual input. In conclusion, we present a simple, easy-to-use and fully automated method for curvilinear reformatting of 3D MRI.

Neonatal Hepatitis in 2 Siblings with Seckel Syndrome

Seckel syndrome was described as the prototype of the primordial bird-head type of dwarfism. We report 2 cases of Seckel syndrome in siblings. Both cases showed peculiar phenotypic features. Autopsy was performed and microscopic examination of the livers displayed histologic features of neonatal hepatitis. In addition, our younger patient had central nervous system anomalies such as agenesis of corpus callosum, cerebral cyst, and primitive convolutional pattern. No previous reports of liver disease exist in patients with Seckel syndrome. The pathologic findings of such an unusual association and a review of literature are presented.

Surface-based approaches to spatial localization and registration in primate cerebral cortex

Explicit surface reconstructions provide invaluable substrates for visualizing and analyzing the complex convolutions of cerebral cortex. This report illustrates the utility of surface-based atlases of human and macaque monkey for representing many aspects of cortical organization and function. These include a variety of cortical partitioning schemes plus an open-ended collection of complex activation patterns obtained from fMRI studies. Surface-based registration from one hemisphere to an atlas provides powerful approach to (i) objectively and quantitatively representing both the consistencies and the variability of the pattern of convolutions and the patterns of functional activation from any given task; and (ii) making comparisons across species and evaluating candidate homologies between cortical areas or functionally delineated regions.

Superficial siderosis 20 years after brain tumour

A 6-year-old girl presented in April, 1962, with headache, vomiting, and an unsteady gait. She had left-sided ataxia and bilateral papilloedema. Skull radiograph showed accentuation of the convolutional pattern and ventriculography showed symmetrical hydrocephalus with blockage at the upper end of the aqueduct. After insertion of a ventricular drain, a posterior fossa craniectomy was performed and a left cerebellar pilocytic astrocytoma was resected on May 16, 1962. Since all the margins were not clear of tumour, she received radiotherapy (4000 rads).

Neuropathological analysis of an adult case of the Cornelia de Lange syndrome.

Cornelia de Lange syndrome (CDLS) is a rare multisystemic malformative syndrome of uncertain etiology characterized by severe psychomotor and mental retardation. Here we report the neuropathological analysis of a 35-year-old patient who displayed the classical clinical symptomatology of CDLS. A congenital dysgenesis of the brain was evident including abnormal convolution patterns of the cerebral gyri, frontal lobe hypoplasia and focal lack of myelination in layers V and VI of the left temporal cortex. In addition, there were vascular scars in the CA2-3 region of the left hippocampus and in the right parietal cortex as well as a few neurofibrillary tangles in the CA fields of the hippocampus and in the entorhinal cortex. In contrast to previous reports, there were no midline cerebral dysgenesis and no ectopic neuron formations in the present case. Neuronal loss and gliosis were also absent in all cortical and subcortical areas. Our observations suggest that the main neurodevelopmental deficits in CDLS occur during the late phase of gestation. Conversely, early neurodegenerative changes are not characteristic of CDLS. In the light of previous studies in younger CDLS patients, the vascular and degenerative lesions observed in the present case may be secondary to his severe congenital heart abnormalities and self-injury behavior, respectively.

Multidirectional associative memory with a hidden layer

AbstractMAM (Multidirectional Associative Memory) is an extended BAM (Bidirectional Associative Memory), and an associative memory model which can deal with multiple associations. If the training set has common terms, the conventional MAM often recalls the convolutional patterns. IMAM (Improved Multidirectional Associative Memory) can store them, but the structure is complex and the storage capacity is extremely small because it must use correlation matrix. In this paper, we propose a MAM with a hidden layer and its learning method. The structure is as simple as MAM and can store the training set which includes common terms. By computer simulation, we show the storage capacity is far larger than correlation learning and it is robust against noise. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(6): 1–9, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10105

Diagnosis of subtle focal dysplastic lesions: Curvilinear reformatting from three-dimensional magnetic resonance imaging

Focal cortical dysplasia is a frequent cause of medically intractable partial epilepsy. These lesions are being increasingly identified by high quality images provided by magnetic resonance imaging (MRI), resulting in improved seizure control of surgically treated patients. Small dysplastic lesions are often missed by conventional MRI methods. The identification of subtle structural abnormalities by rectilinear slices is often limited by the complex convolutional pattern of the brain. We developed a method of curvilinear reformatting of three-dimensional MRI data that improves the anatomical display of the gyral structure of the hemispheric convexities. It also reduces the asymmetric sampling of gray-white matter that may lead to false-positive results. We present 5 patients in whom conventional two-dimensional and three-dimensional MRI with multiplanar reformatting was initially considered normal. Subsequent studies using curvilinear reformatting identified lesions in all. Four patients underwent surgery with histological diagnosis of focal cortical dysplasia. Three patients are seizure-free and 1 had significant improvement in seizure control. These results indicate that an increase in the detection of subtle focal dysplastic lesions may be accomplished when one improves the anatomical display of the brain gyral structure by performing curvilinear reformatting.

Luigi Rolando and his pioneering efforts to relate structure to function in the nervous system.

The fissure separating the motor from the sensory cortex and the substantia gelatinosa capping the posterior horn of the spinal cord are still known by the name of the Italian anatomist Rolando, Luigi Rolando was born in Turin, Italy, in 1773 and died in 1831. His life was not easy, the first of his problems being the death of his father when Rolando was still very young. Three people were to be influential in his life and career: Father Maffei, his maternal uncle who raised him; Dr. Cigna, the anatomy professor who discovered his talent; and Dr. Anformi, a general practitioner who introduced him to the practice of medicine and to the best circles of the city. Forced to leave Turin by the Napoleonic invasion of the country, Rolando first stopped in Florence, where he learned about anatomical dissection, drawing, and engraving and studied the appearance of nervous tissue under the microscope. Later he went to Sardinia where, although cut off from European cultural circles, he developed his major theories. Rolando pioneered the idea that brain functions could be differentiated and located in specific areas and discovered the fixed pattern of cerebral convolutions, highlighting motor and sensory gyri. He demonstrated the complexity of the central gray matter of the spinal cord, describing the "substantia gelatinosa," and he deduced that nervous structures are connected in a network of nervous fibers linked by electrical impulses. Rolando had to struggle for recognition, however, as the priority of his discoveries was challenged by the almost contemporaneous work of Gall and Spurzheim on cerebral localization and of Flourens on cerebellar function. Nevertheless, his efforts contributed greatly to the clarification of brain function. His observations on nervous anatomy have been especially accurate, as shown by the nomenclature "fissure of Rolando."

Optoelectronic morphological image processor

A morphological optoelectronic image processor based on the threshold decomposition concept is described and demonstrated. Binary slices of a gray-scale input image are optically convolved with a binary structuring element of arbitrary size and shape in a noncoherent convolver. The slices are displayed on a liquid-crystal spatial light modulator of 320 x 264 pixels. The kernels are implemented as modifications of the system impulse response. The processor's convolution patterns are recorded with a CCD camera and fed into a PC by a frame grabber. Subsequent elementary morphological operations are looped. Examples of processing an input image of 256 x 256 pixels and 16 gray levels with kernels of arbitrary size are presented.

Developmental history of the transient subplate zone in the visual and somatosensory cortex of the macaque monkey and human brain

The cytological organization and the timetable of emergence and dissolution of the transient subplate zone subjacent to the developing visual and somatosensory cortex were studied in a series of human and monkey fetal brains. Cerebral walls processed with Nissl, Golgi, electron-microscopic, and histochemical methods show that this zone consists of migratory and postmigratory neurons, growth cones, loosely arranged axons, dendrites, synapses, and glial cells. In both species the subplate zone becomes visible at the beginning of the mid-third of gestation as a cell-poor/fiber-rich layer situated between the intermediate zone and the developing cortical plate. The subplate zone appears earlier in the somatosensory than in the visual area and reaches maximal width at the beginning of the last third of gestation in both regions. At the peak of its size the ratio between the width of the subplate zone and cortical plate in the somatosensory cortex is 2:1 in monkey and 4:1 in man while in the occipital lobe these structures have about equal width in both species. The dissolution of the subplate zone begins during the last third of gestation with degeneration of some subplate neurons and the relocation of fiber terminals into the cortex. The subplate zone disappears faster in the visual than in the somatosensory area. The present results together with our previous findings support the hypothesis that the subplate zone may serve as a "waiting" compartment for transient cellular interactions and a substrate for competition, segregation, and growth of afferents originated sequentially from the brain stem, basal forebrain, thalamus, and from the ipsi- and contralateral cerebral hemisphere. After a variable and partially overlapping time period, these fibers enter the cortical plate while the subplate zone disappears leaving only a vestige of cells scattered throughout the subcortical white matter. A comparison between species indicates that the size and duration of the subplate zone increases during mammalian evolution and culminates in human fetuses concomitantly with an enlargement of cortico-cortical fiber systems. The regional difference in the size, pattern, and resolution of the subplate zone correlates also with the pattern of cerebral convolutions. Our findings indicate that, contrary to prevailing notions, the subplate may not be a vestige of the phylogenetically old network but a transient embryonic structure that expanded during evolution to subserve the increasing number of its connections.

Revisiting the South African Taung australopithecine endocast: The position of the lunate sulcus as determined by the stereoplotting technique

AbstractFalk's (1980a) claims regarding the pongid‐like disposition of convolutional patterns on the South African australopithecine endocasts are critically examined. Using a stereoplotter apparatus and a small sample of chimpanzee brain casts, the angular coordinates of the lunate sulcus are recorded, and placed as such on the Taung and SK 1585 endocasts. The resulting location of such pongid‐oriented lunate sulci violates the gross morphology of the australopithecine endocasts. Relative brain: body weight ratios for Australopithecus are shown to be advanced over any of the pongids. In addition, evidence is provided from LeGros Clark's (1947) paper that controverts certain of Falk's claims regarding his methods. It is concluded that the secondary sulci and gyri on the now available australopithecine endocasts are not clear enough to warrant unambiguous demonstration; with regard to the lunate sulcus, the Taung endocast does not show a pongid pattern.

An Unusual Malformation of the Forebrain and Concomitant Destructive Encephalopathy with Calcifications

A 9-year old boy with profound mental retardation and severe neurologic deficit presented an unusual malformation of the forebrain distinguished by the following features: 1) microtelencephalon, alobulation, afissuration, and abnormal convolutional pattern; 2) persistence of hippocampal formation at its embryonic site in the dorsomedial wall of the telencephalon; 3) hypoplasia and abnormal configuration of ventricles; 4) agenesis of cerebral commissures; and 5) abnormal location and orientation of gray structures. Important concomitant findings characterized by severe destructive lesions, massive calcification, granular ependymitis, and low grade inflammation were suggestive of late sequelae of an infectious process, possibly congenital. Transplacental transmission of an unidentified pathogen with teratogenic properties was hypothesized as the probable cause. The teratogenic insult started in an early embryonic period and affected primarily the development of the neopallium in the telencephalic wall. The arrested development of the neopallium disrupted the chain of interdependent developmental events; consequently characteristic morphological modifications normally induced by the continuous growth and differentiation of the neopallium failed to occur or took an abnormal course. The name architelencephalon (Greek: arche, beginning; telencephalon, cerebral hemispheres) proposed for this particular malformation of the forebrain indicates its resemblance both to the human brain at early stages of development and also to mammalian brains on a lower level of phylogeny. Associated anomalies included an unilateral microphthalmia with cataract, severe stenosis of the aqueduct of Sylvius and macrocephaly. The microphthalmia was either a developmental anomaly or was infectious in origin. The stenosis of the aqueduct was attributed to granular ependymitis. Tearing of the thin dorsal diencephalic plate and arachnoid membrane and escape of the cerebrospinal fluid into the subdural space probably accounted for the macrocephaly.

Gyral development of the human brain.

AbstractTo determine the development of the convolutional pattern of the cerebral hemispheres, we have examined multiple gross photographs of 507 brains and serial sections of 207 brains from infants of 10 to 44 weeks' gestational age. The sequential developmental changes of the individual fissures, sulci, and gyri of the cerebral hemispheres throughout the gestational period are tabulated. Schematic drawings made from enlarged photographs show the major changes associated with each month of the second and third trimesters.The brains of twins between 19 and 32 weeks' gestational age show a delay of approximately two to three weeks in the development of convolutional markings compared with the brains of nontwins. There is no significant difference between male and female brains.We found left‐right asymmetries of the transverse temporal gyri, sylvian fissures, and planum temporale. In general, the right cerebral hemisphere shows gyral complexity earlier than the left. Our findings allow speculation about the significance of left‐right asymmetry of the brain as it affects speech and language development.

How the Human Brain Responds to Aging

The characteristic morphologic changes frequently observed in the brain of an old adult include a decrease in weight and volume, a change in the pattern of cerebral cortical convolutions, and an increase in ventricular size. Cell loss varies from region to region in the brain, and may be intensified in Alzheimer's disease and other disorders associated with senile dementia. Among the neuroglial cells, the microglia undergo the most significant changes with age. Although senile brain disease previously has been regarded as secondary to atherosclerosis, recent neuropathologic studies indicate that only 30 to 40 percent of senile brain disease arises from cerebrovascular pathologic lesions. The dilemma remains, however, of how much of the deterioration observed in the aged is related to disease and how much to senescence. The interaction between gene expression and environmental conditions in aging is another important question for the geriatrician. Progress in the control and treatment of disorders associated with old age depends upon further research into the mechanisms that underlie the process of aging in the brain.

Lateral superior olivary nucleus: a comparative analysis

The lateral superior olivary nucleus in 37 species of mammals was drawn with a Zeiss drawing tube from protargol-silver stained material. The pattern of laminar infolding generally conformed to the S-shaped and U-shaped convolutional patterns described by Hoffman (1908). In species with a relatively large cell number and a relative small cross-sectional area, there tends to be substantial laminar infolding within the convolutional pattern. Two independent estimates of the amount of laminar infolding were made and contrasted with the number of segments in the general convolutional pattern. Neither amount of laminar infolding nor number of convolutional segments was found to correlate with number of cochlear turns. However, in species in which the laminar pattern is well defined, the convolutional pattern and amount of laminar infolding appear to conform well to the sensitivity range and area of greatest sensitivity as seen in behavioral audiograms for the species.

Familial microcephalies due to cerebral malformation. Anatomical and clinical study

Five cases of a familial cerebral malformation with micrencephaly are studied. Four of them are characterized by an extreme reduction of the brain volume with only a moderately modified convolutional pattern. The cortical dysplasia which is relatively unimportant, sometimes minimal, predominates in the superficial layers of the cortex, and is associated with anomalies reproducing certain aspects of the fetal cortex during development. The morphogenesis of this malformation is discussed. There are at least three others types of familial malformations giving rise to extreme micrencephalies: familial pachygyrias and agyrias to which one of our cases belongs, familial arhinencephalies and micrencephalies of the Von Monakow type. Associated somatic malformations seem to be frequent. Micrencephalies of the first type seem usually due to a recessive autosomic gene. In the other types a multifactorial heredity is possible.

THE ANATOMY OF POTAMOTHERIUM AN OLIGOCENE LUTRINE

Summary.A detailed account is given of the anatomy of the skeleton and dentition of Potamotherium, the first known otter, from Upper Oligocene lacustrine deposits in Allier, central France. Almost all parts of the skeleton are represented: the bones are plentiful and well preserved, displaying many aquatic adaptations.The taxonomy of the Lutrinae, the stratigraphy of the deposits containing Potamotherium and their associated fauna are briefly discussed in the introduction.Study of the dentition includes consideration of milk teeth. Potamotherium is the only lutrine retaining the second upper molar and the dentitions, both milk and permanent, are rather more complex than those of present day lutrines, though basically very similar to Lutra: the differences are interpreted taxonomically but no functional explanations are possible.The description of the skull bones is outlined and the structures transmitted by the cranial foramina interpolated. Detailed study is centred on the brain, ear and nasal region. The pattern of the cortical convolutions is mapped, and the ratios of brain weight to body weight in various lutrines are compared. The petrosum reveals details of the semi‐circular canals and cochlea, and two of the ossicles are described: an attempt is made to interpret auditory perception. Preservation of maxillo‐ and ethmo‐turbinals, together with the olfactory lobes of the brain leads to an analysis of the nasal region and its functions. The mechanics of jaw movements are discussed and these considered along with the dentition suggest the likely feeding habits.The anatomy of the vertebral column, ribs and sternum is described in detail. The main factors influencing locomotion are discussed and comparisons made with living carnivores. The poise of the neck, arching of the back and length of the tail are each considered. The varying position of the zygapo‐physes are correlated with the degree of flexibility of the back and certain characters of the ribs are shown to be adaptations to aquatic breathing.The anatomy of the pectoral girdle and fore limb includes discussion of the main muscles. The mechanical bases of the limb adaptations are explained, and these compared with fully aquatic and non‐aquatic species. The rotary movements of the manus are correlated with its use in land and in water.The study of the pelvic girdle and hind limb reveals that most bones have different proportions from those of terrestrial carnivores; this effects the mechanics of muscle actions, enabling aquatic movements to be performed more effectively. Prom the shape of the pelvic girdle the probable size of the litters is predicted. The knee joint, the patella, the muscles to the pes and the length of the metatarsals are among the features discussed in the determination of the functions of the hind limb.In conclusion the mode of life and probable appearance of Potamotherium are considered. On land it must have closely resembled Lutra, while in the water this abundantly successful lake‐dweller was a powerful swimmer.

Structure and Function of the Brain of the Opossum (Didelphis virginiana) at the Time of Birth

The developmental stage the mammalian central nervous system may reach at the time of birth is not the same in the various species, the most variable region being the cerebral cortex (Riese, 1944). A mammal can be born at any stage of cortical development, ranging from the still unstratified cortical layer in the new-born bear (Ursus arctos L.) (Riese, 1942) to the practically finished cerebral cortex of the human infant showing all of its regional variations at the time of birth (Conel, 1939, 1941). In spite of the great variation in their cortical development at the time of birth, all of the mammals must meet the requirements of extra-uterine life. Little is known about the developmental stages the constituent elements of the central nervous system (fibers, cells) may reach in the various species at the time of birth. Although there are numerous species in which the morphological (convolutional) pattern of the brain is already finished at the time of birth (ungulates, some carnivores, man), there is no species in which the process of histological maturation would have come to its end at the time of birth at all of the levels of the central nervous system. In the most immature brain hitherto described in a new-born mammal, i.e. that of the newborn bear (Riese, 1942), maturation of nerve cells is obvious in lower levels, but does not reach beyond the midbrain. The results of this investigation are based on the study of four new-born opossums, two of which measured 11 mm, one 10 mm, and one 9 mm, crownrump length. Two specimens were given by the Wistar Institute, Philadelphia. I was further given the opportunity by Dr. A. A. Zimmermann, Professor of Anatomy, University of Illinois, College of Medicine, Chicago, to study his own material. Included in this study are one prenatal stage, about 24 hours before birth, and one pouch young opossum, 22 mm crown-rump length, both being specimens of the collection of Dr. A. A. Zimmermann. I wish to express my gratitude to the Wistar Institute, to Dr. Zimmermann, and to Dr. E. C. L. Miller, secretary of the Virginia Academy of Science.

II. The convolutional pattern of the brains of identical twins: a study on hereditary resemblance in the furrows of the cerebral hemispheres

The study of the similarity of the convolutional pattern of the brains of relatives has been the subject of considerable attention in the Pathological Laboratory at Claybury, under the direction of Dr. F. W. Mott. At his request Dr. Fisher has been forwarding to the Laboratory a number of fœtuses and children born dead that have occurred in his practice at Shoreditch Infirmary. It has thus happened that full term identical twins came into Dr. Mott’s possession. Realising the scientific value of a correct description of the similarity of the convolutional pattern in the brains of these twins, he has handed them to me and I have carefully studied the same on the lines previously adopted by Schuster in his description of the brains of relatives dying in the London Asylums. I have also made a study of the nervous plexuses and other morphological points of interest. I have been able to give my whole attention to laboratory research owing to the liberal grant made by the Medical Research Committee, and this study is a small part of the work which I have accomplished during the last year. But it was thought by the Director to be of sufficient scientific interest to present to the Royal Society, especially having regard to its being a morphological contribution to the important observations of the late Sir Francis Galton on the history of twins.