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At least 253 records · Page 14Linked to original sources
PubMed1987

Structural brain pathology in schizophrenia revisited. Prefrontal cortex pathology is inversely correlated with cerebrospinal fluid levels of homovanillic acid.

Computed tomography scan analysis of 35 schizophrenic patients, 26 medical patients, and 31 normal controls revealed significantly larger ventricular brain ratios and structural changes consistent with cortical atrophy in both schizophrenic and medical patients in comparison with normal controls. The schizophrenic patients, however, differed from both control groups in terms of greater prefrontal cortical markings consistent with prefrontal atrophy, and this finding correlated inversely with levels of cerebrospinal fluid homovanillic acid. Results from this study, in addition to replicating previous findings and addressing methodologic issues concerning controls, provide new evidence implicating abnormality of the prefrontal cortex in schizophrenia and link this abnormality to central nervous system dopaminergic function.

Adult↗
PubMed2004

Brain structural abnormalities in psychotropic drug-naive pediatric patients with obsessive-compulsive disorder.

OBJECTIVE: The authors investigated structural abnormalities in brain regions comprising cortical-striatal-thalamic-cortical loops in pediatric patients with obsessive-compulsive disorder (OCD). METHOD: Volumes of the caudate nucleus, putamen, and globus pallidus and gray and white matter volumes of the anterior cingulate gyrus and superior frontal gyrus were computed from contiguous 1.5-mm magnetic resonance images from 23 psychotropic drug-naive pediatric patients with OCD (seven male patients and 16 female patients) and 27 healthy volunteers (12 male subjects and 15 female subjects). RESULTS: Patients had smaller globus pallidus volumes than healthy volunteers, but the two groups did not differ in volumes of the caudate nucleus, putamen, or frontal white matter regions. Compared to healthy volunteers, patients had more total gray matter in the anterior cingulate gyrus but not the superior frontal gyrus. Total anterior cingulate gyrus volume correlated significantly and positively with globus pallidus volume in the healthy volunteers but not in patients. CONCLUSIONS: These findings provide evidence of smaller globus pallidus volume in patients with OCD without the potentially confounding effects of prior psychotropic drug exposure. Volumetric abnormalities in the anterior cingulate gyrus appear specific to the gray matter in OCD, at least at the gross anatomic level, and are consistent with findings of functional neuroimaging studies that have reported anterior cingulate hypermetabolism in the disorder.

Adolescent↗
PubMed1975

[Arousal thresholds during stimulation of brain structures in nonanesthetized cats].

In cats, there was no apparent difference between the average low thresholds for evoking EEG arousal when stimulating the mesencephalic RF, thalamic CM or some cortical structures (sensorimotor area, inferior part of auditory Ep). Most of other cortical points had much higher thresholds (g. lateralis anterior, g. suprasylvius posterior, g. ectosylvius med. and sup.). The possible role of some cortical and mesencephalic structures in the brain activating mechanisms is discussed.

Animals↗
PubMedDate not supplied

[Effect of castration and testosterone propionate on 3H-noradrenaline metabolism in different brain structures in male rats].

Experimental results demonstrated that castration in male rats led to the changes in catecholamine metabolism in various regions of the brian. In particular there is an acceleration of labeled noradrenalin- disappearance (3H-noradrenaline) from the limbic system of the hypothalamus formations. Testosterone propionate restored the initial level of 3H-noradrenaline in the mentioned structures of the brain. The data obtained indicated that adrenorecption of the rynecephalo-hypothalamic complex took part in the central regulation of the gonadotropic function of the hypophysis.

Animals↗
PubMed2002

MR image-based measurement of rates of change in volumes of brain structures. Part I: method and validation.

A detailed analysis procedure is described for evaluating rates of volumetric change in brain structures based on structural magnetic resonance (MR) images. In this procedure, a series of image processing tools have been employed to address the problems encountered in measuring rates of change based on structural MR images. These tools include an algorithm for intensity non-uniformity correction, a robust algorithm for three-dimensional image registration with sub-voxel precision and an algorithm for brain tissue segmentation. However, a unique feature in the procedure is the use of a fractional volume model that has been developed to provide a quantitative measure for the partial volume effect. With this model, the fractional constituent tissue volumes are evaluated for voxels at the tissue boundary that manifest partial volume effect, thus allowing tissue boundaries be defined at a sub-voxel level and in an automated fashion. Validation studies are presented on key algorithms including segmentation and registration. An overall assessment of the method is provided through the evaluation of the rates of brain atrophy in a group of normal elderly subjects for which the rate of brain atrophy due to normal aging is predictably small. An application of the method is given in Part II where the rates of brain atrophy in various brain regions are studied in relation to normal aging and Alzheimer's disease.

Aged↗
PubMed2006

Automatic volumetric measurement of segmented brain structures on magnetic resonance imaging.

PURPOSE: The purpose of this study was to produce a fully automatic volumetric segmented brain image system (AVSIS) and to evaluate its utility for measuring hippocampal volumes and total intracranial volume (TIV). MATERIALS AND METHODS: We developed a combination technique comprising an anatomical standardization technique to measure TIV, whole brain volume (WBV), and hippocampal volume obtained by magnetic resonance (MR) imaging. Altogether, 15 healthy volunteers and 15 patients with Alzheimer's disease (AD) underwent three-dimensional spoiled gradient echo (3D-SPGR) imaging. Three measurements were performed by manual volumetry as the gold standard, a previous semiautomatic method, and our new method, AVSIS. RESULTS: WBV and hippocampal volume in the AD group were significantly smaller than those in the healthy volunteer group measured by the semiautomatic method, manual method, and AVSIS. Each volume measured by AVSIS or semiautomatic method correlated with that measured by the manual method. The correlation coefficients between TIVs, WBVs, or hippocampal volumes measured by AVSIS and the manual method were 0.910, 0.902, and 0.918, respectively; the correlation coefficients between TIVs, or WBVs, measured by the previous semiautomatic method and the manual method were 0.875, and 0.886, respectively. CONCLUSION: We developed a system for a fully automatic measurement of segmented brain structures and obtained good results.

Age Factors↗
PubMed2002

Magnetization transfer measurements of brain structures in patients with multiple system atrophy.

To determine whether magnetization transfer imaging (MTI) demonstrates abnormalities in the brain structures of patients with multiple system atrophy (MSA), we examined 12 patients with clinically probable MSA and 11 control subjects. We calculated magnetization transfer ratios (MTRs) using region of interest analysis from MTI and assessed abnormal signal changes on T2-weighted images. MTRs of the base of the pons, middle cerebellar peduncle, putamen, and white matter of the precentral gyrus were significantly lower in the MSA patients than in the controls. Abnormal signal changes on T2-weighted images were observed in the base of the pons (n = 6), middle cerebellar peduncle (n = 7), and putamen (n = 7). MTRs of regions with abnormal signals were significantly lower than those of regions without abnormal signals and those in the controls. Even the MTRs of the regions without abnormal signals were lower than those in the controls. MTRs of the pyramidal tract, including white matter of the precentral gyrus, posterior limb of the internal capsule, cerebral peduncle, and base of the pons, were significantly lower in patients with pyramidal tract sign (n = 7) than in the controls. Patients with asymmetrical parkinsonism (n = 5) showed significantly lower MTRs in the putamen contralateral to the predominant side of parkinsonian symptoms than the ipsilateral side, although asymmetry of abnormal signal changes on T2-weighted images was not evident in more than half of those patients. This study showed that MTI demonstrates abnormalities in the brains of patients with MSA that seem to reflect underlying pathological changes and that the pathological changes detected by MTI seem to give rise to clinical symptoms. This study also showed that the abnormalities are detected more sensitively and over a larger area by MTI than by conventional magnetic resonance imaging.

Aged↗
PubMed2004

Structural brain abnormalities in multiple sclerosis patients with major depression.

OBJECTIVE: To assess the association between major depression and structural brain abnormalities in patients with multiple sclerosis (MS). METHODS: Two groups of patients with clinically definite MS were studied: 21 with Diagnostic and Statistical Manual of Mental Disorders (4th ed.)-defined major depression and 19 without. The groups did not differ on demographic, disease, or cognitive measures. All subjects underwent brain MRI. Tissue segmentation and regional brain masking were applied to the MRI data. RESULTS: Compared with the euthymic subjects, those with major depression had a greater T2-weighted lesion volume (p = 0.003) and more extensive T1-weighted lesion volume in the left medial inferior prefrontal cortex (p = 0.01) and less gray matter volume (p = 0.01) and more CSF volume in the left anterior temporal region (p = 0.005). A logistic regression analysis identified two independent predictors of depression: left medial inferior prefrontal cortex T2 lesion volume and left anterior temporal CSF volume. These variables accounted for 42% of the depression variance score. CONCLUSION: Whereas both lesion burden and atrophy are important in the pathogenesis of depression in MS, psychosocial influences should also be considered.

Adult↗
PubMed1999

[The effect of medikhronal on the biogenic amine level in the brain structures and blood of animals with alcohol dependence].

Peculiarities of changes in the content of biogenic amines in the brain structures (hypothalamus, midbrain and new cortex) and blood of rats under alcohol intoxication and formation of alcohol dependence were investigated, and the effect of medichronal and its components on the mentioned processes was found out. It has been established that accumulation of acetaldehide plays a considerable role in the mechanism of formation of alcohol dependence. Changes in the level of ethanol (E) and AcA in blood after the arrival of exogenic E to the organism evokes phase dynamics of content of biogenic amines in the blood and brain sections. Medichronal components, binding and inactivating AcA, as well as taking the mutually supplementing effect on synthesis of biogenic amines, promote normalization of the mentioned processes and elimination of alcohol dependence.

Alcohol Deterrents↗
PubMed1993

Intelligence and brain structure in normal individuals.

OBJECTIVE: This study was designed to evaluate the relation between intelligence and a variety of measures of brain structure. METHOD: Magnetic resonance imaging scans were used to measure the volume of the intracranial cavity, cerebral hemispheres, lateral ventricles, temporal lobes, hippocampus, caudate, and cerebellum, as well as the overall volume of gray matter, white matter, and CSF, in 67 healthy, normal volunteers. Intelligence was measured with the Wechsler Adult Intelligence Scale--Revised. RESULTS: Full-scale IQ was found to be significantly correlated with intracranial, cerebral, temporal lobe, hippocampal, and cerebellar volume but not with caudate and lateral ventricle volume. There were also significant correlations of full-scale, verbal, and performance IQ with overall gray matter volume but not with white matter or CSF volume. Gender differences were noted in the pattern and number of correlations between the volume of the brain and its subregions and full-scale, verbal, and performance IQ. CONCLUSIONS: The results suggest that the size of some cerebral structures may account for a significant, but modest, proportion of the variance in human intelligence.

Brain↗
PubMed2003

Exposure to a retrieval cue in rats induces changes in regional brain glucose metabolism in the amygdala and other related brain structures.

Pre-test exposure to training-related cues is known to improve subsequent retention performance. To identify brain regions engaged in processes promoted by retrieval cues, a brain imaging approach using the [6-14C]glucose autoradiographic technique was used. Sprague-Dawley rats trained in a brightness discrimination avoidance task were submitted to different cueing conditions after a 1- or a 21-day training-to-test interval (TTI). Animals were either non-cued, cued with a box, or cued with a box and the light that served as a discriminative stimulus. Effects of the different cueing conditions on retention performance or on metabolic activity in 58 different brain regions were investigated. Rats cued with the light exhibited a subsequent improvement of their retention performance relative to controls, when tested at the 1- but not 21-days TTI, confirming our previous results. At the 1-day retention interval, a comparison between rats cued with the box and rats cued with the box and the light showed that the light cue significantly increased glucose uptake in a neuronal network composed of the lateral, basal, and central nuclei of the amygdala, the anterior and suprachiasmatic hypothalamic nuclei, the nucleus accumbens, the medial septum, and the insular cortex. In contrast, at the 21-day retention interval, both groups demonstrated similar cerebral metabolic activity. The present results indicate that exposure to a light cue increased metabolic activity in the previously mentioned brain structures only when the light acted as an effective retrieval cue, suggesting an involvement of this network in the processes triggered by a retrieval cue. Arguments are provided supporting the notion that the amygdala may play a key role in these processes. Whether the amygdala is a part of a neural network involved in retrieval processes or in neuromodulating systems that favour the efficacy of retrieval processes is also discussed.

Amygdala↗
PubMed1998

Incidence and description of structural brain abnormalities in newborns exposed to cocaine.

OBJECTIVE: This study was undertaken to determine whether an increased incidence of structural brain abnormalities could be demonstrated in newborns exposed to cocaine. STUDY DESIGN: This study was part of a prospective, longitudinal study of 154 cocaine users matched to 154 control subjects on prenatal risk level, race, parity, and socioeconomic status. Subjects were enrolled prenatally from a rural public health department population or at delivery. Drug exposure was determined by means of repeated, detailed histories and urine screening for drug metabolites. Ultrasonographic examinations were performed within 4 days of birth by experienced technologists and were read by one experienced radiologist, each blinded to drug use history. RESULTS: Cranial ultrasonography results were available for 266 infants (134 cocaine-exposed; 132 control). Only 27 infants had ultrasonography results that were not considered normal, and there were no significant differences between groups (17 cocaine-exposed vs 10 control; p = 0.119). Identified abnormalities included choroid plexus cysts, subependymal cysts, mildly dilated ventricles, and a cyst of the third ventricle. CONCLUSIONS: The incidence of abnormal cranial ultrasonography results in our cocaine-exposed group was lower than that previously reported in the literature and not significantly different from the control group. In addition, the identified lesions were less severe than previously reported, despite a wide range of cocaine use in our sample, including heavy use.

Brain↗
PubMed1990

Structural brain abnormalities in the major psychoses: a quantitative review of the evidence from computerized imaging.

The neuroimaging literature on structural brain abnormalities in the major psychoses is quantitatively reviewed. The mean effect size for studies of lateral ventriculomegaly in schizophrenia (d = .70) corresponded to 43% nonoverlap between the distributions of schizophrenics and control Ss. Planimetry yielded larger effects than linear methods of ventricular size estimation. Although enlargement of the third ventricle was comparable to that of lateral ventriculomegaly (d = .66), it was found to be significantly greater after differences in measurement method were taken into account. The average cumulative length of hospitalization, adjusted for patients' age and duration of illness, predicted ventriculomegaly in schizophrenia. Studies on schizophrenia and affective disorder differed neither in the extent of reported ventriculomegaly nor in the amount of "cortical atrophy."

Brain↗
PubMed2001

[The unilateral space neglect in patients with arteriovenous malformations of the deep brain structures].

Clinical and neuropsychological study has been carried out in 187 patients with arteriovenous malformations (AVM) of the deep brain structures, including 28 patients with caudate nucleus AVM, 35--with thalamus AVM, 45--with cingulated gyrus AVM, 43--with hippocampus AVM, 36--with corpus callosum AVM. Ignoring phenomenon in different modalities has been found in 47 patients, 40 patients having unfixed ignoring. The majority of the patients showed a left-side space and body ignoring and in 3 patients, with left-handedness signs, right-side ignoring has been observed. In all the patients ignoring development was associated with posthemorrhagic and postoperative impairment of the white matter (sensor conductor projections of sincipital and occipital lobes of periventricular white matter) or parietal and corpus callosum. In case of hemispheric local disturbances, ignoring developed in concomitant disorders (hemianopsia and hemihypesthesia) and coincided with them in modality. In case of corpus callosum damage, ignoring may develop without concomitant sensor disorders or may be on the other side (in case of simultaneous left hemisphere damage). The results obtained support the evidence for ignoring phenomenon independence.

Caudate Nucleus↗
PubMedDate not supplied

[Neurophysiological mechanisms of the action of GABA-tropic agents on brain structures].

The effect of systemic administration of agonists and antagonists of GABA system on excitability and intracentral relationships of the brain structures was found during chronic experiments on rabbits with bipolar electrodes implanted in the region of the frontal cortex, dorsal hippocampus, midbrain reticular formation and central gray matter. The changes of the functional state of the cerebral formations were suggested to be related to a different degree of the involvement of GABA receptors of types A and B.

Aminooxyacetic Acid↗
PubMed1997

Brain structure volumes in the mole rat, Spalax ehrenbergi (Spalacidae, Rodentia) in comparison to the rat and subterrestrial insectivores.

Natural blindness and a subterranean, digging mode of life demand peculiar adaptations of the central nervous system in the mole rat Spalax ehrenbergi, which are the focus of this quantitative investigation. Volumes of 25 brain structures in Spalax were evaluated allometrically, using the least encephalized mammalian species, the Madagassian hedgehog-like tenrecs (Tenrecinae) as a reference base, and their sizes compared with those of the rat (as a more generalized representative of rodents) and of some subterranean Insectivora. The allometric approach reveals that Spalax has a larger brain than tenrecs and the rat. Within the brain, the neocortex and diencephalon are well developed, an observation also made in other mammalian species with a relatively high encephalization. An unique feature in Spalax is the enlargement of motor structures of the brain, such as the cerebellum (and cerebellar nuclei), and the striatum. Most conspicuous is the large size of the nucleus motorius nervi trigemini, reflecting the importance of masticatory muscles for the special digging technique, which demand an intense use of the teeth for loosening the soil.

Animals↗
PubMed2005

Quantitative measures of gait characteristics indicate prevalence of underlying subclinical structural brain abnormalities in high-functioning older adults.

Abnormal gait in high-functioning older adults may indicate underlying subtle structural brain abnormalities. We tested the hypothesis that temporal and spatial parameters of gait, including speed, stride length and double support time, are cross-sectionally associated with white matter hyperintensity, subcortical infarcts or brain atrophy on brain MRI. We examined 321 men and women (mean age = 78.3) participating to the Cardiovascular Health Study who were free of dementia or stroke at the time of the gait assessment. Analyses were set with gait as independent variable and brain MRIs as dependent variables. Gait measures were determined from the footfalls recorded on a 4-meter-long instrumented walking surface, the GaitMat II. Brain MRIs were examined for the presence of white matter hyperintensity (WMG, graded from 0 to 9), brain infarcts (predominantly subcortical) and ventricular enlargement (graded from 0 to 9). Slower gait, shorter stride length and longer double support times were associated with greater prevalence of white matter grade > or =3 (p = 0.02), and at least 1 brain infarct (p = 0.04) independent of age. In multivariate logistic regression models adjusted for demographics and clinical cardiovascular diseases, those with gait speed <1.02 m/s were more likely to have WMG > or =3 and at least 1 brain infarct, compared with those with faster gait - odds ratio (OR): 2.85, 95% confidence interval (95% CI): 1.35, 6.02, and OR: 2.09, 95% CI: 1.04, 4.19. Shorter stride length was also associated with greater probability of having at least 1 brain infarct (gait stride <0.88 vs. >1.10 m: OR: 3.20, 95% CI: 1.49, 6.88), while longer double support times were associated with a greater probability of having WMG > or =3 (double support time >0.19 vs. <0.14 s: OR: 2.3, 95% CI: 1.1, 4.7) independent of demographics and clinical cardiovascular diseases. Gait parameters were not significantly associated with ventricular grade. In summary, in this group of high-functioning older adults, poorer gait speed, shorter stride and longer double support time are associated with high white matter disease and subclinical strokes.

Aged↗