Home About us Contact
|
Home About us Contact | ||
|
|
||
Occipital Lobe (occipital + lobe)
Terms modified by Occipital Lobe Selected AbstractsA Proton Magnetic Resonance Spectroscopy Study of Metabolites in the Occipital Lobes in EpilepsyEPILEPSIA, Issue 4 2003Robert J. Simister Summary: ,Purpose: ,-Amino butyric acid (GABA) and glutamate, respectively the principal inhibitory and excitatory neurochemicals in the brain, are visible to proton magnetic resonance spectroscopy (MRS). We report a study of GABA+ (GABA plus homocarnosine) and GLX (glutamate plus glutamine) concentrations in the occipital lobes in patients with idiopathic generalised epilepsy (IGE) and in patients with occipital lobe epilepsy (OLE). Methods: Fifteen patients with IGE, 15 patients with OLE, and 15 healthy volunteers were studied. A single voxel was prescribed in the occipital lobes for each subject. PRESS localised short-echo-time MRS was performed to measure GLX by using LCModel. A double quantum GABA filter was used to measure GABA+. Segmented T1 -weighted images gave the tissue composition of the prescribed voxel. Results: Grey-matter proportion, GLX, and GABA+ were all elevated in IGE. However, analysis using grey-matter proportion as a covariable showed no significant group differences. No correlation was observed between GABA+ concentration and either seizure frequency or time since last seizure. Conclusions: GLX and GABA+ were elevated in IGE. Elevated grey-matter content in the IGE group despite normal MRI appearance can be expected to account for some or all of this observed elevation of GLX and GABA+. GABA+ concentration did not correlate with seizure control or duration since most recent seizure. [source] Brain Apparent Water Diffusion Coefficient Magnetic Resonance Image During a Prolonged Visual AuraHEADACHE, Issue 6 2010Robert Belvís MD (Headache 2010;50:1045-1049) Background., Reversible changes in brain magnetic resonance imaging (MRI) weighted in diffusion-weighted images (DWI) and apparent water diffusion coefficient (ADC) maps have been reported in acute stroke, epilepsy, eclampsia, and hypoglycemia, but they are contradictory regarding to migraine aura. Objective., A 41-year-old woman with known basilar migraine for 5 years consulted about a persistent visual aura (visual snow phenomenon) plus bilateral paresthesias in the extremities for 4 days. The headache was treated with success with 10 mg of wafer rizatriptan and 600 mg of ibuprophen. Methods., The neurologic and ophthalmologic examination were normal. An urgent brain MRI detected no lesions in T1, T2, fluid-attenuated inversion recovery, and DWI, but an abnormal signal appeared in the left occipital lobe in ADC and (r)ADC maps. The brain MRI angiography, carotid ultrasound study, transesophageal echocardiography, 24-hour cardiac Holter monitoring, and thrombophilia study were normal. Results., A new brain MRI 8 days after did not show any previous lesion in the same sequences. Conclusions., We present a patient with migraine and transitory abnormal signals in the ADC map of an occipital region during persistent visual aura. The clinical-radiological relationship is congruent. Some similar cases have showed these MRI signals during the aura, suggesting cytotoxic edema, without ischemic lesions in the MRI controls. Theses ADC images probably appear in complex auras. [source] Quantitative T1 mapping of hepatic encephalopathy using magnetic resonance imagingHEPATOLOGY, Issue 5 2003Nadim Joni Shah M.D. Changes are shown in the spin-lattice (T1) relaxation time caused by the putative deposition of manganese in various brain regions of hepatic encephalopathy (HE) patients using a novel and fast magnetic resonance imaging (MRI) method for quantitative relaxation time mapping. A new method, T1 mapping with partial inversion recovery (TAPIR), was used to obtain a series of T1 -weighted images to produce T1 maps. Imaging of 15 control subjects and 11 patients was performed on a 1.5T MRI scanner. The measurement time per patient with this technique, including adjustments, was ,5 minutes. Regions of interest in the globus pallidus, the caudate nucleus, the posterior and anterior limbs of the internal capsule, the putamen, the frontal and occipital white matter, the white matter of the corona radiata, the occipital visual and frontal cortices, and the thalamus were interactively defined in the left hemisphere and analyzed with respect to their T1 values. T1 changes in the brains of HE patients can be determined quantitatively with TAPIR in short, clinically relevant measurement times. Significant correlations between the change in T1 and HE severity have been shown in the globus pallidus, the caudate nucleus, and the posterior limb of the internal capsule. No significant correlation of T1 with grade of HE was found in the putamen, frontal white matter, white matter of the corona radiata, white matter in the occipital lobe, the anterior limb of the internal capsule, visual cortex, thalamus, or frontal cortex. In conclusion, these measurements show that T1 mapping is feasible in short, clinically relevant acquisition times. [source] Source-based morphometry: The use of independent component analysis to identify gray matter differences with application to schizophreniaHUMAN BRAIN MAPPING, Issue 3 2009Lai Xu Abstract We present a multivariate alternative to the voxel-based morphometry (VBM) approach called source-based morphometry (SBM), to study gray matter differences between patients and healthy controls. The SBM approach begins with the same preprocessing procedures as VBM. Next, independent component analysis is used to identify naturally grouping, maximally independent sources. Finally, statistical analyses are used to determine the significant sources and their relationship to other variables. The identified "source networks," groups of spatially distinct regions with common covariation among subjects, provide information about localization of gray matter changes and their variation among individuals. In this study, we first compared VBM and SBM via a simulation and then applied both methods to real data obtained from 120 chronic schizophrenia patients and 120 healthy controls. SBM identified five gray matter sources as significantly associated with schizophrenia. These included sources in the bilateral temporal lobes, thalamus, basal ganglia, parietal lobe, and frontotemporal regions. None of these showed an effect of sex. Two sources in the bilateral temporal and parietal lobes showed age-related reductions. The most significant source of schizophrenia-related gray matter changes identified by SBM occurred in the bilateral temporal lobe, while the most significant change found by VBM occurred in the thalamus. The SBM approach found changes not identified by VBM in basal ganglia, parietal, and occipital lobe. These findings show that SBM is a multivariate alternative to VBM, with wide applicability to studying changes in brain structure. Hum Brain Mapp, 2009. © 2008 Wiley-Liss, Inc. [source] Assessment of the increase in variability when combining volumetric data from different scannersHUMAN BRAIN MAPPING, Issue 2 2009Santiago Reig Abstract In multicenter MRI studies, pooling of volumetric data requires a prior evaluation of compatibility between the different machines used. We tested the compatibility of five different scanners (2 General Electric Signa, 2 Siemens Symphony, and a Philips Gyroscan) at five different sites by repeating the scans of five volunteers at each of the sites. Using a semiautomatic method based on the Talairach atlas, and SPM algorithms for tissue segmentation (multimodal T1 and T2, or T1-only), we obtained volume measurements of the main brain lobes (frontal, parietal, occipital, temporal) and for each tissue type. Our results suggest that pooling of multisite data adds small error for whole brain measurements, intersite coefficient of variation (CV) ranging from 1.8 to 5.2%, respectively, for GM and CSF. However, in the occipital lobe, intersite CV can be as high as 11.7% for WM and 17.3% for CSF. Compared with the intersite, intrasite CV values were always much lower. Whenever possible, T1 and T2 tissue segmentation methods should be used because they yield more consistent volume measurements between sites than T1-only, especially when some of the scans were obtained with different sequence parameters and pixel size from those of the other sites. Our study shows that highest compatibility among scanners would be obtained using equipments of the same manufacturer and also image acquisition parameters as similar as possible. After validation, data from a specific ROI or scanner showing values markedly different from the other sites might be excluded from the analysis. Hum Brain Mapp, 2009. © 2007 Wiley-Liss, Inc. [source] Assessing spatial probabilistic distributional differences in the common space between schizophrenics and normal controls based on a novel automated probabilistic pattern analysis methodINTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 5-6 2008Bang-Bon Koo Abstract Because of the complex nature of the human brain, a full understanding of its various group specific variation factors such as volume, shape, and location related to age, gender, ethnic, and disease might be provided in both structural and functional neuroimaging studies. To serve this purpose, a novel approach for characterizing the group variability information using group specific labeled probabilistic maps was introduced in this article. An automatic labeling technique was applied to encode group specific probabilistic information for each region of interests (ROIs) covering the overall cortical region and a probabilistic pattern analytic method was proposed to assess the difference in the spatial extent between 70 schizophrenics and 70 controls in the common space. From our proposed method, we found major differences in 17 ROIs that had shown large variation in schizophrenics. Most of these ROIs were in the frontal and the temporal lobe and only three ROIs were in the parietal and the occipital lobe. The ROIs highlighted through our proposed method could be connected with previous morphological findings on schizophrenia and it also might be considered in functional analysis. As a result, our method could provide intuitive information on group difference relevant to the overall anatomical variability in the substructural level. Thus, it could be used as a prompting system to search and examine the regions of the brain that are worthy of further precise analysis by various sub-cortical region based group studies in assessing specific patterns related to diseases. © 2008 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 18, 310,324, 2008 [source] Regional cerebral glucose metabolism during sevoflurane anaesthesia in healthy subjects studied with positron emission tomographyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2010L. SCHLÜNZEN Background: The precise mechanism by which sevoflurane exerts its effects in the human brain remains unknown. In the present study, we quantified the effects of sevoflurane on regional cerebral glucose metabolism (rGMR) in the human brain measured with positron emission tomography. Methods: Eight volunteers underwent two dynamic 18F-fluorodeoxyglucose positron emission tomography (PET) scans. One scan assessed conscious-baseline metabolism and the other scan assessed metabolism during 1 minimum alveolar concentration (MAC) sevoflurane anaesthesia. Cardiovascular and respiratory parameters were monitored and bispectral index responses were registered. Statistical parametric maps and conventional regions of interest analysis were used to determine rGMR differences. Results: All subjects were unconsciousness at 1.0 MAC sevoflurane. Cardiovascular and respiratory parameters were constant over time. In the awake state, rGMR ranged from 0.24 to 0.35 ,mol/g/min in the selected regions. Compared with the conscious state, total GMR decreased 56% in sevoflurane anaesthesia. In white and grey matter, GMR was averaged 42% and 58% of normal, respectively. Sevoflurane reduced the absolute rGMR in all selected areas by 48,71% of the baseline (P,0.01), with the most significant reductions in the lingual gyrus (71%), occipital lobe in general (68%) and thalamus (63%). No increases in rGMR were observed. Conclusions: Sevoflurane caused a global whole-brain metabolic reduction of GMR in all regions of the human brain, with the most marked metabolic suppression in the lingual gyrus, thalamus and occipital lobe. [source] Event-Related fMRI of Inhibitory Control in the Predominantly Inattentive and Combined Subtypes of ADHDJOURNAL OF NEUROIMAGING, Issue 3 2009Mary V. Solanto PhD ABSTRACT BACKGROUND AND PURPOSE To examine the neurophysiological basis for the pronounced differences in hyperactivity and impulsiveness that distinguish the predominantly inattentive type of attention-deficit/hyperactivity disorder (ADHD-PI) from the combined type of the disorder (ADHD-C). METHODS Event-related brain responses to a go/no-go test of inhibitory control were measured with functional magnetic resonance imaging (fMRI) in 11 children with ADHD-C and 9 children with ADHD-PI, aged 7 to 13 years, who were matched for age, sex, and intelligence. RESULTS There were no significant group differences in task performance. Children with ADHD-C and ADHD-PI activated overlapping regions of right inferior frontal gyrus, right superior temporal lobe, and left inferior parietal lobe during inhibitory control. However, the magnitude of the activation in the temporal and parietal regions, as well as in the bilateral middle frontal gyrus, was greater in children with ADHD-PI than those with ADHD-C. Conversely, children with ADHD-C activated bilateral medial occipital lobe to a greater extent than children with ADHD-PI. CONCLUSIONS The results provide preliminary evidence that phenotypic differences between the ADHD-C and ADHD-PI subtypes are associated with differential activation of regions that have previously been implicated in the pathophysiology of ADHD and are thought to mediate executive and attentional processes. [source] Alterations in Brain Serotonin Synthesis in Male Alcoholics Measured Using Positron Emission TomographyALCOHOLISM, Issue 2 2009Masami Nishikawa Background:, A consistent association between low endogenous 5HT function and high alcohol preference has been observed, and a number of serotonergic manipulations (uptake blockers, agonists) alter alcohol consumption in animals and humans. Studies have also shown an inverse relationship between alcohol use and cerebrospinal fluid levels of serotonin metabolites, suggesting that chronic alcohol consumption produces alterations in serotonin synthesis or release. Methods:, The objective of the study was to characterize regional brain serotonin synthesis in nondepressed chronic alcoholics at treatment entry in comparison to normal nonalcoholic controls using PET and the tracer ,-[11C]-methyl- l -tryptophan. Results:, Comparisons of the alcoholics and controls by SPM found that there were significant differences in the rate of serotonin synthesis between groups. Serotonin synthesis was significantly lower among alcoholics in Brodmann Area (BA) 9, 10, and 32. However, serotonin synthesis among the alcoholics group was significantly higher than controls at BA19 in the occipital lobe and around the transverse temporal convolution in the left superior temporal gyrus (BA41). In addition, there were correlations between regional serotonin synthesis and a quantity-frequency measure of alcohol consumption. Regions showing a significant negative correlation with QF included the bilateral rectus gyri (BA11) in the orbitofrontal area, the bilateral medial frontal area (BA6), and the right amygdala. Conclusions:, Current alcoholism is associated with serotonergic abnormalities in brain regions that are known to be involved in planning, judgment, self-control, and emotional regulation. [source] Real-time adaptive sequential design for optimal acquisition of arterial spin labeling MRI dataMAGNETIC RESONANCE IN MEDICINE, Issue 1 2010Jingyi Xie Abstract An optimal sampling schedule strategy based on the Fisher information matrix and the D-optimality criterion has previously been proposed as a formal framework for optimizing inversion time scheduling for multi-inversion-time arterial spin labeling experiments. Optimal sampling schedule possesses the primary advantage of improving parameter estimation precision but requires a priori estimation of plausible parameter distributions that may not be available in all situations. An adaptive sequential design approach addresses this issue by incorporating the optimal sampling schedule strategy into an adaptive process that iteratively updates the parameter estimates and adjusts the optimal sampling schedule accordingly as data are acquired. In this study, the adaptive sequential design method was experimentally implemented with a real-time feedback scheme on a clinical MRI scanner and was tested in six normal volunteers. Adapted schedules were found to accommodate the intrinsically prolonged arterial transit times in the occipital lobe of the brain. Simulation of applying the adaptive sequential design approach on subjects with pathologically reduced perfusion was also implemented. Simulation results show that the adaptive sequential design approach is capable of incorporating pathologic parameter information into an optimal arterial spin labeling scheduling design within a clinically useful experimental time. Magn Reson Med, 2010. © 2010 Wiley-Liss, Inc. [source] Amnestic mild cognitive impairment in Parkinson's disease: A brain perfusion SPECT study,,MOVEMENT DISORDERS, Issue 3 2009Flavio Nobili MD Abstract The purpose of this study was to investigate cortical dysfunction in Parkinson's disease (PD) patients with amnestic deficit (PD-MCI). Perfusion single photon emission computed tomography was performed in 15 PD-MCI patients and compared (statistical parametric mapping [SPM2]) with three groups, i.e., healthy subjects (CTR), cognitively intact PD patients (PD), and common amnestic MCI patients (aMCI). Age, depression, and UPDRS-III scores were considered as confounding variables. PD-MCI group (P < 0.05, false discovery rate,corrected for multiple comparisons) showed relative hypoperfusion in bilateral posterior parietal lobe and in right occipital lobe in comparison to CTR. As compared to aMCI, MCI-PD demonstrated hypoperfusion in bilateral posterior parietal and occipital areas, mainly right cuneus and angular gyrus, and left precuneus and middle occipital gyrus. With a less conservative threshold (uncorrected P < 0.01), MCI-PD showed hypoperfusion in a left parietal region, mainly including precuneus and inferior parietal lobule, and in a right temporal-parietal-occipital region, including middle occipital and superior temporal gyri, and cuneus-precuneus, as compared to PD. aMCI versus PD-MCI showed hypoperfusion in bilateral medial temporal lobe, anterior cingulate, and left orbitofrontal cortex. PD-MCI patients with amnestic deficit showed cortical dysfunction in bilateral posterior parietal and occipital lobes, a pattern that can be especially recognized versus both controls and common aMCI patients, and to a lesser extent versus cognitively intact PD. The relevance of this pattern in predicting dementia should be evaluated in longitudinal studies. © 2008 Movement Disorder Society [source] Methotrexate-related leukoencephalopathy without radiation therapy: Distribution of brain lesions and pathological heterogeneity on two autopsy casesNEUROPATHOLOGY, Issue 2 2009Jun Matsubayashi This report concerns two rare autopsy cases of methotrexate (MTX)-related leukoencephalopathy without radiation therapy. In the first case, there were widespread necrotic foci with prominent spheroids, that is, disseminated necrotizing leukoencephalopathy (DNL), mainly in the cerebral white matter. In contrast, in the second case, there were widespread demyelinated foci without significant axonal changes, which we would like to name disseminated demyelinating leukoencephalopathy (DDL), mainly in the cerebral white matter. We emphasize that the pathology of pure MTX-related leukoencephalopathy is not uniform, and may show at least two kinds of histologic change. Furthermore, both cases did not develop significant vascular changes, which are usually induced by radiation therapy. The distribution of the lesions in two cases was examined by large specimens, including hemisphere specimens. The distribution of the lesions in the brain of our cases was also different. In the first case, the DNL lesions were predominantly distributed in the frontal and temporal lobes. In the second case, the DDL lesions were prominently localized in the occipital lobe. To our knowledge, this is the first report describing not only the pathological findings of MTX-related leukoencephalopathy without irradiation but also the precise distributions of the lesions. [source] Pick's disease with Pick bodies: An unusual autopsy case showing degeneration of the pontine nucleus, dentate nucleus, Clarke's column, and lower motor neuronNEUROPATHOLOGY, Issue 1 2007Tatsuro Oda We report a 51-year-old female with Pick's disease with Pick bodies (PDPB) showing a brainweight of 530 g. This case was considered to be a very rare case of PDPB, in which the lesion developed in the temporal and frontal lobes and later spread to the parietal lobe, occipital lobe, brainstem, cerebellum and spinal cord. This case showed very atypical clinicopathological findings. Clinically, bulging eyes and myoclonus were observed. Neuropathologically, Pick bodies were widely distributed beyond the usual distribution areas to the parietal cortices, occipital cortices, dentate nuclei, motor neuron nuclei in the brain stem, and spinal cord. The atypical clinical symptoms and the widespread neuropathological abnormalities observed in this case seem to represent an extremely extended form of PDPB. [source] Noninvasive quantification of human brain ascorbate concentration using 1H NMR spectroscopy at 7,TNMR IN BIOMEDICINE, Issue 3 2010Melissa Terpstra Abstract Ascorbate (Asc, vitamin C) was quantified in the human brain noninvasively using two different 1H NMR spectroscopy methods: short-echo time STEAM and MEGA-PRESS homonuclear editing. Taking advantage of increased sensitivity and chemical shift dispersion at 7,T, Asc was quantified with increased reliability relative to our previous study accomplished at 4,T. Asc concentration quantified from short-echo time spectra measured from the occipital lobe of eight healthy subjects ([Asc],=,1.1,±,0.3,µmol/g, mean,±,SD) was in excellent agreement with Asc concentration quantified from the same volume of interest using homonuclear editing ([Asc],=,1.2,±,0.2,µmol/g). This agreement indicates that at 7,T, Asc can be reliably quantified in the human brain simultaneously with 15 other metabolites. Additional advantages of the short-echo time approach were: shorter measurement time than homonuclear editing and minimal effect of T2 relaxation on Asc quantification. High magnetic field was also beneficial for Asc quantification with MEGA-PRESS because increased chemical shift dispersion enabled editing with full efficiency, which resulted in a supra-linear gain in signal-to-noise ratio relative to 4,T. Copyright © 2009 John Wiley & Sons, Ltd. [source] The natural endocast of Taung (Australopithecus africanus): Insights from the unpublished papers of Raymond Arthur DartAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue S49 2009Dean Falk Abstract Dart's 1925 announcement of Australopithecus africanus (Dart: Nature 115 [1925] 195,199) was highly controversial, partly because of an interpretation of the Taung natural endocast that rested on an erroneous identification of the lambdoid suture as the lunate sulcus. Unpublished materials from the University of Witwatersrand Archives (Dart, unpublished material) reveal that Dart reacted to the controversy by: 1) describing and illustrating the entire sulcal pattern on the Taung endocast, in contrast to just two sulcal identifications in 1925, 2) identifying a hypothetical part of the lambdoid suture and revising his description of the lunate sulcus, and 3) bolstering his argument that Taung's brain was advanced by detailing expansions in three significant cortical association areas. Four unpublished illustrations of Dart's identifications for sulci and sutures on the Taung endocast are compared here with those published by Keith (Keith: New discoveries relating to the antiquity of man (1931)), Schepers (Schepers: The endocranial casts of the South African ape-men. In: Broom R, Schepers GWH, editors. The South African fossil ape-men; the Australopithecinae [1946] p 155,272), and Falk (Falk: Am J Phys Anthropol 53 [1980] 525,539), and the thorny issue of the location of the lunate sulcus is revisited in light of new information. Archival materials reveal that Dart believed that Taung's brain was reorganized globally rather than in a mosaic manner, and that the shapes of certain cortical association areas showed that Australopithecus was closer to Pithecanthropus than to the living apes. Although a few of Dart's hitherto-unpublished sulcal identifications, including his revision for the lunate sulcus, were questionable, his claim that the Taung endocast reproduced a shape that was advanced toward a human condition in its prefrontal cortex and caudally protruded occipital lobe was correct. Yrbk Phys Anthropol 52:49,65, 2009. © 2009 Wiley-Liss, Inc. [source] Systematization, Distribution and Territory of the Middle Cerebral Artery on the Brain Surface in Chinchilla (Chinchilla lanigera)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2009A. C. P. De Araujo Summary The aim of the present study was to analyse thirty chinchilla (Chinchilla lanigera) brains, injected with latex, and to systematize and describe the distribution and the vascularization territories of the middle cerebral artery. This long vessel, after it has originated from the terminal branch of the basilar artery, formed the following collateral branches: rostral, caudal and striated (perforating) central branches. After crossing the lateral rhinal sulcus, the middle cerebral artery emitted a sequence of rostral and caudal convex hemispheric cortical collateral branches on the convex surface of the cerebral hemisphere to the frontal, parietal, temporal and occipital lobes. Among the rostral convex hemispheric branches, a trunk was observed, which reached the frontal and parietal lobes and, in a few cases, the occipital lobe. The vascular territory of the chinchilla's middle cerebral artery included, in the cerebral hemisphere basis, the lateral cerebral fossa, the caudal third of the olfactory trigone, the rostral two-thirds of the piriform lobe, the lateral olfactory tract, and most of the convex surface of the cerebral hemisphere, except for a strip between the cerebral longitudinal fissure and the vallecula, which extended from the rostral to the caudal poles bordering the cerebral transverse fissure. [source] Learning to read without a left occipital lobe: Right-hemispheric shift of visual word form areaANNALS OF NEUROLOGY, Issue 6 2004Laurent Cohen MD Using anatomical and functional magnetic resonance imaging, we studied the pattern of brain lateralization during spoken and written language tasks, in an 11-year-old girl who underwent a left occipitotemporal resection for a Sturge,Weber angioma at the age of 4 years, that is, after the development of speech but before the acquisition of reading. We observed a selective and successful shift to the right hemisphere of the visual component of reading, particularly the Visual Word Form Area, whereas the verbal components remained strongly left-lateralized. This emphasizes the potential utility of a precise functional and developmental cartography of language for the surgical treatment of focal brain lesions in children. Ann Neurol 2004;56:890,894 [source] Abnormal cerebellum density in victims of rape with post-traumatic stress disorder: Voxel-based analysis of magnetic resonance imaging investigationASIA-PACIFIC PSYCHIATRY, Issue 3 2010Shuang-Ge Sui MD MBA Abstract Introduction: Based on early studies of non-motor function in the cerebellum and dysfunction in the cerebellum of post-traumatic stress disorder (PTSD) patients, we presumed that the cerebellum was involved in the neuropathology of cognitive and emotional processing of PTSD patients, while the density of some sub-areas of the cerebellum of PTSD patients was most likely abnormal. Methods: Eleven female victims of rape with PTSD and 12 age-matched female normal controls received 1.5 T 3D magnetic resonance imaging (MRI) scan. The scans were then analyzed using the voxel-based morphometry 2 (VBM2) toolbox. Results: Victims of rape with PTSD showed increased cerebellum density on the left side compared with normal controls (P<0.001), especially in the pyramis (x=,9, y=,72, z=,36; k=519; t=4.70), uvula (x=,4, y=,66, z=,35; k=256; t=4.02), declive (x=,6, y=,69, z=,30; k=213; t=3.84) and nodule (x=,4, y=,63, z=,31; k=147; t=3.93). In addition, compared with normal controls, the PTSD group showed significant differences in gray matter density of other brain areas, including the frontal lobe, parietal lobe, occipital lobe (P<0.001), insula, posterior cingulate, amygdala and hippocampus (P<0.005). Discussion: These finding suggest that the cerebellum may be involved in the neuropathology and functional compensation in the neurocircuitry of PTSD. [source] Brain dysmorphology in individuals with severe prenatal alcohol exposureDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 3 2001Sarah L Archibald MA Our previous studies revealed abnormalities on structural MRI (sMRI) in small groups of children exposed to alcohol prenatally. Microcephaly, disproportionately reduced basal ganglia volume, and abnormalities of the cerebellar vermis and corpus callosum were demonstrated. The present study used sMRI to examine in detail the regional pattern of brain hypoplasia resulting from prenatal exposure to alcohol using a higher resolution imaging protocol and larger sample sizes than reported previously. Fourteen participants (mean 11.4 years; eight females, six males) with fetal alcohol syndrome (FAS) and 12 participants (mean 14.8 years; four females, eight males) with prenatal exposure to alcohol (PEA) but without the facial features of FAS were compared to a group of 41 control participants (mean 12.8 years, 20 females, 21 males). Findings of significant microcephaly and disproportionately reduced basal ganglia volumes in the FAS group were confirmed. Novel findings were that in FAS participants, white matter volumes were more affected than gray matter volumes in the cerebrum, and parietal lobes were more affected than temporal and occipital lobes. Among subcortical structures, in contrast to the disproportionate effects on caudate nucleus, the hippocampus was relatively preserved in FAS participants. Differences between the PEA group and controls were generally non-significant; however, among a few of the structures most affected in FAS participants, there was some evidence for volume reduction in PEA participants as well, specifically in basal ganglia and the parietal lobe. There were no group differences in cerebral volume asymmetries. Severe prenatal alcohol exposure appears to produce a specific pattern of brain hypoplasia. [source] Posterior Quadrantic Epilepsy Surgery: Technical Variants, Surgical Anatomy, and Case SeriesEPILEPSIA, Issue 8 2007Roy Thomas Daniel Summary:,Objective: Patients with intractable epilepsy due to extensive lesions involving the posterior quadrant (temporal, parietal, and occipital lobes) form a small subset of epilepsy surgery. This study was done with a view to analyze our experience with this group of patients and to define the changes in the surgical technique over the last 15 years. We also describe the microsurgical technique of the different surgical variants used, along with their functional neuroanatomy. Methods: In this series there were 13 patients with a median age of 17 years. All patients had extensive presurgical evaluation that provided concordant evidence localizing the lesion and seizure focus to the posterior quadrant. The objective of the surgery was to eliminate the effect of the epileptogenic tissue and preserve motor and sensory functions. Results: During the course of this study period of 15 years, the surgical procedure performed evolved toward incorporating more techniques of disconnection and minimizing resection. Three technical variants were thus utilized in this series, namely, (i) anatomical posterior quadrantectomy (APQ), (ii) functional posterior quadrantectomy (FPQ), and (iii) periinsular posterior quadrantectomy (PIPQ). After a median follow-up period of 6 years, 12/13 patients had Engel's Class I seizure outcome. Conclusion: The results of surgery for posterior quadrantic epilepsy have yielded excellent seizure outcomes in 92% of the patients in the series with no mortality or major morbidity. The incorporation of disconnective techniques in multilobar surgery has maintained the excellent results obtained earlier with resective surgery. [source] A Distinct Asymmetrical Pattern of Cortical Malformation: Large Unilateral Malformation of Cortical Development with Contralateral Periventricular Nodular Heterotopia in Three Pediatric CasesEPILEPSIA, Issue 8 2005Annapurna Poduri Summary:,Purpose: To describe a distinct asymmetrical pattern of cortical malformation with large focal malformations of cortical development (MCDs) and contralateral periventricular nodular heterotopia (PNH). Methods: We identified three patients with epilepsy and focal EEG abnormalities. Each patient underwent 1.5-Tesla magnetic resonance imaging (MRI) to obtain sagittal T1 -weighted, axial fluid-attenuated inversion recovery (FLAIR), fast spin-echo (FSE) T2 -weighted, and coronal fast spin-echo inversion recovery (FSEIR) T2 -weighted images; coronal spoiled gradient recalled (SPGR) T1 -weighted images were obtained in two cases. Results: Patient 1, an 18-year-old right-handed man, had a 4-year history of intractable seizures. MRI revealed a right frontal subcortical heterotopia (SH) and a single left anterior PNH. Patient 2, a 10-year-old left-handed boy, had a 4-year history of epilepsy. MRI revealed a large region of SH in the left temporal, parietal, and occipital lobes and three right-sided PNH. Patient 3, a 16-month-old girl, had medically refractory infantile spasms. MRI revealed a large MCD in the left parietal lobe with contiguous underlying periventricular heterotopia as well as a small contralateral PNH. Conclusions: These cases together illustrate a distinct asymmetrical pattern of a large focal MCD with small contralateral PNH. The asymmetrical involvement of the two hemispheres suggests that the stage of maximal disruption of cortical development may differ between the two hemispheres. Further study into the mechanisms underlying such asymmetrical patterns of cortical malformation should enhance our understanding of cortical development as well as hemispheric lateralization. [source] A Proton Magnetic Resonance Spectroscopy Study of Metabolites in the Occipital Lobes in EpilepsyEPILEPSIA, Issue 4 2003Robert J. Simister Summary: ,Purpose: ,-Amino butyric acid (GABA) and glutamate, respectively the principal inhibitory and excitatory neurochemicals in the brain, are visible to proton magnetic resonance spectroscopy (MRS). We report a study of GABA+ (GABA plus homocarnosine) and GLX (glutamate plus glutamine) concentrations in the occipital lobes in patients with idiopathic generalised epilepsy (IGE) and in patients with occipital lobe epilepsy (OLE). Methods: Fifteen patients with IGE, 15 patients with OLE, and 15 healthy volunteers were studied. A single voxel was prescribed in the occipital lobes for each subject. PRESS localised short-echo-time MRS was performed to measure GLX by using LCModel. A double quantum GABA filter was used to measure GABA+. Segmented T1 -weighted images gave the tissue composition of the prescribed voxel. Results: Grey-matter proportion, GLX, and GABA+ were all elevated in IGE. However, analysis using grey-matter proportion as a covariable showed no significant group differences. No correlation was observed between GABA+ concentration and either seizure frequency or time since last seizure. Conclusions: GLX and GABA+ were elevated in IGE. Elevated grey-matter content in the IGE group despite normal MRI appearance can be expected to account for some or all of this observed elevation of GLX and GABA+. GABA+ concentration did not correlate with seizure control or duration since most recent seizure. [source] Simple Partial Status Epilepticus Localized by Single-Photon Emission Computed Tomography Subtraction in Chronic Cerebral ParagonimiasisJOURNAL OF NEUROIMAGING, Issue 4 2004Eun Yeon Joo ABSTRACT A patient with chronic cerebral paragonimiasis began to have new motor seizures of the right face manifested by clonic contractions that occurred several hundred times a day, consistent with simple partial status epilepticus. Ictal electroencephalogram discharges started from the left frontal region and then spread to the left hemisphere with left frontal maximum. But clinical seizures were limited to the right face. The frequent partial seizures were controlled by the intravenous infusion of phenytoin. Brain magnetic resonance imaging showed multiple conglomerated round nodules with encephalomalacia in the left temporal and occipital lobes. Applying the technique of ictal-interictal single-photo emission computed tomography subtraction, the authors were able to localize the focal ictal-hyperperfusion on left precentral cortex adjacent to the lesions that correspond to the anatomical distribution of left face motor area. [source] Cerebral Metastasis from Heart Angiosarcoma Presenting as Multiple HematomasJOURNAL OF NEUROIMAGING, Issue 1 2004Charalambos Liassides MD ABSTRACT The authors present the case of a 24-year-old woman with cerebral metastasis from a primary heart angiosarcoma, which appeared as multiple cerebral hematomas. Primary or metastatic brain angiosarcomas are exceedingly rare, and only a few cases have been reported with hemorrhage. Initial neurological symptoms were mild hemiparesis with numbness, and chest pain was first misdiagnosed as pericarditis. A computed tomography (CT) scan and magnetic resonance imaging showed 2 hematomas in the left parietal and occipital lobes. A thoracic CT scan revealed angiosarcoma of the right atrium of the heart with multiple infiltrations of the lung. The patient underwent surgical removal and systemic chemotherapy. She died 6 months after surgery. [source] Characterization of White Matter Microstructure in Fetal Alcohol Spectrum DisordersALCOHOLISM, Issue 3 2009Susanna L. Fryer Background:, Exposure to alcohol during gestation is associated with CNS alterations, cognitive deficits, and behavior problems. This study investigated microstructural aspects of putative white matter abnormalities following prenatal alcohol exposure. Methods:, Diffusion tensor imaging was used to assess white matter microstructure in 27 youth (age range: 8 to 18 years) with (n = 15) and without (n = 12) histories of heavy prenatal alcohol exposure. Voxelwise analyses, corrected for multiple comparisons, compared fractional anisotropy (FA) and mean diffusivity (MD) between groups, throughout the cerebrum. Results:, Prenatal alcohol exposure was associated with low FA in multiple cerebral areas, including the body of the corpus callosum and white matter innervating bilateral medial frontal and occipital lobes. Fewer between-group differences in MD were observed. Conclusions:, These data provide an account of cerebral white matter microstructural integrity in fetal alcohol spectrum disorders and support extant literature showing that white matter is a target of alcohol teratogenesis. The white matter anomalies characterized in this study may relate to the neurobehavioral sequelae associated with gestational alcohol exposure, especially in areas of executive dysfunction and visual processing deficits. [source] Levels of ,-Aminobutyric Acid-Benzodiazepine Receptors in Abstinent, Alcohol-Dependent Women: Preliminary Findings From an 123I-Iomazenil Single Photon Emission Tomography StudyALCOHOLISM, Issue 9 2000A. R. Lingford-Hughes Background: Although alcohol dependence in women is an increasing problem, little is known about the effects of alcohol on the female brain. Evidence from a few structural and functional neuroimaging studies suggests that the female brain may be more susceptible than the male brain to the harmful effects of alcohol. However, no in vivo studies of the neuropharmacology of alcohol dependence in women have been carried out. The aim of this preliminary study was to test the hypothesis that alcohol dependence in women is associated with greater reduction in ,-aminobutyric acid (GABA)-benzodiazepine receptor levels than in men with an equivalent drinking history. Methods: We used single photon emission tomography and 123I-iomazenil to label the central GABA-benzodiazepine receptor and to compare semiquantified levels in 9 abstinent alcohol-dependent and 13 control women. These groups were further compared with equivalent male groups from a previous study. Results: There was a trend toward a reduction in GABA-benzodiazepine receptor levels in alcohol-dependent women, but this did not reach significance. These lower levels were seen primarily in the cerebellum, occipital lobes, and parietal cortex (left > right). This was in marked contrast with the pattern of reduction seen in the previous study of male dependence, where significant reductions were seen primarily in the frontal cortex. Conclusions: Due to the semiquantitative analysis performed and the relatively small number of subjects in this study, which resulted in a nonsignificant trend, we can only comment on the differences in the pattern of lower levels of GABA-benzodiazepine receptors seen in alcohol dependence in men and women. Although we are not able to ascertain whether the female brain is more susceptible to the effects of alcohol, it appears that alcohol has a differential effect on the central GABA-benzodiazepine receptors in men and women. Recent animal evidence supports this hypothesis. Future studies should explore whether other neuropharmacological differences exist between men and women in alcohol dependence that could have implications for pharmacotherapy. [source] Amnestic mild cognitive impairment in Parkinson's disease: A brain perfusion SPECT study,,MOVEMENT DISORDERS, Issue 3 2009Flavio Nobili MD Abstract The purpose of this study was to investigate cortical dysfunction in Parkinson's disease (PD) patients with amnestic deficit (PD-MCI). Perfusion single photon emission computed tomography was performed in 15 PD-MCI patients and compared (statistical parametric mapping [SPM2]) with three groups, i.e., healthy subjects (CTR), cognitively intact PD patients (PD), and common amnestic MCI patients (aMCI). Age, depression, and UPDRS-III scores were considered as confounding variables. PD-MCI group (P < 0.05, false discovery rate,corrected for multiple comparisons) showed relative hypoperfusion in bilateral posterior parietal lobe and in right occipital lobe in comparison to CTR. As compared to aMCI, MCI-PD demonstrated hypoperfusion in bilateral posterior parietal and occipital areas, mainly right cuneus and angular gyrus, and left precuneus and middle occipital gyrus. With a less conservative threshold (uncorrected P < 0.01), MCI-PD showed hypoperfusion in a left parietal region, mainly including precuneus and inferior parietal lobule, and in a right temporal-parietal-occipital region, including middle occipital and superior temporal gyri, and cuneus-precuneus, as compared to PD. aMCI versus PD-MCI showed hypoperfusion in bilateral medial temporal lobe, anterior cingulate, and left orbitofrontal cortex. PD-MCI patients with amnestic deficit showed cortical dysfunction in bilateral posterior parietal and occipital lobes, a pattern that can be especially recognized versus both controls and common aMCI patients, and to a lesser extent versus cognitively intact PD. The relevance of this pattern in predicting dementia should be evaluated in longitudinal studies. © 2008 Movement Disorder Society [source] Systematization, Distribution and Territory of the Middle Cerebral Artery on the Brain Surface in Chinchilla (Chinchilla lanigera)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2009A. C. P. De Araujo Summary The aim of the present study was to analyse thirty chinchilla (Chinchilla lanigera) brains, injected with latex, and to systematize and describe the distribution and the vascularization territories of the middle cerebral artery. This long vessel, after it has originated from the terminal branch of the basilar artery, formed the following collateral branches: rostral, caudal and striated (perforating) central branches. After crossing the lateral rhinal sulcus, the middle cerebral artery emitted a sequence of rostral and caudal convex hemispheric cortical collateral branches on the convex surface of the cerebral hemisphere to the frontal, parietal, temporal and occipital lobes. Among the rostral convex hemispheric branches, a trunk was observed, which reached the frontal and parietal lobes and, in a few cases, the occipital lobe. The vascular territory of the chinchilla's middle cerebral artery included, in the cerebral hemisphere basis, the lateral cerebral fossa, the caudal third of the olfactory trigone, the rostral two-thirds of the piriform lobe, the lateral olfactory tract, and most of the convex surface of the cerebral hemisphere, except for a strip between the cerebral longitudinal fissure and the vallecula, which extended from the rostral to the caudal poles bordering the cerebral transverse fissure. [source] Imaging of amyloid burden and distribution in cerebral amyloid angiopathyANNALS OF NEUROLOGY, Issue 3 2007Keith A. Johnson MD Objective Cerebrovascular deposition of ,-amyloid (cerebral amyloid angiopathy [CAA]) is a major cause of hemorrhagic stroke and a likely contributor to vascular cognitive impairment. We evaluated positron emission tomographic imaging with the ,-amyloid,binding compound Pittsburgh Compound B (PiB) as a potential noninvasive method for detection of CAA. We hypothesized that amyloid deposition would be observed with PiB in CAA, and based on the occipital predilection of CAA pathology and associated hemorrhages, that specific PiB retention would be disproportionately greater in occipital lobes. Methods We compared specific cortical PiB retention in 6 nondemented subjects diagnosed with probable CAA with 15 healthy control subjects and 9 patients with probable Alzheimer's disease (AD). Results All CAA and AD subjects were PiB-positive, both by distribution volume ratio measurements and by visual inspection of positron emission tomographic images. Global cortical PiB retention was significantly increased in CAA (distribution volume ratio 1.18 ± 0.06) relative to healthy control subjects (1.04 ± 0.10; p = 0.0009), but was lower in CAA than in AD subjects (1.41 ± 0.17; p = 0.002). The occipital-to-global PiB ratio, however, was significantly greater in CAA than in AD subjects (0.99 ± 0.07 vs 0.86 ± 0.05; p = 0.003). Interpretation We conclude that PiB-positron emission tomography can detect cerebrovascular ,-amyloid and may serve as a method for identifying the extent of CAA in living subjects. Ann Neurol 2007 [source] Comparison of cerebral magnetic resonance and electroencephalogram findings in pre-eclamptic and eclamptic womenAUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 5 2005Mehmet A. OSMANA Abstract Objective:, To compare the cerebral magnetic resonance (MR) and electroencephalogram (EEG) findings in pre-eclamptic and eclamptic pregnant women. Methods:, A total of 38 pregnant women with mild pre-eclampsia (n = 15), severe pre-eclampsia (n = 11) and eclampsia (n = 12) were included in this study. Cranial MR without contrast and EEG were performed in these women on admission or within 3 days of onset. Follow-up control MR or EEG evaluations were performed 4,6 weeks postpartum in women with MR or EEG abnormalities in the initial examination. To compare differences, X2 test, Fisher exact or Mann,Whitney U -tests were used. Results:, Abnormal cranial MR findings were found in one (6%) pre-eclamptic woman, in four (36%) severe pre-eclamptic women, and in 11 (92%) eclamptic women. Cranial MR findings were consistent with ischaemia in 15 (39%) patients and haemorrhage in one (3%) case. Two (5%) severe pre-eclamptic women showed cerebral infarction during the follow-up period. MR and EEG abnormalities were totally resolved in 88% of cases. The MR findings of 12 (71%) patients were located in the occipital lobes followed by the parietal lobes in six (40%) cases. Three (20%) mild pre-eclamptic women, four (36%) severe pre-eclamptic women and 10 (83%) eclamptic women had abnormal EEGs. The EEG changes were totally resolved in 13 of 14 (93%) patients after the first month. In one patient with cerebral haemorrhage, the EEG changes lasted for a duration of 6 months. Conclusions:, A correlation between EEG abnormalities and MR findings was found in this study. The combined use of MR and EEG may help to determine the prognosis for these patients, but the interictal EEG findings recorded in eclampsia were non-specific. [source] | ||||||||||||||||||||||||||||