Corpus Callosum

Source: www.ncbi.nlm.nih.gov --- 9 days ago
Related Articles Tract shape modelling provides evidence of topological change in Corpus Callosum genu during normal ageing. Neuroimage. 2008 Jul 18; Authors: Bastin ME, Piatkowski JP, Storkey AJ, Brown LJ, Maclullich AM, Clayden JD Understanding how ageing affects brain structure is an important challenge for medical science. By allowing segmentation of fasciculi-of-interest from diffusion magnetic resonance imaging (dMRI) data, tractography provides a promising tool for assessing white matter connectivity in old age. However, the output from tractography algorithms is usually strongly dependent on the subjective location of user-specified seed points, with the result that it can be both difficult and time consuming to identify the same tract reliably in cross-sectional studies. Here we investigate whether a novel method for automatic single seed point placement based on tract shape modelling, termed probabilistic model-based neighbourhood tractography (PNT), can reliably segment the same tract from subject to subject in a non-demented cohort aged over 65 years. For the fasciculi investigated (genu and splenium of Corpus Callosum, cingulum cingulate gyri, corticospinal tracts and uncinate fasciculi), PNT was able to provide anatomically plausible representations of the tract in question in 70 to 90% of subjects compared with 2.5 to 60% if single seed points were simply transferred directly from standard to native space. In Corpus cal ...

Source: www.ncbi.nlm.nih.gov --- 8 days ago
Related Articles Transient splenial DWI abnormality of the Corpus Callosum during a stroke-like episode. Acta Neurol Belg. 2008 Mar;108(1):27-8 Authors: Bocher AL, Caron S, Cordonnier C Focal imaging abnormalities of the Corpus Callosum are rare but have been described in various clinical conditions. Because the MRI appearance may mimic acute stroke, clinicians have to be aware of differential diagnoses. We report a patient with a stroke-like episode and transient hypersignal in diffusion with decreased ADC values of the Corpus Callosum in a setting of sepsis due to a Klebsiella pneumoniae infection. This stroke mimic may be due to an inflammatory process and should be recognized because of therapeutic implications. PMID: 18575185 [PubMed - indexed for MEDLINE] ...

Source: www.ncbi.nlm.nih.gov --- 28 days ago
Related Articles Meta-analysis of magnetic resonance imaging studies of the Corpus Callosum in bipolar disorder. Acta Psychiatr Scand. 2008 Jul 17; Authors: Arnone D, McIntosh AM, Chandra P, Ebmeier KP Objective: The Corpus Callosum (CC) plays a pivotal role in inter-hemispheric transfer and integration of information and is a relatively understudied structure in bipolar disorder (BD). Magnetic resonance imaging (MRI) studies have reported callosal abnormalities in this condition but findings have been inconsistent. Structural changes affecting the CC may underlie functional abnormalities in BD and could contribute to, or explain the pathophysiology of, the condition. Method: A systematic review was carried out to identify, appraise and summarize MRI studies which compared callosal areas in BD with an unrelated control group. The findings were then synthesized using random effects meta-analysis. Consideration was given to a number of variables to explain heterogeneity. Results: Five case-control studies were identified. Bipolar patients showed reduced callosal areas in comparison with healthy volunteers with no evidence of heterogeneity or publication bias. Conclusion: Findings from this study indicate that callosal areas are reduced in BD and suggest that a failure to integrate information across the hemispheres may contribute to the pathophysiology of the disorder. Further research is necessary to clarify the underlying cellular chan ...

Source: www.ncbi.nlm.nih.gov --- 37 days ago
Related Articles Diffusion Tensor Imaging Characteristics of the Corpus Callosum in Mild, Moderate, and Severe Traumatic Brain Injury. AJNR Am J Neuroradiol. 2008 Jul 10; Authors: Rutgers DR, Fillard P, Paradot G, Tadié M, Lasjaunias P, Ducreux D BACKGROUND AND PURPOSE: The Corpus Callosum is an important predilection site for traumatic axonal injury but may be unevenly affected in head trauma. We hypothesized that there were local differences in axonal injury within the Corpus Callosum as investigated with diffusion tensor imaging (DTI), varying among patients with differing severity of traumatic brain injury (TBI). MATERIALS AND METHODS: Ethics committee approval and informed consent were obtained. Ten control subjects (7 men, 3 women; mean age, 37 +/- 9 years) and 39 patients with TBI (27 men, 12 women; 34 +/- 12 years) were investigated, of whom 24 had mild; 9, moderate; and 6, severe TBI. Regions of interest were selected in the callosal genu, body, and splenium to calculate fractional anisotropy (FA), apparent diffusion coefficient (ADC), and the number of fibers passing through. Statistical comparison was made through analysis of variance with the Scheffé post hoc analysis. RESULTS: Compared with controls, patients with mild TBI investigated <3 months posttrauma (n = 12) had reduced FA (P < .01) and increased ADC (P < .05) in the genu, whereas patients with mild TBI investigated >/=3 months posttrauma (n = 12) showed no signific ...

Source: www.ncbi.nlm.nih.gov --- 35 days ago
Related Articles Abnormal Corpus Callosum Integrity in Bipolar Disorder: A Diffusion Tensor Imaging Study. Biol Psychiatry. 2008 Jul 10; Authors: Wang F, Kalmar JH, Edmiston E, Chepenik LG, Bhagwagar Z, Spencer L, Pittman B, Jackowski M, Papademetris X, Constable RT, Blumberg HP OBJECTIVE: Abnormalities in the anterior interhemispheric connections provided by the Corpus Callosum (CC) have long been implicated in bipolar disorder (BD). In this study, we used complementary diffusion tensor imaging methods to study the structural integrity of the CC and localization of potential abnormalities in BD. METHODS: Subjects included 33 participants with BD and 40 healthy comparison participants. Fractional anisotropy (FA) measures were compared between groups with region of interest (ROI) methods to investigate the anterior, middle, and posterior CC and voxel-based methods to further localize abnormalities. RESULTS: In ROI-based analyses, FA was significantly decreased in the anterior and middle CC in the BD group (p < .05). Voxel-based analyses similarly localized group differences to the genu, rostral body, and anterior midbody of CC (p < .05, corrected). CONCLUSION: The findings demonstrate abnormalities in the structural integrity of the anterior CC in BD that might contribute to altered interhemispheric connectivity in this disorder. PMID: 18620337 [PubMed - as supplied by publisher] ...

Source: www.ncbi.nlm.nih.gov --- 45 days ago
Related Articles Diffusion tensor quantification of the human midsagittal Corpus Callosum subdivisions across the lifespan. Brain Res. 2008 Jun 19; Authors: Hasan KM, Kamali A, Kramer LA, Papnicolaou AC, Fletcher JM, Ewing-Cobbs L The midsagittal Corpus Callosum (CC) cross-sectional area subdivisions have been used as early and sensitive markers of human brain white matter connectivity, development, natural aging and disease. Despite the simplicity and conspicuity of the appearance of the CC on anatomical magnetic resonance imaging (MRI), the published quantitative MRI literature on its regional sex and age trajectories are contradictory. The availability of noninvasive quantitative methods to assess the CC regions across the human lifespan would help clarify its contribution to behavior and cognition. In this report, we extended the utility of a recently described semi-automated diffusion tensor imaging (DTI) tissue segmentation method to utilize the high orientation contrast of the CC on DTI. Using optimized DTI methods on a cohort of 121 right-handed children and adults aged 6-68 years, we examined the CC areas and corresponding DTI metrics of the different functionally specialized sectors of the CC. Both the area and fractional anisotropy metrics followed inverted U-shaped curves, while the mean and radial diffusivities followed U-curves reflecting white matter progressive and regressive myelination dynamics that continue into young ...

Source: www.ncbi.nlm.nih.gov --- 39 days ago
Related Articles Corpus Callosum morphology in children and adolescents with attention deficit hyperactivity disorder: a meta-analytic review. Neuropsychology. 2008 May;22(3):341-9 Authors: Hutchinson AD, Mathias JL, Banich MT Several studies have examined Corpus Callosum (CC) morphology in children and adolescents with attention deficit hyperactivity disorder (ADHD). A meta-analysis of atypical brain morphology in children and adolescents with ADHD by Valera, Faraone, Murray, and Seidman (2006) reported a reduction in the splenium of the CC in this group compared with healthy controls. This meta-analysis undertook a more detailed examination of callosal morphology by also considering comorbid conditions and gender differences. The data from 13 studies were analyzed. Consistent with Valera et al. (2006), the splenium was smaller in children and adolescents with ADHD than in healthy controls. However, this result appears to be the result of a smaller splenium in females with ADHD. In addition, boys exhibited a smaller rostral body. There were no significant differences in CC measurements of studies that included ADHD samples with comorbid conditions. However, comorbidities were not consistently reported, making it difficult to accurately evaluate the impact of comorbidity on CC size. Additional research is needed to investigate whether gender differences reflect different ADHD subtypes. In addition, it is not known if these CC differen ...

Source: www.ncbi.nlm.nih.gov --- 50 days ago
Related Articles Diffusion tensor imaging of two unrelated Chinese men with hereditary spastic paraplegia associated with thin Corpus Callosum. Neurosci Lett. 2008 Jun 7; Authors: Chen Q, Lui S, Wang JG, Ou-Yang L, Zhou D, Burgunder JM, Gong QY, Shang HF Hereditary spastic paraplegia (HSP) associated with thin Corpus Callosum is a rare autosomal recessive neurodegenerative disorder characterized by an abnormally thin Corpus Callosum, normal motor development, slowly progressive spastic paraparesis and cognitive deterioration. To investigate and localize abnormalities in the brains of two Chinese patients with HSP-TCC, with mutations in the spatacsin gene. Diffusion tensor imaging (DTI) was used to determine the mean diffusion (MD) and fractional anisotropy (FA) in the brains of the patients in comparison to 20 healthy subjects. Voxel-based analysis (VBA) of both the diffusion and anisotropy values were performed using statistical parametric mapping (SPM). Significant changes with MD increase and FA reduction were found in the already known lesions including the Corpus Callosum, cerebellum and thalamus. In addition, changes were also found in regions that appear to be normal in conventional MRI, such as the brain stem, internal capsule, cingulum and subcortical white matter including superior longitudinal fascicle and inferior longitudinal fascicle. Neither increase in FA nor reduction in MD was detected in the brain. Our study provides ...

Source: www.scienceblogs.com --- 45 days ago
Responding to the innate human desire to have the faster browser possible, I am almost happy with Firefox 3.  But not quite.  Thus, the experiment: compile from source.  This is accomplished as follows: 0. Kubuntu does not come with the packages necessary to build from source, by default.  You must install a bunch of stuff first.  Fortunately, this is easy.  To install the prerequisites necessary to build Firefox from source, open a terminal and type: apt-get build-dep firefox 1. Download the Firefox source code here . 2.  Extract to a suitable place, likely a subdirectory in your home folder. 3. Open a terminal and go to the subdirectory.   4.  Run the configure script: ./configure --enable-optimize --disable-tests  --enable-gnomevfs --enable-application=browser Note that the option to enable gnomefvs is optional.  It allows Firefox to populate the Applications tab in the Preferences dialog box.  That actually was one thing that led to me wanting to do this in the first place.  Enabling optimization is obviously part of the goal of the project.  Disabling tests speeds up the compilation time. Enabling the browser application is required. 5. make 6. make install 7. Find and run the executable.  It will be in a subdirectory named /mozilla/browser/app.  Assuming that works, then... 8. Flash will not work.  To install it, download the tarball from here . 9. Close your browser, extract the files from the tarball, and run the install s ...

Source: www.scienceblogs.com --- 18 days ago
Mammon slept. And the beast reborn spread over the earth and its numbers grew legion. And they proclaimed the times and sacrificed crops unto the fire, with the cunning of foxes . And they built a new world in their own image as promised by the sacred words , and spoke of the beast with their children. Mammon awoke, and lo! it was naught but a follower. from The Book of Mozilla , 11:9 (10th Edition) [ source , background ] Read the comments on this post... ...

Source: www.scienceblogs.com --- 14 days ago
August 6 is the anniversary of the first use of a nuclear weapon in war.   This is a work of the US Government, and is not subject to copyright. Read the comments on this post... ...

Source: www.scienceblogs.com --- 17 days ago
There are other, more interesting things to write about.  But someone is WRONG on the Internet, so it must be corrected.  Moreover, we must speculate about the rationale for this blatant misstatement.  And wonder why it was printed in a prominent newspaper. Pelosi: Save the Planet, Let Someone Else Drill Friday, August 1, 2008 Read the rest of this post... | Read the comments on this post... ...

Source: www.scienceblogs.com --- 45 days ago
We decided to let one artichoke blossom, just to see what it looks like.  It turns out that it looks sort of like a thistle.  That's because it is a kind of thistle.  I hadn't known that.  The thistle is the national flower of Scotland. Read the comments on this post... ...

Source: www.scienceblogs.com --- 37 days ago
Restless Legs Syndrome has been more in the public eye lately.  I understand this is because of aggressive direct-to-consumer advertising.  I'm not much of a consumer, so I haven't seen the ads, but people tell me about them.   Whatever you think of DTC advertising, RLS is real, and it is a significant problem for some people.   Years ago, it was discovered that RLS can be alleviated for some people with carbidopa/levodopa.  But that was an off-patent medicine.  When patented medicines [Requip (ropinirole) and Mirapex (pramipexole)] became available, RLS became an opportunity, hence, the ads. Not all patients required medication.  Sometimes, it was possible to try an underlying cause.  Iron deficiency is one example, easily corrected.  Others could benefit from lifestyle changes.  Quiting caffeine and/or alcohol helped some people.  Others benefited from sleep hygiene.  But some, particularly those with severe symptoms, do require medication. It seems that the focus for most people has been on interventions involving medication.  But if lifestyle and nutritional interventions don't solve the problem, is there any other nonpharmacological intervention that is worthwhile? Read the rest of this post... | Read the comments on this post... ...

Source: www.scienceblogs.com --- 24 days ago
Sustainability is a modern-day buzzword.  It is used so much that it is at risk of suffering from a dilution of meaning.  But is still is an important concept. In August 2004, President Bush boasted that home ownership in the USA was at an all-time high (69.2 percent).  It was important for him to point this out, just before the election.  The reason is that he was advocating trickle-down economics.  He needed to show that concentrating wealth in the hands of a few could lead to improved standards of living for everyone. (That happens to be a lie : "Social mobility is now less fluid in the United States than in other affluent nations. Indeed, a poor child born in Germany, France, Canada or one of the Nordic countries has a better chance to join the middle class in adulthood than an American child born into similar circumstances.") Well, now we find out that home ownership is down to to the same level it was in the summer of 2001.  This means that the increase was not sustainable.  It was fake, based upon a smorgasbord of smoke-and-mirrors economic gimmicks. Perhaps I will be proved wrong, if the housing market turns around.  But there is an abundance of evidence to indicate that it is getting worse.  Meanwhile, the credit crisis is hitting businesses that had nothing to do with the causes of the crisis.  This means that there is an increasing risk that the crisis will spread to other parts of the economy.   Obviously, this does no ...

Source: www.scienceblogs.com --- 42 days ago
Joshua Wolf and Robert Salo of Melbourne's Royal Children's Hospital reported, in the Australian and New Zealand Journal of Psychiatry , on a case of a person with delusional beliefs regarding climate change. There is no openly-accessible abstract, (the link to the paywall page is here ) so we have to make do with a news report : We describe a patient with climate change delusion, a previously unreported phenomenon. A 17-year-old man was referred to the inpatient psychiatric unit at Royal Children's Hospital Melbourne with an 8 month history of depressed mood... He also ...had visions of apocalyptic events... The patient had also developed the belief that, due to climate change, his own water consumption could lead within days to the deaths of 'millions of people' through exhaustion of water supplies. He quoted 'internet research' to substantiate this. The patient described that 'I feel guilty about it', had attempted to stop drinking... He was unable to acknowledge that the belief was unreasonable when challenged. This was taken quickly as fodder for thoughtless commentary : Read the rest of this post... | Read the comments on this post... ...

Source: www.scienceblogs.com --- 46 days ago
The League of Conservation Voters is half-way through the process of selecting the dozen worst environmental offenders in elected office.  Each election year, they select  approximately 12 politicians to target for their campaign, in an effort to unseat, or deny seats to, the politicians with the worst voting records on environmental issues. Last time (2006), the "dozen" (actually 15) included : Senators George Allen (R-VA) Rick Santorum (R-PA) Jim Talent (R-MO) Representatives Bob Beauprez (R-CO) Katherine Harris (R-FL) J.D. Hayworth (R-AZ) Richard Pombo (R-CA Charles Taylor (R-NC) Conrad Burns (R-MT) All of those listed above were defeated.  Rep. Heather Wilson (R-NM), Rep. Henry Cuellar (D-TX), Rep. Dan Boren (D-OK),  Rep. Deborah Pryce (D-OH). Rep. Charles Taylor (R-NC) were targeted, but won their elections.   Tom Delay (R-TX) and Bob Ney (R-OH) were named as well.  They were not defeated; what happened to them is better: they resigned in disgrace. For 2008, they have named, so far, six politicians: Five are in office; one is a former Representative who is angling to get back in.   They are : Senator Jim Inhofe (R-OK) Representative Joe Knollenberg (R - MI) former U.S. Rep. Bob Schaffer (R-CO) Mitch McConnell (R-KY) Representative Stevan Pearce (R-NM) Mary Landrieu (D-LA) This is a reminder that the stake are as high as ever in November. Read the comments on this post... ...

Source: www.scienceblogs.com --- 50 days ago
40% of Internet users do not upgrade their browsers to the most secure version.  Internet Explorer users have the worst record, with more than half having failed to update. OK, people, do your patriotic duty and get with the upgrades!  Then we can see the National Threat Advisory go down to blue, for the first time in history. (source: Ars Technica ) Read the comments on this post... ...

Source: www.ncbi.nlm.nih.gov --- 18 days ago
Related Articles Extensive callosal infarction showing difficulty in knitting as an initial symptom. Intern Med. 2008;47(15):1431-5 Authors: Suzuki K, Takiguchi Y, Miyamoto T, Miyamoto M, Hirata K, Hara K, Suzuki S, Takebayashi K, Aso Y, Inukai T A 66-year-old right-handed woman with type 2 diabetes mellitus was admitted to our hospital with progressive dysarthria and gait disturbance preceded by difficulty in knitting. Brain magnetic resonance imaging (MRI) showed a lesion involving the entire Corpus Callosum. Although tumor was considered in the differential diagnosis because of the atypical imaging findings, she was diagnosed with infarction based on clinical improvement after admission and sequential changes in MRI. We suggest that difficulty in knitting may be an important early manifestation of a callosal disconnection syndrome and that follow-up clinical and imaging examinations would contribute to confirmation of the diagnosis. PMID: 18670151 [PubMed - in process] ...

Source: www.ncbi.nlm.nih.gov --- 5 days ago
Related Articles Intersubject variability in the analysis of diffusion tensor images at the group level: fractional anisotropy mapping and fiber tracking techniques. Magn Reson Imaging. 2008 Aug 11; Authors: Müller HP, Unrath A, Riecker A, Pinkhardt EH, Ludolph AC, Kassubek J INTRODUCTION: Diffusion tensor imaging (DTI) provides comprehensive information about quantitative diffusion and connectivity in the human brain. Transformation into stereotactic standard space is a prerequisite for group studies and requires thorough data processing to preserve directional inter-dependencies. The objective of the present study was to optimize technical approaches for this preservation of quantitative and directional information during spatial normalization in data analyses at the group level. METHODS: Different averaging methods for mean diffusion-weighted images containing DTI information were compared, i.e., region of interest-based fractional anisotropy (FA) mapping, fiber tracking (FT) and corresponding tractwise FA statistics (TFAS). The novel technique of intersubject FT that takes into account directional information of single data sets during the FT process was compared to standard FT techniques. Application of the methods was shown in the comparison of normal subjects and subjects with defined white matter pathology (alterations of the Corpus Callosum). RESULTS: Fiber tracking was applied to averaged data sets and showed similar results ...