Posterior Part Of Corpus Callosum Research Articles

Human ROBO1 regulates white matter structure in corpus callosum

The axon guidance receptor, Robo1, controls the pathfinding of callosal axons in mice. To determine whether the orthologous ROBO1 gene is involved in callosal development also in humans, we studied polymorphisms in the ROBO1 gene and variation in the white matter structure in the corpus callosum using both structural magnetic resonance imaging and diffusion tensor magnetic resonance imaging. We found that five polymorphisms in the regulatory region of ROBO1 were associated with white matter density in the posterior part of the corpus callosum pathways. One of the polymorphisms, rs7631357, was also significantly associated with the probability of connections to the parietal cortical regions. Our results demonstrate that human ROBO1 may be involved in the regulation of the structure and connectivity of posterior part of corpus callosum.

Tract-based spatial statistics analysis of white matter changes in children with anisometropic amblyopia

Amblyopia is a neurological disorder of vision that follows abnormal binocular interaction or visual deprivation during early life. Previous studies have reported multiple functional or structural cortical alterations. Although white matter was also studied, it still cannot be clarified clearly which fasciculus was affected by amblyopia. In the present study, tract-based spatial statistics analysis was applied to diffusion tensor imaging (DTI) to investigate potential diffusion changes of neural tracts in anisometropic amblyopia. Fractional anisotropy (FA) value was calculated and compared between 20 amblyopic children and 18 healthy age-matched controls. In contrast to the controls, significant decreases in FA values were found in right optic radiation (OR), left inferior longitudinal fasciculus/inferior fronto-occipital fasciculus (ILF/IFO) and right superior longitudinal fasciculus (SLF) in the amblyopia. Furthermore, FA values of these identified tracts showed positive correlation with visual acuity. It can be inferred that abnormal visual input not only hinders OR from well developed, but also impairs fasciculi associated with dorsal and ventral visual pathways, which may be responsible for the amblyopic deficiency in object discrimination and stereopsis. Increased FA was detected in right posterior part of corpus callosum (CC) with a medium effect size, which may be due to compensation effect. DTI with subsequent measurement of FA is a useful tool for investigating neuronal tract involvement in amblyopia.

Spatial patterns of whole brain grey and white matter injury in patients with occult spastic diplegic cerebral palsy.

Spastic diplegic cerebral palsy(SDCP)is a common type of cerebral palsy (CP), which presents as a group of motor-impairment syndromes. Previous conventional MRI studies have reported abnormal structural changes in SDCP, such as periventricular leucomalacia. However, there are roughly 27.8% SDCP patients presenting normal appearance in conventional MRI, which were considered as occult SDCP. In this study, sixteen patients with occult SDCP and 16 age- and sex-matched healthy control subjects were collected and the data were acquired on a 3T MR system. We applied voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analysis to investigate whole brain grey and white matter injury in occult SDCP. By using VBM method, the grey matter volume reduction was revealed in the bilateral basal ganglia regions, thalamus, insula, and left cerebral peduncle, whereas the white matter atrophy was found to be located in the posterior part of corpus callosum and right posterior corona radiata in the occult SDCP patients. By using TBSS, reduced fractional anisotropy (FA) values were detected in multiple white matter regions, including bilateral white matter tracts in prefrontal lobe, temporal lobe, internal and external capsule, corpus callosum, cingulum, thalamus, brainstem and cerebellum. Additionally, several regions of white matter tracts injury were found to be significantly correlated with motor dysfunction. These results collectively revealed the spatial patterns of whole brain grey and white matter injury in occult SDCP.

Partial agenesis of corpus callosum - case study

Agenesis of the corpus callosum is an uncommon cerebral malformation usually of unknown etiology. It can be associated with other brain abnormalities, such as ventriculomegaly, or in combination with problems with other organs, such as congenital heart defect, as well as with chromosome anomalies. Diagnosis of this rare anomaly is important not only because of possible association with other developmental anomalies but also because of postnatal treatment and evaluation of children with this disorder. This paper presents prenatal diagnosis of partial agenesis of the posterior part of corpus callosum of a fetus detected in gestational week 33 by ultrasonography as an isolated developmental disorder, i.e., not accompanied by other morphological anomalies of the fetus or chromosome aberrations or other genetic defects.

Changes in subcortical white matter and corpus callosum volumes in patients with type 2 diabetes mellitus

To evaluate the changes in subcortical white matter and corpus callosum volumes in patients with type 2 diabetes mellitus (T2DM). High resolution three-dimensional T1-weighted fast spoiled gradient recalled echo magnetic resonance images were obtained from 16 T2DM patients and 16 normal controls, and 11 T2DM patients also received the same magnetic resonance imaging scans after insulin therapy for 1 year. Volumetric analysis was performed and analysis of covariance and paired t test were applied. A lower volume was demonstrated in T2DM patients than that in the normal controls in bilateral caudal middle frontal lobe, bilateral pars opercularis, right inferior parietal lobe, right inferior temporal lobe, right middle temporal lobe, and left transverse temporal lobe (all P<0.05). After insulin therapy for 1 year, the increased subcortical white matter of brain regions were demonstrated in left medial orbitofrontal lobe, right caudal middle frontal lobe, right inferior parietal lobe, right lingual lobe, right inferior temporal lobe, right middle temporal lobe, left transverse temporal lobe, left entorhinal lobe and left insular lobe at the follow-up level in T2DM patients compared with baseline level (P<0.05). The decreased volumes of subcortical white matter were observed in the bilateral paracentral lobe, right superior forntal lobe and right precuneus lobe in T2DM patients on insulin therapy for 1 year (P<0.05). A decreased trend of subcortical white matter was involved in corpus callosum (P>0.05) and a significant decreased volume was demonstrated in the middle posterior part of corpus callosum after insulin therapy for 1 year(P<0.05). T2DM patients have decreased subcortical white matter of multiple brain regions, and the atrophy of subcortical white matter can be improved by the insulin therapy. The volume analysis of subcortical white matter is a simple and effective tool for the evaluation of white matter damage in T2DM patients.

Auditory Hallucinations as the Only Presenting Symptom of Right-Parietal Spontaneous Hemorrhage: FDG-PET Evidence of Corpus Callosum Hyperactivity

Back to table of contents Previous article Next article LettersFull AccessAuditory Hallucinations as the Only Presenting Symptom of Right-Parietal Spontaneous Hemorrhage: FDG-PET Evidence of Corpus Callosum HyperactivityMassimiliano Godani, M.D., Andrea Ciarmiello, M.D., Cesare Capellini, M.D., and Massimo Del Sette, M.D.Massimiliano GodaniSearch for more papers by this author, M.D., Andrea CiarmielloSearch for more papers by this author, M.D., Cesare CapelliniSearch for more papers by this author, M.D., and Massimo Del SetteSearch for more papers by this author, M.D.Published Online:1 Jan 2012https://doi.org/10.1176/appi.neuropsych.11020054AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail To the Editor: Auditory hallucinations are very rare in stroke patients. We report FDG-PET findings in a case of hemorrhagic stroke presenting with auditory hallucinations.Case ReportA 67-year-old woman was admitted to the emergency room of our hospital for acute onset of complex auditory hallucinations; she reported hearing loud music and voices of known persons speaking “filthy.” She had never suffered any psychiatric disorders in the past, and she was taking atenolol for many years as the only treatment for chronic arterial hypertension.Neurological examination did not show any focal neurological signs, and blood tests were normal. Brain CT scan revealed a right-parietal hemorrhage involving both superficial and deep territory of the posterior branches of middle cerebral artery (Figure 1 [D]). EEG showed absence of focal paroxystic epyleptiform discharges. Brain MRI and MR-angio confirmed the intraparenchimal hemorrhage, excluding the presence of aneurysm or artero-venous malformations. FDG-PET scan showed a significant increase in glucose metabolism (versus normal control database) in the middle and posterior areas of corpus callosum as well as in the precuneus and cuneus cortex (Figure 1 [A, B, C]).The auditory hallucinations gradually resolved in a few days without any treatment. She was discharged after 18 days from onset, and neurological examination showed visuospatial deficit as the consequence of right-parietal damage.DiscussionAuditory hallucinations are uncommon phenomena in patients with acute stroke; in particular, they have been reported in acute ischemic lesions of the brainstem but very rarely reported after cortical ischemic strokes.1 To our knowledge, this is the first case of auditory hallucinations as the only presenting symptom of a spontaneous hypertensive parenchymal hemmorrhage.In our case FDG-PET scan showed high relative glucose metabolic rates in the middle and posterior areas of corpus callosum. Hyperactivity of corpus callosum has already been reported in schizophrenic patients with auditory hallucinations.2,3 In particular, abnormalities in the posterior part of corpus callosum has been associated to schizophrenic positive symptoms.4 We speculate that in our patient the acute cortico-subcortical hemorrhage caused, through rapid development of peri-lesional edema and release of excitatory mediators such as calcium ions and amino-acids, an electrode-like effect,5 which abnormally activated the posterior part of corpus callosum, with consequent development of auditory hallucinations. We believe that a better understanding of corpus callosum pathophysiology could help in clarifying the mechanism of perceptive disturbances of various origin.Neurology UnitS. Andrea HospitalLA Spezia, ItalyCorrespondence: Massimiliano Godani, M.D.; massimiliano.[email protected]liguria.it1. Yair L , Mordechai L , Ronit G, et al.: Auditory hallucinations in acute stroke. Behav Neurol 2005; 16:211–216Crossref, Medline, Google Scholar2. Buchsbaum MS , Buchsbaum BR , Hazlett EA, et al.: Relative glucose metabolic rate higher in white matter in patients with schizophrenia. Am J Psychiatry 2007; 164:1072–1081Crossref, Medline, Google Scholar3. Hubl D , Koenig T , Strik W, et al.: Pathways that make voices. Arch Gen Psychiatry 2004; 61:658–668Crossref, Medline, Google Scholar4. Kubicki M , Styner M , Bouix S, et al.: Reduced interhemispheric connectivity in schizophrenia: tractography base segmentation of the corpus callosum. Schizophr Res 2008; 106(2–3):125–131Crossref, Medline, Google Scholar5. Weber B , Fouad K , Burger C, et al.: White-matter glucose metabolism during intracortical electrostimulation: a quantitative fluorodeoxyglucose autoradiography study in the rat. Neuroimage 2002; 16:993–998Crossref, Medline, Google Scholar FiguresReferencesCited byDetailsCited byJournal of the Neurological Sciences, Vol. 398Frontiers in Psychiatry, Vol. 8PET and SPECT Findings in Patients with Hallucinations29 January 2014 Volume 24Issue 1 Winter 2012Pages E28-E29 Metrics PDF download History Published online 1 January 2012 Published in print 1 January 2012

P03.10: Two and three dimensional sonographic images of isolated partial agenesis of corpus callosum

We report a rare case of isolated partial agenesis of corpus callosum (PACC), and describe the prenatal two- and three- dimensional (2D and 3D) sonographic images. Routine scan was performed on a 32-year-old healthy woman at 20 weeks' gestation of her second pregnancy. Both cerebral lateral ventricles were mildly dilated (left side 1.06 cm and right side 1.04 cm). Subsequent trans-abdominal detailed scan showed mildly dilated cerebral lateral ventricles with tear drop appearance and dilated third ventricle (0.4 cm). Cavum septum pellucidum was not visualized. Although the anterior part of corpus callosum was seen on 2D median planes by aligning the transducer with the anterior fontanelle and midline sutures, its middle and posterior part was not visualized. Color Doppler examination showed only the anterior part of the callosum artery. Median planes were also reconstructed using 3D ultrasonography by multiplanar and multislice analysis of static volumes. There was a good correlation between 2D and 3D images. 2D images could be used for diagnosis. Addition of 3D multiplanar and multislice images confirmed the non-visualisation of middle and posterior part of corpus callosum (Fig 1). MRI brain showed similar findings, and there were no additional abnormalities. Amniocentesis showed normal karyotype, 46 XX. Maternal blood was negative for cytomegalic virus antibodies. The couple was counseled that the prognosis was variable with a risk of neurodevelopmental delay. After termination of pregnancy, pathological examination was performed on the abortus. Supporting information can be found in the online version of this abstract. Three-dimensional multiplanar (plane A and B) images of a fetus with partial agenesis of corpus callosum. In plan A, only the anterior part of the corpus callosum was seen. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.