Entire Corpus Callosum Research Articles

Gender Differences in the Cortical Distribution of Corpus Callosum Fibers.

Introduction Research on gender-based disparities in human brain structure has spanned over a century, yielding conflicting results and ongoing debate. While some studies indicate minimal distinctions, others consistently highlight differences in the corpus callosum (CC), even after accounting for average brain size. Methods Diverging from previous approaches, this study examines the morphology of the entire CC fiber rather than solely focusing on its midsagittal structure. Utilizing advanced neuroimaging techniques and generalized Q-imaging tractography, CC streamlines were constructed to assess gender differences in fractional anisotropy (FA), volume ratio, and cortical distribution. Student's t-test was employed to examine the disparities in FAbetween gender groups, while gender-based distinctions in the normalized volume of the CC and its segments were assessed using analysis of covariance (ANCOVA), with absolute whole white matter volume serving as a covariate. Results No significant gender-based disparities were found in either FA or normalized CC volume. While females exhibited consistently larger normalized volume CC streamlines than males, these differences lost statistical significance after adjusting for absolute total white matter volume as a covariate. Nonetheless, CC streamlines in females displayed a broader spatial distribution, encompassing various cortical regions, including the bilateral prefrontal cortex (medial and lateral surfaces), as well as medial parietal and temporal regions. Conclusion This study elucidates gender-related variations in the morphology of the brain's white matter pathways, indicating a more widespread cortical distribution of CC fibers in females compared to males. However, the study underscores the need for further investigations into connectivity patterns to fully elucidate these gender-based disparities.

Quantitative fetal MRI with diffusion tensor imaging in cases with 'short' corpus callosum.

It has been suggested previously that the presence of Probst bundles (PB) in cases with a short corpus callosum (SCC) on diffusion tensor imaging (DTI) may help to differentiate between corpus callosal (CC) dysplasia and a variant of normal CC development. The objectives of this study were to compare DTI parameters between cases of SCC vs normal CC and between cases of SCC with PB (SCC-PB+) vs SCC without PB (SCC-PB-). This was a retrospective study of patients referred to the Necker Hospital in Paris, France, for magnetic resonance imaging (MRI) evaluation of an apparently isolated SCC detected by sonography between November 2016 and December 2022 (IRB: 00011928). MRI was performed using a 1.5-Tesla Signa system. T2-weighted axial and sagittal sequences of the fetal brain were used to measure the length and thickness of the CC. 16-direction DTI axial brain sequences were performed to identify the presence of PB and to generate quantitative imaging parameters (fractional anisotropy (FA) and apparent diffusion coefficient (ADC)) of the entire CC, genu, body and splenium. Cases in which other associated brain abnormalities were detected on MRI were excluded. Cases were matched for fetal gender and gestational age with controls in a 1:3 ratio. Control cases were normal fetuses included in the LUMIERE on the FETUS trial (NCT04142606) that underwent the same DTI evaluation of the brain. Comparisons between SCC and normal CC cases, and between SCC-PB+ and SCC-PB- cases were performed using ANOVA and adjusted for potential confounders using ANCOVA. Twenty-two SCC cases were included and compared with 66 fetuses with a normal CC. In 10/22 (45.5%) cases of SCC, PB were identified. As expected, dimensions of the CC were significantly smaller in SCC compared with normal CC cases (all P < 0.01). In SCC-PB+ vs SCC-PB- cases, FA values were significantly lower in the entire CC (median, 0.21 (range, 0.19-0.24) vs 0.24 (range, 0.22-0.28); P < 0.01), genu (median, 0.21 (range, 0.15-0.29) vs 0.24 (range, 0.17-0.29); P = 0.04), body (median, 0.21 (range, 0.18-0.23) vs 0.23 (range, 0.21-0.27); P = 0.04) and splenium (median, 0.22 (range, 0.16-0.30) vs 0.25 (range, 0.20-0.29); P = 0.03). ADC values were significantly higher in the entire CC, genu and body in SCC-PB+ vs SCC-PB- cases (all P < 0.05). In SCC-PB+ cases, all FA values were significantly lower, and ADC values in the CC body were significantly higher compared with normal CC cases (all P < 0.05). In SCC-PB- cases, there was no significant difference in FA and ADC compared with normal CC cases (all P > 0.05). Fetal DTI evaluation of the CC showed that FA values were significantly lower and ADC values tended to be significantly higher in SCC-PB+ compared with normal CC cases. This may highlight alterations of the white matter microstructure in SCC-PB+. In contrast, isolated SCC-PB- did not demonstrate significant changes in DTI parameters, strengthening the possibility that this is a normal CC variant. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Abstract 088: Treatment of a Ruptured AVM with Inflow Aneurysms: Mixed approach using coil and liquid embolization

Introduction Arteriovenous malformations(AVMs) are high‐flow vascular abnormalities characterized by direct communications between arteries and veins of various complexities. Cerebral AVMs may manifest with new‐onset seizures or intraparenchymal (IPH) or subarachnoid hemorrhages (SAH). Life‐threatening bleeds may occur from the AVM nidus or associated aneurysms. We report a patient with hemorrhage from a complex AVM that included a prominent nidus and large inflow aneurysms requiring several endovascular techniques for treatment. Methods N/A Results A 35 year old male patient newly arrived from the Philippines with a history of hypertension presented to the hospital after being found unresponsive at home with frothing from the mouth and incontinence. The patient regained consciousness in the ER, complaining of a posterior headache which he had been experiencing for a week. NIHSS of 0 was noted with no neurological deficits. CT‐head revealed extensive SAH in interhemispheric falx anterior to and outlining the entire corpus callosum with intraventricular extension. CT‐ angiogram demonstrated a prominent AVM with a well‐developed nidus situated to the left of midline about the posterior corpus callosum. Two large inflow aneurysms, felt to be the rupture site, projecting from the proximal left pericallosal artery were also demonstrated. An incidental ACA aneurysm was also noted. Cerebral angiography redemonstrated these findings as well as the drainage of the AVM primarily through the straight sinus. Graded as Spetzler Martin 4. Common femoral approach was used. An access catheter was passed into the left ICA. The pericallosal artery was accessed with a detachable tip microcatheter which was further advanced past the inflow aneurysms into the main pedicle feeding the AVM nidus. The inflow aneurysms were accessed and embolized with coils using a second microcatheter prior to AVM embolization. This sealed off access to the aneurysms and parent vessel against liquid agent backflow. Onyx‐18 was then injected into the main AVM pedicle under a blank roadmap. Extensive but partial filling of the AVM was noted anteriorly but full embolization of the posterior aspect of the nidus was not achieved. Finally coiling of the ACA aneurysm was performed after accessing the right ICA. An MRI with and without contrast was performed and an expected acute infarction in the left ACA territory was observed. A repeat angiogram was performed a week later revealing posterior cerebral artery and posterior choroidal branches feeding the posterior 1/3 of the AVM. Embolization of three posterior feeding pedicles was subsequently performed utilizing dilute NBCA. Because of coil impaction the proximal pericallosal inflow aneurysm required re‐treatment with further coil placement 8 months after initial treatment. The patient has regular angiograms to monitor the AVM, which appears stable without significant residual shunting. Conclusion Ruptured AVMs are fatal events requiring careful treatment to prevent further bleeding while preserving viable brain tissue. AVMs are fragile formations of vessels which can receive collaterals from multiple targets and often have associated high risk features like inflow aneurysms. Accordingly endovascular treatment may require a mixture of techniques to ensure adequate and safe embolization. Regular monitoring of these structures and adjacent vessels is required to prevent any poor outcomes.

Reversible splenial lesion syndrome in children: a retrospective study of 130 cases.

Reversible splenial lesion syndrome (RESLES) is a new clinico-radiological syndrome. We retrospectively analyzed the clinical features of 130 children with RESLES in China, which is the largest case series available in the literature. The clinical data of children diagnosed as RESLES in Jiangxi Provincial Children's Hospital between 2017 and 2023 were retrospectively analyzed. The 130 cases were divided into two groups: ≤ 3 years old group (group A) (n = 83) and > 3 years old group (group B) (n = 47). The chi-squared test or Fisher's test was used to evaluate the data. The vast majority of patients (127/130 cases, 97.7%) had prodromal symptoms of infection. Preceding infections of the gastrointestinal tract were statistically more significant in group A (60/83, 72.3%) than in group B (11/47, 23.4%) (P < 0.05). Preceding infections of the respiratory tract were statistically more significant in group B (33/47, 70.2%) than in group A (17/83, 20.5%) (P < 0.05). Seizures were statistically more significant in group A (82/83, 98.8%) than in group B (24/47,51.1%) (P < 0.05). The disturbance of consciousness and headache/dizziness were statistically more significant in group B (27/47, 57.4%; 37/47, 78.7%) than in group A (3/83, 3.6%; 1/83, 1.2%), respectively (P < 0.05). Convulsions with mild gastroenteritis (CwG) were statistically more significant in group A (50/83, 60.2%) than in group B (8/47, 17.0%) (P < 0.05). However, encephalitis/encephalopathy was statistically more significant in group B (20/47, 42.6%) than in group A (10/83, 12.0%) (P < 0.05). MRI showed cytotoxic edema in typical locations (RESLES type-1 limited to the splenium of the corpus callosum and RESLES type-2 spread to the entire corpus callosum, adjacent white matter, or both). There was full recovery of the lesions of MRI in all cases from 3 days to 50 days after the initial examinations. All the children showed normal neurodevelopment. Infection was the most common cause of RESLES. Infections of the gastrointestinal tract are common in ≤ 3 years old children, while infections of the respiratory tract are common in >3 years old children. Younger patients are more likely to develop convulsions, and older children were more likely to have symptoms with disturbance of consciousness and headache/dizziness. RESLES has characteristic MRI manifestations and a good prognosis.

Normative modeling analysis reveals corpus callosum volume changes in early and mid-to-late first episode major depression

BackgroundIt has been widely accepted that major depressive disorder (MDD) impacts brain structures including the Corpus Callosum (CC). However, this assumption is based on scarce literature data involving small sample sizes. Furthermore, it is still unclear whether such CC volume changes may already be present at a first depressive episode. MethodsTo further investigate this question, we compared 369 first-episode MDD patients (mean age = 35 years (sd = 12), 249 females; 283 early onset, 86 mid-to-late onset) from the open-source REST meta-MDD database closely matched for age and gender to 490 never-depressed individuals (mean age = 37 years (sd = 14); 309 females) using Z-scores obtained from normative neuroanatomical modeling to assess individual variability in CC (sub)volumes. ResultsRelative to the norms established by the healthy controls, first-episode MDD patients displayed CC volume (z-score) reductions in the entire CC (including the body), as did mid-to-late-onset first-episode MDD patients (age ≥ 45 y). In early-onset first-episode MDD patients (age ≤ 44 y), depression severity symptoms were related to volume increases in the entire CC, as well as the body and splenium. LimitationsNo data on depressive episode duration. Relatively small sample size for mid-to-late first-episode MDD patients. ConclusionsOur data revealed CC (sub)volume differences in early versus mid-to-late onset first episode MDD. Especially at early onset, depression severity may result in neural white matter activity as potential reaction to stress influences. Our results underline the importance of prompt clinical interventions at early onset MDD.

Diffusion Tensor Imaging Revealed Microstructural Changes in Normal-Appearing White Matter Regions in Relapsing-Remitting Multiple Sclerosis.

BackgroundAxons and myelin sheaths are the physical foundation for white matter (WM) to perform normal functions. Our previous study found the metabolite abnormalities in frontal, parietal, and occipital normal-appearing white matter (NAWM) regions in relapsing–remitting multiple sclerosis (RRMS) patients by applying a 2D 1H magnetic resonance spectroscopic imaging method. Since the metabolite changes may associate with the microstructure changes, we used the diffusion tensor imaging (DTI) method to assess the integrity of NAWM in this study.MethodDiffusion tensor imaging scan was performed on 17 clinically definite RRMS patients and 21 age-matched healthy controls on a 3.0-T scanner. DTI metrics including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were extracted from 19 predefined regions of interest (ROIs), which were generated by removing a mask of manually drawn probabilistic lesion map from the Johns Hopkins University white-matter atlas. The mean values of FA, MD, AD, and RD were compared between different groups in the same ROIs.ResultsA probabilistic lesion map was successfully generated, and the lesion regions were eliminated from the WM atlas. We found that the RRMS patients had significantly lower FA in the entire corpus callosum (CC), bilateral of anterior corona radiata, and right posterior thalamic radiation (PTR). At the same time, RRMS patients showed significantly higher MD in the bilateral anterior corona radiata and superior corona radiata. Moreover, all AD values increased, and the bilateral external capsule, PTR, and left tapetum NAWM show statistical significance. What is more, all NAWM tracts showed increasing RD values in RRMS patients, and the bilateral superior corona radiata, the anterior corona radiata, right PTR, and the genu CC reach statistical significance.ConclusionOur study revealed widespread microstructure changes in NAWM in RRMS patients through a ready-made WM atlas and probabilistic lesion map. These findings support the hypothesis of demyelination, accumulation of inflammatory cells, and axonal injury in NAWM for RRMS. The DTI-based metrics could be considered as potential non-invasive biomarkers of disease severity.

A Deformation-Based Shape Study of the Corpus Callosum in First Episode Schizophrenia.

Background: Previous first-episode schizophrenia (FES) studies have reported abnormalities in the volume and mid-sagittal size of the corpus callosum (CC), but findings have been inconsistent. Besides, the CC shape has rarely been analyzed in FES. Therefore, in this study, we investigated FES-related CC shape abnormalities using 198 participants [92 FES patients and 106 healthy controls (HCs)].Methods: We conducted statistical shape analysis of the mid-sagittal CC curve in a large deformation diffeomorphic metric mapping framework. The CC was divided into the genu, body, and splenium (gCC, bCC, and sCC) to target the key CC sub-regions affected by the FES pathology. Gender effects have been investigated.Results: There were significant area differences between FES and HC in the entire CC and gCC but not in bCC nor sCC. In terms of the localized shape morphometrics, significant region-specific shape inward-deformations were detected in the superior portion of gCC and the anterosuperior portion of bCC in FES. These global area and local shape morphometric abnormalities were restricted to female FES but not male FES.Conclusions: gCC was significantly affected in the neuropathology of FES and this finding was specific to female FES. This study suggests that gCC may be a key sub-region that is vulnerable to the neuropathology of FES, specifically in female patients. The morphometrics of gCC may serve as novel and efficient biomarkers for screening female FES patients.

Corpus callosum morphology in major mental disorders: a magnetic resonance imaging study

Mental disorders diagnosis is based on specific clinical criteria. However, clinical studies found similarities and overlapping phenomenology across a variety of disorders, which suggests a common neurobiological substrate. Thus, there is a need to measure disease-related neuroanatomical similarities and differences across conditions. While structural alterations of the corpus callosum have been investigated in obsessive-compulsive disorder, schizophrenia, major depressive disorder and bipolar disorder, no study has addressed callosal aberrations in all diseases in a single study. Moreover, results from pairwise comparisons (patients vs. controls) show some inconsistencies, possibly related to the parcellation methods to divide the corpus callosum into subregions. The main aim of the present paper was to uncover highly localized callosal characteristics for each condition (i.e. obsessive-compulsive disorder, schizophrenia, major depressive disorder and bipolar disorder) as compared either to healthy control subjects or to each other. For this purpose, we did not rely on any sub-callosal parcellation method, but applied a well-validated approach measuring callosal thickness at 100 equidistant locations along the whole midline of the corpus callosum. One hundred and twenty patients (30 in each disorder) as well as 30 controls were recruited for the study. All groups were closely matched for age and gender, and the analyses were performed controlling for the impact of antipsychotic treatment and illness duration. There was a significant main effect of group along the whole callosal surface. Pairwise post hoc comparisons revealed that, compared to controls, patients with obsessive-compulsive disorder had the thinnest corpora callosa with significant effects almost on the entire callosal structure. Patients with schizophrenia also showed thinner corpora callosa than controls but effects were confined to the isthmus and the anterior part of the splenium. No significant differences were found in both major depressive disorder and bipolar disorder patients compared to controls. When comparing the disease groups to each other, the corpus callosum was thinner in obsessive-compulsive disorder patients than in any other group. The effect was evident across the entire corpus callosum, with the exception of the posterior body. Altogether, our study suggests that the corpus callosum is highly changed in obsessive-compulsive disorder, selectively changed in schizophrenia and not changed in bipolar disorder and major depressive disorder. These results shed light on callosal similarities and differences among mental disorders providing valuable insights regarding the involvement of the major brain commissural fibre tract in the pathophysiology of each specific mental illness.

Restricted diffusion of the corpus callosum in extensive neonatal hypoxic-ischemic encephalopathy

Hypoxic-ischemic encephalopathy (HIE) is a devastating brain injury that may result in death and severe neurologic deficits. Corpus callosum (CC) involvement, especially its entire involvement, is very rare in HIE. A 41-week-old male term neonate had a difficult delivery and developed cardiac arrest after birth. His Apgar scores were low in the first 10 minutes. The magnetic resonance imaging (MRI) showed high signal intensity in bilateral basal ganglia, bilateral thalami, temporofrontal cortex, subcortical white matter, perirolandic region, and the entire corpus callosum in T1 sequences. Restricted diffusion was noted on the diffusion-weighted imaging (DWI) images of all these regions. CC is affected in cases of severe and advanced brain injury, and especially splenial lesions have poor outcomes. Entire CC involvement may lead to worse clinical presentation and can serve as an early neuroradiologic marker.

White Matter Microstructure in Individuals With and At Risk for Bipolar Disorder: Evidence for an Endophenotype From a Voxel-Based Meta-analysis

BackgroundAberrant white matter (WM) microstructure has been proposed as a mechanism underlying bipolar disorder (BD). Given the strong genetic underpinnings of both WM microstructure and BD, such WM aberrations may be not only a disease marker, but also an endophenotype of BD. If so, they should be observable in individuals at risk for BD (AR) (i.e., first-degree relatives). This meta-analysis integrates evidence on perturbed WM microstructure in individuals with or at risk for BD. MethodsA comprehensive search of literature published through April 2020 identified diffusion tensor imaging studies that used a voxel-based approach to compare fractional anisotropy (FA) and radial diffusivity between individuals with BD and/or AR individuals and healthy volunteers. Effect size comparison and conjunction analysis allowed identification of endophenotypes and disease markers of BD. Effects of age, sex, mood state, and psychotropic medication were explored using meta-regressions. ResultsWe included 57 studies in individuals with BD (N = 4631) and 10 in AR individuals (N = 753). Both individuals with and at risk for BD were associated with lower FA in the body and splenium of the corpus callosum. In the BD group, decreased FA and increased radial diffusivity comprised the entire corpus callosum, anterior thalamic radiation, fronto-orbito-polar tracts, and superior longitudinal fasciculus, and were influenced by age, sex, and mood state. Studies with higher proportions of individuals taking lithium or antipsychotics reported smaller FA reductions in BD. ConclusionsFindings suggest that abnormalities in the body and splenium of the corpus callosum may be an endophenotype for BD, and they associate BD with WM tracts relevant for working memory performance, attention, and reward processing.

Diffusion Imaging Biomarkers of Corpus Callosum Injury and Dose-Dependent Volumetric Changes Correlate with Attention and Processing Speed Changes after Brain Radiotherapy

Attention and processing speed are core cognitive functions subserved by the corpus callosum (CC), a critical white matter structure. We hypothesized that CC volume changes and diffusion weighted imaging (DWI) biomarkers of CC injury would correlate with changes in attention and processing speed function after brain radiotherapy (RT). We prospectively studied 29 patients with primary brain tumors who received fractionated RT. Patients underwent formal neuropsychological testing and high resolution volumetric MRI with DWI (b-values 0, 500, 1500 s/mm2 fit to single tensor) prior to and 6 months post RT. Auditory attention was measured with the Weschler Adult Intelligence Scale (WAIS-IV) Digit Span Forward test; processing speed was measured with the Delis-Kaplan Executive Function System Trail Making number sequencing (TM-NS) and letter sequencing (TM-LS) subtests. Reliable change indices accounting for practice effects (RCI-PE) were calculated to determine 0-6 month change on each measure. Image processing at each time point included auto-segmentation with volume calculations of regions of interest (ROIs): the entire CC and anterior, mid-anterior, central, mid-posterior, and posterior subdivisions. Tumor, tumor bed, edema, and segmentation errors were censored. DWI biomarkers including mean diffusivity (MD, increases with injury) and fractional anisotropy (FA, decreases with injury) were calculated. Mean dose to each ROI was determined. One sample t-tests (H0=0) were performed to determine significant group cognitive decline. Pearson correlation coefficients evaluated the relationship between RCI-PEs and clinical variables, dose, changes in volume, MD, and FA. Statistical significance was set at α=0.05. Processing speed (TM-LS) significantly declined 6-months post-RT (mean change -0.472, p = 0.003). Age and years of education did not influence attention or processing speed changes. Significant dose-dependent atrophy was seen in the mid-anterior (r = -0.432, p = 0.024), mid-posterior (r = -0.408, p = 0.031), and posterior CC (r = -0.600, p = 0.001). Smaller mid-anterior CC volume was associated with worse processing speed (TM-LS, r = 0.424, p = 0.031). Decreased FA in the anterior CC was associated with worse attention (digits forward, r = 0.401, p = 0.038) and decreased FA in the posterior CC was correlated with worse processing speed (TM-LS, r = 0.444, p = 0.02). Increased MD in the anterior CC (r = -0.386, p = 0.046) was correlated with worse attention (digits forward). In this prospective study, dose-dependent atrophy of CC subdivisions was seen after fractionated brain RT. Microstructural damage, including atrophy and white matter injury, within CC subdivisions was significantly associated with worse attention and processing speed. Damage to this critical structure is highly implicated in attention/processing speed changes after brain RT.

Longitudinal study examining abnormal white matter integrity using a tract-specific analysis in individuals with a high risk for psychosis.

Although volume reductions in the grey matter have been previously observed in individuals with an at-risk mental state (ARMS) for psychosis, the features of white matter integrity and their correlation with psychiatric symptoms remain unclear. Forty-six ARMS subjects were examined using magnetic resonance imaging (MRI) to acquire diffusion tensor imaging (DTI); the subjects were also evaluated using the Scale of Prodromal Symptoms at baseline and at 52 weeks. Sixteen healthy controls also underwent MRI scanning. The DTI results were longitudinally analyzed using a tract-specific analysis to measure the fractional anisotropy (FA) values of the entire corpus callosum (CC), as well as its genu, trunk, and splenium. During the 52-week study period, seven patients developed psychosis (ARMS-P) and 39 did not (ARMS-NP). In the entire CC and the genu, trunk, and splenium of the CC, the FA values of the ARMS subjects were each significantly smaller than the respective values of the healthy controls at baseline. In the genu and trunk, the baseline FA values in the ARMS-NP group were, paradoxically, smaller than those of the ARMS-P group at baseline. Regarding the association between the FA values and psychiatric symptoms, a reduction in the FA value in the genu was significantly correlated with a deterioration of negative symptoms among the ARMS subjects. Abnormal white matter integrity in the CC may predict the long-term outcome of patients with prodromal psychosis, since negative symptoms are associated with poor functioning.

Minimally Invasive Robotic Laser Corpus Callosotomy: A Proof of Concept.

IntroductionWe describe the feasibility of using minimally invasive robotic laser interstitial thermotherapy (LITT) for achieving an anterior two-thirds as well as a complete corpus callosotomy.MethodsTen probe trajectories were plotted on normal magentic resonance imaging (MRI) scans using the Brainlab Stereotactic Planning Software (Brainlab, Munich, Germany). The NeuroBlate® System (Monteris Medical, MN, USA) was used to conform the thermal burn to the corpus callosum along the trajectory of the probe. The distance of the ideal entry site from either the coronal suture and the torcula or nasion and the midline was calculated. The distance of the probe tip from the dorsal and ventral limits of the callosotomy in the sagittal plane were also calculated.ResultsAnterior two-thirds callosotomy was possible in all patients using a posterior parieto-occipital paramedian trajectory through the non-dominant lobe. The average entry point was 3.64 cm from the midline, 10.6 cm behind the coronal suture, and 9.2 cm above the torcula. The probe tip was an average of 1.4 cm from the anterior commissure. For a total callosotomy, an additional contralaterally placed frontal probe was used to target the posterior one-third of the corpus callosum. The average entry site was 3.3 cm from the midline and 9.1 cm above the nasion. The average distance of the probe tip from the base of the splenium was 0.94 cm.ConclusionThe directional thermoablation capability of the NeuroBlate® system allows for targeted lesioning of the corpus callosum, to achieve a two-thirds or complete corpus callosotomy. A laser distance of < 2 cm is sufficient to reach the entire corpus callosum through one trajectory for an anterior two-thirds callosotomy and two trajectories for a complete callosotomy.

Infarction of the entire corpus callosum as a complication in subarachnoid hemorrhage: A case report

Abstract The corpus callosum is the major commissural pathway connecting the cerebral hemispheres. This pathway receives its blood supply from anterior communicating artery, pericallosal artery, and posterior pericallosal artery. However, in some cases, the entire corpus callosum is supplied by median callosal artery; thus, occlusion of this artery can lead to infarction of the entire corpus callosum. Few reports have described this type of infarction, and no reports after subarachnoid hemorrhage (SAH) exist. Here, we report on a 42-year-old female who was diagnosed with SAH after two aneurysms were discovered in bifurcation of left anterior cerebral artery (A1-A2). After successful clipping was performed, the patient was alert and had no neurological deficits; moreover, the computed tomography images that were acquired after the operation showed no evidence of infarction. Nine days after admittance to the hospital, drowsiness and weakness of the left limbs with brain swelling appeared and decompressive hemi-craniectomy was performed. Diagnostic cerebral angiography revealed vasospasms in both anterior and middle cerebral arteries, thus fasudil hydrochloride was administered intra-arterially. While blood flow in all arteries improved, diffusion-weighted magnetic resonance imaging detected infarction along the entire length of the corpus callosum and in the medial region of the right frontal lobe. We believe this infarction was due to secondary ischemia of median callosal artery. This case reminded us of the anatomical variation wherein median callosal artery is the sole blood supply line for the corpus callosum and demonstrated that infarction of the entire corpus callosum is possible.

Restricted diffusion in the corpus callosum: A neuroradiological marker in hypoxic-ischemic encephalopathy.

Background:Restricted diffusion within the splenium of the corpus callosum has been described by other authors in various conditions, however, restricted diffusion in the entire corpus callosum or isolated involvement of the splenium, genu, or body has been infrequently reported on magnetic resonance imaging (MRI) in neonatal hypoxic–ischemic encephalopathy. We report a series of cases showing different patterns of involvement.Methods and Materials:Perinatal imaging with MRI including diffusion-weighted imaging was performed in 40 neonates with hypoxic–ischemic encephalopathy, including 11 premature neonates. Sixteen out of 40 patients demonstrated restricted diffusion within the corpus callosum. Out of 16 patients, 9 showed restricted diffusion in the entire corpus callosum, 4 had isolated splenium involvement, 2 had body and splenium signal abnormality, and 1 showed diffusion restriction only in the genu.Conclusions:Changes in the corpus callosum were also associated with more severe clinical presentation of encephalopathy. Restricted diffusion within the corpus callosum in infants with hypoxic–ischemic encephalopathy is often associated with extensive brain injury and appears to be an early neuroradiologic marker of adverse neurologic outcome.

Diffusion Tensor Imaging to Map Brain Microstructural Changes in CADASIL.

Diffusion tensor imaging (DTI) is sensitive to brain microstructural changes. The aims of this DTI study were to map voxelwise the spatial distribution of brain microstructural changes in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and to investigate any correlation between DTI-derived indices and extension of T2 hyperintensity. Eighteen patients with CADASIL and 18 age-, sex-, and education-level-matched healthy controls underwent magnetic resonance imaging at 3 T. Differences in DTI-derived indices (mean diffusivity [MD], fractional anisotropy [FA], axial [AD] and radial [RD] diffusivities, and mode of anisotropy [MO]) of brain white matter (WM) between CADASIL patients and healthy subjects were assessed through tract-based spatial statistics. Then, DTI-derived indices were correlated with the patient's score on the extended Fazekas visual scale of the T2 hyperintensity. When compared to healthy controls, CADASIL patients showed extensive symmetric areas of increased MD/RD and decreased AD/FA/MO that involved almost the entire hemispheric cerebral WM (internal and external capsule, WM of the temporal poles, superior and inferior longitudinal fasciculus, inferior frontal-occipital fasciculus, uncinate fasciculus, cingulum, forceps major and minor, corticospinal tracts, and thalamic radiations), thalami, and corpus callosum. Additional areas of increased RD were observed in pons, midbrain, cerebellar peduncles, and cerebellar WM. Only FA was negatively correlated with extended Fazekas visual score. Our results indicate that brain damage in CADASIL is associated with extensive microstructural changes implying impairment of intra- and inter-hemispheric cerebral, thalamocortical, and cerebrocerebellar connections. Severity of microstructural changes correlates with extension of T2 hyperintensity.

What is Known about Corpus Callosum Prenatally?

ABSTRACT The corpus callosum is the main commissure of the fetal brain and can be displayed with two-dimensional (2D) and threedimensional (3D) ultrasound. However, only 3D ultrasound provides the operator with the possibility to adjust the three orthogonal planes of the brain in that way that the entire corpus callosum is shown precisely in the median plane. The aim of this article is to provide the most recent information on the assessment of the fetal corpus callosum by means of 3D ultrasound. Different topics are highlighted, such as advantage of 3D ultrasound over 2D ultrasound, indications for displaying the fetal corpus callosum, demonstration of the normal and abnormal corpus callosum and biometric measurements of the fetal corpus callosum by 3D ultrasound. Furthermore the question is raised whether fetal magnetic resonance imaging (MRI) can give additional information to the 3D ultrasound examination and whether the diagnosis resulting from 3D neurosonography gives us the chance for a better counseling of parents who are confronted with the diagnosis of a fetal corpus callosum pathology. How to cite this article Merz E, Pashaj S. What is Known about Corpus Callosum Prenatally? Donald School J Ultrasound Obstet Gynecol 2016;10(2):163-169.

Marchiafava-Bignami Disease: A Less Known Neurological Complication of Alcoholism

Marchiafava-Bignami disease (MBD) is a disorder associated with chronic alcohol consumption and characterized by demyelination and necrosis of the corpus callosum. Patients may have reduced consciousness, psychotic symptoms, apathy, hemiparesis, ataxia and coma. Although some cases of recovery have been reported, the outcome is poor, with disability or dead. We reported a case of a 56-year-old woman with chronic alcoholism admitted to our hospital with impaired consciousness and a history of gait disturbance. On examination, she was in a coma, with increased muscle tone and left arm paresis. Laboratory studies showed a folic acid deficiency and the CT scan was normal. Magnetic resonance imaging revealed lesions in periventricular white matter and the entire corpus callosum with restriction of water diffusion consistent with the diagnosis of MBD. Despite treatment with B vitamin complex, the patient died. Coma and radiological involvement of the entire corpus callosum are compatible with type A MBD and associated with poor prognosis. Although being a rare alcoholism complication, it should not be forgotten since an early diagnosis and prompt supportive therapy may enable a better outcome. J Med Cases. 2016;7(5):171-173 doi: http://dx.doi.org/10.14740/jmc2477w

Longitudinal Brain Changes Associated with Prophylactic Cranial Irradiation in Lung Cancer

IntroductionThe toxic effects of prophylactic cranial irradiation (PCI) and platinum-based chemotherapy on cognition in the lung cancer population have not yet been well established. In the present study we examined the longitudinal neuropsychological and brain structural changes observed in patients with lung cancer who were undergoing these treatments. MethodsTwenty-two patients with small cell lung cancer (SCLC) who underwent platinum-based chemotherapy and PCI were compared with two control groups: an age- and education-matched group of healthy controls (n = 21) and a group of patients with non-SCLC (NSCLC, n = 13) who underwent platinum-based chemotherapy. All groups were evaluated using a neuropsychological battery and multimodal structural magnetic resonance imaging: T1-weighted and diffusion tensor imaging at baseline (before PCI for SCLC and chemotherapy for NSCLC) and at 3 months after treatment. T1 voxel-based morphometry and tract-based spatial statistics were used to analyze microstructural changes in gray matter (GM) and white matter (WM). The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire—Core Questionnaire was also completed. ResultsPatients with SCLC exhibited cognitive deterioration in verbal fluency over time. Structural magnetic resonance imaging showed decreases in GM at 3 months in the right subcortical regions, bilateral insular cortex, and superior temporal gyrus in patients with SCLC compared with both control groups. Additionally, patients with SCLC showed decreases in GM over time in the aforementioned regions plus in the right parahippocampal gyrus and hippocampus, together with changes in the WM microstructure of the entire corpus callosum. These changes had a limited impact on responses to the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire—Core Questionnaire, however. Patients with NSCLC showed no cognitive or brain structural differences after chemotherapy. ConclusionsThis longitudinal study documents moderate neuropsychological deficits together with notable brain-specific structural changes (in GM and WM) in patients with SCLC after chemotherapy and PCI, suggesting that chemotherapy and especially PCI are associated with the development of cognitive and structural brain toxic effects.

Marchiafava-Bignami Disease: A Less Known Neurological Complication of Alcoholism

Marchiafava-Bignami disease (MBD) is a disorder associated with chronic alcohol consumption and characterized by demyelination and necrosis of the corpus callosum. Patients may have reduced consciousness, psychotic symptoms, apathy, hemiparesis, ataxia and coma. Although some cases of recovery have been reported, the outcome is poor, with disability or dead. We reported a case of a 56-year-old woman with chronic alcoholism admitted to our hospital with impaired consciousness and a history of gait disturbance. On examination, she was in a coma, with increased muscle tone and left arm paresis. Laboratory studies showed a folic acid deficiency and the CT scan was normal. Magnetic resonance imaging revealed lesions in periventricular white matter and the entire corpus callosum with restriction of water diffusion consistent with the diagnosis of MBD. Despite treatment with B vitamin complex, the patient died. Coma and radiological involvement of the entire corpus callosum are compatible with type A MBD and associated with poor prognosis. Although being a rare alcoholism complication, it should not be forgotten since an early diagnosis and prompt supportive therapy may enable a better outcome. J Med Cases. 2016;7(5):171-173 doi: http://dx.doi.org/10.14740/jmc2477w