Total Corpus Callosum Research Articles

Corpus callosum areas in first-episode patients with bipolar disorder

Morphological changes in the corpus callosum (CC) have been described in bipolar disorder, but with inconsistencies among the reports. We investigated the CC areas by magnetic resonance imaging (MRI) in 12 first-episode patients with bipolar disorder and 12 controls. Twelve medication-naive patients with bipolar I disorder (six males, six females; aged 28 x 2+/-6 x 5 years) with manic or mixed episodes and 12 age- and gender-matched healthy controls (six males, six females; aged 26 x 8+/-7 x 6 years) were recruited to the study. MRI scans was obtained using a 1.5-T GE Signa Excite high-speed scanner. Anatomical measurements were conducted on a computer workstation with the software Scion Image Beta-3b for Windows. Statistical analysis was performed using an analysis of covariance (ANCOVA), the t test, chi2 and partial correlation analyses. Bipolar patients had significantly smaller areas of total CC, anterior body posterior body and isthmus compared with healthy control subjects by ANCOVA, with age, gender and intracranial volume (ICV) as covariates. There was a negative correlation between total CC, posterior body and isthmus areas and Young Mania Rating Scale (YMRS) scores. The findings suggest that CC morphology may be associated with the pathophysiology of bipolar disorder.

Functional and magnetic resonance imaging correlates of corpus callosum in normal pressure hydrocephalus before and after shunting

Background: Normal pressure hydrocephalus (NPH) is associated with corpus callosum abnormalities. Objectives: To study the clinical and neuropsychological effect of callosal thinning in 18 patients with idiopathic NPH and to...

Corpus callosum atrophy is associated with mental slowing and executive deficits in subjects with age-related white matter hyperintensities: the LADIS Study

Background: Previous research has indicated that corpus callosum atrophy is associated with global cognitive decline in neurodegenerative diseases, but few studies have investigated specific cognitive functions. Objective: To investigate the...

Diffusion tensor imaging of the corpus callosum in Autism

The corpus callosum is the largest commissural white matter pathway that connects the hemispheres of the human brain. In this study, diffusion tensor imaging (DTI) was performed on subject groups with high-functioning autism and controls matched for age, handedness, IQ, and head size. DTI and volumetric measurements of the total corpus callosum and subregions (genu, body and splenium) were made and compared between groups. The results showed that there were significant differences in volume, fractional anisotropy, mean diffusivity, and radial diffusivity between groups. These group differences appeared to be driven by a subgroup of the autism group that had small corpus callosum volumes, high mean diffusivity, low anisotropy, and increased radial diffusivity. This subgroup had significantly lower performance IQ measures than either the other individuals with autism or the control subjects. Measurements of radial diffusivity also appeared to be correlated with processing speed measured during the performance IQ tests. The subgroup of autism subjects with high mean diffusivity and low fractional anisotropy appeared to cluster with the highest radial diffusivities and slowest processing speeds. These results suggest that the microstructure of the corpus callosum is affected in autism, which may be related to nonverbal cognitive performance.

Joubert Syndrome Associated with Total Corpus Callosum Agenesis

Joubert syndrome was first described in 1969. It is a rare inherited disorder demonstrating one of the developmental defects of the cerebellar vermis. The main clinical signs of the syndome include developmental delay, hypotonia, ataxia, abnormal ocular movements and abnormal respiratory pattern of alternating episodic tachypnea-hyperpnea and apnea. Radiological findings comprise a midline cerebellar cleft in place of the vermis and a characteristic shape of the fourth ventricule. Associated supratentorial abnormalities such as callosal dysgenesis have been infrequently reported in patients with Joubert syndrome This report describes the clinical and neuroradiological findings of a rare patient presenting Joubert syndrome associated with total corpus callosum agenesis.

The role of the corpus callosum in dichotic listening: A combined morphological and diffusion tensor imaging study.

The objective of the present study was to examine the role of the corpus callosum (CC) in dichotic listening. For this purpose, 40 right-handed healthy male participants were assessed with morphological and diffusion tensor imaging, which yielded macrostructural (midsagittal area) and microstructural (mean diffusion, fractional anisotropy) measures of the total CC and predefined subregions. Applying the standard consonant-vowel Bergen Dichotic Listening Test (including 3 different attentional instructions), the authors found dichotic listening performance to be substantially related to the integrity of the CC at both macro- and microstructural levels. Results indicate a dual role of the CC; it is relevant not only for the stimulus-driven (bottom-up) transfer of left-ear input to the left hemisphere but also for its attentional (top-down) modulation.

Decreased corpus callosum size in sickle cell disease: Relationship with cerebral infarcts and cognitive functioning

We assessed midsagittal corpus callosum size in sickle cell disease (SCD) and its relationship to lesion volume, lesion location, and cognitive functioning. Twenty-eight children with SCD and 16 demographic controls completed magnetic resonance imaging (MRI) and neuropsychological testing. Corpus callosum (CC) size was smaller for children with silent infarcts (n = 8) or overt stroke (n = 8) than for those without visible infarcts (n = 12) or control participants. Lesion volume was a robust predictor of IQ and other cognitive scores; total CC size did not typically add explanatory power for these measures. The size of the rostral body of the CC, however, independently predicted measures of distractibility, speeded production, and working memory. Posterior CC size was also decreased among many of the children with SCD, even in the absence of visible infarcts in this region. Brain morphology appears to provide additional information about SCD-related effects on the brain above and beyond visible infarcts.

Corpus Callosum Atrophy in Wernicke's Encephalopathy

Neuropathologic changes in Wernicke's encephalopathy (WE) involve variable brain structures. Corpus callosum involvement in WE, however, is largely unknown. The authors investigated the degree and the pattern of corpus callosum changes in WE according to the etiologies. Nineteen patients with WE (between 34 and 81 years) and 19 age- and sex-matched control participants were included. The total cross-sectional callosal area and 5 callosal subregions (C1-C5) were measured by tracing outer margins in the midsagittal sections. Subregions were determined by placing radial dividers with 10 rays. The pixel numbers for corpus callosums were calculated, and the values obtained were adjusted for head size variations. The causes of WE were alcoholism (10), intestinal surgery (5), anorexia (3), and hyperemesis gravidarum (1). The mean size of the total corpus callosum was significantly reduced in alcoholic WE (P< .001; 527.8 +/- 70.8 mm2 for alcoholic WE; 664.6 +/- 58.1 mm2 for the corresponding controls), but not in nonalcoholic WE. In subregion analysis, prefrontal callosum (C2) atrophy was the most prominent in alcoholic WE. In contrast, only splenium (C5) was atrophied in nonalcoholic WE. The degree of atrophy did not change throughout the follow-up period (mean 5.3 weeks). This study suggests that the extent and location of corpus callosum atrophy differs between alcoholic WE and nonalcoholic WE, implying separate contribution of alcohol neurotoxicity and nutritional deficiency.

Corpus Callosum Atrophy in Wernicke's Encephalopathy

ABSTRACTBackground and Purpose. Neuropathologic changes in Wernicke's encephalopathy (WE) involve variable brain structures. Corpus callosum involvement in WE, however, is largely unknown. The authors investigated the degree and the pattern of corpus callosum changes in WE according to the etiologies. Methods. Nineteen patients with WE (between 34 and 81 years) and 19 age‐ and sex‐matched control participants were included. The total cross‐sectional callosal area and 5 callosal subregions (C1‐C5) were measured by tracing outer margins in the midsagittal sections. Subregions were determined by placing radial dividers with 10 rays. The pixel numbers for corpus callosums were calculated, and the values obtained were adjusted for head size variations. Results. The causes of WE were alcoholism (10), intestinal surgery (5), anorexia (3), and hyperemesis gravidarum (1). The mean size of the total corpus callosum was significantly reduced in alcoholic WE (P&lt; .001; 527.8 ± 70.8 mm 2for alcoholic WE; 664.6 ± 58.1 mm 2for the corresponding controls), but not in nonalcoholic WE. In subregion analysis, prefrontal callosum (C2) atrophy was the most prominent in alcoholic WE. In contrast, only splenium (C5) was atrophied in nonalcoholic WE. The degree of atrophy did not change throughout the follow‐up period (mean 5.3 weeks). Conclusion. This study suggests that the extent and location of corpus callosum atrophy differs between alcoholic WE and nonalcoholic WE, implying separate contribution of alcohol neurotoxicity and nutritional deficiency.

Sexual dimorphism and handedness in the human corpus callosum based on magnetic resonance imaging

The corpus callosum (CC) is a major anatomical and functional commissure linking the two cerebral hemispheres. With MR imaging in the sagittal plane, the corpus callosum can be depicted in great detail. Mid-sagittal magnetic resonance images of 80 normal individuals were analyzed to assess whether or not the morphology of the corpus callosum and its parts are related to sex and handedness. The subjects were 40 males (20 right-handers and 20 left-handers) and 40 females (20 right-handers and 20 left-handers). The midsagittal area of the corpus callosum was divided into seven sub-areas using Witelson's method. The most striking morphological changes concerned left-handers, who had larger areas of the anterior body, posterior body and isthmus than right-handers. In addition, right-handed males had larger rostrums and isthmuses than right-handed females. These significantly increased areas were related to handedness in right-handed males. However, left-handed males had larger anterior and posterior bodies than right-handed males. In contrast, there was no significant difference between left-handers and right-handers in females. The areas of the rostrum and posterior body of the corpus callosum increased significantly with sex in males. Moreover, there were no significant age-related changes in the total corpus callosum and sub-areas of the corpus callosum. In conclusion, these anatomical changes in corpus callosum morphology require taking the sexual definition and dominant handedness into consideration.

Corpus Callosal Microstructural Integrity Influences Interhemispheric Processing: A Diffusion Tensor Imaging Study

Normal aging and chronic alcoholism result in disruption of brain white matter microstructure that does not typically cause complete lesions but may underlie degradation of functions requiring interhemispheric information transfer. We examined whether the microstructural integrity of the corpus callosum assessed with diffusion tensor imaging (DTI) would relate to interhemispheric processing speed. DTI yields estimates of fractional anisotropy (FA), a measure of orientation and intravoxel coherence of water diffusion usually in white matter fibers, and diffusivity (<D>), a measure of the amount of intracellular and extracellular fluid diffusion. We tested the hypothesis that FA and <D> would be correlated with (i) the crossed-uncrossed difference (CUD), testing visuomotor interhemispheric transfer; and (ii) the redundant targets effect (RTE), testing parallel processing of visual information presented to each cerebral hemisphere. FA was lower and <D> higher in alcoholics than in controls. In controls but not alcoholics, large CUDs correlated with low FA and high <D> in total corpus callosum and regionally in the genu and splenium. In alcoholics but not controls, small RTEs, elicited with equiluminant stimuli, correlated with low FA in genu and splenium and high <D> in the callosal body. The results provide in vivo evidence for disruption of corpus callosum microstructure in normal aging and alcoholism that has functional ramifications for efficiency in interhemispheric processing.

Reduced area of the corpus callosum in posttraumatic stress disorder

Magnetic resonance imaging (MRI) studies have revealed decreases in the mid-sagittal area of the corpus callosum (CC) in pediatric posttraumatic stress disorder (PTSD), but at present no data are available in adult PTSD patients. We have previously reported decreased whole-brain white matter (WM) volume in adults with PTSD and now report corpus callosum area from the same sample. MRI was used to obtain whole-brain images in 12 adult patients with PTSD and 10 matched controls. Total parenchyma (white matter plus gray matter [GM]) volume, mid-sagittal area of the CC and seven sub-regions of this structure were calculated. In PTSD patients, the total CC area, absolute and normalized to total brain parenchyma, was smaller compared with control values. Several absolute and normalized CC sub-regions were also smaller in PTSD patients: genu (region 2), mid-body (region 5) and isthmus (region 6). There was also a trend for the anterior mid-body (area 4) to be smaller in PTSD patients. No differences were found in the rostrum (region 1), rostral body (region 3) or splenium (region 7). Adult patients with PTSD had decreased CC area after correcting for total brain tissue, indicating that these differences are not attributable to generalized white matter atrophy. These findings are similar to previous results in children with PTSD and suggest specific changes in the CC.

Effects of handedness and gender on macro- and microstructure of the corpus callosum and its subregions: a combined high-resolution and diffusion-tensor MRI study

The corpus callosum (CC) represents the major commissural tract connecting the two cerebral hemispheres and is supposed to play crucial integrative role in functional hemispheric specialization. The present study examined whether interindividual variations in macro- and microstructure of the human CC are associated with handedness and gender. Therefore, a combined diffusion-tensor (DTI) and high-resolution morphological MRI study was performed on 34 right- and 33 left-handed subjects of both sexes. The mid-sagittal surface areas and quantitative measures of molecular diffusion (relative anisotropy, mean diffusion) of the total CC and its subregions (genu, truncus, posterior third) were determined. Analysis revealed a larger total callosal area in right- as compared to left-handed subjects and in males as compared to females. Throughout all callosal subregions, anisotropy was found to be increased in left-handed as well as in male subjects, while the mean diffusion was diminished only in left-handers. For the posterior third of the CC, a significant negative correlation ( r=−0.34) between anisotropy and area was detected in right-handed subjects. Summarized, significant alterations in the molecular diffusion and in the size of the CC with respect to gender and handedness were revealed in the present study. These findings can be interpreted as handedness- and gender-related differences in macro- and microstructure of the callosal pathways. It was demonstrated that the inspection of the callosal microstructure using DTI yields empirical evidence on interhemispheric connectivity that goes well beyond the information revealed by anatomical measurements alone. Thus, DTI has proven to be a useful additional method in cognitive neuroscience.

Corpus callosum size and very preterm birth: relationship to neuropsychological outcome.

Thinning of the corpus callosum (CC) is often observed in individuals who were born very preterm. Damage to the CC during neurodevelopment may be associated with poor neuropsychological performance. This study aimed to explore any evidence of CC pathology in adolescents aged 14-15 years who were born very preterm, and to investigate the relationship between CC areas and verbal skills. Seventy-two individuals born before 33 weeks of gestation and 51 age- and sex-matched full-term controls received structural MRI and neuropsychological assessment. Total CC area in very preterm adolescents was 7.5% smaller than in controls, after adjusting for total white matter volume (P = 0.015). The absolute size of callosal subregions differed between preterm and full-term adolescents: preterm individuals had a 14.7% decrease in posterior (P < 0.0001) and an 11.6% decrease in mid-posterior CC quarters (P = 0.029). Preterm individuals who had experienced periventricular haemorrhage and ventricular dilatation in the neonatal period showed the greatest decrease in CC area. In very preterm boys only, verbal IQ and verbal fluency scores were positively associated with total mid-sagittal CC size and mid-posterior surface area. These results suggest that very preterm birth adversely affects the development of the CC, particularly its posterior quarter, and this impairs verbal skills in boys.

Childhood neglect is associated with reduced corpus callosum area

Background Childhood abuse has been associated with abnormalities in brain development, particularly corpus callosum (CC) morphology. The impact of neglect has not been assessed, though it is the most prevalent form of childhood maltreatment. Methods Regional CC area was measured from magnetic resonance imaging scans in 26 boys and 25 girls admitted for psychiatric evaluation (28 with abuse or neglect) and compared with CC area in 115 healthy control subjects. Data were analyzed by multivariate analysis of covariance, with age and midsagittal area as covariates. Results Total CC area of the abused/neglected patients was 17% smaller than in control subjects ( p = .0001) and 11% smaller than in psychiatric patients who had not been abused or neglected (contrast group; p = .01). Control subjects and the contrast group did not differ in total CC area. Neglect was the strongest experiential factor and was associated with a 15%–18% reduction in CC regions 3, 4, 5, and 7 (all p < .02). In contrast, sexual abuse seemed to be the strongest factor associated with reduced CC size in girls. Conclusions These data are consistent with animal research that demonstrated reduced CC size in nursery-reared compared with semi-naturally reared primates. Early experience might also affect the development of the human CC.

Abnormalities of the corpus callosum in nonpsychotic children with chromosome 22q11 deletion syndrome

Chromosome 22q11 deletion syndrome (22q11DS) is associated with elevated rates of schizophrenia and other psychoses in adulthood. Childhood morphologic brain abnormalities are frequently reported, but the significance of these and their relationship to the development of schizophrenia are unclear. We sought to delineate midline neuroanatomical abnormalities in nonpsychotic children with 22q11DS and their age- and sex-matched controls and compare these to those reported in individuals with schizophrenia. On qualitative analysis, we found a high incidence of midline developmental abnormalities (cavum septum pellucidum, or CSP). On quantitative analysis, the total corpus callosum (CC) area was significantly increased in the patient group and among the subregions, the patients had a significantly larger isthmus. These findings of an increased area of the corpus callosum, specifically the isthmus, have not been reported before in individuals with 22q11DS. We also found a relative lack of the age-related increase in the size of the corpus callosum in the children with 22q11DS. There were no differences in cerebellar vermis measurements between the patient and control groups. Our findings are indicative of frequent midline brain anomalies, including dysgenesis of the corpus callosum, in nonpsychotic children with 22q11DS. Although the increased size of the corpus callosum in our 22q11DS patients is in direct contrast to the decrease seen in schizophrenia, the high frequency of structural midline abnormalities in these nonpsychotic children with 22q11DS is similar to that seen in schizophrenia. Further longitudinal studies on these children will help determine which of these structural abnormalities is/are pertinent to the development of psychosis.

Corpus callosum in first-episode patients with schizophrenia – a magnetic resonance imaging study

Morphometric studies on the corpus callosum (CC) in schizophrenia have yielded contradictory results. The aim of the present study was to investigate magnetic resonance imaging (MRI) abnormalities of the CC in first-episode patients with schizophrenic psychoses. We assessed volumetric MRI in 31 patients with diagnoses of schizophrenia, schizophreniform or schizoaffective disorder (DSM-IV) and a maximum exposure to neuroleptics of 2 weeks. As a control group, 12 healthy age- and sex-matched individuals were included in the study. A whole body scanner at 1.5 Tesla was used to obtain 3D T1- and T2-weighted MR datasets. The data were evaluated semi-automatically (intracranial volume, total brain volume) and manually (CC) with the software NMRwin. Patients had smaller CC and CC subdivisions than controls. Schizophrenic and unaffected women exhibited larger total CC and rostral subdivisions than men in both groups. Handedness did not exert an influence. Our findings are in line with other in vivo morphometric studies on the CC in schizophrenia. The larger CC area in women may reflect general gender-related differences in CC size as described in healthy individuals.

Magnetic resonance imaging study of corpus callosum abnormalities in patients with bipolar disorder

Background This study was conducted to further examine the hypothesis of abnormalities in size of corpus callosum in subjects with bipolar disorder. Methods Sixteen right-handed DSM-IV bipolar I patients and 27 right-handed healthy control subjects were studied. A 1.5-T GE Signa magnet was used, and three-dimensional gradient echo imaging (spoiled gradient recall acquisition) was conducted. Area measurements of corpus callosum were obtained blindly, with a semi-automated software, by a well-trained rater. Results Right-handed bipolar I patients had significantly smaller total corpus callosum, genu, posterior body, and isthmus areas compared with right-handed healthy control subjects (analysis of covariance with age, gender, and intracranial volume as covariates, p < .05). Partial correlation analyses, controlled for intracranial volumes, found a significant inverse relationship between age and total callosal, genu, anterior body, isthmus, and circularity in healthy control subjects ( p < .05) but not in bipolar patients ( p > .05). Conclusions Smaller callosal areas may lead to altered inter-hemispheric communication and be involved in the pathophysiology and cognitive impairment found in bipolar disorder.

Sex differences in the corpus callosum of patients with schizophrenia

The corpus callosum (CC) has been of interest in schizophrenia research because of its possible role in reduced lateralization and because of its sexually dimorphic characteristics. The literature has been replete with structural brain studies that have yielded equivocal results because of failure to address sex differences, handedness, and overall reductions in total brain volume (TBV) associated with schizophrenia. We performed midsagittal corpus callosum area MRI measurements on 71 chronically ill patients with schizophrenia (52 males, 19 females) and 67 controls (49 males, 18 females) using a semiautomated analytic technique subdividing the corpus callosum into five segments. Consistent with a meta-analysis [J. Neurol., Neurosurg. Psychiatry 58 (1995) 457], reductions in total CC area (after controlling for TBV and age) were found in schizophrenia patients relative to controls. However, our effect size, though not statistically significant, was −0.33 compared to −0.18 for the meta-analysis, indicating greater reductions in total CC area in our group of patients. Statistical significance was achieved only in male patients versus male controls (effect size=−0.50). The effect size remained the same when only right-handers were included in the analysis; thus, handedness did not account for this result. CC size was not related to psychiatric symptoms nor cognitive functioning in this group of patients.

Sex differences in brain maturation in maltreatment-related pediatric posttraumatic stress disorder

Background. Recent investigations suggested that pediatric posttraumatic stress disorder (PTSD) is associated with adverse brain development. However, sex differences are poorly understood. Methods. In this study, 61 medically healthy children and adolescents (31 males and 30 females) with chronic PTSD secondary to abuse, who had similar trauma and mental health histories, and 122 healthy controls (62 males and 60 females) underwent comprehensive psychiatric assessments and an anatomical MRI brain scan. Results. When gender groups were analyzed separately, findings of larger prefrontal lobe CSF volumes and smaller midsagittal area of the corpus callosum subregion 7 (splenium) were seen in both boys and girls with maltreatment-related PTSD compared to their gender-matched comparison subjects. Subjects with PTSD did not show the normal age related increases in the area of the total corpus callosum and its region 7 (splenium) compared to non-maltreated subjects; however, this finding was more prominent in males with PTSD. Significant sex by group effects demonstrated smaller cerebral volumes and corpus callosum regions 1 (rostrum) and 6 (isthmus) in PTSD males and greater lateral ventricular volume increases in maltreated males with PTSD than maltreated females with PTSD. Conclusions. These data suggest that there are sex differences in the brain maturation of boys and girls with maltreatment-related PTSD. Longitudinal MRI brain investigations of childhood PTSD and the relationship of gender to psychosocial outcomes are warranted.