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PubMed2000

A magnetic resonance imaging study of corpus callosum size in familial schizophrenic subjects, their relatives, and normal controls.

The corpus callosum is one of several brain regions thought to be abnormal in schizophrenia. We sought to investigate whether the size of the corpus callosum would be abnormally small in schizophrenic subjects from families with familial schizophrenia and their healthy relatives. We wished to determine whether an abnormal corpus callosum size is found in healthy relatives who are genetically at a greater risk than normal of developing or transmitting the disorder. Twenty-seven familial schizophrenics, 53 of their healthy first-degree relatives, and 35 normal volunteers underwent MRI brain scans. We defined 11 of the relatives as presumed 'obligate carriers', i.e. an individual who appears to be transmitting the schizophrenic gene(s). The mid-sagittal slice of the corpus callosum and the whole brain volume were measured blind to diagnostic and family group. We found no difference between schizophrenics, their relatives, and normal controls in the mid-sagittal area of the corpus callosum. There remained no difference when the relatives were divided into two groups comprising presumed 'obligate carriers' and 'non-obligate carriers'. Adjusting for age and whole brain area made no difference to the results. Families with several schizophrenic members are not associated with abnormality in the size of the corpus callosum.

Adult↗

PubMed1994

Partial development of the corpus callosum.

PURPOSE: To determine whether the MR findings of callosal dysgenesis suggest that the partially formed corpus callosum in humans is the result of arrested growth or delayed continued development. METHODS: The MR scans of 25 patients with callosal dysgenesis were reviewed to determine whether the observed corpus callosum corresponded to the form and position of a portion of a normal corpus callosum, as suggested by a theory of arrested growth. RESULTS: In 10 of the 25 cases, the partially formed corpus callosum corresponded to a portion of a normal corpus callosum. In the remaining 15 cases, the partially formed corpus callosum was located posterior to the expected location of a normal genu and inferior to the expected location of a normal body. CONCLUSIONS: Corpus callosum dysgenesis in humans may be caused by arrested growth in some cases; in other cases it is most likely caused by delayed continued development that attempts to compensate for earlier abnormalities in the evolution of midline structures.

Abnormalities, Multiple↗

PubMed2002

[Value of fetal cerebral magnetic resonance imaging for the prenatal diagnosis and prognosis of corpus callosum agenesis].

OBJECTIVE: To evaluate MR contribution to prenatal diagnosis and prognosis of corpus callosum agenesis suspected by ultrasound and to ascertain how and when this examination should be included part in prenatal management of such malformation. PATIENTS AND METHODS: During a six-year period from January 1st 1994 and December 31st 2000, fifteen patients (and fifteen fetuses) were referred to our fetal medicine unit with suspicion of corpus callosum agenesis on prenatal ultrasound. Cerebral MRI was performed in all cases to confirm prenatal diagnosis. In our study, prenatal MRI examinations were retrospectively studied and compared with neuropathological examinations (n=8) or postnatal imaging (n=6). RESULTS: Corpus callosum agenesis were either complete (n=13) or partial (n=1). All were visible on prenatal MRI but only six on prenatal ultrasound. In one case, ultrasound suspicion of corpus callosum agenesis was ruled-out (false positive on prenatal ultrasound) by fetal cerebral MRI. In five cases corpus callosum agenesis was an isolated finding whereas in 12 cases associated malformations were encountered (cerebral n=7 or extra-cerebral n=5). MR depicted 7 of the 12 associated neurologic abnormalities. CONCLUSION: Prenatal MRI is a valuable complementary technique for either diagnosis of corpus callosum agenesis and depiction of associated neurologic abnormalities. Superiority of MR on prenatal sonography and its help in post-mortem examination of the brain (help in the choice of the pathologic technique and localisation of the samples) makes it essential even when pregnancy termination is considered.

Adult↗

PubMed2002

In vivo imaging of region and cell type specific neocortical neurodegeneration in Alzheimer's disease. Perspectives of MRI derived corpus callosum measurement for mapping disease progression and effects of therapy. Evidence from studies with MRI, EEG and PET.

Neuropathological studies in Alzheimer's disease (AD) indicate specific loss of layer III and V large pyramidal neurons in association cortex. These neurons give rise to long cortico-cortical connections, projecting through the corpus callosum, in an anterior-posterior topology. Based on these findings we hypothesized that regional corpus callosum atrophy may be a potential in vivo marker for neocortical neuronal loss in AD. To evaluate this hypothesis, we developed a method to measure cross-sectional area of the corpus callosum and of five corpus callosum subregions on midsagittal magnetic resonance imaging scans (MRI). In a subsequent series of six experimental studies using MRI, (18)FDG-PET and EEG, we investigated the relation of white matter hyperintensities (WMH) to corpus callosum size and correlated regional pattern of corpus callosum atrophy with regional cortical metabolic decline as well as intracortical coherencies. Mean total corpus callosum area was reduced significantly in AD patients compared to healthy age-matched controls, with the greatest changes in the rostrum and the splenium and relative sparing of the truncus. The regional pattern of corpus callosum atrophy was independent of WMH load and correlated significantly with pattern of regional metabolic decline measured with (18)FDG-PET, the degree of cognitive impairment and regional decline of bilateral intracortical-coherency in EEG in AD patients. We further found that hippocampus atrophy, as a marker of early allocortical degeneration, was more pronounced than total corpus callosum atrophy in mild stages of AD. Regional corpus callosum atrophy in mild disease, however, suggested early neocortical degeneration in AD. In a longitudinal study, AD patients showed significantly greater rates of corpus callosum atrophy than controls. Rates of atrophy correlated with progression of clinical dementia severity in AD. Our results indicate that regional corpus callosum atrophy in AD patients represents the loss of callosal efferent neurons in corresponding regions of the neocortex. As these neurons are a subset of cortico-cortical projecting neurons, region-specific corpus callosum atrophy may serve as a marker of progressive neocortical disconnection in AD. In combination with measurement of hippocampal atrophy, assessment of corpus callosum atrophy over time in individual patients is useful to evaluate effects on brain structure of currently developed drugs, thought to slow or modify AD progression.

Alzheimer Disease↗

PubMed2006

[Sexual dimorphism of the human corpus callosum--digital morphometric study].

BACKGROUND/AIM: Changes in the morphology and the size of the corpus callosum, are related to various pathological conditions. An analysis of these changes requires data about sexual dimorphism of the corpus callosum, which we tried to obtain in our study. We also investigated the method of digital morphometry and compared the obtained results with the results of other authors obtained by magnetic resonance imaging or by planimetry. METHODS: A morphological research included 34 human brains (cadavers of both sexes--19 female and 15 male aged 26-72 years). By digital morphometry using an AutoCAD software we performed measurements in the corpus callosum: the length (L), width in the half of its length (WW'), length of its cortical margin (LCM), area and perimeter of the anterior and posterior callosal segments, as well as the area and perimeter of the corpus callosum section area. The investigated parameters were analyzed and compared between the females and males. RESULTS: There was not a statistically significant difference between the males and females in the investigated parameters of the corpus callosum (t test; p > 0.05), including the mean values of the two most important parameters, the surface of its mid-sagittal section area (males 654.11 mm2; females 677.40 mm2) and of its perimeter (males 19.61 cm; females 19.72 cm). The results obtained by digital morphometry were in the range of the results of other authors obtained by magnetic resonance and by planimetry. However, the value of Pearson coefficient of linear correlation between the section surface area and perimeter of the corpus callosum in the males was highly significant (rxy = 0.6943, p < 0.01), while in the females this value was statistically insignificant. CONCLUSION: Digital morphometry is accurate method in encephalometric investigations. Our results suggest that the problem of sexual dimorphism of the corpus callosum is very complex, because the identical variables (section surface area or its perimeter) do not exhibit the same behavior in males and in females, implicating that these variables even cannot be simply compared between the sexes.

Adult↗

PubMed2005

Sex differences in the human corpus callosum: diffusion tensor imaging study.

In order to assess underlying structural differences between the male and female corpus callosum, the fractional anisotropy and volume of the corpus callosum, and also its T1 signal intensity, were measured. The corpus callosum of the 15 normal women and 15 normal men was drawn on the mid-sagittal T1-weighted image, for determining its volume and signal intensity, and this region of interest was projected onto the coregistered fractional anisotropy image, in order to obtain the value for the corpus callosum. We found increased T1 signal intensity and decreased fractional anisotropy in the female corpus callosum, as compared with that of the male. Despite the long-standing debates, the corpus callosum remains a region of sex differences.

Adult↗

PubMed2002

Prenatal diagnosis of hypoplasia of the corpus callosum in association with non-ketotic hyperglycinemia.

Abnormalities of the corpus callosum are often associated with a poor prognosis due to the anatomical defect itself and associated anomalies that include malformations and inherited metabolic disorders. We report a case of the prenatal diagnosis of hypoplasia of the corpus callosum that was associated with non-ketotic hyperglycinemia. Metabolic disorders are a known association with corpus callosum abnormalities and carry a dismal prognosis. A diagnosis of non-ketotic hyperglycinemia should be considered when a fetus presents with an abnormality of the corpus callosum. A literature search reviews other inherited diseases associated with hypoplasia of the corpus callosum.

Abnormalities, Multiple↗

PubMed2002

Spatial attention in agenesis of the corpus callosum: shifting attention between visual fields.

The role of the corpus callosum in spatially selective visual attention is uncertain. Research using commissurotomy and callosotomy patients has attempted to determine if the corpus callosum plays a role in reorienting attention between visual fields, as if spatial attention is unitary or divisible between the cerebral hemispheres. Reorienting of selective visuospatial attention within versus between visual fields was tested in 10 individuals with agenesis of the corpus callosum (ACC) and nine matched controls. Spatially focused attention to the most likely location of target appearance was created using both peripheral sensory cues and central symbolic cues in separate tests. Results demonstrated that individuals with ACC have significantly greater difficulty reorienting attention to an invalidly cued target stimulus occurring in the opposite visual field. However, this effect did not interact with the type of cueing (sensory or symbolic). Individuals with ACC did not differ from controls either with respect to the laterality of within-field reorientation of attention, or with respect to the most efficient direction of between-field shifting of attention. Since congenital absence of the corpus callosum significantly reduces efficiency in the reorienting of attention between visual fields, spatial attention cannot be completely unified based on a subcortical mechanism and the mobilization of attentional resources within each hemisphere must depend on callosal processes.

Adult↗

PubMed1994

Corpus callosum development in preterm and term infants.

The development of the corpus callosum was documented by magnetic resonance imaging in low-risk preterm infants and results were compared with those of term infants. Thirty-three magnetic resonance imaging studies were performed on 21 preterm infants whose corrected ages were 1-13 months. Twenty-one magnetic resonance imaging studies were performed on 17 term infants. All infants exhibited normal development. The thickness of the corpus callosum was measured at a point one-third of the length of the entire corpus callosum from the most anterior aspect of the genu. The thickening of the corpus callosum was related to age in the preterm group. The development of the corpus callosum in preterm infants was suggested to be the same as that of term infants matched by conceptional age.

Birth Weight↗

PubMed2006

Focal transient lesions of the corpus callosum in systemic lupus erythematosus.

Focal lesions limited to the splenium of the corpus callosum are rare and little is known about their etiology. We describe three patients with systemic lupus erythematosus (SLE) that presented transient lesions of the corpus callosum. We reviewed three patients with SLE whose magnetic resonance imaging (MRI) results revealed focal lesions in the splenum of corpus callosum. The medical records, including clinical, serological, and treatment features, were reviewed to determine the etiology of these lesions. Of 115 patients who had MRI for research purposes, three patients with focal nonhemorrhagic lesions of the corpus callosum were identified. All patients had active SLE at the time of MRI. One patient had other findings on MRI, including cerebral venous thrombosis. On follow-up MRI, patients had an inactive disease and the corpus callosum lesions disappeared. A transient lesion in the splenium of corpus callosum seems to be a nonspecific endpoint of different disease processes leading to vasogenic edema. The complete and rapid reversibility in all cases with disease control is emphasized and any invasive diagnostic or therapeutic approach is discouraged.

Adolescent↗

PubMedDate not supplied

Attention-deficit hyperactivity disorder: magnetic resonance imaging morphometric analysis of the corpus callosum.

OBJECTIVE: The following study seeks to document possible differences in corpus callosal area and shape between children with attention-deficit hyperactivity disorder (ADHD) and controls. METHODS: Fifteen carefully diagnosed right-handed male subjects with ADHD with overactivity symptomatology were compared to 15 right-handed male control subjects. The corpus callosum was divided into seven areas on the midsagittal slice of a magnetic resonance image with shape analysis also conducted. RESULTS: An exploratory shape analysis showed no significant differences in shape between the groups. No group differences were found in the area, length, or anterior regions of the corpus callosum. The ADHD subjects were found to have significantly smaller posterior corpus callosum regions than the control group, with the splenium accounting for most of the variance between the groups. CONCLUSIONS: The splenial area of the corpus callosum is smaller in children with ADHD than in a sample of normally developing children. These smaller areas may relate to commonly seen sustained attention deficits which in turn negatively impact on the development of more advanced levels of attention such as self-regulation. Further study of the regions surrounding the splenial area is suggested to determine whether they are correlated in size to the smaller corpus callosum.

Adolescent↗

PubMed1993

Distribution of transitory corpus callosum axons projecting to developing cat visual cortex revealed by DiI.

Functional studies of the development of the corpus callosum in the cat have shown that an intact callosum during postnatal month 1 is necessary for normal visual development. In vivo tracing techniques have not provided enough information on corpus callosum connectivity to fully evaluate the evidence for a morphological mechanism for the functional effects of neonatal callosum section. However, lipophilic in vitro membrane tracers permit a more detailed search for such evidence because the entire limit of many cells can be labeled simultaneously. To investigate the morphological basis for the observed functional results in cats, the corpus callosum was labeled in vitro with the carbocyanine dye, DiI. Crystals of DiI were placed in the midsagittal callosum in tissue from 2 to 277-day-old cats. Tissue was coronally sectioned 3-22 months later. Sections were photographed and reconstructed to show the overall distribution of corpus callosum projections, as well as the locations of individual corpus callosum axons and their presumed terminals. The distribution of corpus callosum projections, examined in cortical areas 17-19, 7, and posterior medial lateral suprasylvian cortex, changes significantly during development. During postnatal week 1, callosal axons extend throughout these cortical areas to layer I. Numerous varicosities on callosal axons are located en passant and at axon terminals in layer I. During postnatal week 2, the density of callosal projections is reduced in all cortical areas, although many axons still extend to layer I. By postnatal month 2, the callosal axons extending to layer I are predominantly near the border with adjacent cortical areas; in the nonborder regions of these areas, many axons extend to layer VI while a much smaller number of axons extend to layers II-V. By postnatal month 3, the callosal projections to supragranular layers are almost exclusively restricted to cytoarchitectonic border regions; in the remaining regions, including medial area 17, there are occasional axons extending to the supragranular layers and only a moderate number of axons extending to infragranular layers. Thus, a substantial number of elaborately formed transitory corpus callosum axons, distributed throughout visual cortex, exist for several weeks during postnatal development; in area 17, these axons are found in central through peripheral visual field representations. The transitory callosal axons appear to have axon terminals in layer I as well as en passant terminals while extending through layers II-VI. If some of these terminals were to form synapses, there would be extensive opportunities for the corpus callosum to provide input to layers I-VI throughout visual cortex during the period of development in which cortical microcircuitry is being established.

Aging↗

PubMed1996

Size of the corpus callosum in cerebral palsy.

It has been suggested that the size of the corpus callosum may have diagnostic significance in cerebral palsy, although this relationship is incompletely defined. Ninety-one patients with cerebral palsy had been studied by magnetic resonance imaging in the 5-year period from 1990 to 1994. Fifty-seven of these 91 patients had a technically appropriate midsagittal magnetic resonance image for quantitative morphometric analysis. The ratio of the area of the corpus callosum to the area of the supratentorial brain was compared to published age- and gender-specific norms. Imaging findings were correlated with clinical history and cause of cerebral palsy. The corpus callosum was of normal size in 43 patients and more than 2 standard deviations below the mean in 14 patients. The causes for cerebral palsy included hypoxic ischemic encephalopathy (32), cerebral dysgenesis (8), and porencephalic strokes (6); the etiology could not be established in 11 patients. The size of the corpus callosum was highly correlated with the cause of cerebral palsy, such that all patients with cerebral dysgenesis had hypoplasia of the corpus callosum (one-sided z test, p < 0.0001). Conversely, the callosum was of normal size in 32 of 38 patients with hypoxic ischemic encephalopathy and porencephalic strokes. The presence of a hypoplastic corpus callosum is highly associated with cerebral dysgenesis as a cause for cerebral palsy.

Adolescent↗

PubMed1998

Dissociation between corpus callosum atrophy and white matter pathology in Alzheimer's disease.

OBJECTIVE: To determine whether the size of the corpus callosum is related to the extent of white matter pathology in patients with AD and age-matched healthy control subjects. METHODS: White matter hyperintensity load and corpus callosum size were compared between 20 clinically diagnosed AD patients and 21 age-matched healthy control subjects. We investigated the effect of age and disease severity on corpus callosum size and white matter hyperintensity, in addition to the relation between corpus callosum areas and white matter hyperintensity load. RESULTS: We found significant regional atrophy of the corpus callosum in AD when compared with control subjects, although the groups did not differ in their white matter hyperintensity load. We further showed a region-specific correlation between corpus callosum size and white matter hyperintensity in the control group but not in AD patients. In the AD group, corpus callosum size correlated with age and dementia severity, whereas white matter hyperintensity correlated only with age. CONCLUSION: Corpus callosum atrophy in AD can occur independent of white matter degeneration, likely reflecting specific AD pathology in projecting neurons.

Aged↗

PubMed2004

Corpus callosum signal intensity in patients with bipolar and unipolar disorder.

BACKGROUND: Anatomical abnormalities in the corpus callosum have been reported in magnetic resonance imaging (MRI) studies in patients with bipolar but not unipolar disorder. MRI signal intensity can be used as a putative index of corpus callosum myelination. OBJECTIVES: To measure MRI signal intensity in patients with bipolar and unipolar disorder to investigate abnormalities of corpus callosum myelination. METHODS: The study involved 29 DSM-IV bipolar patients (mean (SD) age, 35 (11) years; 16 male, 13 female), 23 DSM-IV unipolar patients (41 (10) years; 4 male, 19 female), and 36 healthy controls (37 (10) years; 23 male, 13 female). A 1.5T GE Signa magnet was employed, with a fast spin echo sequence. Corpus callosum signal intensity was obtained blindly using the semiautomated software NIH Image 1.62. RESULTS: Bipolar patients had lower corpus callosum signal intensity for all callosal subregions (genu, anterior and posterior body, isthmus, splenium) than healthy controls (ANCOVA, age and sex as covariates, p<0.05). No significant differences were found between unipolar and healthy subjects (ANCOVA, age and sex as covariates, p>0.05). CONCLUSIONS: The findings suggest abnormalities in corpus callosum white matter in bipolar but not unipolar patients, possibly because of altered myelination. Such abnormalities could lead to impaired interhemispheric communication in bipolar disorder. Longitudinal MRI studies involving first episode and early onset bipolar patients will be necessary for a better understanding of the potential role of abnormalities of corpus callosum myelination in the pathophysiology of bipolar disorder.

Adult↗

PubMed1984

Agenesis of the corpus callosum: sonographic features.

Sonographic features of agenesis of the corpus callosum and its related intracranial abnormalities are described in four patients. A brief review of clinical, radiologic, and pathologic manifestations of agenesis of the corpus callosum is presented. Both agenesis of the corpus callosum and its potentially serious associated intracranial abnormalities can be effectively diagnosed with transfontanelle sonography.

Abnormalities, Multiple↗

PubMed1992

[Behavioral asymmetry in BALB/cCF mice with corpus callosum abnormalities].

The possible homology between anomalies of the corpus callosum in mice and in humans remains questionable. The small number of existing behavioural studies in mice have not shown effects, at the behavioural level, of the absence or reduction in size of the corpus callosum. We therefore examined the development, during the first 3 weeks of postnatal life, of a number of simple reflex and integrative responses in the members of a sample of 101 BALB/cCF mice; at autopsy carried out at 50 days of age, 29 mice showed anomalies of the corpus callosum (total absence or an area less than 0.75 mm2). Asymmetry of the development of these responses was measured either as the proportion of animals showing asymmetrical appearance of responses on the left and right sides, and as the delay between appearances on the left and right sides in "asymmetrical" mice. Both measures decreased over the first 15 postnatal days, at the same rate in normal and abnormal mice; in each case the decrease is better described by a second-order, quadratic, function than by a simple linear function. We therefore conclude that the integrity of the corpus callosum is not necessary for the normal maturation of sensorimotor behaviour in mice, and suggest that this conclusion may possibly be explained by the relatively recent appearance of mice in the mammalian radiation.

Agenesis of Corpus Callosum↗

PubMed1993

The corpus callosum: normal fetal development as shown by transvaginal sonography.

OBJECTIVE: Detection of the corpus callosum in the developing fetus on sonograms usually is difficult. We determined the normal appearance and development of this structure during the second half of pregnancy, as shown on transvaginal sonograms. SUBJECTS AND METHODS: One hundred one fetuses were evaluated with transvaginal sonography between 18 and 42 weeks' gestation. The length of the corpus callosum and the thicknesses of the genu, body, and splenium were measured, and growth tables were produced. RESULTS: The corpus callosum was detected in 95% of cases and showed gradual enlargement during pregnancy; growth was linear, from nearly 17 mm in length at 18 weeks' gestation to 44 mm at term. The ratios of the length of the corpus callosum to the anteroposterior diameter of the brain remained relatively constant from 20 to 21 weeks' gestation to term. CONCLUSION: Transvaginal sonography can be used to visualize and measure the corpus callosum in the developing fetus. Data from this study may be useful as a reference for normal development of the corpus callosum.

Corpus Callosum↗