Diffusion weighted imaging evidence of extra-callosal pathways for interhemispheric communication after complete commissurotomy
Jason S. NomiE.A. MarshallEran ZaidelBharat B. BiswalF. Xavier CastellanosAnthony Steven DickLucina Q. UddinEric Mooshagian
11
Citation
36
Reference
10
Related Paper
Citation Trend
Keywords:
Commissurotomy
Commissure
Cases of absence or defect of the corpus callosum are of interest not only because of their great rarity, but because of the light which they throw on the distribution and functions of this commissure, and on the development of the mesial aspects of the cerebral hemispheres.
Commissure
Anterior commissure
Human brain
Cite
Citations (38)
Cerebral commissurotomy, the "split-brain" procedure, has been employed for the control of intractable seizures, in conjunction with moderate doses of anticonvulsant drugs. The results have been encouraging in several small series. The use of microsurgical techniques and the restriction of surgery to one commissure, the corpus callosum, has reduced morbidity without apparent change in result. The eight patients in our first series who underwent the prescribed division of several forebrain commissures are compared to the four patients in our second series who underwent division of the corpus callosum alone. The technique of callosotomy is described.
Commissure
Anterior commissure
Commissurotomy
Forebrain
Corpus callosotomy
Cite
Citations (134)
This research investigates the chronic effect of moderate to severe traumatic brain injury on brain white matter integrity, as reflected by diffusion tensor imaging metrics, and the assessment of their correlation to neuropsychological response. Thirteen male participants with traumatic brain injury (8.4 years average post-injury time) were compared to a matched group of neurologically healthy controls. None of the traumatic brain injury subjects had received post-acute neurocognitive and/or neuropsychological rehabilitation. Between-group comparison of fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity was performed for the whole brain and corpus callosum. An extensive battery of visual and verbal memory tasks was employed for the comparative assessment of neurocognitive performance. Between-group and within-group performance differences were correlated with fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity of corpus callosum. Significant changes in global fractional anisotropy, mean diffusivity, and radial diffusivity were associated with traumatic brain injury. Visual memory capacity was reduced in traumatic brain injury, and this deficit was correlated to white matter integrity loss at the corpus callosum. Participants with traumatic brain injury underperformed controls in verbal memory as well, but no correlation with corpus callosum diffusion tensor imaging properties was established. Between-group performance difference was correlated with corpus callosum diffusion metrics in several tasks. Significant correlations were found between corpus callosum diffusion tensor imaging metrics and neuropsychological response within the traumatic brain injury group. Changes in whole brain and corpus callosum diffusion tensor metrics inflicted by moderate to severe traumatic brain injury are still evident several years post-injury and relate to neurocognitive impairment, while loss of white matter integrity seems to correlate with episodic and working memory impairment.
Diffuse axonal injury
Splenium
Cite
Citations (10)
The corpus callosum is the largest and phylogenetically one of the oldest of the commissures, yet its function is an enigma. In primitive mammals (edentata) it is formed by a thin membrane. In phylogenesis the corpus callosum becomes larger and larger. It is proportional to the growing size of the telencephalon and to the number of cerebral convolutions. Congenital absence of the corpus callosum in man is a rare occurrence. However, we have had the opportunity to observe 24 cases of agenesis of this commissure. The main purpose of this chapter is to demonstrate some typical variations of this pathological condition.
Commissure
Anterior commissure
Corpus Callosum Agenesis
Cite
Citations (9)
Commissure
Splenium
Anterior commissure
Rostrum
Posterior commissure
Cite
Citations (11)
Commissurotomy
Splenium
Cite
Citations (74)
Abstract The cerebral commissures house the fibers that interconnect the two hemispheres of the brain. The main fiber tract, namely the corpus callosum, varies greatly in size in the human brain. Factors such as sex of the individual and chronological age affect its size. Relationships exist between callosal size, degree of functional asymmetry and cognitive ability. The callosum may play a crucial role in the experience of conscious unity.
Commissure
Brain asymmetry
Cite
Citations (0)
Commissure
Cite
Citations (7)
Splenium
Cite
Citations (579)
AbstractThe corpus callosum contributes to the interhemispheric transfer of somatosensory information. Since the somatosensory pathways are essentially crossed, a number of studies have postulated that the corpus callosum may be responsible for the presence of bilateral receptive fields (RFs) in cortical area SII. Moreover, subcortical structures, as well as some of the other commissures, may also contribute to the bilateral nature of these cells. In order to assess the relative importance of the corpus callosum, this study compared the RF properties of cells in area SII of callosum-sectioned cats to normal cats, using single-cell recordings. Results showed that the corpus callosum makes an important contribution to the bilateral activation of cells in SII, since the proportion of cells with bilateral RFs found in callosum-sectioned cats was less than half that obtained in normal cats. The decrease in the proportion of bilateral RFs was found for all body regions with the exception of the face. However, the substantial number of bilateral RFs remaining in callosotomized cats indicates that this structure is not the sole contributor to the bilateral activation of cells in SII. In order to determine whether this residual bilateral activation might be mediated by the other interhemispheric commissures, a group of cats was subjected, besides the callosotomy, to the additional transection of their subcortical commissures, including the anterior, posterior, habenular, and intertectal commissures, as well as the massa intermedia. When this group of deep-split cats was compared to the callosotomized group, the results indicated that the contribution of the other commissures to bilateral activation is negligible, since approximately the same proportion of bilateral RFs was encountered in the two groups. The relative importance of the callosal contribution to bilateral RFs of different body regions is discussed with respect to the roles commonly attributed to this structure.Key Words: corpus callosuminterhemispheric commissurearea SIIbilateral receptive fieldipsilateral pathwaymidline fusion
Commissure
Cite
Citations (22)