Alien Hand Syndrome
Alexander R. Toftness in Incredible Consequences of Brain Injury, 2023
Each half of your brain contributes to controlling the muscles on the opposite half of your body, such that your right brain hemisphere is more in charge of controlling your left arm than is your left hemisphere and vice versa. When the hemispheres of your brain cannot communicate effectively because of a damaged corpus callosum, they may control their own half of the body with less discussion about it with the other hemisphere. For example, “damage to the corpus callosum results in the left [hand] being controlled only by the right hemisphere” without contribution from the left hemisphere (Scepkowski & Cronin-Golomb, 2003, p. 264). This may result in one half of the brain being surprised by the actions taken by the other half of the brain, because one hemisphere did not know what the other hemisphere was planning. Sometimes corpus callosum damage is accidental, but it can be performed intentionally as a treatment for seizures (see Seizures). Callosal alien hand syndrome is strongly associated with intermanual conflict as the two hemispheres of the brain end up disagreeing with one another because of the loss in communication efficiency (Feinberg et al., 1992).
Therapeutic Gases for Neurological Disorders
Sahab Uddin, Rashid Mamunur in Advances in Neuropharmacology, 2020
Corpus callosum is one of the most important commissural pathways linking the cerebral hemispheres. The procedure of callosotomy works by separating the interhemispheric seizures spread. The main goal of this process is to reduce the frequency of seizure because the outcome of seizures is hardly ever a cure. This process makes only the quality of life better and therefore patients are made to stay on an antiepileptic treatment. Patients often continue to have drop attacks and generalized seizures, which are thought to be due to other commissural pathways, such as anterior, posterior, and hippocampal commissures (Rougier et al., 1997). Thus, the degree of sectioning in callosotomy is to attain the equilibrium between good seizure control and minimizing consequences to reduce the disconnection syndrome. In most cases, an anterior corpus callosotomy is enough but if the patient still has seizures very repeatedly, complete callosotomy is important (Choudhri et al., 2015).
Nervous system
David Sturgeon in Introduction to Anatomy and Physiology for Healthcare Students, 2018
US neuroscientists Roger Sperry and Michael Gazzaniga performed a number of experiments on individuals whose corpus callosum had been removed (split-brain patients). One of the experiments involved presenting one object to the left eye and a different object to the right eye. The split-brain patient was then asked to place their left hand under a screen and draw what they had observed with their left eye. When asked to explain the picture, however, they always described what they had seen with their right eye. This and other experiments helped to demonstrate that without the corpus callosum, the left and right hemispheres are unable to communicate with each other. Agenesis of the corpus callosum is a rare congenital disorder where the corpus callosum is partially or totally absent at birth. Typical characteristics associated with this condition may include visual and hearing impairment, poor motor coordination, difficulty with abstract reasoning, misinterpretation of non-verbal communication and poor perception of pain. The most notable person to have agenesis of the corpus callosum was Kim Peek (1951–2009) who became famous as the inspiration for the character Raymond Babbitt in the film Rain Man. Peek had an exceptional memory and was able to read two pages of a book simultaneously. He read one page with his left eye and the other with his right and it took him about ten seconds in total.
Diffusion tensor imaging in glioblastoma patients treated with volumetric modulated arc radiotherapy: a longitudinal study
Published in Acta Oncologica, 2022
Anna Rydelius, Björn Lampinen, Andreas Rundcrantz, Johan Bengzon, Silke Engelholm, Danielle van Westen, Sara Kinhult, Linda Knutsson, Jimmy Lätt, Markus Nilsson, Pia C. Sundgren
DTI parameters in different normal-appearing structures were analyzed after defining regions of interest (ROI) in homogenous tissue. Three different structures of the corpus callosum were examined: splenium, corpus, and genu. In each of these structures, a ROI of 50 voxels was placed, which equals 0.05 cm3. The structures were contoured on the directionally encoded color-map using the baseline-examination and manually confirmed. If needed, manual adjustments were performed, on the subsequent scans (Figure 1). Normal-appearing white matter in the centrum semiovale in the right hemisphere was contoured on the T1-weighted image. The ROIs in this structure comprised 350–545 voxels, which equals 0.35–0.545 cm3. The hippocampus and amygdala were contoured bilaterally on the T1-weighted image and manually adjusted, to exclude partial volume effects, using the MD map. The ROIs in these structures comprised 300–640 voxels and 80–120 voxels respectively, which equals to 0.30–0.64 cm3 and 0.08–0.12 cm3, respectively (Figure1). DTI measurements were excluded from the analysis when edema and/or tumor infiltration seemed to have a direct effect of the structural integrity of a specific ROI. This was determined by manual inspection of all acquired images.
SPG11: clinical and genetic features of seven Czech patients and literature review
Published in Neurological Research, 2022
Kristyna Doleckova, Jan Roth, Julia Stellmachova, Tomas Gescheidt, Vladimir Sigut, Pavel Houska, Robert Jech, Michael Zech, Martin Vyhnalek, Emilie Vyhnalkova, Pavel Seeman, Anna Uhrova Meszarosova
Thin corpus callosum and the ´ears of the lynx´ sign are typically (but not necessarily) seen in the brain MRI of SPG11 patients [9,29]. Thin corpus callosum was present in five of the seven Czech SPG11 patients. In two patients thin corpus callosum (TCC) was not observed, one of these two patients presented with an atypical late onset of the disease. Although TCC has been described as typical, and often found in the brain MRI of patients with SPG11, it is not present in all of them. In concordance with our findings, SPG11 cases without TCC have been described previously [25]. The ´ears of the lynx´ sign was observed on the brain MRI in six of our patients. Except for Cases 4 and 6, the brain MRIs of all five remaining patients show atrophies to varying degrees in different brain structures.
The association between White matter microstructure alterations detected by Diffusional kurtosis imaging in Neural circuit and post-stroke depression
Published in Neurological Research, 2021
Weijing Liang, Zexin Fan, Sha Cui, Xueyong Shen, Li Wang
Besides, the anterior and posterior limb of internal capsule and corpus callosum are important tissues connecting the bilateral neostriatum, thalamus and cerebral hemisphere. Corpus callosum is a transverse nerve fiber bundle and the largest commissural fiber in the hemisphere, which plays an important role in integration and transmission of information. White matter fibers communicate with the bilateral prefrontal cortex through the genu of corpus callosum. We found that MK value of PSD group in the genu of corpus callosum is lower, but there was no significant decrease of MK/RK value in anterior and posterior limb of internal capsule (p > 0.05), suggesting that the corpus callosum may be associated with the occurrence of PSD. However, there was no significant difference in FA value in corpus callosum between the depressive and control group in Nobuhara K’s study [29]. Therefore, the role of corpus callosum and internal capsule in the development of PSD needs further study.
Related Knowledge Centers
- Axon
- Cerebral Cortex
- Cerebral Hemisphere
- Lateral Ventricles
- Nerve Tract
- Brain
- Commissural Fiber
- Longitudinal Fissure
- White Matter
- Brain