Brain regions, lesions, and stroke syndromes
Christos Tziotzios, Jesse Dawson, Matthew Walters, Kennedy R Lees in Stroke in Practice, 2017
The anterior cerebral artery (ACA) arises as the medial branch of the bifurcation of the internal carotid (ICA) at the level of the anterior clinoid process. The anterior cerebral artery passes above the optic nerve and into the great longitudinal fissure between the frontal lobes. It is joined to its mirror vessel from the contralateral hemicranium by the short anterior communicating artery. The ACA supplies the whole of the medial surface of each hemisphere above the corpus callosum and extending back up to the parieto-occipital sulcus (below and behind which lies the occipital lobe). It thus supplies the medial surface of the frontal and parietal lobes and its territory includes the motor and sensory cortices for the contralateral perineum, leg, and foot as well as micturition and defaecation.
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).
Neurosurgery And Clinical Tales
Andrew P. Wickens in A History of the Brain, 2014
Nonetheless, Van Wagenen had amassed a sizeable group of patients with corpus callosum lesions, and decided to enlist the help of psychologist Andrew Akelaitis to assess the behavioural consequences of his operation more carefully. Although Akelaitis was to be thorough, testing the patients on a wide range of neurological and psychological tests between 1940 and 1945, he could find little evidence of any behavioural impairment. The patients experienced no sensory and motor abnormalities, or had problems with speech and language comprehension. They also performed normally on all tests of intelligence. One unusual effect, but only found in two of the patients, was a conflict between the right and left hands. For example, one patient reported trying to open a door with his right hand, while shutting it with his left. However, in both cases, this ‘opposition’ effect proved temporary. Considering the large size and prominence of the corpus callosum in the brain, and its known role in connecting the two cerebral hemispheres, these were surprising findings. It would lead Karl Lashley in 1951 to remark, perhaps not entirely in jest, that the only known function of the corpus callosum was to stop the two cerebral hemispheres from sagging!
Reduction of white matter integrity correlates with apathy in Parkinson's disease
Published in International Journal of Neuroscience, 2018
Yang Zhang, Jiayong Wu, Wenbo Wu, Renyuan Liu, Lingen Pang, Dening Guan, Yun Xu
In our study, the results showed that compared to non-apathetic group, the apathetic PD patients presented lower FA values in the genu and body of the corpus callosum. The corpus callosum is the largest WM structure, constructed by a bundle of neural fibres. The right and left hemisphere of the brain are connected by the corpus callosum. These neural fibres facilitate communication between the left and right sides of the brain. Structurally, the corpus callosum is divided into the genu, body and splenium. Through the genu, the neural fibres extend to the frontal lobe and connect the prefrontal cortex between the two sides and are associated with the feeling of motivation [21]. Similarly, the splenium communicates with the bilateral parietal lobes and the visual cortex at the occipital lobes and functions in integrating multisensory information [22]. The impairment of the splenium will result in the occurrence of disconnection syndrome. Recently, several DTI studies have revealed that the decrease of the FA value at the corpus callosum was correlated with apathy in AD [23,24] and post-stroke [25] patients. Although there are no similar results in PD patients previously, our results are consistent with a research of AD [24]. Therefore, we speculate that the disconnection between the bilateral hemispheres of PD patients may lead to apathy.
Repatriation is associated with isthmus cingulate cortex reduction in community-dwelling elderly
Published in The World Journal of Biological Psychiatry, 2018
Raffaella Calati, Jerome J Maller, Chantal Meslin, Jorge Lopez-Castroman, Karen Ritchie, Philippe Courtet, Sylvaine Artero
The ICC connects the PCC to the parahippocampal gyrus. It is located behind the thalamus, posteroinferior to the splenium of the corpus callosum, and medial to the superior cerebellar cistern (Mark et al. 1993). A larger proportional isthmus has been found in females (both right- and left-handed) in comparison to males (right-handed) (Witelson 1989). Since the isthmus was found to be a language-related area (left hemisphere) (Binder et al. 1997), the reported sexual difference may be linked to differences in hemispheric language organisation between males and females. Moreover, the ICC includes the retrosplenial cortex (Brodmann areas 29 and 30) and overlaps with the broader retrosplenial complex area, and which are involved in spatial cognition (Bar & Aminoff 2003) and episodic memory (Valenstein et al. 1987).
Effects of constraint-induced movement therapy on brain glucose metabolism in a rat model of cerebral ischemia: a micro PET/CT study
Published in International Journal of Neuroscience, 2018
Ying-Ying Li, Bei Zhang, Ke-Wei Yu, Ce Li, Hong-Yu Xie, Wei-Qi Bao, Yan-Yan Kong, Fang-Yang Jiao, Yi-Hui Guan, Yu-Long Bai
The corpus callosum is the largest intercommunication neural pathway of the two cerebral hemispheres in mammals [42]. It is hypothesized that the corpus callosum inhibits transfer of information between the two hemispheres so as to enhance the function of the dominant hemisphere and suppress the non-dominant hemisphere activity ‘inhibitory model’. This will ultimately lead to independent information processing in each hemisphere and increase the degree of the cerebral functional lateralization [43]. CIMT increased FDG uptake in the contralateral brain regions associated with decreased glucose utilization in the ipsilateral hemisphere. The ‘inhibitory model’ can partly explain the decreased FDG uptake (decreased glucose utilization) in brain regions observed in the ipsilateral hemisphere in the CIMT group compared to the Control group (Figure 7 and 8(A)). In addition, the Sham group showed decreased FDG uptake in the ipsilateral cingulate and motor cortex compared to the Normal group (Figure 7), which might be attributed to the constraint of movement in the unaffected limb.
Related Knowledge Centers
- Axon
- Cerebral Cortex
- Cerebral Hemisphere
- Lateral Ventricles
- Nerve Tract
- Frontal Lobe
- Brain
- Commissural Fiber
- Longitudinal Fissure
- White Matter