China
Africa
Explore chapters and articles related to this topic
Brain swelling, raised intracranial pressure and hypoxia-related brain injury
Published in Helen Whitwell, Christopher Milroy, Daniel du Plessis, Forensic Neuropathology, 2021
A supratentorial mass may produce herniation of the ipsilateral uncus of the temporal lobe as well as the medial part of the parahippocampal gyrus (Figure 12.3). This is displaced through the tentorial opening. It is also known as lateral transtentorial herniation. Compression of the contralateral cerebral peduncle against the free edge of the tentorium may result in pressure-related secondary injury with or without haemorrhage in the dorsal part of the peduncle and adjacent tegmentum, a lesion referred to as Kernohan's notch. Ipsilateral cerebral peduncular compression may lead to contralateral limb weakness as a more common associated feature of severe asymmetric tentorial herniation. The oculomotor nerve may show kinking around the ipsilateral posterior cerebral artery and pressure related bleeding. Necrosis may occur along the parahippocampal gyrus. Compression of the anterior choroidal arteries may cause infarction in the medial part of the globus pallidus, internal capsule and optic tract. A not uncommon complication is compression of the posterior cerebral artery leading to infarction in the posterior inferior temporal lobe including the hippocampus, together with the medial and inferior surfaces of the occipital cortex and even thalamus. This is characteristically haemorrhagic in nature (Figure 12.4). Cerebellar infarction may also occur due to compression of a superior cerebellar artery (SCA). These infarctions are most commonly ipsilateral to the side of the mass lesion but can be bilateral.
Sex-related functional asymmetry of the amygdala: Preliminary evidence using a case-matched lesion approach
Published in Howard J. Rosen, Robert W. Levenson, Neurocase, 2020
Daniel Tranel, Antoine Bechara
The amygdala lesion for 2897 is depicted in Figure 2b. It can be seen that the amygdala is substantially damaged on the right, and the little remaining amygdala tissue likely has no meaningful connectivity judging from the adjacent damage to the parahippocampal gyrus. The surgical report from the first surgery (from the Mayo Clinic) indicated that the amygdala had been resected.
Anatomy for neurotrauma
Published in Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor, Essentials of Anesthesia for Neurotrauma, 2018
Vasudha Singhal, Sarabpreet Singh
Limbic cortex—situated at the inferomedial aspect of the cerebral hemisphereCingulate gyrus—lies dorsal to the corpus callosum, and is interconnected with the association areas of cerebral cortex. It functions to regulate the heart rate and blood pressure and is also involved in cognitive and emotional processing.Parahippocampal gyrus is located in the medial temporal lobe and plays a major role in spatial memory. It contains the entorhinal cortex, which is concerned with olfactory memories.
Training flexible conceptual retrieval in post-stroke aphasia
Published in Neuropsychological Rehabilitation, 2022
Sara Stampacchia, Glyn P. Hallam, Hannah E. Thompson, Upasana Nathaniel, Lucilla Lanzoni, Jonathan Smallwood, Matthew A. Lambon Ralph, Elizabeth Jefferies
MRI scans were traced onto standardized templates (Damasio & Damasio, 1989) and lesion identification was manually performed (see Table 2 and Figure 1 for lesion overlay). All eleven patients had lesions affecting the left posterior LIFG; in eight cases this damage extended to mid-to-anterior LIFG. Parietal regions (supramarginal gyrus and/or angular gyrus) were also affected in 9 cases out of 11, and pMTG was affected in all but four cases. While there was some damage to ATL in 4 patients (SD, KQ, KA, VN), the ventral portion of ATL, which has been implicated in conceptual representation across modalities (Binney et al., 2012; Visser et al., 2012), was intact in all cases. This region is supplied by both the anterior temporal cortical artery of the middle cerebral artery and the anterior temporal branch of the distal posterior cerebral artery, reducing its vulnerability to stroke (Borden, 2006; Conn, 2008; Phan et al., 2005). The hippocampus and parahippocampal gyrus were intact in all patients.
Resting state functional brain imaging in obsessive-compulsive disorder across genders
Published in The World Journal of Biological Psychiatry, 2022
Yinzhu Ma, Qing Zhao, Tingting Xu, Pei Wang, Qiumeng Gu, Zhen Wang
The right parahippocampal gyrus was the brain region which differed the most between mOCD and fOCD patients in our present study. This brain region is the part of the limbic system located in the medial side of the occipital and temporal lobes. Since the parahippocampal gyrus is the main cortical input of the hippocampus, structural or functional damage can lead to emotional and cognitive dysfunction (Jung et al. 2017). Functional and structural studies have shown that there may be pathological changes in the right parahippocampal gyrus in OCD. Zhao et al. (2017) explored the differences in ALFF between OCD patients and HCs before and after cognitive-coping therapy (CCT) and pharmacotherapy and CCT, demonstrating that the ALFF value of OCD subjects in the parahippocampal gyrus increased before treatment, and disappeared after treatment. Yang et al.’s (2019) study on abnormal regional homogeneity (REHO) values in OCD patients showed that their REHO values in the right parahippocampal gyrus were decreased compared with those of HCs. Studies on brain structure have also found abnormal changes in this brain region in patients with OCD. Tang et al.’s (2015) voxel-based morphometry study of OCD participants found increased grey matter volume in the right parahippocampal gyrus. Using these studies as a guide, our study further verified the changes in the right parahippocampal gyrus in patients with OCD of different genders, while also demonstrating novel brain regions to investigate functional changes in OCD.
Altered dynamic parahippocampus functional connectivity in patients with post-traumatic stress disorder
Published in The World Journal of Biological Psychiatry, 2021
Hui Juan Chen, Rongfeng Qi, Jun Ke, Jie Qiu, Qiang Xu, Zhiqiang Zhang, Yuan Zhong, Guang Ming Lu, Feng Chen
The parahippocampal gyrus is closely associated with the temporal lobes and plays a critical role in memory encoding and subsequent retrieval. Our study revealed that both the PTSD group and the TEC group showed increased DC in the left parahippocampal gyrus relative to the HC group. Importantly, a gradually increasing trend was observed from the TEC group to the PTSD group. This finding provides further evidence of increased activation in the parahippocampal region in PTSD subjects during direct exposure to negative stimuli (Sakamoto et al. 2005). Previous studies have demonstrated that abnormal connectivity in the parahippocampus results from disruptions in episodic and autobiographical memory encoding and storage and that this region may be a part of the temporal lobe network; therefore, this region may be abnormally active in patients with PTSD (Sakamoto et al. 2005; Thomaes et al. 2009). These findings demonstrate hyperactivity in the parahippocampus in PTSD patients. However, the exact behavioural correlates of these anti-correlated regions are not clear at the moment and warrant more research.