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Topographical Disorientation
Published in Alexander R. Toftness, Incredible Consequences of Brain Injury, 2023
Somewhat similarly, if an area of the brain called the posterior cingulate is damaged, it may produce heading disorientation (Aquirre & D'Esposito, 1999). These people are not lost in space themselves, but they cannot use positional relationships. This means that the person becomes unable to derive directional information from their environment such that they no longer know, for example, which way is north or which way is the way towards home. When shown photographs of buildings, these people may be unable to decipher where the photograph was taken, and they may also be completely unable to determine in which compass direction they are facing when looking at a map (Suzuki et al., 1998). They may also struggle to explain how two locations are located relative to one another, such as describing that a restaurant is located north of the shopping mall (Takahashi et al., 1997). Overall, their sense of heading is disrupted when it comes to the world around them.
Comparison of Healing Effect of DMSP in Green Sea Algae and Mesenchymal Stem Cells on Various Inflammatory Disorders
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Alzheimer’s disease is the most common dementia. Many reports indicated that microglia activation and amyloid deposits appear at the early stage and then tau and Aβ fibrillary tangles were formed with aging (Wyss-Coray et al., 1997; Yan et al., 1997; Arends, 2000; Uboga & Price, 2000; Heneka et al., 2012; Boche & Nicoll, 2013). These incidences result in the disfunction of medial temporal lobe consisting of structures that are vital for declarative or long-term memory (Collie & Maruff, 2000). However, recent studies reveal that the extent of Aβ deposition and senile tangles (plaques) in the brain does not necessarily correlate with dementia because healthy elderly people can exhibit abundant plaques even in the absence of AD. Moreover, the recent findings have indicated that neurogenerative disorders are related to loss of function, aggregation, deposition and degradation of misfolding proteins in the brain (Adav & Sze, 2016). Neurofunctional studies demonstrate that age-related atrophy is incident in the hippocampal region (retrosplenial region/posterior cingulate cortex, left hippocampus, and bilateral inferior and middle frontal areas) (DE Vogelaere, 2012; Du et al., 2006). Whereas recent other reports indicated that earliest pathological diagnosis of Alzheimer’s disease is possible by the determination of the mounts of several amyloid-beta-associated peptide fragments in the blood by immunoprecipitation-coupled with mass spectrometry (Nakamura et al., 2018). For the moment, the effect of MSCs on Alzheimer’s disease are described in brief.
The Influence of Physical Activity on Brain Aging and Cognition: The Role of Cognitive Reserve, Thresholds for Decline, Genetic Influence, and the Investment Hypothesis
Published in James M. Rippe, Lifestyle Medicine, 2019
Maureen K. Kayes, Bradley D. Hatfield
Healthy APOE-ε4 carriers also show altered brain activation under memory challenge tasks.35,122 Sperling reported that ε4 carriers displayed increased hippocampal activation that subsequently converted to hypoactivation as memory became more impaired, possibly forecasting a path toward dementia.35 (see Figure 112.1). Numerous studies have revealed that older adults carrying the APOE-ε4 allele exhibit lower cognitive function in areas of executive function, working memory, episodic memory, and perceptual processing, as well as cognitive deficits in the absence of pathology.123–125 Some findings in younger adults have also shed some new light on possible effects of the ε4 allele. One study that examined postmortem gene transcripts from brain cortical samples of young adults who were either ε3 or ε4 revealed differences in mitochondrial function in ε4 carriers before any evidence of plaque or tangle formation.126 Another study revealed mitochondrial damage post mortem in the posterior cingulate cortex in young adults, again found without plaque.127 Both studies offer support for a theory of mitochondrial dysfunction mediating, at least in part, the role the APOE-ε4 allele in cognitive aging and development of AD. The mitochondrial synthetic effect of exercise reported above may mitigate this process.
Identification and effective connections of core networks in patients with temporal lobe epilepsy and cognitive impairment: Granger causality analysis and multivariate pattern analysis
Published in International Journal of Neuroscience, 2023
Yanchun Jiang, Yanbo Zhang, Liluo Nie, Huihua Liu, Jinou Zheng
In healthy individuals, the posterior cingulate and right dorsolateral prefrontal lobe are involved in memory function together with the medial temporal lobe, which could explain cognitive dysfunction [26]. These regions participate in cognitive processing related to self-awareness, incidental memory, and the interactive regulation between internal brain activities and external tasks [32]. The impairment of cognitive function could be attributed to changes in functional connectivity. According to previous evidence, the functional connectivity of the DMN is significantly reduced in the posterior cingulate cortex (PCC) and the middle of the prefrontal cortex (MPFC) and is positively correlated with cognitive function [33]. At the same time, the posterior cingulate has been considered to be an essential component of the default network [26]. As one of the core nodes, the PCC is widely considered to be related to the encoding, storage, and retrieval of memory.
Learnings in developmental and epileptic encephalopathies: what do we know?
Published in Expert Review of Neurotherapeutics, 2023
Martina Giorgia Perinelli, Antonella Riva, Elisabetta Amadori, Roberta Follo, Pasquale Striano
WS is defined by the triad of (1) spasms, (2) hypsarrhythmia, and (3) psychomotor arrest or regression [38]. Children with WS initially appear to follow a typical developmental trajectory, but later, difficulties emerge, including autism traits, behavioral disorders, and learning difficulties. In one study [38], a well-organized sleep electroencephalography (EEG) pattern and cognitive development, measured with the Griffiths Mental Development Scales, were positively correlated. Chapple and Kinsella [39] conducted a study on a group of patients with WS aged 8 to 13 years. Patients displayed delays in literacy, numeracy, and adaptive and behavioral skills despite generally functioning being at an average level. Difficulties were also demonstrated in modulation, awareness, and attention processes [40–42]. According to Siniatchkin [43], hypsarrhythmia is frequently associated with changes in Blood Oxygenation Level Dependent (BOLD) signals in the brainstem, putamen, and thalamus. In addition to the prefrontal cortex, parietal cortex, posterior cingulate cortex and cerebellum, disruptions of cortical activity also affect the thalamocortical and hippocampal-cortical networks, which cause difficulties with memory, psychomotor functions and executive processes.
18F-fluorodeoxyglucose positron-emitted tomography for predicting neurological outcome in hypoxic-ischemic encephalopathy
Published in Brain Injury, 2021
Giannettore Bertagnoni, Andrea Lupi, Marta Fedeli, Giovanni Sensi, Matteo Nogara
All patients underwent FDG-PET. Z-score cortical maps including 25 different regions (12 pairs of right and left areas and cerebellum) were calculated according to the Cortex ID algorithm (see “data acquisition” and “data analysis” sections). Patients were subdivided into two groups: “good performers” had fewer than two pairs of brain regions with low glucose uptake compared to corresponding regions in healthy subjects (Figures 1 and Figures 2) and “bad performers” had two or more cerebral regions with low glucose uptake compared to normal values (Figures 3 and Figures 4); “low” was defined as at least five standard deviation of difference. This cut-off was chosen by consensus between expert readers, based on the empirical observation that, for this Z-score level and above, the activities in each single cortical area generally tend to show clusters of more homogeneous values (which is the typical result expected in hypoxic patients), rather than the much more disperse patterns observed for Z scores below this value. The pairs of cerebral regions were prefrontal lateral, anterior cingulate, posterior cingulate, precuneus, parietal superior, parietal inferior and temporal lateral. Two physiatrists reviewed the clinical data and one specialist in nuclear imaging separately analyzed FDG-PET scans.