Encephalitis and Its Mimics in the Critical Care Unit
Cheston B. Cunha, Burke A. Cunha in Infectious Diseases and Antimicrobial Stewardship in Critical Care Medicine, 2020
Differentiating between such encephalopathies and primary brain processes involves two key elements. From the systemic perspective, identification of a specific underlying medical abnormality is key. Neurologically, it is essential to establish whether the observed changes are focal or not—brain disorders resulting from localized damage to the brain cause abnormalities of function related to the site of damage. Damage to the cerebral cortex can cause seizures, an altered level of consciousness and cognitive difficulty. Damage to the deep white matter causes spasticity, ataxia, visual, and sensory problems but not seizures and has a less severe impact on alertness and cognition. Damage to the brainstem can affect level of consciousness, long tracts that pass through the brainstem, and, important diagnostically, cranial nerve function.
Computational Neuroscience and Compartmental Modeling
Bahman Zohuri, Patrick J. McDaniel in Electrical Brain Stimulation for the Treatment of Neurological Disorders, 2019
Figure 3.5 illustrates the parts of a nerve cell or neuron. Each neuron consists of a cell body, or soma, that contains a cell nucleus. Branching out from the cell body are a number of fibers called dendrites and a single long fiber called the axon. The axon stretches out for a long distance, much longer than the scale in this diagram indicates. Typically, an axon is 1 cm long (100 times the diameter of the cell body) but can reach up to 1 meter. A neuron makes connections with 10 to 100,000 other neurons at junctions called synapses. Signals are propagated from neuron to neuron by a complicated electrochemical reaction. The signals control brain activity in the short term and also enable long-term changes in the connectivity of neurons. These mechanisms are thought to form the basis for learning in the brain. Most information processing goes on in the cerebral cortex, the outer layer of the brain. The basic organizational unit appears to be a column of tissue about 0.5 mm in diameter, containing about 20,000 neurons and extending the full depth of the cortex about 4 mm in humans).38
Neurological issues
Andrea Utley in Motor Control, Learning and Development, 2018
The cerebral cortex is the executive suite of the nervous system, and it enables us to communicate, perceive and produce voluntary movement. Three types of functional areas can be found in the cerebral cortex: motor areas, sensory motor areas and associated areas. The cerebral cortex is the largest part of the human brain, associated with higher brain functions such as thought and action. The cerebral cortex is divided into two hemispheres which, although they look symmetrical, have somewhat different functions. The left and right hemispheres of the cerebral cortex are connected by the corpus callosum, a large bundle of interconnecting nerve fibers. The cerebral cortex can be divided into four ‘lobes’: the frontal lobe, parietal lobe, occipital lobe and temporal lobe, with each lobe being represented in each hemisphere. Initial learning is dependent on the frontal cerebral cortex, control is ‘passed’ to cerebellum with practice and researchers are interested in how type of practice, context and feedback influence this process (Marsh et al. 2011).
Assessing lesion location, visual midline perception and proprioception may assist outcome predictions for people affected by lateropulsion
Published in Disability and Rehabilitation, 2023
Unlike the vestibular and proprioceptive systems, inputs from the eyes do not reach the medulla or pons. Instead, visual inputs travel via the optic tract mostly to the lateral geniculate nucleus of the thalamus, and from there to the primary visual cortex in the occipital lobe [9]. From the primary visual cortex, visual inputs undergo multimodal processing in the dorsal (for spatial location) and ventral (for object recognition) streams [9]. Of particular interest is the dorsal stream which terminates in the inferior parietal lobe, the cortical destination of proprioceptive and vestibular inputs. Due to the segregation of the visual system, the inferior parietal lobe is the only cerebral cortex where sensory integration of inputs from all three modalities takes place. In addition, the non-dominant inferior parietal lobe plays a pivotal role in multimodal sensory processing related to spatial location, thus it may be a key cortical region to consider in relation to lateropulsion.
Stretching beyond our perceived boundaries: The role of speech-language pathology in realising autonomy through supported decision-making
Published in International Journal of Speech-Language Pathology, 2023
A deep dive into emerging theories of neuroscience and the source of consciousness has led to a comparison of the respective functioning of the cerebral cortex and the brain stem. The cerebral cortex is historically assumed to be the seat of conscious action and intelligence, while the brain stem is responsible for performing automatic/unconscious functions. Solms, however, argue that consciousness arises not in the cortex, but in the more primitive brain stem, where basic emotions begin. As it is the cortex that is typically damaged for people with profound intellectual and multiple disability, there is a long held hypothesis that people with PIMD lack the ability to engage in conscious action and thought. It is this hypothesis that neuroscientists such as Solms and colleagues are challenging (Solms, 2015, 2022; Solms & Panksepp, 2012; Solms & Turnbull, 2018).
Short-term consumption of alcohol (vodka) mixed with energy drink (AMED) attenuated alcohol-induced cerebral capillary disturbances and neuroinflammation in adult wild-type mice
Published in Nutritional Neuroscience, 2022
Ryusuke Takechi, John Mamo, Sukanya Das, Liam Graneri, Zachary D’Alonzo, Michael Nesbit, Edwin Junaldi, Virginie Lam
Hippocampal formation of the brain plays a critical role in retrieving the sequence of events that forms episodic memory [30]. Parts of the cerebral cortex play critical role in performance monitoring, other cognitive control and task switching [31, 32]. Increasing evidence indicates that the disruption of BBB in those particular brain regions are causally associated with the onset of cognitive impairment. Montagne et al. found that the breakdown of BBB and cerebral capillary pericyte degeneration accurately predicts cognitive decline in clinically healthy participants and subjects with cognitive decline [33]. Furthermore, in animal models of cognitive deficits, disruption of the BBB was shown to precede neurodegeneration and cognitive decline, suggesting causality [3]. Thus, the present study offers valuable insight on the potential effects of alcohol and ED consumption on brain capillary integrity and risk of cognitive impairment.
Related Knowledge Centers
- Allocortex
- Cerebral Hemisphere
- Corpus Callosum
- Neocortex
- Nervous Tissue
- Cerebrum
- Cortex
- Brain
- Longitudinal Fissure
- Neuron