China
Africa
Explore chapters and articles related to this topic
Cortical Visual Loss
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Optic ataxia is associated classically with damage to the occipitoparietal lobes, at the junction between the inferior parietal lobule and the superior occipital cortex (406). However, reaching under visual guidance is mediated by recursive processes involving a sensorimotor network (407) that can be disrupted at a number of points, including parietal and frontal cortex (408, 409). Hence a variety of other lesions can cause optic ataxia, including damage to premotor cortex, cortex below the angular gyrus (397), and occipital-frontal white matter tracts (409, 410). These lesions can be unilateral (395, 409, 411), in which case the patient can have poor reaching with either the contralateral hand or to objects in the contralateral hemi-space.
Stress and the brain-gut axis across the spectrum of digestive disorders
Published in Simon R. Knowles, Laurie Keefer, Antonina A. Mikocka-Walus, Psychogastroenterology for Adults, 2019
IBS patients demonstrate reduced capacity to properly interpret signals from the GI tract compared with healthy individuals, leading to enhanced emotional arousal in response to both expected and delivered GI stimulation [12]. These alterations in the brain’s emotional network may lead to enhanced catastrophising and over-estimation of abdominal pain experiences often present in patients with moderate to severe GI symptoms [13]. Increased EAS responses to visceral stimuli are particularly prominent in women, and may partially account for some of the observed gender differences in IBS prevalence [14–16]. Cortical thickness and volumetric analyses have revealed grey matter increases within key regions of the sensorimotor network, including the primary somatosensory cortex, thalamus, posterior insula, and cingulate cortex. These structural changes were associated with increased IBS symptom duration in one study of 14 IBS patients and 14 healthy controls [17].
The cortical processing of pain
Published in Camille Chatelle, Steven Laureys, Assessing Pain and Communication in Disorders of Consciousness, 2015
In addition to measuring the functional connectivity between brain regions responding to a sensory stimulus, or brain regions activated during the performance of a given task, it is also possible to measure functional connectivity during “rest” (Biswal, Yetkin, Haughton, & Hyde, 1995). Without external stimulation, the human brain spontaneously produces low-frequency fluctuations of activity. These spontaneous fluctuations show a high degree of correlation across separated brain regions, indicating that they may reflect networks of functionally-connected brain regions, such as the “default mode network,” the “salience network,” and the “sensorimotor network” (Cordes et al., 2000; Hampson, Peterson, Skudlarski, Gatenby, & Gore, 2002; Seeley et al., 2007). However, interpreting differences across conditions or between groups of subjects is not straightforward (Cole, Smith, & Beckmann, 2010). Observed differences could be related to changes in the connectivity of the networks but could also be related to instructed or self-initiated changes in mental state. For example, being instructed to “rest” and refrain from moving in an fMRI scanner may lead to a very different mental state in patients experiencing pain as compared to healthy controls. Furthermore, differences in resting-state functional connectivity are difficult to disentangle from fluctuations in BOLD signals due to physiological (respiratory, cardiac, vasomotor) and motion confounds.
Clinical trials for neuroregenerative therapies for spinal cord injury: what have we learnt so far?
Published in Expert Review of Neurotherapeutics, 2023
Raymond Wong, Nader Hejrati, Michael G. Fehlings
Lastly, imaging biomarkers, which are provided by advanced quantitative MRI techniques such as microstructural MRI, can reveal functional reorganization of the sensorimotor network in patients who experience significant sensory and motor recovery following SCI [44]. For example, a previous study reported that SCI patients with a shorter intramedullary lesion length (IMLL) had improved neurological outcomes [45]. IMLL was later validated as a significant imaging biomarker that correlated with neurologic recovery, where an increase in IMLL was associated with a poorer prognosis [46]. Although more research is needed to better elucidate the diverse roles that these different biomarkers play and how they may interact following traumatic SCI, examining CSF, serum, genetic, and imaging biomarkers can provide valuable insight on how well potential treatments may work in certain patient populations [28].
Resolution of chronic lower back pain symptoms through high-intensity therapeutic exercise and motor imagery program: a case-report
Published in Physiotherapy Theory and Practice, 2022
Jorge Ribas, Maria Armanda Gomes, António Mesquita Montes, Cláudia Ribas, José Alberto Duarte
Common conditions induced by chronic pain, such as sensorimotor, proprioceptive, and tactile deficits, may affect postural stability and motion control (Christakou and Zervas, 2007; Gibbons, 2011; Hodges, 2003). Furthermore, they may lead to maladaptive changes in the sensorimotor network, causing reduced cerebral activity in the supplementary motor area and the superior temporal gyrus (Vrana et al., 2015). In young adults with CLBP, the reorganization of the primary motor cortex has revealed a discrete loss of trunk representation in the brain (Tsao, Danneels, and Hodges, 2011). Moreover, CLBP is associated with a loss of laterality recognition and a reduced accuracy of left/right judgments (Bray and Moseley, 2011; Flor, Braun, Elbert, and Birbaumer, 1997; Stanton et al., 2013). The recognition of laterality is fundamental to the integrity of the body schema and is involved in initial decision-making and mental movement (Bray and Moseley, 2011; Breckenridge, Ginn, Wallwork, and McAuley, 2019; Moseley, Sim, Henry, and Souvlis, 2005; Pelletier et al., 2018).
Efficiency of Sensorimotor Networks: Posture and Gait in Young and Older Adults
Published in Experimental Aging Research, 2019
G. Di Scala, M. Dupuy, E. Guillaud, E. Doat, E. Barse, B. Dillhareguy, F.A.M. Jean, M. Audiffren, J.R. Cazalets, S. Chanraud
In order to construct a graph of the sensorimotor network and analyze its characteristics, we first performed resting-state Region-Of-Interest, “ROI-to-ROI”, analyses using the CONN functional connectivity toolbox (http://www.conn-toolbox.org, (Whitfield-Gabrieli & Nieto-Castanon, 2012) implemented in Matlab 2012a (The Mathworks Inc., Natick, Massachusetts, USA). Four ROIs, i.e., bilateral pre- and postcentral gyri separately, defined in the AAL2 (Tzourio-Mazoyer et al., 2002) and AICHA atlas (Joliot et al., 2015), were used as seeds for mapping sensorimotor functional networks in the two groups. Two different atlases were chosen in order to improve biological plausibility through the use of different brain imaging modalities (anatomical and functional) for defining brain regions. The two analyses carried-out with the AAL2 or AICHA atlases revealed the same findings. Therefore, the analyses and results presented from here are based on the AAL2 atlas exclusively.