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Leg Pain
Published in Benjamin Apichai, Chinese Medicine for Lower Body Pain, 2021
The corticospinal tract is the largest descending tract present in humans2 and is comprised of a lateral (85%) and an anterior (ventral) tract (15%) (Rea 2015). The lateral corticospinal tract sends fibers predominantly to the muscles of the extremities to control the voluntary movement of the limbs, and the cortical innervation is contralateral; in other words, the left motor cortex controls the right extremities. When a stimulus is engaged, the cell body of the lateral corticospinal tract will send an impulse through the tract that travels to the anterior horn of the spinal cord, proceeds through the spinal nerve root, plexus, and peripheral nerve, and is then transmitted via the lower motor neurons into the muscle fibers, resulting in contraction of the limb muscles. The anterior corticospinal tract sends fibers mainly to the trunk or axial muscles. The control is both ipsilateral and contralateral. Therefore, the trunk muscles are generally bilaterally cortically innervated.3
Spine
Published in Bobby Krishnachetty, Abdul Syed, Harriet Scott, Applied Anatomy for the FRCA, 2020
Bobby Krishnachetty, Abdul Syed, Harriet Scott
Descending tracts (motor)Lateral corticospinal tract (crossed pyramidal tract): fibres carry voluntary motor activity from cortex, decussate in the medulla and descend the spinal cord on the contralateral side.Anterior corticospinal tract (uncrossed pyramidal tract): voluntary motor activity from the cortex reaches the spinal cord without decussation.Tecto spinal tract: this extrapyramidal tract causes movement of the head in response to visual and auditory stimuli from the midbrain tectum to the contralateral spinal cord.Rubro spinal tract: this extrapyramidal tract regulates voluntary movements and reflexes. Fibres originate from the red nucleus of midbrain, cross to the opposite midbrain and then descend down the spinal cord.
Review of the Human Brain and EEG Signals
Published in Teodiano Freire Bastos-Filho, Introduction to Non-Invasive EEG-Based Brain–Computer Interfaces for Assistive Technologies, 2020
Alessandro Botti Benevides, Alan Silva da Paz Floriano, Mario Sarcinelli-Filho, Teodiano Freire Bastos-Filho
From all fibers of the pyramidal tract, 80% cross its side in the decussation15 of pyramids in the Bulb16 (contralaterally), forming the lateral corticospinal tract, and 20% follow caudally to lateral funiculus of the spinal cord (ipsilaterally), forming the anterior corticospinal tract. The anterior corticospinal tract also crosses its side, but only at medullar level, where it makes synapse [2]. Therefore, the behavior of the pyramidal pathways leads to the conclusion that the voluntary motricity is 100% crossed, either at the bulbar level or at the spinal cord level.
Neuroanniversary 2018
Published in Journal of the History of the Neurosciences, 2018
Ludwig Türck (1810–1868) was an Austrian neurologist/otolaryngologist and a full professor at the University of Vienna from 1864 on. He is remembered for his pioneer investigations of the central nervous system, particularly his studies involving nerve fiber localization, direction and degeneration. The terms Türck’s bundle, Türck’s column, and Türck’s tract refer to the anterior corticospinal tract.
Ipsilesional Arm Aiming Movements After Stroke: Influence of the Degree of Contralesional Impairment
Published in Journal of Motor Behavior, 2018
Flavia Priscila de Paiva Silva, Sandra Maria Sbeghen Ferreira Freitas, Renata Morales Banjai, Sandra Regina Alouche
The results of the present study provide support for the idea that ipsilesional upper limb impairment is dependent on the degree of motor impairment of the contralesional limb. This dependence can be explained as follows: (a) by the same cortical regions regulating both the motor control of the ipsilesional limb and contralesional limb; (b) by the decreased use of both upper limbs after a stroke, with the decrease more prevalent among individuals with more severe paretic upper limb impairment; or (c) by a combination of both. With regard to the first proposition (same cortical areas regulating both the motor control of the ipsilesional limb and contralesional limb), up to 30% of corticospinal axons may descend ipsilaterally—anterior corticospinal tract. Although the trajectories of these ipsilateral tracts are well established, there is less information about where they end, which can reach the ipsilateral gray matter (Jankowska & Edgley, 2006). The influence of information transmitted through the brain hemispheres by the corpus callosum is also a possibility and may be altered after a stroke (Chen & Schlaug, 2013; Haaland et al., 2009; Yin et al., 2012). A previous study described an association between the degree of functional impairment of the contralesional hand, damage to the corticospinal tract (Rosso et al., 2013), and integrity of transcallosal fibers (Chen & Schlaug, 2013). Functional connectivity between ipsilesional cortical areas and the contralesional cerebellum (Rosso et al., 2013), as well as motor areas of the resting cerebral hemispheres (Chen & Schlaug, 2013; Yin et al., 2012), were also shown to be related to the degree of functional impairment of the contralesional hand. Therefore, the degree of contralesional hand impairment displayed by individuals with lesions in areas responsible for motor control that are supplied mainly by the middle cerebral artery, may, in the same way, negatively influence the behavior of the ipsilesional upper limb, as shown by the results of the present study.