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Brain Motor Centers and Pathways
Published in Nassir H. Sabah, Neuromuscular Fundamentals, 2020
The main projections of the vestibular nuclei are to: (i) the cerebellum, mainly to the flocculonodular node from the medial and inferior vestibular nuclei, (ii) the thalamus, mainly the ventral posterior complex of the thalamus, and thence to the cerebral cortex, including areas in the parietal and temporal regions, motor and premotor regions, and frontal eye fields; (iii) the nuclei controlling extraocular muscles that mediate eye movements, namely, the oculomotor nucleus, the abducens nucleus, and the trochlear nucleus; these projections are mainly from the superior and medial vestibular nuclei; (iv) the spinal cord via the vestibulospinal tract, and (v) other vestibular nuclei on the same side or the opposite side.
Back and central nervous system
Published in Aida Lai, Essential Concepts in Anatomy and Pathology for Undergraduate Revision, 2018
Vestibulospinal tract– facilitates extensor muscles (increase tone in anti-gravity muscles) and inhibits flexor muscles– vestibular nuclei → does not cross over → alpha and gamma motor neurons
Discussions (D)
Published in Terence R. Anthoney, Neuroanatomy and the Neurologic Exam, 2017
Most authors of recent textbooks in basic neuroanatomy describe neuronal fibers descending from cell bodies in the medial vestibular nuclei into the anterior funiculi of the spinal cord; and they usually label the collection of these fibers on either side as the “medial vestibulospinal tract” (e.g., B&K, p. 75–76; Brod, p. 201, 204; Heim, p. 160 [Fig. 99B], 192; Nolt, P-150 [including Fig. 9–24]; A&B, p. 149). Several other authors, however, note that the medial vestibulospinal tract may originate in other vestibular nuclei as well—either the medial and inferior (Gar, p. 107 [Fig. 85]); the medial, inferior, and lateral (W&W, p. 875, 940; ch&l, p. 102); or those plus the superior nucleus (i.e., all of the vestibular nuclei: n&f, p. 194).1
Central vestibular dysfunction: don’t forget vestibular rehabilitation
Published in Expert Review of Neurotherapeutics, 2022
Sulin Zhang, Dan Liu, E. Tian, Jun Wang, Zhaoqi Guo, Weijia Kong
Pathogenesis of VM is still poorly understood and researchers fail to agree regarding whether its origin is predominantly central or peripheral. The factors involved in the pathogenesis of VM do not work separately but are intricately interwoven [81,82]. Abnormal sensory modulation or integration within the thalamo-cortical network could result in dizziness and spatial disorientation, which may lead to a ‘higher level’ dysfunction of the multisensory integration function of spatial orientation. Activities such as ballet dancing and yoga can enhance spatial perception and physical coordination [64]. Cortical spreading depression hypothesis assumes that, during aura migraine, various factors stimulate the cerebral cortex and then the inhibitory cortical electrical activity spreads from the stimulation site to the surrounding regions. Vestibular connections can be divided into downward-projecting vestibulospinal tracts and upward projections [i.e. to the ocular motor nuclei that organize the VOR] [83]. When it diffuses to the vestibular cortex (the parietal lobe and insular lobe), the activity is inhibited, and the inhibitory effect on the brainstem vestibular nucleus is weakened, thereby affecting the processing of vestibular signals and causing vestibular symptoms, or leading to transient vestibulo-ocular dysfunction or vestibular hypersensitivity associated with migraine [84].
Absence of Ankle Stiffening While Standing in Focus and Cognitive Task Conditions in Older Adults
Published in Journal of Motor Behavior, 2020
Natalie Richer, Kien Ly, Noémy Fortier, Yves Lajoie
The reason cognitive tasks improve postural control is thought to be the automaticity of postural control. As described previously, removing attention from the control of movement allows automatic processes to function in an unconstrained manner. For instance, the control of posture could be regulated by more reflexive structures such as the vestibulospinal tract and cerebellum. Focusing on an aspect of movement production would promote a more conscious control involving higher-level brain areas such as the frontal lobe, and would interfere with automatic processes. This would lead to less efficient movement control (McNevin et al., 2003; Wulf et al., 2001a; Wulf et al., 2001b). However, another hypothesis states that improvements in postural control in challenging dual-task conditions might reflect the use of a stiffening strategy. According to this view, individuals cocontract the muscles surrounding the ankle joint to maximize stability and allow the allocation of cognitive resources to the challenging concurrent task (Dault et al., 2001; Melzer, Benjuya, & Kaplanski, 2001; Weeks et al., 2003).
Standing postural stability during galvanic vestibular stimulation is associated with the motor function of the hemiplegic lower extremity post-stroke
Published in Topics in Stroke Rehabilitation, 2020
Tsubasa Mitsutake, Maiko Sakamoto, Kozo Ueta, Etsuo Horikawa
This study has a few limitations. First, the vestibular system related to postural control responses was measured using a C7-mounted accelerometer during vestibular stimulation, and not using a device measuring actual vestibulospinal tract. Future investigations should involve measurements of vestibulospinal tract function using modulation of the soleus H-reflex following GVS. Second, it was difficult to determine which areas of cerebral injuries actually affected body sway during vestibular stimulation. It is necessary to investigate the relationship between the locations of cerebral injuries and the body sway during vestibular stimulation in future studies. Third, in the standing body sway test, we did not evaluate the difference between the affected and non-affected sides. The affected side may influence standing stability during GVS due to decreased posture control strategy.25 Future studies should clarify the difference between affected and non-affected sides while assessing the postural control during GVS.