Motor Functions and Praxis in the Elderly
José León-Carrión, Margaret J. Giannini in Behavioral Neurology in the Elderly, 2001
The internal segment of the globus pallidus transmits information from the motor cortices to the ventrolateral (VL) nucleus of the thalamus.9 However, it seems that the only indicator that the thalamus is engaged in the preparation of voluntary movements has been provided by Decety et al.,10 who found an increase in the left ventrolateral thalamus when subjects were preparing for a reaching movement with their right arm. One additional structure involved in voluntary movement is the cerebellum, which receives information from the motor cortex, the somatosensory cortices, the posterior prefrontal cortex, and in a smaller part from the visual association cortex via the pontine nuclei. The somatotopical field laterally in the anterior lobe of the cerebellum is activated when performing motor and sensoriomotor tasks, whereas the deep nucleus, the dentate, is only activated by sensorimotor tasks (Figure 7.2).
Other atypical parkinsonian disorders and their differentiation from dementia with Lewy bodies
John O'Brien, Ian McKeith, David Ames, Edmond Chiu in Dementia with Lewy Bodies and Parkinson's Disease Dementia, 2005
In MSA, one may find supra and/or infratentorial changes (Schrag et al, 2000). The former include a hyperintense slitlike appearance at the lateral border of the putamen, which correlates with the highest ferric iron levels, and microgliosis and astrogliosis. However, this has also been described in some cases with PSP, CBD and Huntington's disease. There may be putaminal atrophy or posterior putaminal hypointensity. Infratentorially, one may see a hyperintense 'cross' appearance in the pons, secondary to pontine atrophy. Degeneration of the pontine nuclei and transverse pontine fibers leads to conspicuous retention of the superior cerebellar peduncles and pyramidal tracts. This appearance may also be found in spinocerebellar ataxias 2 and 3 (SCA2 and SCA3), and has been reported in some patients with PSP, CBD and vasculitis. Hyperintensity of the middle cerebellar peduncles is also common
Anatomy for neurotrauma
Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor in Essentials of Anesthesia for Neurotrauma, 2018
The cerebellum is connected with the other parts of the nervous system by three paired cerebellar peduncles—superior, middle, and inferior. The superior cerebellar peduncle carries efferent fibers to the upper motor neurons in the cerebral cortex via thalamic nuclei. The middle cerebellar peduncle receives its input from the pontine nuclei via transverse pontine fibers. The inferior cerebellar peduncle receives afferent fibers from the vestibular nuclei, tegmentum, and the spinal cord.
Smooth Pursuit Eye Movements as a Biomarker for Mild Concussion within 7-Days of Injury
Published in Brain Injury, 2021
Melissa Hunfalvay, Nicholas P. Murray, Revathy Mani, Frederick Robert Carrick
Smooth pursuits can be further understood by considering the difference between HSP, VSP and CSP pathways. In HSPs, the signal originates in the M ganglion cells in the retina (23). From there, signals are relayed to the striate cortex (V1 area) and then to the V2, V3 and mid temporal (MT) areas. From the MT areas, the signal travels to the medial superior temporal (MST) and the frontal and posterior parietal cortex’s. The MT, MST and frontal eye field all share projections to the dorsolateral pontine nuclei (DLPN), which propagates the signal along a double decussation pathway before the contralateral medial rectus is innervated. Parallel to this, the nucleus of the optic tract receives projections from the MT and MST areas and sends them to the DLPN, a process which is specific to HSPs.
What is the potential of neurostimulation in the treatment of motor symptoms in schizophrenia?
Published in Expert Review of Neurotherapeutics, 2020
Stephanie Lefebvre, Anastasia Pavlidou, Sebastian Walther
The human motor system is organized in different parallel circuits, three of which have been strongly associated with psychosis; the basal-ganglia circuit, the cerebello-thalamo-motor circuit and the cortico-motor circuit [5,26]. The basal-ganglia circuit is involved in the inhibition and excitation of movements and encompasses connections from the primary motor cortex (M1), to the putamen, internal and external pallidum, thalamus and back to M1. The cerebello-thalamo-motor circuit, is involved in motor timing and sensorimotor dynamics and comprises connections between M1, thalamus, cerebellum, and pontine nuclei. Finally, the cortico-motor circuit has been suggested to be involved in motor organization and speed and consists of connections between M1, supplementary motor area (SMA), the posterior and ventral cingulate cortex, posterior parietal cortex (PPC) and medial prefrontal cortex (PFC) [5,26]. Patients with schizophrenia are reported to have functional and structural alterations within the aforementioned circuits across various motor tasks.
Injury of the dentato-rubro-thalamic tract in a patient with intentional tremor after mild traumatic brain injury: a case report
Published in Brain Injury, 2020
Min Cheol Chang, Jeong Pyo Seo
The CPCT and DRTT are two main neural pathways that constitute the cortico-cerebellar-cortical circuit (1). The CPCT projects from the frontal lobe to the pontine nuclei and arrives at the cerebellar cortex via the middle cerebellar peduncle. The DRTT starts from the dentate nucleus of the cerebellum and passes via the superior cerebellar peduncle to project onto the ventrolateral thalamus (1). After the DRTT reaches the thalamus, it is finally connected to the motor cortex. A lesion to this circuit causes cerebellar symptoms, including tremor and ataxia (1). We think that traumatic axonal injury is one possible mechanisms for the occurrence of tremor or ataxia following TBI.
Related Knowledge Centers
- Arcuate Nucleus
- Middle Cerebellar Peduncle
- Motor Neuron
- Nucleus
- Pons
- Primary Motor Cortex
- Medulla Oblongata
- Corticopontine Fibers
- Motor Skill