Voluntary Motor Control

2017 ◽  
Author(s):  
Peggy Mason
Keyword(s):  
Motor Control ◽  
Basal Ganglia ◽  
Building Blocks ◽  
Muscle Contractions ◽  
Brain Lesions ◽  
Upright Posture ◽  
Voluntary Motor ◽  
Motor Commands ◽  
Cortical Regions ◽  
The Brain

The motor hierarchy uses muscle twitches as building blocks for complex and consciously driven actions requiring neocortical involvement. Cortical regions operate in concert with the cerebellum and basal ganglia to generate well-timed and organized muscle contractions that produce movements, ranging from simple to complex. Once imbued with meaning, these movements are considered actions. Adjustments in motor commands are made to accommodate changes in muscle load, maintain an upright posture, and anticipate and avoid errors. Brainstem motor control centers employ circuits in lower parts of the motor hierarchy to produce fairly complex movements, such as ingestion or locomotion. Since the brain adds meaning to movements, two different actions can share the same component movements and serve different end goals. Brain lesions may independently impair movements made under different contexts. For example, patients may be unable to smile volitionally while retaining the ability to smile in response to a joke.

scholarly journals Symptomatic Dystonias Associated with Structural Brain Lesions: Report of 16 Cases

1996 ◽  
Vol 23 (1) ◽  
pp. 53-56 ◽  
Author(s):  
Vladimir S. Kostià ◽  
Marina Stojanovié-Svetel ◽  
Aleksandra Kacar
Keyword(s):  
Basal Ganglia ◽  
Caudate Nucleus ◽  
Brain Lesions ◽  
Focal Dystonia ◽  
The Brain ◽  
Insight Into ◽  
Structural Brain

ABSTRACT:Background:Symptomatic (secondary) dystonias associated isolated lesions in the brain provide insight into etiopathogenesis of the idiopathic form of dystonia and are a basis for establishing the possible correlation between the anatomy of a lesion and the type of dystonia according to muscles affected.Methods:In 358 patients with differently distributed dystonias, a group of 16 patients (4.5%) was encountered in whom dystonia was associated with focal brain lesions.Results:Of the 16 patients, 3 patients had generalized, 3 segmental and 4 hemidystonia, while the remaining 6 patients had focal dystonia. The most frequent etiologies were infarction in 7, and tumor in 4 patients. These lesions were usually found in the lenticular and caudate nucleus, thalamus, and in the case of blepharospasm in the upper brainstem.Conclusions:Our results support the suggestion that dystonia is caused by a dysfunction of the basal ganglia.

Focal brain syndromes in neuropsychiatry

2020 ◽  
pp. 453-462
Author(s):  
Paul Shotbolt
Keyword(s):  
Eighteenth Century ◽  
Prefrontal Cortex ◽  
Basal Ganglia ◽  
Case Studies ◽  
Medial Prefrontal Cortex ◽  
Brain Lesions ◽  
Anatomical Localization ◽  
Psychiatric Conditions ◽  
Neurological Conditions ◽  
The Brain

The idea that the brain’s different regions are responsible for specific functions was first described by François Chaussier in the eighteenth century, leading to the neuroscientific delineation of the lobes. This chapter goes on to describe the functions of different regions of the brain, before listing the neurological conditions which can result from damage to each region, such as spasticity and hyperreflexia from lesions on the medial prefrontal cortex, or Parkinson’s disease and Wilson’s disease from damage to the basal ganglia. Case studies are used to show the behavioural changes which can arise from such lesions and to demonstrate that similar groupings of psychiatric responses to lesions in different areas, paired with the rarity of truly focal brain lesions, make the process of anatomical localization more complicated with psychiatric conditions than neurological ones.

scholarly journals Using voluntary motor commands to inhibit involuntary arm movements

2014 ◽  
Vol 281 (1794) ◽  
pp. 20141139 ◽  
Author(s):  
Arko Ghosh ◽  
John Rothwell ◽  
Patrick Haggard
Keyword(s):  
Motor Control ◽  
Silent Period ◽  
Neural Mechanism ◽  
Deltoid Muscle ◽  
Motor Command ◽  
Blind Spot ◽  
Neural Function ◽  
Motor Inhibition ◽  
Voluntary Motor ◽  
Motor Commands

A hallmark of voluntary motor control is the ability to stop an ongoing movement. Is voluntary motor inhibition a general neural mechanism that can be focused on any movement, including involuntary movements, or is it mere termination of a positive voluntary motor command? The involuntary arm lift, or ‘floating arm trick’, is a distinctive long-lasting reflex of the deltoid muscle. We investigated how a voluntary motor network inhibits this form of involuntary motor control. Transcranial magnetic stimulation of the motor cortex during the floating arm trick produced a silent period in the reflexively contracting deltoid muscle, followed by a rebound of muscle activity. This pattern suggests a persistent generator of involuntary motor commands. Instructions to bring the arm down voluntarily reduced activity of deltoid muscle. When this voluntary effort was withdrawn, the involuntary arm lift resumed. Further, voluntary motor inhibition produced a strange illusion of physical resistance to bringing the arm down, as if ongoing involuntarily generated commands were located in a ‘sensory blind-spot’, inaccessible to conscious perception. Our results suggest that voluntary motor inhibition may be a specific neural function, distinct from absence of positive voluntary motor commands.

scholarly journals Acute Psychosis Associated with Subcortical Stroke: Comparison between Basal Ganglia and Mid-Brain Lesions

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Aaron McMurtray ◽  
Ben Tseng ◽  
Natalie Diaz ◽  
Julia Chung ◽  
Bijal Mehta ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Psychiatric Symptoms ◽  
Symptomatic Relief ◽  
Acute Onset ◽  
Brain Lesions ◽  
Psychotic Symptoms ◽  
History Of ◽  
The Brain ◽  
Brain Ischemic Stroke ◽  
New Onset

Acute onset of psychosis in an older or elderly individual without history of previous psychiatric disorders should prompt a thorough workup for neurologic causes of psychiatric symptoms. This report compares and contrasts clinical features of new onset of psychotic symptoms between two patients, one with an acute basal ganglia hemorrhagic stroke and another with an acute mid-brain ischemic stroke. Delusions and hallucinations due to basal ganglia lesions are theorized to develop as a result of frontal lobe dysfunction causing impairment of reality checking pathways in the brain, while visual hallucinations due to mid-brain lesions are theorized to develop due to dysregulation of inhibitory control of the ponto-geniculate-occipital system. Psychotic symptoms occurring due to stroke demonstrate varied clinical characteristics that depend on the location of the stroke within the brain. Treatment with antipsychotic medications may provide symptomatic relief.

“Miliary” metastatic tumors in the brain

1997 ◽  
Vol 86 (3) ◽  
pp. 564-566 ◽  
Author(s):  
Chhabi Bhushan
Keyword(s):  
Basal Ganglia ◽  
Primary Tumor ◽  
Metastatic Tumor ◽  
Mass Effect ◽  
Brain Lesions ◽  
Metastatic Tumors ◽  
Content Type ◽  
Brain Parenchymal ◽  
The Brain ◽  
Fine Print

✓ An extremely unusual “miliary” metastatic tumor of the brain in a 69-year-old man is reported. Although there was no known primary tumor, the patient had innumerable brain lesions involving both cerebral and both cerebellar hemispheres, the basal ganglia, and the brainstem. There was no associated edema, mass effect, or brain parenchymal reaction. None of the lesions showed any calcification.

Local cerebral metabolic rates of glucose in movement and language disorders from positron tomography

1984 ◽  
Vol 246 (6) ◽  
pp. R897-R900
Author(s):  
E. J. Metter ◽  
W. H. Riege ◽  
W. R. Hanson ◽  
M. E. Phelps ◽  
D. E. Kuhl
Keyword(s):  
Basal Ganglia ◽  
Language Disorders ◽  
Basic Process ◽  
Metabolic Data ◽  
Language And Cognition ◽  
Focal Abnormality ◽  
Language Measures ◽  
Cortical Regions ◽  
Functional Process ◽  
The Brain

Positron-computed tomography with [18F]fluorodeoxyglucose to measure glucose metabolism has shown changes in the brain distant to a focal area of infarction, demonstrating that what appears as a focal abnormality represents a more widespread functional process. Several approaches are presented to better understand quantitative metabolic data and focus on caudate and basal ganglia function. Area-to-area correlations in Parkinson's and Huntington's diseases showed decreases in the number of cortical relationships compared with control subjects, suggesting that the basal ganglia are involved with the ability of cortical regions to function together. In aphasia, caudate metabolism correlated with several language measures that suggested a role in some undefined basic process, seemingly related to Broca's area function. The studies presented suggest that the caudate may involve integrating the processing of language and cognition with the execution of the resulting response. Motor and cognitive function seem related to similar and overlapping brain systems. The disruption of such systems may result in loss of both cognitive and motor aspects of a function.

scholarly journals Basal Ganglia Herniation into the Fourth Ventricle

1997 ◽  
Vol 24 (1) ◽  
pp. 62-63 ◽  
Author(s):  
Mensura Altumbabic ◽  
Marc R. Del Bigio ◽  
Scott Sutherland
Keyword(s):  
Basal Ganglia ◽  
Intracerebral Hemorrhage ◽  
Fourth Ventricle ◽  
Transtentorial Herniation ◽  
Intracerebral Bleeding ◽  
Rare Phenomenon ◽  
The Brain

ABSTRACT:Background:Transtentorial herniation of large cerebral fragments is a rare phenomenon.Method:Case StudyResults:Examination of the brain of a 35-year-old male showed massive intracerebral hemorrhage resulting in displacement of basal ganglia components into the fourth ventricle.Conclusions:Sufficiently rapid intracerebral bleeding can dissect fragments of cerebrum and displace them long distances across the tentorial opening.

scholarly journals Toward asleep DBS: cortico-basal ganglia spectral and coherence activity during interleaved propofol/ketamine sedation mimics NREM/REM sleep activity

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jing Guang ◽  
Halen Baker ◽  
Orilia Ben-Yishay Nizri ◽  
Shimon Firman ◽  
Uri Werner-Reiss ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Rem Sleep ◽  
Standard Procedure ◽  
Low Frequency ◽  
Nrem Sleep ◽  
Sleep Cycle ◽  
Advanced Parkinson’S Disease ◽  
Low Frequency Power ◽  
The Brain ◽  
Frequency Power

AbstractDeep brain stimulation (DBS) is currently a standard procedure for advanced Parkinson’s disease. Many centers employ awake physiological navigation and stimulation assessment to optimize DBS localization and outcome. To enable DBS under sedation, asleep DBS, we characterized the cortico-basal ganglia neuronal network of two nonhuman primates under propofol, ketamine, and interleaved propofol-ketamine (IPK) sedation. Further, we compared these sedation states in the healthy and Parkinsonian condition to those of healthy sleep. Ketamine increases high-frequency power and synchronization while propofol increases low-frequency power and synchronization in polysomnography and neuronal activity recordings. Thus, ketamine does not mask the low-frequency oscillations used for physiological navigation toward the basal ganglia DBS targets. The brain spectral state under ketamine and propofol mimicked rapid eye movement (REM) and Non-REM (NREM) sleep activity, respectively, and the IPK protocol resembles the NREM-REM sleep cycle. These promising results are a meaningful step toward asleep DBS with nondistorted physiological navigation.

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