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Handbook of Clinical Neurology 2022Airway function is under constant neurophysiological control, in order to maximize airflow and gas exchange and to protect the airways from aspiration, damage, and... (Review)
Review
Airway function is under constant neurophysiological control, in order to maximize airflow and gas exchange and to protect the airways from aspiration, damage, and infection. There are multiple sensory nerve subtypes, whose disparate functions provide a wide array of sensory information into the CNS. Activation of these subtypes triggers specific reflexes, including cough and alterations in autonomic efferent control of airway smooth muscle, secretory cells, and vasculature. Importantly, every aspect of these reflex arcs can be impacted and altered by local inflammation caused by chronic lung disease such as asthma, bronchitis, and infections. Excessive and inappropriate activity in sensory and autonomic nerves within the airways is thought to contribute to the morbidity and symptoms associated with lung disease.
Topics: Autonomic Nervous System; Cough; Humans; Lung Diseases; Reflex; Respiratory System
PubMed: 35965034
DOI: 10.1016/B978-0-323-91534-2.00013-8 -
Cerebellum (London, England) Jun 2012In this paper, we will review the anatomical components of the visuomotor cerebellum in human and, where possible, in non-human primates and discuss their function in... (Review)
Review
In this paper, we will review the anatomical components of the visuomotor cerebellum in human and, where possible, in non-human primates and discuss their function in relation to those of extracerebellar visuomotor regions with which they are connected. The floccular lobe, the dorsal paraflocculus, the oculomotor vermis, the uvula-nodulus, and the ansiform lobule are more or less independent components of the visuomotor cerebellum that are involved in different corticocerebellar and/or brain stem olivocerebellar loops. The floccular lobe and the oculomotor vermis share different mossy fiber inputs from the brain stem; the dorsal paraflocculus and the ansiform lobule receive corticopontine mossy fibers from postrolandic visual areas and the frontal eye fields, respectively. Of the visuomotor functions of the cerebellum, the vestibulo-ocular reflex is controlled by the floccular lobe; saccadic eye movements are controlled by the oculomotor vermis and ansiform lobule, while control of smooth pursuit involves all these cerebellar visuomotor regions. Functional imaging studies in humans further emphasize cerebellar involvement in visual reflexive eye movements and are discussed.
Topics: Animals; Cerebellum; Eye Movements; Humans; Movement; Nerve Fibers; Neural Pathways; Primates; Pursuit, Smooth; Reflex; Reflex, Vestibulo-Ocular; Saccades; Vision, Ocular
PubMed: 20809106
DOI: 10.1007/s12311-010-0204-7 -
Brain : a Journal of Neurology Sep 2023Although rigidity is a cardinal motor sign in patients with Parkinson's disease (PD), the instrumental measurement of this clinical phenomenon is largely lacking, and...
Although rigidity is a cardinal motor sign in patients with Parkinson's disease (PD), the instrumental measurement of this clinical phenomenon is largely lacking, and its pathophysiological underpinning remains still unclear. Further advances in the field would require innovative methodological approaches able to measure parkinsonian rigidity objectively, discriminate the different biomechanical sources of muscle tone (neural or visco-elastic components), and finally clarify the contribution to 'objective rigidity' exerted by neurophysiological responses, which have previously been associated with this clinical sign (i.e. the long-latency stretch-induced reflex). Twenty patients with PD (67.3 ± 6.9 years) and 25 age- and sex-matched controls (66.9 ± 7.4 years) were recruited. Rigidity was measured clinically and through a robotic device. Participants underwent robot-assisted wrist extensions at seven different angular velocities randomly applied, when ON therapy. For each value of angular velocity, several biomechanical (i.e. elastic, viscous and neural components) and neurophysiological measures (i.e. short and long-latency reflex and shortening reaction) were synchronously assessed and correlated with the clinical score of rigidity (i.e. Unified Parkinson's Disease Rating Scale-part III, subitems for the upper limb). The biomechanical investigation allowed us to measure 'objective rigidity' in PD and estimate the neuronal source of this phenomenon. In patients, 'objective rigidity' progressively increased along with the rise of angular velocities during robot-assisted wrist extensions. The neurophysiological examination disclosed increased long-latency reflexes, but not short-latency reflexes nor shortening reaction, in PD compared with control subjects. Long-latency reflexes progressively increased according to angular velocities only in patients with PD. Lastly, specific biomechanical and neurophysiological abnormalities correlated with the clinical score of rigidity. 'Objective rigidity' in PD correlates with velocity-dependent abnormal neuronal activity. The observations overall (i.e. the velocity-dependent feature of biomechanical and neurophysiological measures of objective rigidity) would point to a putative subcortical network responsible for 'objective rigidity' in PD, which requires further investigation.
Topics: Humans; Parkinson Disease; Muscle Rigidity; Reflex, Stretch; Reflex, Abnormal; Electromyography
PubMed: 37018058
DOI: 10.1093/brain/awad114 -
Disease Markers 2022To explore the diagnostic value of bulbocavernosus muscle reflex and pudendal somatosensory evoked potentials for diabetic neurogenic bladder.
OBJECTIVE
To explore the diagnostic value of bulbocavernosus muscle reflex and pudendal somatosensory evoked potentials for diabetic neurogenic bladder.
METHODS
From January 2021 to December 2021, 104 patients with type 2 diabetes mellitus admitted to the hospital were recruited, with 57 allocated to the case group and 47 to the control group. Outcome measures included bulbocavernosus muscle response, pudendal somatosensory evoked potentials, and bladder residual urine volume. The connection of bulbocavernosus muscle response and pudendal somatosensory evoked potentials with bladder residual urine volume was investigated using the Pearson analysis.
RESULTS
In both males and females, the latency of the left and right bulbocavernosus muscle reflexes in the case group was longer than in the control group, but the difference was not statistically significant ( > 0.05), and the wave amplitude of the left and right bulbocavernosus muscle reflexes was significantly smaller than that of the control group ( < 0.05). The diabetic neurogenic bladder was associated with a significantly longer latency and a smaller wave amplitude of pudendal somatosensory evoked potentials versus without neurogenic bladder ( < 0.05). Patients with a diabetic neurogenic bladder had more residual bladder urine volume versus those without ( < 0.05). Bladder residual urine volume was significantly positively correlated with bulbocavernosus muscle reflex and pudendal somatosensory evoked potential latency and negatively correlated with wave amplitude ( < 0.05).
CONCLUSION
The bulbocavernosus muscle reflex and pudendal somatosensory evoked potentials demonstrate great potential as adjuncts to diagnose diabetic neurogenic bladder and correlate with ultrasound results in determining bladder function in patients.
Topics: Diabetes Mellitus, Type 2; Evoked Potentials, Somatosensory; Female; Humans; Male; Muscles; Reflex; Urinary Bladder, Neurogenic
PubMed: 36157205
DOI: 10.1155/2022/6096326 -
Environmental Health Perspectives Aug 2001In this article, we review the cardiovascular responses to the inhalation of irritants and pollutants. Many sensory receptors in the respiratory system, from nose to... (Review)
Review
In this article, we review the cardiovascular responses to the inhalation of irritants and pollutants. Many sensory receptors in the respiratory system, from nose to alveoli, respond to these irritants and set up powerful reflex changes, including those in the cardiovascular system. Systemic hypotension or hypertension, pulmonary hypertension, bradycardia, tachycardia, and dysrhythmias have all been described previously. Most of the experiments have been acute and have been performed on anesthetized experimental animals. Experiments on humans suggest we have similar sensory systems and reflex responses. However, we must use caution when applying the animal results to humans. Most animal experiments, unlike those with humans, have been performed using general anesthesia, with irritants administered in high concentrations, and often to a restricted part of the respiratory tract. Species differences in the response to irritants are well established. We must be even more careful when applying the results of acute experiments in animals to the pathophysiologic changes observed in prolonged exposure to environmental pollution in humans.
Topics: Air Pollutants; Animals; Autonomic Nervous System; Cardiovascular System; Humans; Reflex; Respiratory System
PubMed: 11544167
DOI: 10.1289/ehp.01109s4579 -
American Journal of Physiology.... Sep 2021Defined as a structural or functional cardiac abnormality accompanied by symptoms, signs, or biomarkers of altered ventricular pressures or volumes, heart failure also... (Review)
Review
Defined as a structural or functional cardiac abnormality accompanied by symptoms, signs, or biomarkers of altered ventricular pressures or volumes, heart failure also is a state of autonomic disequilibrium. A large body of evidence affirms that autonomic disturbances are intrinsic to heart failure; basal or stimulated sympathetic nerve firing or neural norepinephrine (NE) release more often than not exceed homeostatic need, such that an initially adaptive adrenergic or vagal reflex response becomes maladaptive. The magnitude of such maladaptation predicts prognosis. This Ludwig lecture develops two theses: the elucidation and judiciously targeted amelioration of maladaptive autonomic disturbances offers opportunities to complement contemporary guideline-based heart failure therapy, and serendipitous single-participant insights, acquired in the course of experimental protocols with entirely different intent, can generate novel insight, inform mechanisms, and launch entirely new research directions. I précis six elements of our current synthesis of the causes and consequences of maladaptive sympathetic disequilibrium in heart failure, shaped by patient-inspired epiphanies: arterial baroreceptor reflex modulation, excitation stimulated by increased cardiac filling pressure, paradoxical muscle sympathetic activation as a peripheral neurogenic constraint on exercise capacity, renal sympathetic restraint of natriuresis, coexisting sleep apnea, and augmented chemoreceptor reflex sensitivity and then conclude by envisaging translational therapeutic opportunities.
Topics: Autonomic Nervous System; Exercise; Heart; Heart Failure; Humans; Reflex; Sympathetic Nervous System
PubMed: 34259047
DOI: 10.1152/ajpregu.00143.2021 -
Pain Research & Management 2021Trigeminal neuralgia is often misdiagnosed at initial presentation due to close connotation with dental pain and is often over diagnosed for the very same reasons... (Review)
Review
Trigeminal neuralgia is often misdiagnosed at initial presentation due to close connotation with dental pain and is often over diagnosed for the very same reasons leading to numerous unnecessary surgical procedures such as peripheral neurectomy and alcohol injections, while the actual cause may remain elusive for decades. Evaluation of the neurosensory system may disclose the correct anatomical location of the etiology. The neurological examination may be clouded by the sensory deficits subsequent to previous peripheral surgical procedures. The corneal and blink reflexes are integral measures of the trigeminal and facial neurosensory assessment, and their abnormal function may facilitate the identification of intrinsic disease of the brain stem. These reflexes can be employed to discover pathological lesions including intracranial space-occupying trigeminal, lateral medullary, cerebral hemispheric lesions, and degenerative diseases of the central nervous system. Dental surgeons and oral and maxillofacial surgeons should consider corneal reflex in neurological assessment of patient presenting with trigeminal neuralgia-like symptoms. Failure to evaluate corneal sensitivity may lead to delayed or inaccurate diagnosis and unsuitable or redundant treatment interventions. This simple noninvasive reflex can be performed by chair-side and may provide significant information regarding the origin of facial pain and is an invaluable part of clinical methods especially in remote and peripheral healthcare center practitioners where sophisticated radiographic investigations such as computed tomography and magnetic resonance imaging may not be available.
Topics: Blinking; Cornea; Facial Pain; Humans; Magnetic Resonance Imaging; Neurologic Examination; Reflex; Trigeminal Neuralgia
PubMed: 33628353
DOI: 10.1155/2021/6664736 -
Annals of Palliative Medicine Dec 2021The blink reflex (BR) can be used as a routine monitoring method during facial nerve microvascular decompression. This study aimed to investigate whether the use of the...
BACKGROUND
The blink reflex (BR) can be used as a routine monitoring method during facial nerve microvascular decompression. This study aimed to investigate whether the use of the BR in hemifacial spasm (HFS) surgery is comparable to that of the lateral spread reflex (LSR), and to explore its significance for guiding intraoperative neurophysiological monitoring (IONM).
METHODS
Patients undergoing facial nerve microvascular decompression from 2016 to 2018 were included in the study. According to the results of IONM, the intraoperative monitoring items of the BR and two conventional facial nerve microvascular decompression procedures, namely the marginal mandibular branch LSR (MAR-LSR) and zygomatic branch LSR (ZYG-LSR), were compared. We mainly compared whether there were differences in the occurrence rate, disappearance rate, waveform, occurrence current, and prognosis of the three monitoring methods.
RESULTS
The occurrence rate of the BR was lower than that of the MAR-LSR and ZYG-LSR, as well as the three combined detection groups. The disappearance rate of the BR was not different to that of the MAR-LSR, but higher than that of the ZYG-LSR group. In addition, the waveform of the BR showed differences from that of the MAR-LSR and ZYG-LSR. The incidence of postoperative residual symptoms in patients with any kind of reflex on the first day after surgery and the day of discharge was significantly higher than that of patients in which all three reflexes disappeared.
CONCLUSIONS
Combined BR and LSR monitoring can reduce the occurrence of postoperative residual symptoms. We suggest that by increasing the use of BR examination during surgery, the integrity of the trigeminal nerve can be protected.
Topics: Blinking; Facial Nerve; Humans; Microvascular Decompression Surgery; Reflex; Retrospective Studies; Treatment Outcome
PubMed: 35016487
DOI: 10.21037/apm-21-3197 -
The Journal of Physiology May 2001During locomotion many segmental hindlimb reflex pathways serve not only to regulate the excitability of local groups of motoneurones, but also to control the basic... (Review)
Review
During locomotion many segmental hindlimb reflex pathways serve not only to regulate the excitability of local groups of motoneurones, but also to control the basic operation of the central pattern-generating circuitry responsible for locomotion. This is accomplished through a reorganization of reflexes that includes the suppression of reflex pathways operating at rest and the recruitment during locomotion of previously unrecognized types of spinal interneurones. In addition presynaptic inhibition of transmission from segmental afferents serves to regulate the gain of segmental reflexes and may contribute to the selection of particular reflex pathways during locomotion. The fictive locomotion preparation in adult decerebrate cats has proved to be an important tool in understanding reflex pathway reorganization. Further identification of the spinal interneurones involved in locomotor-dependent reflexes will contribute to our understanding not only of reflex pathway organization but also of the organization of the mammalian central pattern generator.
Topics: Animals; Locomotion; Motor Neurons; Neurons, Afferent; Reflex; Spinal Cord
PubMed: 11351011
DOI: 10.1111/j.1469-7793.2001.0041b.x -
Journal of Applied Physiology... Apr 2018Roller massage (RM) interventions have shown acute increases in range of motion (ROM) and pain pressure threshold (PPT). It is unclear whether the RM-induced increases... (Randomized Controlled Trial)
Randomized Controlled Trial
Roller massage (RM) interventions have shown acute increases in range of motion (ROM) and pain pressure threshold (PPT). It is unclear whether the RM-induced increases can be attributed to changes in neural or muscle responses. The purpose of this study was to evaluate the effect of altered afferent input via application of RM on spinal excitability, as measured with the Hoffmann (H-) reflex. A randomized within-subjects design was used. Three 30-s bouts of RM were implemented on a rested, nonexercised, injury-free muscle with 30 s of rest between bouts. The researcher applied RM to the plantar flexors at three intensities of pain: high, moderate, and sham. Measures included normalized M-wave and H-reflex peak-to-peak amplitudes before, during, and up to 3 min postintervention. M-wave and H-reflex measures were highly reliable. RM resulted in significant decreases in soleus H-reflex amplitudes. High-intensity, moderate-intensity, and sham conditions decreased soleus H-reflex amplitudes by 58%, 43%, and 19%, respectively. H-reflexes induced with high-intensity rolling discomfort or pain were significantly lower than moderate and sham conditions. The effects were transient in nature, with an immediate return to baseline following RM. This is the first evidence of RM-induced modulation of spinal excitability. The intensity-dependent response observed indicates that rolling pressure or pain perception may play a role in modulation of the inhibition. Roller massage-induced neural modulation of spinal excitability may explain previously reported increases in ROM and PPT. NEW & NOTEWORTHY Recent evidence indicates that the benefits of foam rolling and roller massage are primarily accrued through neural mechanisms. The present study attempts to determine the neuromuscular response to roller massage interventions. We provide strong evidence of roller massage-induced neural modulation of spinal excitability to the soleus. It is plausible that reflex inhibition may explain subsequent increases in pain pressure threshold.
Topics: Adult; Afferent Pathways; Female; Healthy Volunteers; Humans; Male; Massage; Muscle, Skeletal; Reflex; Young Adult
PubMed: 29357488
DOI: 10.1152/japplphysiol.00732.2017