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Clinical Neurophysiology : Official... Mar 2002The anatomy, pathophysiology, and clinical evaluation of radiculopathies are discussed. Defining whether root injury is present and which roots are involved can be... (Review)
Review
The anatomy, pathophysiology, and clinical evaluation of radiculopathies are discussed. Defining whether root injury is present and which roots are involved can be difficult but critical for patient management. In conjunction with clinical and radiological information, studies that establish physiological abnormalities of roots should be helpful and important. Clinical neurophysiological studies for radiculopathies are performed frequently but have yet to achieve a universally accepted role in the evaluation of these patients. Electrophysiological techniques for the evaluation of radiculopathies are reviewed. Needle electromyography is the best established of these procedures but has the disadvantage of requiring injury to motor fibers of both a certain degree and distribution. Nerve conduction studies may rarely be abnormal in radiculopathies but are needed to be certain other conditions that may produce similar symptoms and signs are not present. H reflexes and F waves probably have roles in the evaluation of radiculopathies but published reports about F waves in radiculopathies have been marred by inadequate methodology. There is evidence based on large series of patients that somatosensory evoked potentials can be helpful for evaluating patients with multilevel injury such as spinal stenosis, patients where electrophysiological studies may have their greatest clinical utility. Further work using either electrical stimulation with needles or magnetic stimulation of roots seems warranted. The demonstration of meaningful electrophysiological changes with activities that reproduce radicular symptoms may be a promising experimental approach. Available information does not necessarily answer critical questions about the role of electrophysiology in patients with radiculopathies. This cannot be done using analyses based on current ideas about evidence based medicine given the absence of a 'gold standard' for defining radiculopathies as well the absence of blinded studies. The available information provides strong arguments for further investigations evaluating different clinical neurophysiological techniques in the same patient, and for evaluating the value of these techniques by concentrating on their clinical import.
Topics: Electrodiagnosis; Electromyography; Electrophysiology; Evoked Potentials, Somatosensory; H-Reflex; Humans; Neural Conduction; Radiculopathy; Spinal Diseases; Spinal Nerve Roots
PubMed: 11897532
DOI: 10.1016/s1388-2457(02)00018-4 -
The Journal of Physiology May 19981. Paralysis of the diaphragm in the dog causes a non-vagal, non-chemical increase in the activity of the inspiratory intercostal muscles. In the present studies, the...
1. Paralysis of the diaphragm in the dog causes a non-vagal, non-chemical increase in the activity of the inspiratory intercostal muscles. In the present studies, the hypothesis was tested that phrenic afferent fibres may elicit a reflex inhibition of inspiratory intercostal activity. 2. The electrical activity of the three groups of inspiratory intercostal muscles (parasternal intercostals, external intercostals, levator costae) was recorded in twenty vagotomized, spontaneously breathing dogs, and the proximal end of one or both C5 phrenic nerve roots was stimulated during inspiration. 3. Stimulation of the ipsilateral and contralateral C5 phrenic roots caused an immediate reduction in inspiratory intercostal activity. This reduction was abolished when phrenic stimulation was repeated after section of the C5 dorsal roots. 4. The reduction in external intercostal and levator costae activity during bilateral C5 afferent stimulation appeared when the stimulus strength was 3 times the motor threshold and it increased in magnitude when stimulus intensity was increased further. In contrast, the reduction in parasternal intercostal activity occurred only when the stimulus strength was 12 times the motor threshold. 5. These observations confirm the hypothesis that diaphragmatic receptors may reflexly inhibit efferent activity to the inspiratory intercostal muscles, in particular the external intercostals and levator costae. This inhibition appears to be primarily mediated by small myelinated fibres.
Topics: Animals; Diaphragm; Dogs; Electric Stimulation; Electromyography; Intercostal Muscles; Neurons, Afferent; Phrenic Nerve; Reflex; Respiration; Spinal Nerve Roots
PubMed: 9518742
DOI: 10.1111/j.1469-7793.1998.919bp.x -
International Urogynecology Journal Dec 2010The lower urinary tract dysfunction encompasses voiding, postvoiding, and storage symptoms. Conventional treatment modalities include pharmacotherapy and behavioural... (Review)
Review
The lower urinary tract dysfunction encompasses voiding, postvoiding, and storage symptoms. Conventional treatment modalities include pharmacotherapy and behavioural therapy. Sacral neuromodulation (SNM) is a safe and minimally invasive treatment modality that has recently gained wide acceptance in the management of urinary urge incontinence, urge frequency, and nonobstructive urinary retention, in particular, among those patients with conditions refractory to conventional methods. We searched multiple electronic databases through June 30, 2009 for eligible studies. We examined published clinical and experimental studies concerning the mechanisms of action of SNM. In the first part of the manuscript, we describe the anatomy and functions of the lower urinary tract including the reflexes involved in its functions and then review the pathophysiology of major types of the lower urinary tract dysfunction. In the second part, we discuss different ways for SNM to control various types of voiding dysfunction. The lower urinary tract dysfunctions affect millions of people worldwide and have a severe impact on their quality of life. SNM offers a safe and minimally invasive modality in the treatment of voiding dysfunctions, especially in patients with conditions refractory to conventional therapies.
Topics: Electric Stimulation Therapy; Humans; Implantable Neurostimulators; Reflex; Sacrum; Spinal Nerve Roots; Urinary Tract; Urinary Tract Physiological Phenomena; Urination Disorders
PubMed: 20972548
DOI: 10.1007/s00192-010-1273-3 -
Acta Paediatrica (Oslo, Norway : 1992) Mar 1993A common breast-feeding problem is when the infant "places its tongue in its palate" and has difficulties in attaching to its mother's nipple. The aim of this study was...
A common breast-feeding problem is when the infant "places its tongue in its palate" and has difficulties in attaching to its mother's nipple. The aim of this study was to document the position of the tongue in the mouth cavity during rooting reflexes elicited in newborn infants before the first suckle. Eleven healthy, full-term infants were videotaped 101 +/- 31 min after birth during an evoked distinct rooting reflex before the first suckle. The videotaped rooting reflex was analyzed in detail concerning the degree of turning of the head, mouth opening and position of the tongue, in pictures that were "frozen" at specific intervals. "Licking movements" preceded and followed the rooting reflex in the alert infants. In 10 of the 11 infants the tongue was placed in the bottom of the mouth cavity during a distinct rooting reflex (p = < 0.05). It is suggested that forcing the infant to the breast might abolish the rooting reflex and disturb placement of the tongue. A healthy infant should have the opportunity of showing hunger and optimal reflexes, and attach to its mother's nipple by itself.
Topics: Breast Feeding; Humans; Infant, Newborn; Reflex; Sucking Behavior; Tongue
PubMed: 8495085
DOI: 10.1111/j.1651-2227.1993.tb12660.x -
Neuroscience and Biobehavioral Reviews Jan 2022Play has been recognized as a complex and diverse set of behaviors that has been difficult to define. Play can range from rough and tumble play among rats to a human... (Review)
Review
Play has been recognized as a complex and diverse set of behaviors that has been difficult to define. Play can range from rough and tumble play among rats to a human child playing a computer game. Play has been understood to exist in multiple forms such as social, object, and locomotor (Burghardt, 2005). In this article we review the literatures on the neural basis of social play, on heart rate variability, on behavioral switching and set-shifting, on prepulse inhibition of the acoustic startle reflex, and on learning at the level of the basal ganglia. Each of these neuronal pathways, aside from heart rate variability, is rooted in the parafascicular nucleus of the thalamus, an important neural substrate for social play. We argue that social play optimally balances a number of opposing neural pathways by engaging systems involved in safety versus danger (heart rate variability), automatized reactions versus learned reactions to new stimuli (behavioral switching and set-shifting), and gating relevant versus less relevant stimuli (prepulse inhibition of the acoustic startle reflex). The idea that play, in addition to its role in interpersonal adaptation to social life, may have a central role in optimizing flexibility and creativity in individual response to novelty has been explored by previous authors (Huizinga, 1955; Spinka et al., 2001; Pellegrini et al., 2007; Pellis and Pellis, 2017). In this paper we explore the possible underlying neural basis for this function of play, having to do with balancing various neural networks, and in doing so propose an expanded understanding of the nature and function of social play.
Topics: Acoustic Stimulation; Animals; Neural Inhibition; Neural Pathways; Prepulse Inhibition; Rats; Reflex, Startle
PubMed: 34767879
DOI: 10.1016/j.neubiorev.2021.11.005 -
The Urologic Clinics of North America Feb 2005The authors believe that the principles underlying the multiple possible SNS mechanisms of action can be summarized as somatic afferent inhibition of sensory processing... (Review)
Review
The authors believe that the principles underlying the multiple possible SNS mechanisms of action can be summarized as somatic afferent inhibition of sensory processing in the spinal cord. Regardless of whether the lower urinary tract dysfunction involves storage versus emptying abnormalities, the pudendal afferent signaling serves as a common crossroads in the neurologic wiring of the system. Not only can pudendal afferent input turn on voiding reflexes by sup-pressing the guarding reflex pathways, pudendal afferent input to the sacral spinal cord also can turn off supraspinally mediated hyperactive voiding by blocking ascending sensory pathway inputs. For these reasons, SNS can take advantage of the complex neurologic pathways described and offer successful treatment for a seemingly disparate group of lower urinary tract pathologies. SNS is a urologic technique that has proved safe and minimally invasive, and it holds great promise for many patients who have lower urinary tract dysfunction.
Topics: Afferent Pathways; Animals; Brain; Electric Stimulation Therapy; Humans; Parasympathetic Nervous System; Reflex; Sacrum; Spinal Nerve Roots; Urinary Bladder; Urination; Urination Disorders
PubMed: 15698871
DOI: 10.1016/j.ucl.2004.09.004 -
American Journal of Physical Medicine &... 1994
Topics: Cervical Vertebrae; Humans; Muscles; Pronation; Reflex; Spinal Nerve Roots
PubMed: 8043243
DOI: 10.1097/00002060-199407000-00001 -
Ideggyogyaszati Szemle Sep 2019Despite of the symptoms of vertigo have been known since thousands of years, it was evident by the research of the pioneer scientists of the 19th century (Flourens,... (Review)
Review
Despite of the symptoms of vertigo have been known since thousands of years, it was evident by the research of the pioneer scientists of the 19th century (Flourens, Ménière, Breuer and others) that dizziness can also be attributed to inner ear disfunctions. The discovery of the vestibulo-ocular reflex was an important milestone (Endre Hőgyes, 1884). The vestibulo-ocular reflex stabilizes images on the retina by rotating the eyes at the same speed but in the opposite direction of head motion. The milestone discovery of Hőgyes by stimulating individual labyrinth receptors and recording the activity of eye muscles were verified by János Szentágothai in 1950. Low-frequency lesions of the angular vestibulo-ocular reflex can be investigated by caloric test (Robert Bárány,1906), high-frequency lesions by head impulse test (Gabor Michael Halmagyi and Ian Stewart Curthoys, 1988).
Topics: Head Impulse Test; History, 19th Century; History, 20th Century; Humans; Hungary; Neurotology; Reflex, Vestibulo-Ocular; Vertigo
PubMed: 31625696
DOI: 10.18071/isz.72.0295 -
Journal of Neurophysiology Jan 1955
Topics: Nervous System Physiological Phenomena; Reflex; Spinal Nerve Roots; Spinal Nerves
PubMed: 13222153
DOI: 10.1152/jn.1955.18.1.1 -
Gastroenterology Dec 1979In 4 patients, trauma to the lumbosacral area produced abnormalities similar to those seen after resection of the nervi erigentes. Mechanisms of the resulting...
In 4 patients, trauma to the lumbosacral area produced abnormalities similar to those seen after resection of the nervi erigentes. Mechanisms of the resulting constipation and fecal incontinence for liquid stools included a prolonged transit time through the entire colon, a low rectal pressure, spasticity of the anal canal, and abnormal anal reflexes. Previous trauma to the lower spine must be considered in the differential diagnosis of chronic constipation.
Topics: Adolescent; Adult; Anal Canal; Cauda Equina; Colon; Constipation; Female; Gastrointestinal Motility; Humans; Male; Rectum; Reflex, Abnormal; Spinal Cord Injuries; Spinal Nerve Roots
PubMed: 499713
DOI: No ID Found