Action Potential Parameters in Different Human Muscles

Buchthal, Fritz; Rosenfalck, Poul

doi:10.1111/j.1600-0447.1955.tb06052.x

Cited by 118 publications

(43 citation statements)

References 6 publications

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“…They partly explain the apparent discrepancy between low anal squeeze pressures and anal sphincter injury documented by imaging in asymptomatic older women (17) and emphasize the need to consider neurogenic injury as an explanation for anal weakness, particularly prior to anal sphincteroplasty. Increasing age was also associated with longer MUP in distal lower extremity muscles (9). While healthy individuals loose, on average, ϳ25% of motor neurons in the lumbo spinal segments (L1-S3) from the second to tenth decade of life, several subjects older than 60 yr of age have only 50% of those in early adult or middle age (35).…”

Section: Discussionmentioning

confidence: 99%

Anal sphincteric neurogenic injury in asymptomatic nulliparous women and fecal incontinence

Bharucha¹,

Daube²,

Litchy³

et al. 2012

American Journal of Physiology-Gastrointestinal and Liver Physi

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Bharucha AE, Daube J, Litchy W, Traue J, Edge J, Enck P, Zinsmeister AR. Anal sphincteric neurogenic injury in asymptomatic nulliparous women and fecal incontinence. Am J Physiol Gastrointest Liver Physiol 303: G256 -G262, 2012. First published May 4, 2012 doi:10.1152/ajpgi.00099.2012.-While anal sphincter neurogenic injury documented by needle electromyography (EMG) has been implicated to cause fecal incontinence (FI), most studies have been uncontrolled. Normal values and the effects of age on anal sphincter motor unit potentials (MUP) are ill defined. The functional significance of anal sphincter neurogenic injury in FI is unclear. Anal pressures and EMG were assessed in 20 asymptomatic nulliparous women (age, 38 Ϯ 5 yr; mean Ϯ SE) and 20 women with FI (54 Ϯ 3 yr). A computerized program quantified MUP duration and phases. These parameters and MUP recruitment were also semiquantitatively assessed by experienced electromyographers in real time. Increasing age was associated with longer and more polyphasic MUP in nulliparous women by quantitative analysis. A higher proportion of FI patients had prolonged (1 control, 7 patients, P ϭ 0.04) and polyphasic MUP (2 controls, 9 patients, P ϭ 0.03) at rest but not during squeeze. Semiquantitative analyses identified neurogenic or muscle injury in the anal sphincter (11 patients) and other lumbosacral muscles (4 patients). There was substantial agreement between quantitative and semiquantitative analyses ( statistic 0.63 Ϯ 95% CI: 0.32-0.96). Anal resting and squeeze pressures were lower (P Յ 0.01) in FI than controls. Anal sphincter neurogenic or muscle injury assessed by needle EMG was associated (P ϭ 0.01) with weaker squeeze pressures (83 Ϯ 10 mmHg vs. 154 Ϯ 30 mmHg) and explained 19% (P ϭ 0.01) of the variation in squeeze pressure. Anal sphincter MUP are longer and more polyphasic in older than younger nulliparous women. Women with FI have more severe neurogenic or muscle anal sphincter injury, which is associated with lower squeeze pressures. aging; electromyography; pudendal neuropathy INITIALLY DOCUMENTED BY HISTOLOGICAL evidence of sphincter denervation (27), the concept that pudendal nerve injury contributes to anal weakness in fecal incontinence (FI) gained traction when prolonged pudendal nerve terminal motor latencies were documented in FI and after obstetric anal sphincter injury (2, 22, 30). However, prolonged pudendal nerve latencies are flawed markers of pudendal nerve function (13). Hence, needle electromyography (EMG) is the only technique that can reliably identify anal sphincter neurogenic injury that can result from damage to the sacral spinal cord, cauda equina, S2-4 spinal nerves, the pudendal nerve, or its branches as they enter the anal sphincter (28,29,34). Anal sphincter EMG can also identify local muscle trauma (3). However, anal sphincter EMG is not widely available and infrequently used, mainly when neurogenic injury is suspected, in clinical practice. Also, based on limited data that suggest that anal sphincter denervation predicts poore...

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Section: Discussionmentioning

confidence: 99%

Anal sphincteric neurogenic injury in asymptomatic nulliparous women and fecal incontinence

Bharucha¹,

Daube²,

Litchy³

et al. 2012

American Journal of Physiology-Gastrointestinal and Liver Physi

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“…Contraction of the adductor pollicis muscle is simple and differs markedly from the abduction of the vocal cords. In addition, there are different microanatomical and histological structures and types of innervation (Rossi & Cortesina, 1965;Johnson et al, 1973), which result in different neurophysiological manifestations (Buchthal & Rosenfalck, 1955;Buchthal, 1959) between muscles. Furthermore, differences in muscle temperature and blood supply, presumably responsible for different pharmacokinetic and pharmacodynamic effects at the site of action, i.e.…”

Section: Discussionmentioning

confidence: 99%

A method for studying the pharmacodynamic profile of neuromuscular blocking agents on vocal cord movements in anaesthetized cats

Vandenbrom

Houwertjes

Ágoston

1991

British J Pharmacology

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1 A new in vivo experimental method is described whereby the neuromuscular blocking effects of muscle relaxants can be investigated on the intrinsic laryngeal muscles of anaesthetized cats. The peripheral tibialis anterior muscle preparation is employed in the same animal to compare the blocking effect on both preparations. 2 The intrinsic laryngeal muscles react with different sensitivities to the neuromuscular blocking agents when compared to the tibialis anterior muscle. 3 The neuromuscular response in both muscle preparations is similar with steroidal agents but appeared to be different after suxamethonium or isoquinoline analogues. 4 It is concluded that this preparation may become a useful tool for studying new muscle relaxants developed to facilitate rapid intubation conditions.

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“…The discharge pattern during maximal voluntary contraction was also observed. At the preoperative and 1-year postoperative EMF examinations, a t least 20 different motor unit potentials from the anterior tibial and gastrocnemius muscles were recorded for later measurements of motor unit potential durations, according to Buchthal & Rosenfalck (1955). The motor unit potentials were evaluated quantitatively only in those ten patients who were followed for 1 year.…”

Section: Neurophysiological Methodsmentioning

confidence: 99%