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Biomedical subjects

L Penders

Publications and source records attributed to L Penders.

At least 37 records · Page 2Linked to original sources
PubMed1984

Enuresis and urethral instability.

31 patients with refractory enuresis underwent simultaneous urethrocystometry. Pure urethral instability was encountered in 14, urethral and bladder instability in 11 and isolated uninhibited bladder in 3. This allows us to discuss the functional relationship between the urethra and the bladder. We consider urethral instability as being a trigger mechanism for detrusor contraction, and the explanation for the paradox of stable bladder enuresis. Phenylpropanolamine (Ornade), 25-50 mg at bedtime, stabilizes the vesicosphincteric unit and stopped bedwetting in 11 of 16 patients.

Adolescent↗
PubMed1984

[The striated sphincter of the urethra. 2: Specific methods for studying the striated sphincter of the urethra].

Radiology and electromyography of the lower urinary tract are specific techniques for exploration of the urethral rhabdosphincter. Retrograde and mictional urethrography provide data on the extent of the membranous urethra. In the presence of rhabdosphincter lesions a mictional urethrogram is often sufficient to establish a diagnosis from the direct and indirect signs of obstruction it supplies. A retrograde urethrography examination can be added validly to the previous exploration to improve precise definition of sclerosis: in contrast it is indispensable when miction is impossible. Differential diagnosis between spasm and stenosis of striated and dyssynergy of smooth muscle sphincter is by pharmacologic tests. Radiologic study of sphincter contraction is generally by cineradiography with arrest of miction. Results are limited, however, when compared with those of a radiodynamic study: the latter supplies information on the functioning of the para- and peri-urethral rhabdosphincter, and allows measurement of contraction. The electromyogram, with its different practical technical modalities, provides details of the urethral rhabdosphincter. The contact electromyogram gives quantitative data but fails to diagnose a neurological lesion. It analyzes behavior of the sphincter in its para-urethral part and can localize its diaphragmatic portion; dynamic electric profiles are of little reliability, in contrast to static profiles which quantify electric activity at all points in the urethra during the same contraction. The standard percutaneous needle electromyography examination provides qualitative data on the peri-urethral rhabdosphincter, but lacks precision as to the region explored, while qualitative information on the para-urethral sphincter requires the use of an endo-urethral approach. A difference in potential between para- and peri-urethral musculature has been demonstrated a fact confirmed by anatomical findings in Goslings study. In normal subjects, the rhabdosphincter differs from other skeletal muscles by its constant activity except during miction; potentials in children differ from those in adults by their duration. In lower motor neurone disease signs of denervation appear after several weeks, while in upper motor neurone affections the potentials are normal but nociceptive and bulbocavernous stimuli provoke bursts of hyperactivity which reappear very shortly after the paraplegia. Striated muscle fibrosis provokes peripheral signs with persistence of regions of increased reflexes. Tests of responses to stimuli provide important information enabling the site of the neurogenic lesion to be determined.

Electromyography↗
PubMed1984

[The striated sphincter of the urethra. 3: Urodynamic and physiopathologic study of the striated sphincter].

Dysfunction of the rhabdosphincter results from an increase (dyssynergia) or decrease in activity of either neurological or non-neurological origin. We have defined dyssynergia as the absence of urethral relaxation and/or sphincter contraction during and/or before detrusor muscle contraction. Non-invasive exploratory methods include flowmetry, anal contact EMG and an abdominal pressure or EMG examination. Invasive techniques are of various types: urethro-cystometry with EMG, via the perineum in males and the endo-urethral approach in females, provides quantitative data on extent of altered function and relative involvement of either smooth or striated muscle sphincters. An essential complement to urodynamic exploration is a conventional mictional cystogram. We have proposed an etiologic classification of dyssynergia: tonic dyssynergia is pathognomonic of supra-sacral medullary lesions while clonic dyssynergia reflects the bladder-sphincter conflict, whether it be of neurologic or other origin. Clonic dyssynergia in patients with neurologic affections is seen mainly in those with supra-sacral medullary lesions at whatever level, and with a 50 to 100% frequency. Its serious nature is not related to the bladder-sphincter equilibrium but to the high pressures developed by the system. The neurologic rhabdosphincter presents characteristic persistent reflex activity at the spinal shock phase and a possible course leading to fibrosis. In patients without neurologic disease the terms dyssynergia or pseudodyssynergia are used depending on whether the sphincter contraction during bladder contraction is involuntary or voluntary. To explain this non-neurologic pseudodyssynergia, Lapides suggested as a basis the theory of the evolution of sphincter control, Tanagho that of sphincter spasticity. In reality it involves a vicious circle centered on the bladder-sphincter conflict, entry being possible at various levels: bladder instability, urethral instability, urethral hypersensitivity, rhabdosphincter spasticity. These disturbed functions induce the urethral syndrome, repeated urinary infections, reflux and sometimes even renal stasis. Deficient sphincter activity of neurologic origin presents pathognomonic electromyographic signs; from a functional point of view valid data can be obtained from measurement of variations in maximum urethral pressure during a retention effort. Among the neurologic etiologies, the rhabdosphincter is only rarely affected by poliomyelitis or amyotrophic lateral sclerosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Ataxia↗
PubMed1984

[Simultaneous urethrocystometry and hyperactive bladders: differential diagnosis and types of dyssynergia].

The authors reviewed the simultaneous urethrocystometry (SUCM) of 96 hyperactive bladders subclassified into 4 groups (pure detrusor instability, mixed instability, suprasacral spinal lesion, and CNS lesion) and compared the frequency of various urethral parameters. The absence of urethral relaxation before or during the augmentation of the detrusor pressure is the most specific sign of suprasacral spinal lesions. It constitutes what we call passive or tonic dyssynergia. When, in the beginning of SUCM, the maximal closure pressure is greater than or equal to 30 cm H20, or when a sphincteric contraction is associated with, either before ("kick") or during (active or clonic dyssynergia) the detrusor contraction, this urethral non relaxation is pathognomonic of such a spinal lesion. A "kick" is also specific of hyperreflexia but is less constant. On the contrary, in this series and with this technic, an active dyssynergia has no etiological significance; it' only reflects the degree of the vesicosphincteric imbalance.

Diagnosis, Differential↗
PubMed1984

[Urethral instability: diagnosis and clinical significance].

Simultaneous urethrocystometry, the advantages of which are outlined, enabled us to diagnose 27 cases of pure urethral instability (male and female) and 16 cases of mixed instability (urethral and bladder instability). We analysed the relationship between the main symptom, this urethral dysfunction and the competence of the bladder neck. Definition, characteristics and frequency of urethral instability are discussed. It is responsible of: frequency or urgency, in the absence of bladder instability, when the bladder neck is closed, intermittent sphincteric incontinence, in the presence of a normal closure pressure on the urethral pressure profile, when the bladder neck is incompetent, enuresis, particularly in case of stable bladder; a new treatment is proposed for this entity. The clinical interest of this diagnosis is stressed in these three situations.

Adolescent↗
PubMed1984

[The striated sphincter of the urethra. 1: Recall of knowledge on the striated sphincter of the urethra].

The first part of this report is devoted to the anatomy, nerve supply, and physiology of the striated sphincter, three subjects which greatly aroused a great deal of controversies. The conclusions of the authors are as follows. The striated sphincter of the urethra is a muscle of the perineum, arising from the cloacal sphincter. The deep transverse, bulbo-cavernous, anal sphincter, ischio-cavernous and superficial transverse muscles have the same embryological origin and together with the sphincter of the urethra form the accessory pelvic diaphragm. The embryological origin of the levator ani muscles is different. These arise from the caudal muscles and form the principal pelvic diaphragm. The striated sphincter of the urethra is unequally distributed in the male and female fetus. According to our anatomical concept, the urethral sphincter includes two structures: the para-urethral sphincter and the peri-urethral sphincter. The para-urethral sphincter form an integral part of the urethra and is distributed principally along the membranous part of urethra but extends approximately to the bladder neck and distally under the perineum aponeurosis. In the adult as in the fetus, the para-urethral striated sphincter is unequally distributed along the urethra, according to sex. In the male, it surrounds the membranous urethra and is absent from the posterior face of the prostatic urethra. By contrast, in the female, the sphincter surrounds the proximal third of the urethra and the rings are incomplete on the distal third. The peri-urethral striated sphincter includes the other muscles of the perineum and of the principal pelvic diaphragm. These two structures differ from a microscopic stand point; the para-urethral striated sphincter contains only narrow calibre slow fibers, with the absence of the neuro-muscular spindles. By contrast, the peri-urethral sphincter consists of slow and rapid fibers and contains neuro-muscular spindles. The nerve supply of the peri-urethral striated sphincter is insured by internal pudendal nerves. The para-urethral striated sphincter is supplied in great part of the same internal pudendal nerves arising from neurones situated in the nucleus of Onuf. However, the pelvic nerves may contain a group of accessory fibers from the same origin. There is no proof available as to the role played by the sympathetic nervous system. When micturition comes to an end, the para-urethral sphincter causes a constriction of the membranous urethra in the male, and single flattening of the middle part of the urethra in the female.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1983

[The bethanechol test in the diagnosis of neurogenic bladder. 60 cases].

Bethanechol denervation hypersensitivity test seems useful although sometimes disregarded, for the diagnosis of lower neurogenic bladder. Our own experience of 60 patients is presented. When the indications are good (large capacity, hypotonic bladder, clinical suspicion of lower neuron lesion) and when the interpretation is based on a right understanding of its mechanism, this test appears to be very reliable. Except in 4 cases, the difference of pressure is greater than 20 or less than 10 cm H20. Factors susceptible to interfere with its accuracy are summarized. We must admit some discrepancies between the results of this test (exploring the pelvic nerve) and the perineal EMG (exploring the pudendal nerve); this fact is illustrated here. The importance of a wide bladder neck as a radiologic sign of neurogenic bladder is also stressed.

Bethanechol↗
PubMedDate not supplied

[Defecation disorders. Characteristics of manometric studies and rehabilitation].

The authors review the literature and their personal experience about the systematic exploration of defecation disorders by anorectal manometry and colpocystodefecography. They stress the importance of combining functional and morphological evaluation, in order to avoid inappropriate surgery. Concerning anorectal manometry, the determination of the smallest volume of rectal distention inducing a complete relaxation of the internal anal sphincter was found more useful than the maximal tolerable volume in the exploration of defecation disorders. Finally, the authors report the results of biofeedback conditioning prescribed in 30 patients (27 women, 3 men, mean age: 55 years) with defecation disorders (terminal constipation in 21, fecal incontinence in 9 patients). Several characteristics of anorectal manometry and of defecography were significantly improved after biofeedback conditioning.

Adult↗