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Biomedical subjects

G Amarenco

Publications and source records attributed to G Amarenco.

At least 19 recordsLinked to original sources

[Relationship between gait speed and strength parameters in multiple sclerosis].

INTRODUCTION: Recent studies have focused on correlation between strength and gait parameters in hemiplegia, suggesting the interest for strength training in patients with central nervous system lesions. The aim of this study was to evaluate this correlation in multiple sclerosis (MS) patients with special regard to the different clinical forms including proprioceptive loss or cerebellar ataxia. PATIENTS AND METHOD: Gait speed and muscular function were performed in 27 patients with moderate affected gait (EDDS < 6). Gait speed was evaluated with Locometre and peak-torques of quadriceps and hamstrings were evaluated with isokinetic dynamometer. Patients were separated in three groups related to their deficiency: spastic group (8 patients), spastic with proprioceptive loss (12 patients) and spastic with cerebellar ataxia (7 patients). Gait parameters were evaluated in 10 healthy subjects as control group. RESULTS: Gait speeds (spontaneous and maximal) and peak torques of quadriceps and hamstring were similar in the three groups. In the whole patients group, gait speed was reduced and related to hamstring peak torque (r = 0.56 at spontaneous speed and 0.51 at high speed) but not with quadriceps peak torque. Patients with proprioceptive loss exhibited not only a higher correlation between gait speed and hamstring torque (r = 0.76 and 0.65 respectively) than other patients but also with quadriceps torque (r = 0.66 and 0.59 respectively) when patients in other groups did not. CONCLUSION: As it was previously pointed out in hemiplegic patients, MS patients exhibit some correlation between gait speed and muscle strength, mainly with hamstrings. These correlations can change in special sensory conditions suggesting that patients with sensory loss use different muscular strategies to maintain gait speed. Strength training may therefore be discussed in MS including specific modalities as a function of clinical parameters.

Biomechanical Phenomena↗

[Botulinum toxin in headache].

Use of botulinum toxin in headache is a recent method. More and more studies are dedicated to this method. However, despite the large number of published studies, results are contradictory. It is actually difficult to conclude that this therapy is effective or not due to the disparity of clinical studies. Nevertheless, some results are encouraging and studies with a large number of patients have to be done. Here, we take stock about pathophysiological data on the effect of botulinum toxin on pain. Then, we'll report a review of clinical studies available on literature.

Anti-Dyskinesia Agents↗

Urodynamic effect of acute transcutaneous posterior tibial nerve stimulation in overactive bladder.

PURPOSE: Of the various treatments proposed for urge incontinence, frequency and urgency electrostimulation has been widely tested. Different techniques have been used with the necessity of surgical implantation (S3 neuromodulation or sacral root stimulation) or without requiring surgery (perineal transcutaneous electrostimulation). Recently peripheral electrical stimulation of the posterior tibial nerve was proposed for irritative symptoms in first intention or for intractable incontinence. Clinical studies have demonstrated good results and urodynamic parameters were improved after chronic treatment. However, to our knowledge no data concerning acute stimulation and immediate cystometry modifications have been reported. We verified urodynamic changes during acute posterior tibial nerve stimulation. MATERIALS AND METHODS: A total of 44 consecutive patients with urge incontinence, frequency and urgency secondary to overactive bladder were studied. There were 29 women and 15 men with a mean age +/-SD of 53.3 +/- 18.2 years. Of the patients 37 had detrusor hyperreflexia due to multiple sclerosis (13), spinal cord injury (15) or Parkinson's disease (9), and 7 had idiopathic detrusor instability. Routine cystometry at 50 ml. per minute was done to select the patients with involuntary detrusor contractions appearing before 400 ml. maximum filling volume. Repeat cystometry was performed immediately after the first study during left posterior tibial nerve stimulation using a surface self-adhesive electrode on the ankle skin behind the internal malleolus with shocks in continuous mode at 10 Hz. frequency and 200 milliseconds wide. Volume comparison was done at the first involuntary detrusor contraction and at maximum cystometric capacity. The test was considered positive if volume at the first involuntary detrusor contraction and/or at maximum cystometric capacity increased 100 ml. or 50% during stimulation in compared with standard cystometry volumes. RESULTS: Mean first involuntary detrusor contraction volume on standard cystometry was 162.9 +/- 96.4 ml. and it was 232.1 +/- 115.3 ml. during posterior tibial nerve stimulation. Mean maximum cystometric capacity on standard cystometry was 221 +/- 129.5 ml. and it was 277.4 +/- 117.9 ml. during stimulation. Posterior tibial nerve stimulation was associated with significant improvement in first involuntary detrusor contraction volume (p <0.0001) and significant improvement in maximum cystometric capacity (p <0.0001). The test was considered positive in 22 of the 44 patients. CONCLUSIONS: These results suggest an objective acute effect of posterior tibial nerve stimulation on urodynamic parameters. Improved bladder overactivity is an encouraging argument to propose posterior tibial nerve stimulation as a noninvasive treatment modality in clinical practice.

Female↗

[Physiology and evaluation of overactive bladder].

Detrusor overactivity is a urodynamic observation characterized by involuntary detrusor contractions during the filling phase which may be spontaneous or provoked. There are certain patterns of detrusor overactivity. Phasic detrusor overactivity is defined by a characteristic wave form and may or may not lead to urinary incontinence. Terminal detrusor overactivity is defined as a single involuntary detrusor contraction occurring at cystometric capacity, which cannot be suppressed. Neurogenic detrusor overactivity is qualified as neurogenic when it is a relevant neurological condition (old term is "detrusor hyperreflexia"), idiopathic detrusor overactivity when there is no defined cause (this term replaces "detrusor instability"). In neurogenic patients, detrusor overactivity is secondary to various pathophysiologic factors: interruption of inhibitor pathways issued from cerebral regions, activation de novo of vesical C reflex mediated by unmyelinated capsaicin fibers, and ultrastructural modifications of bladder urothelium. Bladder overactivity treatment is necessary to avoid renal complications and improve quality of life of neurogenic patients.

Humans↗

Electrophysiological analysis of pudendal neuropathy following traction.

Pudendal neuropathy is an unusual but important complication of orthopedic surgical procedures involving traction on the fracture table. We describe the clinical and electrophysiological features in six patients presenting with perineal sensory disorders and sexual dysfunction following surgical repair of femoral fracture, hip dislocation, or intra-articular foreign body, in which the traction table was used. All underwent electrophysiological recordings: bulbocavernosus muscle electromyography (EMG), measurements of the bulbocavernosus reflex latencies (BCRLs), somatosensory evoked potentials of the pudendal nerve (SEPPNs), sensory conduction velocity of the dorsal nerve of the penis (SCVDNP), and pudendal nerve terminal motor latencies (PNTMLs). Signs of denervation localized to the territory of the pudendal nerve were found in 3 patients, normal BCRL in 6, abnormal SEPPNs in 4, and abnormal SCVDNPs and PNTMLs in all cases. The outcome at 2-year follow-up was good, except in one patient with initially unrecordable PNTML. Perineal electrophysiological examination can thus confirm the pudendal neuropathy and give prognostic information.

Adolescent↗

[Suprapubic reflex. Electrophysiological study in normal patients].

INTRODUCTION: In spinal cord injuries patients, tapping the suprapubic aera is a strong stimulus to ellicit detrusor contraction and can be used in the management of neurogenic bladder. This stimulation also determines a perineal muscles contraction. This striated response was mentionned in animal studies but never specifically analysed in men especially in normal subjects. AIMS OF THE STUDY: Our objective was to describe pelvic floor responses with measurement of reflex latency following suprapubic mechanical stimulation. METHODS: 21 patients without neurological disease were studied. They were 14 women and 7 men. Mean age was 51 (SD=14,2). Motor responses were recorded with a needle electrode inserted in the left bulbocavernosus muscle. Stimulation was delivered with an electromechanical hammer, tapping directly on the suprapubic aera. RESULTS: A polyphasic muscular response was always and easily elicited in all patients. Mean latency was 67,5 ms. (SD = 14,7). The reproducibility between the first and second mechanical responses was good with no statistical difference (r=0,966; p=0,0001). DISCUSSION: Our study clearly demonstrates a suprapubic bulbocavernosus reflex (SBR). Many arguments can be retained for a polysynaptic reflex (polyphasic response, habituation and short latency of the reflex, mean latency in the habitual values of R2 responses following electrical stimulation of the dorsal nerve of the penis). We hypothetize that: the true stimulus is the stimulation of the bladder wall tenso-receptors; integration level of the SBR is the sacral segments and the efferent limb the pudendal nerve; afferent pathways could be vehicled by pelvic nerve fibers. CONCLUSION: Competition between a preponderant (or exaggerated) SBR and a bladder contraction following suprapubic tapping, may constitute a real functional outlet obstruction giving incomplete or complete retention in some suprasacral bladders. In normal subjects, SBR can be considered as a continence reflex with increase of perineal tone following the stimulation of the bladder wall tenso-receptors during stress.

Analysis of Variance↗

Results of the tension-free vaginal tape procedure for the treatment of type II stress urinary incontinence at a minimum followup of 1 year.

PURPOSE: We evaluated the safety and efficacy of the tension-free vaginal tape procedure for treating type II stress urinary incontinence in females. MATERIALS AND METHODS: Between April 1998 and April 1999, 62 women 28 to 86 years old (mean age 62.8) were treated consecutively for stress urinary incontinence with the tension-free vaginal tape procedure. Preoperative evaluation included history, physical examination and multichannel video urodynamics. All patients had type II stress urinary incontinence, none had preoperative detrusor instability or significant pelvic prolapse and in 16 previous surgery for stress incontinence had failed. RESULTS: All patients were followed at least 12 months after the procedure (median 16.2). A total of 42 and 20 women received spinal and local anesthesia, respectively. We noted 6 bladder perforations, including 5 in patients with a history of surgery for stress urinary incontinence. Blood loss was less than 200 cc in all cases. We observed no prolonged postoperative pain, infection or sling rejection. Post-void residual urine was less than 100 cc the day after surgery in 59 cases. Only 3 patients self-catheterized a maximum of 4 days. At followup 54 women (87.1%) were cured of stress urinary incontinence, 6 were improved (9.6%) and 2 had failure (3. 3%), while 4 (6.4%) had new onset detrusor instability without evidence of bladder outlet obstruction. CONCLUSIONS: The tension-free vaginal tape procedure appears to be a minimally invasive, safe and effective treatment for type II stress urinary incontinence. A history of surgery for stress incontinence seems to be a risk factor for bladder perforation.

Adult↗

Quality of life in spinal cord injury patients with urinary difficulties. Development and validation of qualiveen.

BACKGROUND: Quality of life (QoL) may be severely affected in patients with spinal cord injury (SCI) and resulting urinary difficulties (UD). There is, however, a need for instruments capable of measuring QoL in these patients. The aim of this study was to develop and validate a questionnaire suitable for use in SCI patients with urinary disorders. METHODS: Following patient interviews, a questionnaire was developed in French that was subjected to item reduction and cross-sectional validation. The resulting Qualiveen (Qualiveen is a pending registration trade mark of Coloplast A/S, DK-3050 Humlebaek, Denmark) questionnaire underwent multi-trait and principal component analysis and the test-retest reliability of the questionnaire was examined in stable patients. RESULTS: Patient interviews identified 257 concepts relevant to SCI patients with urinary disorders. Item reduction led to a 30-item questionnaire, which was psychometrically validated in 281 SCI patients with UD. The median age of patients was 41 years, 78% were male and the majority were paraplegic (55%). The construct and clinical validity of the Qualiveen was confirmed, as well as its reliability in patients whose condition was stable over a 15-day period. Patients confirmed that it was easy to understand, complete and comprehensive. CONCLUSIONS: The Qualiveen is a reliable and psychometrically validated instrument that may be used to measure the QoL of SCI patients with UD.

Adult↗

[Clinical evaluation of urinary incontinence in the woman].

Clinical assessment of stress and urge incontinence in women is always necessary before making therapeutic decisions. During the full bladder examination stress incontinence triggered by cough may suggest cervicourethral hypermobility. Leakage during the Vasalva manoeuvre may reveal incontinence due to intrinsic sphincter deficiency. The pad test provides an objective quantitative measurement of the degree of incontinence. Symptom scores enable intra- and inter-individual comparisons. Psychosocial implications are studied with specific quality-of-life scales. Together, these tests improved therapeutic strategies for managing stress and urge incontinence, providing an objective evaluation of the different treatments and thus a better medico-economic approach to the problem.

Female↗

[Clinical evaluation of female urinary incontinence].

EXAMINATION: Clinical evaluation of stress and urge incontinence is always necessary before therapeutic decisions. Full bladder examination may reveal stress incontinence during cough when cervico-urethral hypermobility is suspected, and leak during Vasalva manoeuvre when incontinence is due to intrinsic sphincter deficiency. OBJECTIVE SCORES: Pad test objectives the quantitative importance of incontinence. Symptom scores allow intra and inter individual comparisons. Psychosocial implications are studied with specific quality of life scales. They allow better therapeutic strategies in the management of urge and stress urinary incontinence. Objective evaluation of the different treatments and medico-economic approach of incontinence are thus possible.

Diagnosis, Differential↗

Clinical value of ipsi- and contralateral sacral reflex latency measurement: a normative data study in man.

The latency of the bulbocavernosus reflex (BCR) evoked by electrical stimulation of the penis provides a measure of the conduction velocity over the sacral reflex arc at the S2-4 level but does not allow evaluation of the side affected since it results from the simultaneous excitation of both dorsal nerves of the penis (DNP) at the penile root. To evaluate the reliability of the side-to-side BCR latency measurement, this study compared the reflex characteristics of the response elicited by both DNP stimulation and unilateral DNP block. After a unilateral selective DNP anesthesic block, we found that the early response of the contralateral BCR is strictly ipsilateral with no differences in terms of latency, morphology, and reflex threshold from controls. This result may indicate that the side-to-side BCR latency measurement allows a comparative study of the respective right and left sacral reflex arcs in men. We found a mean inter-latency difference of 1.8 +/- 0.4 millisecond of the early BCR response after simultaneous recording of the right and left sides in 10 normal men. We established that an inter-latency difference >3 milliseconds may be indicative of a significant alteration in the conduction over the sacral reflex arc.

Adult↗

Postpartum lumbosacral plexopathy limited to autonomic and perineal manifestations: clinical and electrophysiological study of 19 patients.

The objective was to describe perineal electrophysiological findings and to determine their diagnostic value in a type of lumbosacral plexopathy after vaginal delivery, which only involves the lower part of the plexus (S2-S4). Consecutive female patients referred to an outpatients' urodynamic clinic were the source. Nineteen previously healthy women, 13 multiparae and six para 1, were investigated. Mean age was 33.7 (SD 5.4) (range 28-41) years. All of them presented with urinary (stress incontinence 14, dysuria five), anorectal (faecal incontinence eight, dyskesia one), or sexual dysfunctions (hypoorgasmia or anorgasmia six) after vaginal delivery. No associated lower limb sensory or motor deficits were noted. All the patients had electrophysiological recordings (bulbocavernosus muscle EMG, measurements of the bulbocavernosus reflex latencies (BCRLs), somatosensory evoked potentials of the pudendal nerve (SEPPNs), and pudendal nerve terminal motor latencies (PNTMLs)). Cystometry and urethral pressure profile (UPP) were performed in the 14 patients with stress urinary incontinence. Perineal electrophysiological examination disclosed signs of denervation in the perineal muscles in all the cases, prolonged BCRLs in 17/19, and abolished BCRLs in 2/19, abnormal SEPPN in 1/19, and normal PNTMLs in all the patients. Urodynamic investigations disclosed low urethral closure pressure for age (< 50 cm H(2)O) in half of the patients. In conclusion, Lower postpartum lumbosacral plexopathy is evoked when perineal sensory disturbances whether or not associated with urinary or faecal incontinence persist after a history of a difficult vaginal delivery. Electrophysiological investigations precisely identify the site of the lesion and demonstrate distal innervation integrity.

Adult↗

[Treatments with alpha-stimulants in urology].

Neuropharmacology is a rapidly expanding field due to the regular discovery of new neurotransmitters or neuroreceptors. Hopes have now been raised for the treatment of vesicosphincteric disorders by developing molecules with a potential selective clinical action on the detrusor or the urethra. After a brief review of the neuroanatomy and general neuropharmacology of the sympathetic nervous system, the current indications for alpha agonists are reviewed and discussed. These indications include the treatment of priapism, retrograde ejaculation, and incontinence due to sphincter incompetence. The more recent use of agents with a central mechanism of action is also discussed (detrusor hyperactivity of spinal cord injury patients). The authors review the current indications and note that, although the use of these drugs is very specific and limited in the field of urology, it is nevertheless based on an interesting concept. Like molecules at the stage of clinical trials for peripheral or central targets, the mechanism of action of these molecules on the sympathetic adrenergic system needs to be more fully elucidated. Their adverse effects remain the limiting factor for use on peripheral targets.

Adrenergic alpha-Agonists↗

Bladder cooling reflex in patients with multiple sclerosis.

PURPOSE: We describe the effect of intravesical ice water instillation in patients with multiple sclerosis and without an overactive bladder. MATERIALS AND METHODS: Of 131 consecutive patients with multiple sclerosis who presented with a urinary disorder we selected for study 10 men and 29 women with a mean age plus or minus standard deviation of 50 +/- 9 years who had multiple sclerosis without an overactive bladder. Nonoveractive bladder was defined as no involuntary detrusor contraction up to 400 ml. of maximum fill on routine cystometry. We performed cystometry with saline at 25 to 30C at an infusion rate of 50 and 100 ml. per minute, and with ice water at 0 to 4C at a rate of 100 ml. per minute. Ice water cystometry was considered positive when an involuntary detrusor contraction occurred before 200, and between 200 and 400 ml. of filling. Ice water cystometry was considered negative when there was no involuntary detrusor contraction during ice water filling up to 400 ml. RESULTS: Ice water cystometry enabled us to elicit involuntary detrusor contractions in 21 patients, which remained undetected by warm water cystometry at rates of 50 and 100 ml. per minute. The test was positive before 200, and between 200 and 400 ml. in 10 and 11 cases, respectively. Positive ice water cystometry was significantly associated with irritative signs or significant post-void residual urine volume. CONCLUSIONS: An involuntary detrusor contraction was not elicited by cystometry at 50 or 100 ml. per minute, implying that the afferent mechanoreceptor reflex limb via ADelta fibers is not involved. In contrast, ice water cystometry at 100 ml. per minute elicited an involuntary detrusor contraction, suggesting involvement of an afferent reflex limb via capsaicin sensitive C fibers. These involuntary detrusor contractions revealed by ice water cystometry are probably relevant to an overactive bladder. In urinary disorders such a positive test indicates a spinal lesion. In multiple sclerosis it may have pathophysiological value, indicating a spinal rather than cerebral mechanism of overactive bladder, and diagnostic value, indicating multifocal demyelination.

Cold Temperature↗

Pudendal nerve terminal sensitive latency: technique and normal values.

PURPOSE: We evaluated a new technique to study the terminal sensory branches of the pudendal nerve in 30 normal men. MATERIALS AND METHODS: To elicit response endorectal stimulation of the pudendal nerve was delivered just to the left then right of the ischiatic spine using an electrode. The sensory potential was recorded in the balanopreputial zone with ring contact electrodes wrapped around the shaft of the penis. From 5 to 40 responses were averaged to obtain the sensory potential. RESULTS: The pudendal nerve terminal sensory response was obtained for each normal subject. Mean latency value plus or minus standard deviation was 5.35+/-0.97 milliseconds for the left side with a mean amplitude of 4.24 microV. and 5.33-/+0.77 milliseconds for the right side with a mean amplitude of 3.77 microV. CONCLUSIONS: This method allows comparative study of the right and left terminal sensory branches of the pudendal nerve, and may be helpful in the diagnosis of different perineal disorders, such as sexual dysfunction, perineal pain and fecal incontinence, but further experience is necessary.

Electrodes↗