|
Biol
Psychiatry. 1985 Jul;20(7):758-63. |
Sexual
activity and sleep in humans.
Brissette S, Montplaisir J, Godbout R, Lavoisier P.
Polysomnographic recordings
were obtained in 10 subjects (5 men and 5 women) for three conditions:
following masturbation with orgasm, following masturbation without orgasm, and
after reading neutral material. The analysis of several sleep parameters did
not reveal any effect of masturbation on sleep. These results suggest that
physiological changes that occur during masturbation, with or without orgasm,
have no major effect on sleep organization. Other factors associated with
sexual activity and potentially responsible for sleepiness after orgasm are
discussed, and further strategies to study the interrelationship of sexual
activity and sleep are proposed.
|
J Urol.
1986 Oct;136(4):936-9. |
Correlation
between intracavernous pressure and contraction of the ischiocavernosus muscle
in man.
Lavoisier P, Courtois F, Barres D, Blanchard M.
An artificial erection was
induced in nine patients consulting for erectile dysfunction. Changes in the
intracavernous pressure (ICP) and in the integrated EMG of the ischiocavernosus
muscle were recorded during voluntary muscular contractions. During such
contractions elevations in ICP, varying between 100 and 525 mm. Hg, were
recorded. Changes in ICP were always in phase with changes in the integrated
electromyogram (EMG) of the ischiocavernosus muscle, and correlations between
the duration of changes showed an almost perfect linear relationship between
both physiological events. Correlations between maximum changes in ICP and integrated
EMG generally showed a positive relationship between both measures. Results are
interpreted to suggest involvement of the ischiocavernosus muscle in the
process of penile rigidity.
|
1: Ann
Endocrinol (Paris). 1988;49(4-5):404-7.
|
[Several
techniques proposed for the differential diagnosis of diabetic impotence]
[Article in French]
Lavoisier P.
Centre d'Etudes pour les Dysfonctions Sexuelles, Hopital Hotel Dieu,
Montreal, Quebec, Canada.
The measurements of changes in
penile circumference during nocturnal erection is commonly used to
differentiate between organic and psychogenic impotence. Unfortunately, this
measuring technique do not record variations in penile rigidity which may be
insufficient to achieve coitus despite a normal circumference. We carried out a
study with a penile cuff to measure penile rigidity. The validation of this
penile cuff as a measurement device of penile rigidity permits us to determine
the criteria of normality of penile rigidity and, subsequently, to
differentiate more accurately between organic and psychogenic dysfunctions.
Measurement of the bulbocavernous reflex (BCR) is widely used to diagnose
underlying neurologic disorders in erectile dysfunctions. A prolonged BCR
latency, more than 45 ms, or absence of a reflex response of the BC muscles
during electrical stimulation of the glans penis, is considered like a sign of
neurologic disease. We recorded the BCR in 90 subjects. Nineteen had abnormal
BCR latencies. Furthermore, eight of these 19 subjects had normal nocturnal
erections, thus confirming the diagnosis of psychogenic impotence. These
results cast doubt on the validity of BCR measurements of the diagnosis of
organic erectile dysfunction due to a neurologic disease. We recorded the BCR
in 90 subjects. Nineteen had abnormal BCR latencies. Furthermore, eight of
these 19 subjects had normal nocturnal erections, thus confirming the diagnosis
of psychogenic impotence. These results cast doubt on the validity of BCR
measurements for the diagnosis of organic erectile dysfunction due to a
neurologic disease.
|
1: J Urol. 1988 Jan;139(1):176-9. |
Relationship
between perineal muscle contractions, penile tumescence, and penile rigidity
during nocturnal erections.
Lavoisier P, Proulx J, Courtois F, De Carufel F, Durand LG.
Hopital Hotel-Dieu, Department
de psychiatrie, Montreal, Quebec, Canada.
The mechanism of penile erection and erectile dysfunction is still unclear and
widely debated. The role of the perineal muscles in the erectile process,
especially in changes in intracavernous pressure, is increasingly being studied
on the hypothesis that perineal muscular contractions are essential to full
penile rigidity. In a previous investigation we studied the correlation between
voluntary perineal muscle contractions and intracavernous pressure during
artificially induced erections. The purpose of the current study was to examine
whether under normal conditions of nocturnal erection a similar relationship
exists between the electromyographic activities of perineal muscles and changes
in penile rigidity. Nocturnal penile recordings were made of seven volunteers
with psychogenic erectile dysfunctions. During nocturnal erections simultaneous
computerized recordings were made of penile tumescence, penile rigidity, and
electromyographic activities of perineal muscles. The peaks for the three
variables were reached simultaneously. The results of this study suggest the
existence of two different physiologic phases: a vascular phase and a muscular
phase. Furthermore, in cases of dysfunctions, specific diagnostic assessment
and therapeutic management will be required for both penile tumescence and
penile rigidity.
|
1: J Urol. 1988 Feb;139(2):396-9. |
Reflex
contractions of the ischiocavernosus muscles following electrical and pressure
stimulations.
Lavoisier P, Proulx J, Courtois F.
Hopital Hotel-Dieu, Departement de psychiatrie, Montreal, Quebec, Canada.
In a previous study, we have
demonstrated that voluntary muscular contractions of the ischiocavernosus
muscles (IC) correlate with changes in intracavernous pressure and, therefore,
with penile rigidity. The purpose of our current research project was to verify
whether reflex contractions of the IC muscles exist and under what conditions.
Our results confirm that reflex contractions occur following electrical or
pressure stimulations. Following electrical stimulation, the mean latency of
the reflex contractions was 67.5 ms for the IC muscles and 34.9 ms for the
bulbocavernosus muscles (BC). Following pressure stimulation, the pressure
threshold necessary to elicit contractions of the IC muscles varied between
18.2 mm. Hg and 34.8 mm. Hg. We also observed that pressure variation (increase
and decrease) rather than a relatively constant pressure is necessary to
produce this reflex response. We interpret these results to suggest that
pressure stimulations on the glans penis during coitus contribute to the
erectile process and, specifically, to the increase in intracavernous pressure.
These findings suggest the possibility of a physiotherapeutic management for
patients with penile rigidity problems.
|
1: J Urol. 1989 Feb;141(2):311-4. |
Bulbocavernosus
reflex: its validity as a diagnostic test of neurogenic impotence.
Lavoisier P, Proulx J, Courtois F, De Carufel F.
Departement de Psychiatrie, Hopital Hotel-Dieu, Montreal, Canada.
Measurement of the
bulbocavernosus reflex is used widely to diagnose underlying neurogenic
disorders in erectile dysfunction. A prolonged bulbocavernosus reflex latency
(that is more than 45 msec.) or the absence of a reflex response of the
bulbocavernosus muscles during electrical stimulation of the glans penis is
considered a sign of neurological disease. Since only a few experimental
studies have been performed in man related to the neurophysiological mechanism
of erection, and since the results of these studies were contradictory the
diagnostic validity of bulbocavernosus reflex measurement was reassessed. We
determine whether men with abnormal bulbocavernosus reflex latencies have
concomitant organic erectile dysfunction as confirmed by nocturnal
plethysmographic and rigidity recordings. The bulbocavernosus reflex was
recorded in 90 subjects and 19 had abnormal bulbocavernosus reflex latencies.
Of these 19 subjects 8 had normal nocturnal erections, thus, confirming a
diagnosis of psychogenic impotence. These results cast some doubts on the
validity of bulbocavernosus reflex measurement for the diagnosis of organic
erectile dysfunction due to a neurological disease.
|
1: Br J Urol. 1990 Jun;65(6):624-8. |
Validation
of a non-invasive device to measure intracavernous pressure as an index of
penile rigidity.
Lavoisier P, Courtois F, Proulx J, Durand LG, de Carufel F.
Department of Psychiatry,
Hotel-Dieu, Montreal, Canada.
Many authors agree with the importance of developing devices to measure penile
rigidity. The devices that have been developed over recent years have defined
penile rigidity in terms of stiffness. Penile stiffness, however, is believed
to result from an increase in intracavernous pressure. The device presented
here was therefore designed to estimate intracavernous pressure, rather than
penile stiffness, as an index of penile rigidity. Validation of the penile cuff
device was achieved by simultaneously recording penile cuff pressure and
intracavernous pressure on patients undergoing artificial erections. The
results showed a linear relationship and highly positive correlation
coefficients between the 2 measures. The results demonstrate that the penile
cuff may be used to estimate intracavernous pressure as an index of penile
rigidity. The findings are discussed in terms of the possible applications of the
cuff as a clinical tool to measure both penile tumescence and penile rigidity.
|
1: Prog Urol. 1992 Feb;2(1):119-27. |
[The
physiology of penile rigidity]
[Article in French]
Lavoisier P, Aloui R, Iwaz J, Kokkidis MJ.
Centre de Recherche sur les Dysfonctions Sexuelles, Clinique
Saint-Maurice, Lyon.
Penile tumescence and rigidity
are considered to be a purely vascular process related to an increased inflow
and a decreased outflow. This theory, which provides a satisfactory explanation
for tumescence, is unable to explain the existence of high intracavernous
pressures recorded both in animals and in man. Based on a hydrostatic model,
the authors distinguish two phases involving different physiological
mechanisms: an infrasystolic vascular phase and a suprasystolic muscular phase.
During the vascular phase, the intracavernous pressure (ICP) can never exceed
the systolic blood pressure. However, during the muscular phase, the ICP
largely exceeds the systolic pressure, reaching values as high as 400 mmHg in
man and 1,000 mmHg in animals. These variations in ICP can be explained by the
contraction of perineal muscles, particularly the ischiocavernosus muscles.
Various animal and human experiments are presented in support of this
hypothesis. The pressure variations exerted on the glans during coitus by the
perivaginal musculature are sufficient to induce reflex contractions of the
ischiocavernosus muscles, promoting penile rigidity.
[Supra-systolic elevation of the intra-cavernous pressure secondary to
stimulation of the glans penis]
[Article in French]
Lavoisier P, Aloui R, Schmidt M, Gally M.
Centre d'Etudes pour les Dysfonctions Sexuelles, Lyon.
The role of the perineal
muscles in human penile erections is still controversial. The authors
investigated surface electromyographic activity of the ischiocavernous muscles
together with intracavernous pressure recordings during pressure stimulations
of the glans penis. Successive glans stimulations were associated with
ischiocavernous muscle contractions and increases in intracavernous pressure
reaching two- to fourfold the systolic blood pressure. High correlation
coefficients were found between electromyographic and intracavernous pressure
amplitudes. Voluntary contractions were accompanied by intracavernous pressure peaks
of similar durations, and areas delineated by integrated electromyographic and
intracavernous pressure curves showed very high correlation coefficients.
Anaesthesia of the dorsal nerve resulted in dramatic reductions of muscle
activity and intracavernous pressures in response to glans stimulation. These
results suggest that the activity of the muscles in response to pressure
stimulation of the glans penis is important to augment rigidity during vaginal
penetration and intercourse due to their ability to increase intracavernous
pressures.
|
1: Ann Urol (Paris). 1993;27(3):172-5. |
[Considerable
increase in the perineal arterial flow secondary to stimulation of the glans
penis]
[Article in French]
Lavoisier P, Aloui R, Schmidt M, Gally M.
Centre d'Etudes pour les Dysfonctions Sexuelles, Lyon.
The authors investigated the
changes in human perineal blood flow by Doppler ultrasonography before, during,
and after pressure stimulations (30,150 mm Hg) applied to the glans penis. We
found a local increased blood flow response in 72% of 50 patients who consulted
our center for erectile dysfunctions. Precise measurement analyses of 10 of
these subjects allowed us to further characterize this response. Its latency
ranged from 0.1 to 0.8 sec. and its duration from 4 to 13 sec. The blood flow
increased up to 8 times the prestimulation level. This consistent increase in
perineal blood flow showed much less variability than either the latency or
duration of the response. The results of this study suggest that intravaginal pressures
exerted on the glans penis during vaginal penetration and intercourse trigger
an augmentation of blood flow into the corpora cavernosa. The reflex nature of
this response is currently under investigation.
|
1: Arch Sex Behav. 1995 Feb;24(1):37-45. |
Clitoral
blood flow increases following vaginal pressure stimulation.
Lavoisier P, Aloui R, Schmidt MH, Watrelot A.
Centre de Recherche sur les Dysfonctions Sexuelles, Clinique Saint Maurice,
Lyon, France.
The vascular responses of
clitoral arteries to vaginal pressure stimulation in 10 volunteer women were
evaluated by Doppler ultrasonography. Pressure stimulations (20-160 mm Hg)
along the lower third of the vagina increased blood velocity and flow into
clitoral arteries in 9 of the 10 women. The latency and duration of the Doppler
responses ranged from 0.1 to 1.6 sec and from 3.2 to 9.5 sec, respectively, and
the response was associated with a blood flow increase of 4 to 11 times the
baseline prestimulation level. This response parallels that recorded in the
cavernous arteries in men when a similar range of pressure stimulations are
applied to the glans penis. Similar responses evoked in the male and female
suggest a sexual synergy that may occur during intercourse in that such
physiological responses and reflexes may be reciprocally reinforced.
|
1: Int
J Impot Res. 2002 Apr;14(2):116-20. |
Validation
of a continuous penile blood-flow measurement by pulse-volume-plethysmography.
Lavoisier P, Barbe R, Gally M.
Centre d'Etudes des Dysfonctions Sexuelles, Lyon, France.
Today, in the assessment of
cavernous artery blood-flow, the most commonly used technique is Doppler
ultrasound velocimetry (continuous, pulsed, color-coded or power), which is
often considered as the gold standard. Plethysmographic techniques and
radioactive tracers have been widely used for the assessment of global penis
flow variations but are not adequate for continuous blood-flow measurement. A
new pulse-volume plethysmographic (PVP) device using a water-filled penile cuff
was employed to assess continuous blood-flow measurement in the penis.
Simultaneously Doppler velocity was recorded and served as a gold standard. A
penile water-cuff is connected through a pressure tube to a three-way tap. The
pulse-volume changes in the penile water-cuff are measured by means of a latex
membrane placed over one of the three-way taps. The displacements of the latex
are recorded by a photoplethysmograph. The third tap is connected to a 5 l
perfusion bag placed 30 cm above the penis so as to maintain constant pressure
in the whole device whatever the penis volume. Twenty-four volunteers were
tested. The Doppler velocity signal and pulse volume of cavernous arteries were
measured simultaneously after PGE1 intra-cavernous injection. Blood-flow
variations were induced by increasing penis artery compression with a second
penile water-cuff used as a tourniquet fitted onto the penis root, and the
pressure of which could be modified by a water-filled syringe. The amplitude of
the plethysmographic pulse-volume signal and the area under the Doppler
velocity signal were correlated. The inter-patient (n=24) correlation ranged
from 0.455 to 0.904, with a mean correlation of 0.704 and P<0.0001. PVP
measurement by a water-filled cuff was validated by ultrasound velocimetry.
This new continuous, non-invasive and easy-to-use technique enables
physiological and physiopathological flow-measurement during sleep, under
visual sexual stimulation (VSS), or following artificial erection. Simultaneous
recording of penile blood-flow by PVP and intra-cavernous pressure (ICP)
measured by a non-invasive device will provide fundamental inflow and outflow
information in both physiological and pathophysiological conditions, and
further enable venous leakage to be assessed by a mathematical model.