[Surgical decompression of pudendal nerve by transperineal approach using a probe with a small balloon]. / Décompression chirurgicale du nerf pudendal par voie périnéale à l'aide d'une sonde à ballonnet.

AIM OF THE STUDY: Describe and analyze the surgical decompression of pudendal nerve by transperineal approach using a probe with a small balloon. PATIENTS AND METHOD: Since 2009 may, 43 patients (31 females, 12 males) underwent for a pudendal nerve decompression. These patients had clinical symptoms of pudendal neuralgia. Neurophysiological tests based on differential staged sacral reflexes and on somesthesic evoked potentials and ultrasound investigations of pudendal vessels evoked a zone of compressive hyperpressure at the level of the axis infrapiriformis area-ischiorectal fossea. In all of these 43 patients, injection block at the level of the infrapiriformis area appeared positive between one to nine months. Patients were known for this pathology since many years. Among these 43 patients, six had already pudendal nerve decompression, four by transgluteal approach and two by transvaginal (♀)/transischiorectal (♂) approach but without clinical efficiency. In all of these 43 patients, surgical decompression was done by transperineal approach using a probe with a small balloon. RESULTS AND CONCLUSION: Surgical methodology, post-operation follow-up and results are reported hereby, which appear quite successful: after two days 77%, after one month 84% and after three months 89% of the subjects are symptom-free or with a significant reduction of pain.

[Anatomophysiological consideration on the sacral reflex]. / Considérations anatomo- physiologiques à propos du réftexe sacré.

Sacral reflex testing is a very specific one. Coming from sensory receptors afferent neuronal pudendal passway enters the spinal cord S2 to S4 via spinal dorsal roots and transmits the bioelectrical activity to a complex interneuronal circuitry. Information is processed at this level and dispached into spinal motoneurones for innervating the pelviperineal muscles according to their specific radicular origins. Selective staged sacral reflexes contribute to locate the site of compression. Sacral reflex configuration was based on clinical and electrophysiological findings which is actually confirmed and valided by anatomical studies. This testing is the most efficacious and useful procedure of assessing the pudendal neuralgia, the S2 to S4 reflexes and the pelvic floor dysfunctions.

[Sacral staged reflexes to localize the pudendal compression: an anatomical validation of the concept]. / Les réflexes sacrés etagés dans l'etude de la névralgie pudendalte: validation anatomique.

Pudendal neuropathy is common. The diagnosis is clinical and the confirmation is electrophysiological. Distal pudendal nerve latencies have been used but they are unspecific and do not allow to localize the site of compression. A preliminary electrophysiological study has suggested separate innervations of the anterior and the posterior anal sphincter quadrants, so diverging from what main anatomy textbooks teach. By detailed dissections of pudendal nerve region we can confirm a dichotomy in the innervation of the two quadrants. Therefore, it seems feasible, by using the differences of staged sacral reflexes, to better localize the compressive neuropathy, with a stimulation of the clitoris and by recording latencies of different muscles.

[Modern algorithm for treating pudendal neuralgia: 212 cases and 104 decompressions]. / La prise en charge moderne des névralgies pudendales. A partir d'une série de 212 patientes et 104 interventions de décompression.

Clinical signs and symptoms of the pudendal neuralgia are very rich, with a great individual variability. The clinical diagnosis is difficult. It is confirmed or invalidated by the electrophysiologicals tests. Since October 1998 patient selection has been possible using a diagnosis score. Over a four-year period, the diagnosis of pudendal neuralgia was confirmed by electrophysiological investigations in 212 subjects. We rejected 12 patients because of a radiculo-medullary organic etiology. We only describe here cases of women with a peripheral pudendal nerve injury (200 patients). Thirty-eight neuropathies free of canal symptoms (obstetrical, post-traumatic...) were treated by infiltration therapy. The study of a total of 162 canal syndromes showed prevalent injury at the sacro-spino-tuberal ligamental grip which was observed in 68% of the cases, compared to the Alcock canal which was present in only 20% of the cases. One hundred four of these patients underwent surgical decompression via a trans-ischio-rectal approach after negative results of the infiltration therapy. We report here the surgical methodology, the post-op follow-up and the results, which appear quite successful: after one year 86% of the subjects are symptom-free or with a significant reduction of pain.

[Selection of electrophysiological investigations for diagnosis in idiopathic facial palsy. Twenty years experience in an ENT department]. / Les explorations électrophysiologiques des paralysies faciales idiopathiques. Standardisation après vingt années de pratique dans un service ORL.

Electrophysiological exploration of the facial nerve requires different tests to differetciate the importance of the block, denervation and canal conduction. We must answer five questions: 1) Assessing the degree and the phase of the nerve lesion, 2) Deciding on the advisability of a facial decompression in the early stage of the palsy, 3) Evaluating the prognosis, 4) Choosing the best therapeutic approach, 5) Detecting facial hyperkinesis in an infraclinic period. In order to answer these questions, we select the following methods: 1) Quantified Electroneuronography should be applied as early as the 2nd day after onset, repeated on the 7th and 10th days. Unfortunately this is not always possible for practical reasons. In any case a minimum of two investigations should be performed during the 12 first days. 2) We add Computer EMG in order to control the evolution of the blocked fibers with regard to denervated fibers. 3) Blink reflex and Stapedius reflex are investigated from the 3rd day. After the acute phase of the palsy, recovery is detected by the reappearance of the blink and stapedius reflexes and the evolution of the computed EMG. These tests are sufficient for answering the five questions mentioned above without discomfort for the patient.

Effect of amino acid administration on uremic muscle metabolism: a 31P-spectroscopy study.

The effect of a six-month peritoneal amino acid administration on muscle metabolism at rest and during exercise was examined in 12 patients (4 control and 8 amino acid treated) on continuous ambulatory peritoneal dialysis. 31P-magnetic resonance spectroscopy was used to measure several high-energy phosphates (PCr, Pi) in resting muscle and during exercise and recovery. At rest, no significant changes were detected between the non-treated (control) and the amino acid treated (experimental) group. Before the administration of amino acids, the exercise-induced fall in [PCr], the increase in [ADP] and [Pi] and the pH were not significantly different in the control and experimental group. The initial rate of PCr recovery and the calculated maximal rate of ATP-synthesis (Qmax) for the control subjects was not significantly different at the onset and the end of the study. In the treated group, however, the fall in [PCr] and increase in [ADP] after exercise were significantly lower after than before treatment, while [Pi] and pH were identical. The initial rate of PCr recovery and Qmax were also significantly improved. These changes indicate an improved oxidative phosphorylation under the treatment and suggest that the impaired oxidative metabolism of the dialysis patients could be the result of their bad nutritional state.

In vivo comparison of MR phase distribution and 1/T2* with morphologic parameters in the distal radius.

A new approach based on the calculation of the phase variance in a region of interest on the phase images of a simple gradient echo sequence, was used to assess the properties of trabecular bone in the distal radius. The phase variance reflects the distribution of field inhomogeneities due to the difference in magnetic susceptibility between bone and marrow in a way similar to T2*. However, the phase variance monitors the intervoxular differences, whereas T2* studies the intravoxular inhomogeneities. In this study of the radius of seven volunteers, both techniques were compared with parameters characterizing trabecular bone structure derived from high resolution MR images. Parameters such as the apparent bone area fraction, trabecular number, thickness and spacing, and box-counting fractal dimension were determined.

Quantification of trabecular structure in the distal femur using magnetic resonance phase imaging.

A new approach for quantifying trabecular bone tissue using the phase images of a simple gradient-echo sequence is presented. The proposed method is based on the hypothesis that the differences in susceptibility between bone and bone marrow cause magnetic field (i.e., precession phase) variations between the image voxels. Phase images of the distal femur were obtained in vivo and characterised with the use of the phase variance. Computer simulations and experimental results indicate that the distribution of the phases varies with echo time and image resolution, as expected. Keeping these fixed, however, the phase variance is found to strongly reflect variations in trabecular structure.

Fat fraction of lumbar bone marrow using in vivo proton nuclear magnetic resonance spectroscopy.

Localized proton spectra of the human lumbar vertebral body were recorded in vivo at 1.5 T, using the STEAM (stimulated echo acquisition mode) pulse sequence. Thirty-seven patients (18 men, 19 women) were examined, ranging in age from 21 to 68 years (mean = 40, SD = 13). The fat fraction of the bone marrow was calculated from the areas of the fat and water peaks in the spectrum. The results demonstrate that, in the course of aging, there is a systematic increase in measured fat percentage of about 7% per decade of age. No sex difference could be established on the basis of our results.

Absolute quantification of 31P liver metabolites in rat using an external reference and a surface spoiling magnetic field gradient.

A simple method for measuring absolute concentrations of 31P metabolites in rat liver using an external reference is described. It neutralizes systematic errors due to conductive losses by calibration of the matching capacitor and selects liver signals via an electrically driven, surface spoiling magnetic field gradient. The technique avoids the chemical shift problems associated with linear field gradient localization methods at 4.7 T and allows combination with the double standard method for absolute metabolite concentration determination. Application of the method to the in vivo measurement of the absolute concentrations of ATP and P(i) in eight rat livers yields results that are in good agreement with literature values. Absolute phosphomonoester concentrations were also obtained, but no literature data were available.

Absolute quantification of 31P muscle metabolites using NMRS with an internal standard and a high-Q, double-tuned coil.

31P-nuclear magnetic resonance spectroscopy (NMRS) is used to determine absolute concentrations of 31P metabolites in rat muscle. A technique exploiting tissue water 1H as internal concentration reference and a highly sensitive, double-tuned coil is described and evaluated experimentally. On KH2PO4 solutions of known concentration and varying coil loading it is shown to allow neutralization of systematic errors due to conductive losses, which normally range up to 20% or more. In vivo application in the determination of the absolute concentrations of ATP, PCr and Pi in eight rat thighs yields results that are in good agreement with literature values.