[Comparison between the terminal motor pudendal nerve terminal motor latency, the localization of the perineal neuralgia and the result of infiltrations. Analysis of 53 patients]. / Comparaison entre la latence distale motrice du nerf pudendal, la topographie de la douleur périnéale et le résultat d'infiltrations. Analyse pour 53 patients.

AIM: The aim is to study the value of the pudendal nerve terminal motor latency (PNTML) testing, in respect to the painful side in patients with pudenda neuralgia, and to determine whether a possible increased latency in the painful side is predictive of a good result with the infiltration. METHOD: This retrospective study included 53 outpatients (42 women, mean age 62) with suffering from pudendal neuralgia, who were seen between 2000 and 2004. The mean duration of the pain was 30+/-47 months. The PNTMPNL was measured by the Saint-Mark hospital technique, by the same operator. The following criteria have been were defined: significant increased latency greater than above 6 ms, significant difference of 2 ms in latency between 2 sides from 2 ms, and side of the infiltration corresponding to the side of the neuralgia. The infiltrations were performed either by perineal (30 cases) or transgluteal (8 cases) way. The results on pain were have been considered as good when a substantial reduction of the pain was observed for 6 months or more. Statistical analysis involved was done by the exact Fischer's test to seek for a possible relation between variables. RESULTS: Of 53 patients (42 women, 11 men, mean age 62) suffered from a with perineal neuralgia. The duration of the neuralgia was 30+/-47 months. It was bilateral in 10 cases and unilateral in 43 cases. In 43 patients with When the pain was unilateral pain, PNTML we find that the MDLPN was increased in both sides in 39.5% of the population, in the painful side in 14% and in the side opposite side of the to pain in 11%. In 10 patients with the neuralgia was bilateral pain, in 10 patients. Among then, 4 had a bilateral increase of the latency, one patient had an increase only on the right side, and another one an increase only on the left side. We did not find any correlation between the increased of the PNTML TMPNL and, either neither the duration of the neuralgia nor the result of the infiltrations, whatever the method way of the infiltration. CONCLUSION: The PNTML can be increased whether it corresponds or not to an entrapment of the pudendal nerve. Thus, the management of perineal pain is based mainly, from us, on clinical findings.

Magnetoencephalography in stroke: a 1-year follow-up study.

Recovery after stroke is closely linked to cerebral plasticity. Magnetoencephalography (MEG) is a non-invasive technique, which allows location of cerebral cells activities. In the present work, a cohort of patients has been studied with MEG. Twelve patients with a recent ischemic or hemorragic stroke were included as soon as possible after onset of stroke. Neurologic assessment, including standard neurologic examination, functional independence measure (FIM) and Orgogozo's scale was performed for 1 year in addition to a study of the somatosensory evoked field (SEF) using a 37-channel Biomagnetometer system. No response could be recorded in five patients at the first SEF exploration. In three cases, no response was ever recorded during the study. All these patients had a bad recovery. The location of the SEF sources was always in the normal non-infarcted cortex of the postcentral gyrus. Sensory recovery seemed to be linked to the reorganization of the persistent functional cortex, which was a limiting factor for recovery. These observations confirm the experimental results obtained in animal models. After stroke it can be assumed that in the case of incomplete lesion, an intensive sensory peripheral stimulation could maximize the use of residual sensory function and then contribute to improve the sensory deficit. In case of total sensory loss other techniques have to be used, such as visual monitoring of hand activity in order to improve hand function.

Non-supervised spatio-temporal analysis of interictal magnetic spikes: comparison with intracerebral recordings.

OBJECTIVE: Our main goal was to evaluate the accuracy of an original non-supervised spatio-temporal magnetoencephalography (MEG) localization method used to characterize interictal spikes generators. METHODS: MEG and stereotactic intracerebral recordings (stereo-electro-encephalographic exploration, SEEG) data were analyzed independently in 4 patients. MEG localizations were performed with and without anatomical constraints. RESULTS: We analyzed 1326 interictal spikes recorded using MEG. For each patient, 2-3 typical source patterns were described. These source configurations were compared with SEEG. SEEG findings and MEG spatio-temporal localization results were remarkably coherent in our 4 patients. Most of the MEG patterns were similar to interictal SEEG patterns from a spatio-temporal point of view. CONCLUSIONS: We were able to evaluate the usefulness of our non-invasive localization method. This approach described correctly the part of the epileptogenic network involved in the generation of interictal events. Our results demonstrate the potential of MEG in the non-invasive spatio-temporal characterization of generators of interictal spikes.

[Magnetocardiography: principles and potential uses in cardiology]. / La magnétocardiographie: principes et utilisations potentielles en cardiologie.

Magnetocardiography (MCG) is a non-invasive technique of studying cardiac electrophysiology activity. It appears that electric and magnetic measurements are not only complementary but provide independent information. Described over 25 years ago, recent technical progress in the field of supraconductivity has provided MCG with real clinical applications. It is still mostly used in research, but its clinical applications are beginning to develop. The most interesting clinical application of the MCG is certainly its capacity to provide a non-invasive anatomical localisation of the arrhythmogenic substrate or of accessory pathways. Nowadays, however, the accuracy of these localisations needs to be improved. When this has been accomplished, MCG could play a significant role in non-invasive cardiological investigation with well-defined clinical applications.

Model-based diagnosis of brain disorders: a prototype framework.

This paper describes a prototype framework, named NEUROLAB, dedicated to research and diagnosis in the area of brain disorders. The diagnostic task uses a blending of factual knowledge, formal knowledge, and experiential knowledge. The prototype's first target clinical application is partial seizures in epilepsy. Diagnosis is carried out using qualitative electroencephalographic descriptions, clinical attack pattern descriptions, and pre- and post-ictal observations. From this information, the system builds explanations in the form of candidate epileptogenic foci and trajectories of the seizure spread. Hypothesis-testing and discrimination is based on minimal set coverage, and consistency-checking is performed using the general background knowledge. Upon completion, NEUROLAB will provide specific physiological knowledge for solving the so-called inverse problems in electroencephalography (EEG) and magnetoencephalography (MEG).

[Delay in the effect of antidepressive agents: pharmacologic approach]. / Le délai d'action des antidépresseurs: l'approche pharmacologique.

A paradox which is not resolved in the use of antidepressants (ATD) is that in pharmacological studies of animal models of depression and in neurochemical studies, the onset of activity of all drugs is extremely rapid, whereas in human clinical practice the onset is delayed (15 days). An attempt is made to explain this in 3 ways, involving the synapse, transduction mechanisms, and cognition. Analysis of the impact of all ATDs shows that we are confronted with slow adaptive processes which are correlated with the delay observed in clinical practice. The interest of such considerations is that they may give rise to alternative therapies which are able not only to accelerate response, but also to increase it.

[Urination disorders in multiple sclerosis: value of urodynamic assessment]. / Les troubles urinaires dans la sclérose en plaques: intérêt du bilan urodynamique.

Urinary troubles are common in patients with multiple sclerosis. The management of these troubles requires an accurate analysis. Urodynamic assessment was preformed in 117 patients with urinary symptoms positively diagnosed as suffering from multiple sclerosis. Urinary symptoms are not always correlated to urodynamic patterns. We have studied the correlation between urinary symptoms and urodynamic findings. Urodynamic results are similar to most of previous series: detrusor hyperreflexia is the most frequent abnormality, detrusor sphincter dyssynergia is diagnosed in 50% of the patients. There is some correlations with symptoms, but there are insufficient for an accurate diagnosis. Postvoid residue for urinary tracts infectious diseases, and sphincter incompetence for urinary incontinence are the main risk factors.

Surface electromyogram automatic analysis and Guillain-Barré syndrome follow up.

An automatic and quantitative framework for the analysis of surface EMG interference patterns at maximal non-controlled force is described. The main contents are focused on different ways to represent surface EMG signals and to analyse collected data set through principal component analysis. The methods are tested on control individuals and on patients with Guillain-Barré Syndrome examined at different moments after the beginning of the disease (first week, three months, and one year). The results exhibit that a high diagnostic yield can be provided and furthermore that quantification and differentiation can be expected. Surface EMG interference pattern may be hoped to be a useful tool in daily practice.

Muscle fatigue unrelated to phosphocreatine and pH: an "in vivo" 31-P NMR spectroscopy study.

Metabolic events were followed by 31-P NMR spectroscopy during mechanical exhaustion of directly stimulated rat gastrocnemius. During mechanical fatigue, phosphocreatine (PCr) and pH first declined but although stimulation continued high values were recovered without mechanical recovery. Total recovery was only observed after cessation of stimulation. Partial mechanical recovery was elicited by lowering stimulation rhythm; it was accompanied by decrease in PCr to a steady-state level without pH alteration. When exhaustive exercise was induced immediately after nonexhaustive exercise, failure of mechanical function occurred without decrease in pH. Major findings were: first, during exhaustive stimulations, the greater the muscle fatigue, and the higher the PCr level at the end of stimulation. Secondly, PCr and force levels did not depend on preceding levels of PCr and pH. Thirdly, acidosis was observed transiently during the first minutes of the first exercise period. These findings strongly suggested that electrical events and/or excitation-contraction (EC) coupling play a crucial role in this type of fatigue.

Phosphocreatine and pH recovery without restoration of mechanical function during prolonged activity of rat gastrocnemius muscle: an in vivo 31P NMR study.

Metabolic impairment in skeletal muscle was suggested to be involved in the development of local mechanical fatigue but until now results have dealt with short activity periods whereas little data on exhaustive and prolonged exercises are available. Stimulations of rat leg muscle lasting 45 min were induced by tetanic trains delivered via sciatic nerve at five different rhythms. Energy metabolism of the stimulated gastrocnemius muscle was followed by 31P NMR spectroscopy using surface coil while mechanical function was recorded. Our data showed a decrease in the force level to very low values a few minutes after exercise onset. This mechanical impairment only induced a transient metabolic failure followed by rapid restoration of high phosphocreatine (PCr) values and intracellular pH, without mechanical recovery. In addition, at the end of exercise, the PCr content was proportional to the fatigue level. As these experiments could not have impaired neuromuscular junction, the data would indicate that fatigue was maintained by a mechanism which does not appear to depend directly on muscle cell energy stores.

Water phases in rat striated muscles as determined by T2 proton NMR relaxation times.

The spin echo decay curve of NMR protons in in-vitro rat muscle is two or three exponential as Hazlewood demonstrated in 1974. This author hypothesized that the longer T2 component is extracellular water and that the medium T2 is intracellular water. Our purpose was to test the histological significance of these two T2. Variations of water contents in two types of rat muscles were induced by electrical stimulation and osmotic diuresis and their incidence on the decomposition of the proton spin echo signal analysed. Decomposition of signal in resting muscles revealed two phases with T2 values similar to the Hazlewood's: a short phase, S, with T2 of 40 ms (20 MHz, 276 degrees K) representing 90-97% of the total signal and a long one, L, with T2 of 100-120 ms representing 3-10% of the signal. Increasing vascular volume appeared to increase the percentage of phase (L) in the total signal. Osmotic diuresis decreased the volume of the phase (S) and increased the volume of the phase (L). The use of Gd-DTPA allowed to differentiate the vascular compartment: Gd DTPA decreased in a great extent the T2 values of phase (L) and in low extent the T2 values of phases (S). From these results, it appears that phase (L) could correspond to vascular volume and that phase (S) would be interstitial and intracellular water. Elements of comparison with classical methods for determination of water compartmentation in tissues are given.

An attempt to differentiate female relatives of Duchenne type dystrophy from healthy subjects using an automatic EMG analysis.

A new automatic EMG analysis and on-line assignment of MUAP into 8 dynamic cluster algorithm classes (P1......P8) were applied to female relatives of patients with Duchenne type dystrophy. Promising results are given. MUAP amplitude and duration differed significantly in the female relatives compared to the control subjects. MUAP distribution patterns found in the carrier population were significantly different from those found in controls; the carrier population exhibited higher percentages of MUAP (than healthy subjects) in the classes where were assigned the great majority of the potentials obtained from patients with Duchenne type dystrophy. All the known carriers and 55.5% of the possible carriers were detected using these methods. Nevertheless, the absolute accuracy of the results cannot yet be considered achieved because no recognizable distribution pattern was observed in carrier's daughters. No correlation was found between CK levels and EMG distribution.

[Automated analysis of motor unit potentials of a normal population]. / Analyse automatique des potentiels d'unités motrices d'une population normale.

The real-time and automatic system that we have developed, providing EMG signal acquisition, processing and storage, helps in decision making. This implies the formation of a reference signal set and the accurate determining of the influence of various parameters. Using data analysis methods, our normal population analysis investigates the effects of age, sex and muscle. Assignment tests have been carried out with learning classes (formed with signals obtained from healthy and myopathic subjects) to measure the variability of a possible aid-to-diagnosis procedure.

[Urinary disorders in multiple sclerosis. Apropos of 47 cases]. / Les troubles urinaires dans la sclérose en plaques. A propos de 47 cas.

The authors report a series of 47 patients suffering from disseminated sclerosis who required neuro-urological management because of micturition disturbances. They were in general young (mean age 43 years) and had been suffering from disseminated sclerosis for 10 years (on average). The neurological disease was in general severe since it was progressive in 32 cases and pure remittent in 13 only. Two-thirds of the patients were autonomous from a locomotor standpoint. Micturition disturbances developed in the first five years of the disease in 2/ 3rds of the patients and became really troublesome only after disseminated sclerosis had been progressive for five years. Dysuria, frequency and incontinence with urgency were the commonest symptoms. Persistent or transient retention of urine remained relatively common. Nocturnal urine loss was rarer. Sphincter incompetence was marked in half of the patients but this did not necessarily go hand in hand with locomotor incapacity. Symptoms and signs were grouped as irritative, obstructive and mixed syndromes. From a urodynamic standpoint, the detrusor was sometimes normal but more often behaved pathologically, being either hyperactive or hypoactive. Hypoactivity of the detrusor was accompanied in 9 cases out of 10 by spasticity of the striate sphincter. Spasticity of the striate sphincter was the commonest type of behaviour, although normal striate sphincter electromyography was possible and; rarely, results were of peripheral neurogenic type. There was no evidence of any correlation between the type of micturition syndrome, detrusor function and striate sphincter function. Similarly, no correlation could be established between the type of detrusor dysfunction and the period for which disseminated sclerosis had been present.(ABSTRACT TRUNCATED AT 250 WORDS)

Automatic classification of electromyographic signals.

The results of the application of classification methods to electromyograph signals of weak contractions in normal and myopathic subjects are described. Methods of pattern recognition, previously presented, allow the selection of representative motor unit action potentials. The analysis is done with ordinal qualitative variables obtained by identification of shape descriptive parameters (amplitude, duration, number of phases, number of extrema). From this analysis, characteristic classes for normality and myopathy appear, from which a diagnostic aid by assignment can be made.

Facilitation of monosynaptic reflexes by voluntary contraction of muscle in remote parts of the body. Mechanisms involved in the Jendrassik Manoeuvre.

The facilitation of the tendon reflex of quadriceps, induced by voluntary contraction of a muscle group in the upper limb, evolves in the three phases and depends on several factos. These include the strength and type (ballistic or ramp) of the contraction. In the absence of any electromyographic activity in the conditioning muscle (from a lesion of its nerve trunk or by blockage of conduction by injection of xylocaine), a voluntary attempt to contract it causes only a moderate facilitation of the quadriceps motor nucleus; while reflex activation of the conditioning muscles, by vibration or sudden stretching. causes a more marked facilitation. Thus, it is concluded that at least two distinct mechanisms act sequentially. First, a general motor facilitation of supraspinal origin induces the first moderate phase of facilitations (phase I). This early facilitation precedes the onset of electromyographic activity in the conditioning muscle. Secondly, the more marked facilitation (phase II) is related to the stimulation of afferents originating from the conditioning muscles, either by fusimotor excitation in voluntary contraction or by manoeuvres which stimulate the spindle receptors mechanically. To investigate the transmission pathways of these facilitations, the latencies of these two phases were compared at two distant motor nuclei, the trigeminal motor nucleus and the quadriceps nucleus, following voluntary contractions of the tibialis anterior. Since the facilitations of the trigeminal motor nucleus precede those of the quadriceps motor nucleus, a slowly-travelling rostro-caudal facilitation is postulated during phase II when the facilitation is related to afferents coming from the contracting muscle. A long loop, therefore, is postulated to interpret the second phase of the facilitation curves.