[Is the afferent auditory message modulated by the cortex?]. / Le message afférent auditif est-il modulé par le cortex?

An eventual modulation of the afferent auditory message by the cortex is the subject of this study. To test this hypothesis, clicks (10 Hz, 100 microseconds) of white noise of 40 and 70 dB Hl were sent alternatively into the ears of normally hearing volunteers, while the brainstem evoked potentials were recorded. The subjects were asked to focus or relax their attention on one or other ear. Thirty subjects aged less than 25 years (15 men and 15 women) with normal hearing level, were split into two groups. The first group was asked to focus first on the more strongly stimulated ear (70 dB), the second group on the more weakly stimulated one (40 dB). Each subject received (1) without any instruction about attention: 40 dB on the left ear (L), 70 dB on the right ear (R); 40 dB then 70 dB bilateral; (2) 2 runs with 40 dB on the L and 70 dB on the R focussing on the most or less strongly stimulated ear; (3) a run without instruction with 70 dB on the L and 40 dB on the R, and (4) two runs with 70 dB on the L and 40 dB on the R focussing enough on the more or less strongly stimulated ear. On the evoked potentials simultaneously recorded, amplitudes and latencies of the pikes were measured and compared. From these experiments, the following elements were obtained. (1) The measured potentials were always caused by ipsilateral stimuli. (2) Focussing on left or right ear was not equivalent. (3) A gender difference appeared in the brainstem auditory responses. (4) Preferential attention paid to the left ear was more efficient than to the right one. (5) Attention can alter the whole nervous pathway with considerable lengthening of O-I, O-III, O-V, III-V, I-V but not I-III latencies. The III wave amplitude generally decreased on the side where attention was focussed while V waves seemed not to vary. These first results indicate that a cortico-efferent pathway stimulated by the attention plays a role in the auditory responses modifying the afferent message. These effects were not the same among the side focussing attention and among sex.

[Monitoring of the permeability of the inferior esophageal sphincter using sound signals]. / Contrôle de la perméabilité du sphincter oesophagien inférieur á l'aide de signaux sonores.

An original method is described for graphic display of sounds arising from the cardia during the swallowing of saliva or water. Two dynamic microphones were placed on the skin of epigastric xyphoid area and simultaneously on the latero-cervical position. The following conditions must be filled: position of the subject (upright or lying), correct application of microphone with pressure (2 kPa), specially for the xyphoid situation. For graphic restitutions from magnetic signal, a time-recording paper was used, on line or off line, with an analogical device including Butterworth band active filter (optimal frequency range 0.8-1.2 kHz), amplifier and integrator (tau = 2 s). Occurrence of typical cardia sounds were 86-97 % for saliva and 95-100 % for water in two normal subjects for the evaluation of reproducibility (one man and one woman 35 and 47 years old respectively, n = 234 sequences, interval 20 s). Using the distance between the upper and lower microphones, the esophageal time transit can be measured. The signal was more unconstantly recorded for saliva 40 +/- 44 % in adults (n = 10) and 76 +/- 17 % in children (n = 7), than for 80 et 87 % for water respectively. The optimal interval between two swallows appeared to be 15-25 s. In patients with presumption of achalasia (n = 8), the two phonic signals were recorded during esophageal pressure measurement. The presence of esophageal sounds seems to be the sign of absence of achalasia.

Brainstem auditory evoked responses in patients with tinnitus.

Brainstem auditory evoked responses of 355 patients with uni- or bilateral tinnitus were recorded in order to evaluate the effect of tinnitus on the central auditory system. The amplitudes of waves I, III and V and the latencies of each wave and interpeak latencies were compared to those of a group of 129 controls with normal hearing. The study of the control group initially identified a certain number of concurrent parameters. The brainstem evoked responses of men and women evolved differently from the age of 30 years, latencies of I-III and I-V in men lengthening with age and those of women tending to shorten. The patient groups were therefore compared to a control group of the same sex ratio or of the same sex, half being between 30 and 56 years of age. The tinnitus patients were divided into three groups according to the side affected by tinnitus. Latencies and amplitudes in these groups differed significantly from those of the control group. In order to eliminate hearing loss, the most difficult concurrent factor and almost always associated with tinnitus, the results of individuals with symmetrical hearing loss were compared to those of the control group. Tinnitus was always associated with significant lengthening of 0-I and I-V latencies on the tinnitus-affected side, with a significant reduction in amplitudes of waves I and III, and sometimes of wave V, particularly in the group with left-sided tinnitus. Comparison of tinnitus patients with symmetrical and asymmetrical hearing by sex showed that tinnitus patients of all groups had lengthening of right and left 0-I latencies, apart from the women in the group with right-sided tinnitus, and significant reduction in amplitudes of waves I and III in women and of left III only in men. When hearing loss was asymmetrical and on the tinnitus-affected side, there was also lengthening of 0-I latencies on the tinnitus-affected side in both sexes and of ipsi- and contralateral I-V latencies in women. Right- and left-sided tinnitus was associated with additional differences between the three groups. Correlation coefficient study confirmed that 0-I, I- III and I-V latencies were independent of the mean degree of deafness, deafness at high frequencies and at frequencies around the tinnitus, up to a threshold of hearing loss of 40 dB, above which 0-I and 0-V lengthened in addition to tinnitus. On the other hand, whatever the frequency, tinnitus involved significant lengthening of wave I latencies and modification of the previously recorded amplitudes. Two groups of tinnitus patients could be distinguished: the first, with symmetrical hearing loss, with symmetrical normal latencies, apart from 0-I latencies and the amplitude of the wave on the tinnitus side, and the second with hearing loss predominant on the tinnitus-affected side, with different latencies on each side, 0-I being shorter on the unaffected side, I-III and I-V being lengthened on the unaffected side and 0-I being lengthened on the tinnitus-affected side. Moreover, as disturbances of brainstem evoked responses caused by tinnitus particularly affected waves I and III, the hypothesis of possible involvement of the efferent systems could be proposed.

[Lateral efferent system and evoked auditory potentials. Response in tinnitus]. / Système efférent latéral et potentiels évoqués auditifs. Réponse des porteurs d'acouphènes.

The effects of ipsi- or contralateral masking have been studied in 45 normal hearing subjects and in 49 tinnitus patients. With normal subjects, ipsilateral masking during auditory stimulation involves--in opposition to contralateral masking which does not alter any latencies--a significant lengthening of all the latencies in the brainstem, except that of the first wave (right and left), and a significant decreasing of the amplitudes of the waves I L and R. It was important to know whether the lengthening of the latencies in the brainstem--which we suppose to be due to the stimulation of the lateral efferent system--was not in fact due to a preferential stimulation of the auditory cells from the basis of the cochlea. Yet experiments have shown that continuous masking of 40 dB at 750 Hz or 4000 Hz added to stimulation, involved no significant modification of the latencies in normal subjects. Therefore the lengthening of the latencies obtained with white noise masking, belonged to an other sphere. The second problem concerned the responses of tinnitus patients. Ipsilateral masking in white noises does not alter any latencies in the patients' brainstem. They seem to have lost the possibility of reacting to any additional noise coming from the outside. As we have already noticed, their latencies before masking were different from those of normal subjects. With masking the patients, latencies remained unchanged whereas the latencies of normal subjects lengthened and caught up the patients. To conclude, we suppose the lateral efferent system can be explored by the adjunction of white noise masking, ipsilateral to the stimulation. The expected response is a lengthening of interpeak I-V latency, without any modification of the latency of the first wave. Tinnitus patients generally do not have that type of response to white noise masking. Their lateral efferent system may not be operating.

[Possibility of functional exploration of mastication from acoustic signals]. / Possibilité d'exploration fonctionnelle de la mastication à partir de signaux phoniques.

The chewing abnormalities are frequently evoked during odontological and medical examinations. Unfortunately, few means of investigation are available to appreciate the functional disorders. The aim of this paper was to assess masticatory parameters from observation and audiosignals of mastication with a simple analysis of records. In a first time, sixty five students (mean age = 20) applied the sugar test for the salivary capacity (dissolution time = 2 to 3 minutes). Then the chewing movements were analysed with three types (I, II, III) of salt or sweet cookies. The total duration of activity was 29.8 and 28.2 seconds respectively for the tests I and II, only 18.2 seconds for the test III. The number of cycles were 32.5, 28.1 and 19.2 mastications for respectively I, II and III tests. The later type (III) had a softer consistency than the formers. The duration Dc of masticatory cycles was constant for the same type of aliment. The values were between 0.70 for the test II and 0.90 second for the I and II ones. Signal analysis showed an important and rapid decrease of amplitude AS with an exponential-like pattern. The time constant appeared in relation with the softness. Thus, our method allows to characterize the pattern of mastication and could be used for appreciation of degrees in salivary and/or cranio-mandibular functional abnormalities.

[Restarting of electric gastric activity in situ after a minor gastric intervention]. / Reprise de l'activité électrique de l'estomac in situ après une intervention gastrique mineure.

The restarting of the electrical gastric activity after an extramucous myotomy according to the Heller's techniques with Dor's fundoplicatio was observed in a woman by 3 pairs of electrodes implanted in the wall of the gastric fundus, corpus and antrum at 3, 11 and 20 cm from the pylorus. The electrical activity was recorded on the day of surgery and on the 1st, 3rd and 5th postoperative day. Feeding was allowed on the 5th day. The gastric frequency decreased significantly on the 1st (2.92 +/- 0.09 c/min), increased on the 3rd (3.29 +/- 0.04 c/min.) and appeared normal on the day of surgery and on the 5th day (3.10 +/- 0.09 c/min). The pattern of the Potential Pacesetter (PP) changed during the observation: it appeared with a great amplitude on the day of surgery, slowed on the 1st, was polyphasic on the 3rd and shorter and weaker on the 5th day. The spiking activity was observed on the 3rd day for 20 minutes and it allowed to establish the restoration of the normal migrating complexes. A decrease of the gastric frequency and an increase of the slow wave progression was induced by the first alimentary resumption (yoghurt). The gastric frequency increased and the velocity of the slow wave progression decreased as soon as the ingestion was over. The receptive relaxation of stomach should be related to these latter phenomena.

[Changes in slow and fast electrical activity of the gastro-duodeno-jejunal junction after cholecystectomy in humans]. / Evolution des activités électriques lentes et rapides du carrefour gastroduodénojéjunal après cholécystectomie chez l'homme.

The re-establishment of regular gastrointestinal electrical activity (Migrating Myoelectrical Complex-MMC- and slow wave) after cholecystectomy for gallstones was investigated in six female patients (50-77 years) by means of serosal electrodes implanted in the wall of the antrum, duodenum and jejunum during surgery. Five hour recordings were made on the first, third and fifth postoperative days, in patients who were on a liquid diet. The recordings were made after a twelve hour fast. On the fifth postoperative day, a test meal (250 g yoghurt) was given to the patients ant its effects on electrical activity were monitored for 2 hours. Even though MMC were present on the first and third postoperative days, a detailed study of their origin, the length of the Phase 3 and the speed of gastro-jejunal propagation showed that there existed an inhibition of gastric MMC until the fifth postoperative day and that intestinal MMC was slower than normal until the third postoperative day. On the fifth postoperative day, gastric inhibition disappeared since the length of the Phase 3 of the MMC of the stomach corresponds to those of the duodenum and jejunum, and the speed of propagation corresponded to that in normal subjects. Further, the slow wave frequency peculiar to each segment studied increased progressively from the first to the fifth postoperative day and the same was true of the slow waves with superimposed action potentials. In conclusion, notwithstanding the presence of MMC from the first postoperative day, it was only on the fifth day that normal coordination was restored and hence that patients were able to eat again.

[Can the efferent auditory system be explored via early evoked potentials? Preliminary results in normal hearing subjects and people with tinnitus]. / Le système efférent auditif peut-il être exploré par les potentiels évoqués précoces? Premiers resultats chez le normal et les porteurs d'acouphènes.

The use of masking in brainstem auditory evoked potential technic remains one of the important issue regarding the evaluation of different auditory control systems. Brainstem auditory evoked response wave form latencies and amplitudes have been studied on 14 normal hearing subjects. On one hand the contralateral masking which theoretically stimulates the medial contralateral efferent bundle did not modify the responses. On the other hand, the ipsilateral masking stimulating the lateral bundle reduced the amplitude of wave I and lengthened the latency of interwave I to V. The same protocol has been applied to 21 tinnitus patients. In these subjects before masking, the waves amplitude was lower and inter wave I-V latency was lengthened. The ipsilateral did not modify the responses as in the normal population. Comparing brainstem responses obtained in masking and no masking condition offers the possibility of evaluating the lateral efferent system function but we can conclude that the contralateral masking is of no use studying the medial system and that dysfunctions of the lateral efferent system could be one mechanism responsible for tinnitus.

[Modification of precocious evoked auditory potential amplitudes observed in tinnitus]. / Modifications des amplitudes des potentiels évoques auditifs précoces observées dans les acouphènes.

Brainstem evoked response audiometry has been performed in 139 patients complaining of tinnitus, unilateral or bilateral. Amplitudes of I, III, V waves and the amplitude relations I/III, I/V, III/V have been compared with those obtained in a normal population (n = 20). Amplitudes of waves I and III decreased according to their localization: decrease of left I and III for left tinnitus, decrease of left I and right III for right tinnitus, and for I and III both left and right for bilateral tinnitus. Recording of brainstem evoked response before any therapeutical treatment, especially study of amplitudes, could therefore provide information an localization of tinnitus.

[The spectral component of electrogastrography (EGG): factors of variation in normal subjects, and in patients with cancer and ulcers]. / La composante spectrale de l'électrogastrogramme (EGG): ses facteurs de variation chez le sujet normal, cancéreux et ulcéreux.

A study of the spectral analysis of the electrogastrography has been mad in man in a non-invasive condition: normal subjects in two groups: young and old subjects (n = 72) were compared with gastric cancers (n = 42) and ulcerous (n = 22) subjects. Morning recording (10-11 h a.m.), in fasting conditions, were repeated every three successive days. In normal subjects, the mean frequency of the spectral gastric component is very stable (2.8 +/- 0.2 cycles per min), whatever be the sex, the age of the body weight. In normal subjects, the mean spectral amplitude (y) varied with the derivation: in derivation 3-6 (according to the antro-pyloric axis) is the greatest amplitude (y = 52 +/- 22 microV). In the cancerous condition, the range of the frequencies increases, but the mean frequency does not change (2.8 +/- 0.3 cycles per min). However, in 7 cancerous subjects the frequencies (x) fell beyond the limits of the population with an (x) being either less than or equal to 2.4 or greater than or equal to 3.2 cycles per min. In a great proportion (forty-seven per cent) of the cancerous subjects, an important and significant increase of amplitude is recorded (at least in one derivation). In these cases, the location of the cancer is the cardia, the fundus or the pylorus. The amplitudes fall significantly beyond those observed in ulcerous patients. The possible explanations of these variations and the applications to the future monitoring of patients are discussed.

[Auditory evoked potentials in distinguishing between peripheral and central tinnitus]. / Potentiels évoqués auditifs dans la distinction entre acouphènes périphériques et centraux.

Brainstem evoked response audiometry has been performed in 164 patients complaining of tinnitus, unilateral or bilateral. The latency of every wave and the latency between the peak of every wave have been compared with those obtained in a normal population (n = 57). The latency of the first wave is increased significantly at the same side of the tinnitus. But I-V latency is shorter at the side of the tinnitus. When this increase is absent, the I-V latency is prolonged the side of the tinnitus. It is possible to differentiate between tinnitus of peripheral origin and that of central origin, although the existence of unilateral deafness is constant. The same results have been obtained in the deaf patients with bilateral symmetric deafness, in accordance with Maurizi et al., 1985.

Nuclear collective flow and charged-pion emission in Ne-nucleus collisions at E/A = 800 MeV.

Triple-differential cross sections of charged pions were measured for collisions of Ne projectiles at E/A = 800 MeV with NaF, Nb, and Pb targets. The reaction plane was estimated event by event from the light-baryon momentum distribution. For heavy targets, preferential emission of charged pions away from the interaction zone towards the projectile side was observed in the transverse direction. Such a preferential emission, which is not predicted by cascade calculations, may be attributed to a stronger pion absorption by the heavier spectator remnant.

[Surface electrogastrography (EGG) in cancer: influence of the localization and tumor characteristics on the spectral components of the signal]. / Electrogastrogramme de surface (EGG) dans le cancer: influence de la localisation et des caractéristiques tumorales sur les composantes spectrales du signal.

1) The present paper concerns the relationship between localization and extension of gastric cancers and the spectral characteristics of the EGG in 73 subjects (32 women and 41 men). 2) The recordings were made in the morning (during 1 h) on fastened patients. Three sets of bipolar cutaneous electrodes were placed on the abdomen around the pyloric radiological projection taken for axis (radius 7 cm; angle 60 degrees); sampling period for analysis is 1 per sec. The spectrum is computed (FFT) for 256 samples in each channel. 3) In the control subjects (n = 72: 24 women and 48 men), the "normal characteristics" of the peak EGG are the following: frequency: 2.89 +/- 0.2 c/min; amplitude 40 +/- 20 microV (2-5 derivation), whatever the age. 4) In the cancerous subjects significative increase of the mean spectral component amplitude of the gastric frequency was always found in all different localizations. However, this criterion of amplitude was missing for the corpus localization. 5) The process of infiltration of the wall was accompanied by a significative decrease of the mean frequency. But in ulcerous, vegetant or stenosant cases the frequency was not affected in contrast with the amplitude. 6) In extensive cases the decrease of the frequency was more important. If in several cases (early cancers, mucous cancers of the lesser or greater curvature), no significative abnormality of the spectrum was observed, abnormalities are frequent in cardiac, fundic and antral neoplasies.

[Spectral characteristics of electrogastrography in gastric cancer. Possibilities of screening]. / Caractéristiques spectrales de l'électrogastrogramme dans le cancer gastrique. Possibilités de dépistage.

A standardised application of electrogastrography (EGG) using spectral analysis was used in 182 subjects (72 normals, 74 cancerous and 36 ulcerous) in a large range of the aging (10 to 70 years). The conditions of derivations from the abdominal surface electrodes (n = 6) are following: bipolar distance 14 cm around the pyloric point at 0 degrees (antrum axis), 60 degrees and 120 degrees. In fasting situation in normal subjects the gastric frequency (N) and the spectral amplitude (Y) of the most energetic component of EGG was 2.89 +/- 0.2 c/min for N and 54 +/- 44 microV for Y in antropyloric axis. In the cancerous group a significative increase of mean amplitude is observed (P = 0.01). On the contrary any mean change of frequency was observed (2.89 +/- 0.3 c/min). The individual comparison with normal parameters leads to following selection: neoplasia, n = 42/74 cases (57%); ulcer, n = 13/36 (36%); however 7/72 normal subjects (10%) fall in this abnormal class as false positive. After an ingestion of tea (120 ml) giving a volumetric stimulation, the modifications of frequency are not significative contrary to the amplitude increase. Finally, the association of one or two abnormalities leads to the following percentages: 66% in cancerous, 45% in ulcerous and 23% in normal subjects. Thus a better proportion of abnormalities was observed in cancerous subjects with the stimulation but this procedure may lead to an increase of false abnormality in the non-neoplastic subjects.

Proton-proton correlations at small relative momentum in neon-nucleus collisions at E/A=400 and 800 MeV.

Proton-proton small angle correlations have been measured in neon-nucleus collisions, using the 4 pi detector Diogene, at 400 and 800 MeV per nucleon incident energies. Values of the size of the emitting region are obtained by comparison with the Koonin formula, taking into account the biases of the apparatus. The dependence of the density on target mass and incident energy is also analysed.

Exclusive measurements of mean pion multiplicities in 4He-nucleus reactions from 200 to 800 MeV/nucleon.

Mean multiplicities of pi+ and pi- in 4He collisions with C, Cu, and Pb at 200, 600, and 800 MeV/u, and with C and Pb at 400 MeV/u have been measured using the large solid angle detector Diogene. The independence of pion multiplicity on projectile incident energy, target mass and proton multiplicity is studied in comparison with intra-nuclear cascade predictions. The discrepancy between experimental results and theory is pointed out and discussed.

[Effects of nicotine on precocious evoked auditory potentials of the rat in the presence or absence of endogenous serotonin]. / Effets de la nicotine sur les potentiels évoqués auditifs précoces du rat, en présence ou en l'absence de sérotonine endogène.

In the rat, nicotine bitartrate (100 micrograms/kg) by intraperitoneal route provokes modifications of the brain stem auditory evoked potentials. These changes are complex: a) decrease of the amplitude of waves IV and V, probably by fixation on nicotinic type receptors, neuronal serotonin stores being normal; b) increase of the amplitude of waves I, I' and II, more important when endogenous stores are depleted; c) increase in the latency of these waves when serotonin stores are normal.

[Study by auditory evoked potentials of the efficacy of transcutaneous electric stimulation in the treatment of tinnitus]. / Etude par les potentiels évoqués auditifs de l'efficacité de l'électrostimulation transcutanée dans le traitement des acouphènes.

Thirty patients complaining about tinnitus were treated by transcutaneous tragal electrical stimulation. The effect of this treatment has been evaluated by BASR recordings before and after treatment. Taking into account the subjective results three groups are described. The first one (10 patients) is relieved of tinnitus. In second and third group the symptoms still exist, whatever the electrode's position (anode or cathode in tragal position). When BASR are studied before the electrical stimulation no inter-subjects difference can be found. After stimulation, the left delta I-V latency is significatively lengthened, and the wave I latency is shortened in the first group. The study of the two other groups do not reveal any difference between the pre- and the post- stimulation evaluation. So the BASR appears to be a good predictive tool for tinnitus suppression by electrical stimulation.

[Reorganization of the electrical activity of the transverse colon after cholecystectomy. Study in humans with implanted electrodes]. / Réorganisation de l'activité électrique du côlon transverse après cholécystectomie. Etude chez l'homme porteur d'électrodes implantées.

Electrical activity of the colon was investigated in the postoperative period in 12 patients, 1 to 6 days after cholecystectomy. The polygraphic records are obtained during 2 hours each day late in the morning (10-12 h) in a preprandial situation from serosal implantation of bipolar copper wires inserted into each circular and longitudinal layer in narrow portion of the middle part of the transverse colon. The time presence diagrams was built up after recognition of the basic patterns activity previously definite by Sarna as follows: Electro-Control-Activity, with it slow waves (ECA), Electro-Response-Activity (ERA) with Discrete bursts (DERA) or Continuous ones (CERA). In the former postoperative period 1 to 3 days ECA is present with a low range frequency 1-5 c/min. The higher frequency (10-12 c/min) activity arises sporadically, in this case associated with DERA bursts. From the 4th day all activities ECA and DERA increase significantly. The continuous response activity CERA may be observed in all periods but more frequently from the 3rd day with the same mean duration (12.4 +/- 1.85 s for the circular fibers and 21.6 +/- 2.56 s for the longitudinal ones); the predominance of longitudinal activity duration is significative (p = .001). The complex CEC (26-40 c/min) associated with CERA is observed only in 3% of the time recording. Thus after the onset of colonic motility with DERA and CERA in the 3th day, the normalization is obtain the 6th day with the predominant rythm of 1-2 c/min.

[Relationship between taenia coli electric activity and circular fibers. Study of the human transverse colon]. / Relations entre les activités électriques du taenia coli et des fibres circulaires. Etude sur le côlon transverse chez l'homme.

First results of the comparison between the electrical activity of taenia coli and circular muscle are described. Experimental techniques consisted in recording electrical activity for 83 h in 12 patients during the post-operative period after cholecystectomy. Bipolar wire electrodes were surgically inserted in each muscle of the transverse colon's median portion. Statistical treatment leads to the principal conclusion as follows: Whatever type of muscles we have investigated, always could be found slow rhythmic components (called electro-control activity, ECA) in frequency ranges of 1-5 c/min and 9-12 c/min. Major part of taenia coli ECA is in frequency range between 1-5 c/min. ECA in this frequency range can be found in 21% of circular ECA, 23% of taenia coli ECA and 9% of common ECA (% means percents of total recording time). Higher frequencies are found in 7% of circular ECA, 4% of taenia coli ECA and 3% of common ECA. Using long time constant (more than 2 s) the bursts of spikes (10-50 microV) meaning active responses are always accompanied with slower components of important amplitude (greater than or equal to 100 microV): In the discrete mode of activity (DERA) short bursts (during 1-2.5 s) always follow the ECA, whereas in the continuous mode of activity (CERA) mostly longlasting bursts (up to 30 s) could be found. The bursts represent 14% of total time, namely in 8% of longitudinal ECA, 4% of circular ECA and 2% of common ECA. ECA of taenia coli in the case of common ECA is always prolonged. Typical slow waves of greater amplitude (greater than or equal to 500 microV) different from ECA are frequently recorded probably due the intensive contractile process.