Biomedical subjects
Publications and source records attributed to A Robier.
The first case of an infection caused by Nocardia farcinica on a cochlear implant and its progression is described. As it is difficult to diagnose Nocardia spp., the identification was confirmed by phylogenetic analysis using 16S rDNA sequencing.
Teratomas are tumors which develop in childhood or early adulthood, generally in the gonads. More rarely these tumors may be found in an axial localization, notably in cervicofacial forms. We report three cases of teratomas observed in rhinopharynx of three neonates operated at the Clocheville General Hospital. We present the main anatomoclinical features of these tumors, focusing on the cervicofacial forms in neonates. All three cases occurred in female neonates presenting acute dyspnea within the first hours of life, requiring intubation in two cases. The first two tumors invaded the infratemoral region and the third was a pediculated tumor of the velum exteriorized via the mouth. In one case antenatal ultrasound had suggested the diagnosis of a right temporomaxillary tumor. Rapid excision of the rhinopharngyeal component allow extubation for the two intubated infants and pathology diagnosis. In the first infant operated at 2 months, the lateral route was adapted to age, with mandibulotomy with section of the coronoid process but preserving the mandibular condyle. The second infant was operated at the age of 3 weeks using a wide frontotemporoperitonial approach then at the age of 3.5 months for recurrence extending to the floor of the temporal fossa and the middle ear. A type C infratemporal approach was used with lost-bone temporal craniectomy. Per-buccal excision was possible in the third infant with resection at the base of implantation. No recurrence has been observed in the first two cases at 3.5 and 2.5 months follow-up in the first two cases. The third infant was lost to follow-up.
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OBJECTIVES: To evaluate the effects of the size of the footplate opening on the hearing results in surgical treatment of otosclerosis and the use of CO2 laser in this indication. PATIENTS AND METHODS: 190 patients with otosclerosis underwent 227 procedures between 1986 and 1995. Hearing results and symptoms were analyzed to compare the different procedures: 140 stapedectomies, 87 Fisch's stapedotomies, 35 of them with manual perforator, 52 of them with CO2 laser. RESULTS: Air/bone gap closure within 10 dB was obtained in 87, 92 and 97 percent of stapedectomies and in 80, 84 et 90 percent of stapedotomies after 3 months, 1 and 3 years (NS). Bone conduction was improved in 81, 80 et 63 percent of stapedectomies and 87, 97, 60 percent of stapedotomies after the same time (NS). Air/bone gap closure within 10 dB was obtained in 75 and 80 percent of manual perforator stapedotomies and in 84 and 88 percent of CO2 laser stapedotomies after 3 months, and 1 year (NS). Bone conduction was improved in 78 and 96 percent of manual perforator stapedotomies and 95 and 100 percent of CO2 laser stapedotomies after the same time (NS). No facial palsy or prolonged vertigo occurred. There was one case of anucusis following a stapedectomy. CONCLUSION: Although both stapedectomy and stapedotomy produced equivalent air/bone gap closure, reduction of inner ear trauma was noted with Fisch's stapedotomy. CO2 laser technique is a safe procedure, which optimizes the Fisch's stapedotomy.
A case of bilateral progressive stenosis of both external auditory canals with resultant conductive hearing loss is presented. The stenosis revealed multifocal erosive and synechiant lichen planus. To our knowledge, this is the first reported case of lichen planus involvement of the external ear.
Vestibular neurotomy, in addition to the fact that it preserves the hearing, is considered to be the most effective form of treatment for incapacitating unilateral Menières disease which is resistant to medical treatment. The authors have carried out a retrospective study of 20 cases of vestibular neurotomy operated on between 1986 and 1996. They have evaluated the results of the suppression of vertigo and the improvement of quality of life. Each patient was given a questionnaire. The parameters studied were the quality of daily life, professional life and driving ability. The mean follow-up period was 3 years. This study confirms the good results obtained with vestibular neurotomy for vertigo: complete control of attacks of vertigo was obtained in 90% of cases according to the criteria laid down by the American Committee on Hearing and Balance, as modified in 1985 (AAO, 1985). This study has also confirmed that the quality of patients lives is greatly enhanced both for everyday activities, professional activities and driving.
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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.
Development of auditory stimulation tests associated with single-photon emission tomography (SPET) shows evidence of variations in perfusion related to the stimuli. Three brain SPET examinations with technetium-99m hexamethylpropylene amine oxime were performed on eight right-handed adults with normal hearing, the first one without stimulation and the other two associated with a 500-Hz/30-dB stimulation of the right ear. Temporal regions of interest covering auditory areas, as well as parietal ones (internal control), were drawn on three successive coronal slices. A cortico-cerebellar index R was calculated, and the variation in activity was defined for each subject using the ratio R poststimulation--R prestimulation/R prestimulation. A significant increase in the temporal cortex count occurred in all subjects. This increase was bilateral, except for one subject in whom it was not significant on the right side. This result recurred during the second stimulation study. Overall the response of the left temporal cortex was stronger, although the asymmetry was not significant. The asymmetry repeated itself after each stimulation. The perfusion response is globally reliable in our study. We must ascertain how sensitive this test is with regard to deaf adults and adults with normal hearing before extending its use to children.
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Brain activation procedures associated with single photon emission computed tomography (SPECT) recently have been developed in healthy controls and in diseased patients to help in their diagnosis and treatment. We investigated the effects of an electrical stimulation of the auditory nerve on the cerebral distribution of 99mTc-HMPAO in seven profoundly deaf adults. The promontory test was positive (PT+) in six patients and negative (PT-) in one. A count increment of the temporal cortex was observed in all patients, and was higher in all patients with PT+ (right 20%, left 19%) than in the patient with PT- (right 9%, left 3%). These results led us to consider 99mTc-HMPAO brain SPECT imaging as a potential preoperative test for cochlear implant. It might be helpful for the evaluation of cortical perfusion response to an electrical stimulation. Sensitivity tests for the method are requested before this clinical application.
Brain activation procedures associated with single photon emission tomography (SPET) have recently been developed in healthy controls and diseased patients in order to help in their diagnosis and treatment. We investigated the effects of a promontory test (PT) on the cerebral distribution of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) in 7 profoundly deaf patients, 6 PT+ and one PT-. The count variation in the temporal lobe was calculated on 6 coronal slices using the ratio (Rstimulation-Rdeprivation)/Rdeprivation where R = counts in the temporal lobe/whole-brain count. A count increase in the temporal lobe was observed in all patients and was higher in all patients with PT+ than in the patient with PT-. The problems of head positioning and resolution of the system were taken into account, and we considered that the maximal count increment was related to the auditory cortex response to the stimulus. Further clinical investigations with high-resolution systems have to be performed in order to validate this presurgery test in cochlear implant assessment.
A study on the dynamic exploration of the auditory pathway is presented, in which technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPET) was used in volunteers with normal hearing. Changes in 99mTc-HMPAO distribution were calculated using a region of interest/whole-brain count ratio. The results showed a temporal perfusion increment of 17% (right) and 19% (left) during tonal supraliminar stimulation, which was significantly different from the control ROI. Sensitivity tests for the method were requested before any clinical application.
A new method of dynamic exploration of central auditory pathway is presented, using measurement of cortical temporal perfusion variations, during auditory stimulation (tonal stimulation in normal hearing patients, electrical stimulation with promontory test in profoundly deaf patients). This study shows a perfusion increment in normal hearing and deaf patients with positive promontory test, which doesn't exist in a patient with negative promontory test. Further development of this study could help for optimization of post implantation auditory results.
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Of a series of 23 patients presenting sudden deafness, treatment by normovolemic hemodilution yielded good results in 17 cases (74%), including 14 excellent results (61%) with constant efficacy on the tinnitus aurium (100%). These results appear overall superior to the 40 to 65% improvements reported in the literature. Nevertheless, comparisons in this area must take into account the very different assessment criteria applied from one series to another. The authors propose using the formula established to assess professional deafness, but taking the other ear as a reference.
Otogenic thrombosis of the lateral sinus, which has become rare since the use of antibiotics, nevertheless still poses diagnostic and therapeutic problems. Based on 4 cases treated at the University Teaching Hospital in Tours since 1982, the authors study the various clinical and paraclinical elements in the diagnosis, stressing the value of CT examination using contrast. Management is then proposed in diagramatic form: the indication for surgery depending on the efficacy of antibiotic therapy and internal jugular vein ligation being required in the event of septic emboli manifest cervical signs.
An oto-neuro-surgical experience on patients older than 65 years is reported. 25 patients have been operated: 9 meningiomas, 5 trigeminal neuroglia, 2 vestibular neurectomies, 9 acoustic neuromas. The assessment, the indication, the surgical techniques are discussed. Are also evaluated the anesthetic technique, the patient drugs, position, and the post-operative survey.