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Biomedical subjects

J Magnan

Publications and source records attributed to J Magnan.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Secretory otitis media].

Secretory otitis media is defined as the presence of effusion behind an intact eardrum without symptoms of acute infections. It is a common problem of infants between 1 to 5 years old. Most of cases of secretory otitis media are asymptomatic and discovered during child check up. The diagnosis is otoscopic and confirmed by tympanometry. A proportion of secretory otitis media resolves spontaneously or with the treatment of upper respiratory infections. The failures require the surgical solution of ventilating tube and adenoidectomy which leads to more 90% resolution with very low side effects.

Acoustic Impedance Tests↗
PubMed1998

[Functional surgery on the acoustic-facial pedicle].

The authors present their expertise and their results concerning the functional surgery on the acoustic facial nerve bundle in various disorders such as incapacitating vertigo, hemifacial spasm and tinnitus.

Facial Nerve↗
PubMed1998

[Fixed mallear head syndrome].

Fixed head malleus syndrome is a rare anatomoclinical entity first described by Goodhill in 1966. We present a series of 9 patients who underwent surgery between 1991 and 1997 and discuss the technical procedures used and functional outcome. Ossicular mobility can be re-established with two surgical methods. The more simple method consists in a classical incus transposition with malleus neck section. The more physiological method consists in drilling the synostosis fixing the malleus without disrupting the ossicular chain; stapedotomy is associated in certain cases (Type III).

Adult↗
PubMed1998

[Intact ossicular chain cholesteatoma: aspects and results of conservative surgery].

We present a 24 case-study of intact ossicular chain cholesteatomas among 158 first-look procedures performed between august 93 and april 96 (15%). The eradication of the disease was achieved via canal wall up technique without disrupting the ossicular chain in 20 cases (84%). Technical procedures are described. This new surgical attitude has enabled us to achieve better functional results. Second look procedures have not been necessary in all cases and occurrence of residuals has not been increased on a 14 months follow up period (2 cases out of 24 patients: 8%). Therefore, a longer follow up period is necessary to validate the results obtained using this recent concept.

Adolescent↗
PubMed1997

Sensory strategies in human postural control before and after unilateral vestibular neurotomy.

Vestibular inputs tonically activate the anti-gravitative leg muscles during normal standing in humans, and visual information and proprioceptive inputs from the legs are very sensitive sensory loops for body sway control. This study investigated the postural control in a homogeneous population of 50 unilateral vestibular-deficient patients (Ménière's disease patients). It analyzed the postural deficits of the patients before and after surgical treatment (unilateral vestibular neurotomy) of their diseases and it focused on the visual contribution to the fine regulation of body sway. Static posturographic recordings on a stable force-plate were done with patients with eyes open (EO) and eyes closed (EC). Body sway and visual stabilization of posture were evaluated by computing sway area with and without vision and by calculating the percentage difference of sway between EC and EO conditions. Ménière's patients were examined when asymptomatic, 1 day before unilateral vestibular neurotomy, and during the time-course of recovery (1 week, 2 weeks, 1 month, 3 months, and 1 year). Data from the patients were compared with those recorded in 26 healthy, age- and sex-matched participants. Patients before neurotomy exhibited significantly greater sway area than controls with both EO (+52%) and EC (+93%). Healthy participants and Ménière's patients, however, displayed two different behaviors with EC. In both populations, 54% of the subjects significantly increased their body sway upon eye closure, whereas 46% exhibited no change or significantly swayed less without vision. This was statistically confirmed by the cluster analysis, which clearly split the controls and the patients into two well-identified subgroups, relying heavily on vision (visual strategy, V) or not (non-visual strategy, NV). The percentage difference of sway averaged +36.7%+/-10.9% and -6.2%+/-16.5% for the V and NV controls, respectively; +45.9%+/-16.8% and -4.2%+/-14.9% for the V and NV patients, respectively. These two distinct V and NV strategies seemed consistent over time in individual subjects. Body sway area was strongly increased in all patients with EO early after neurotomy (1 and 2 weeks) and regained preoperative values later on. In contrast, sway area as well as the percentage difference of sway were differently modified in the two subgroups of patients with EC during the early stage of recovery. The NV patients swayed more, whereas the V patients swayed less without vision. This surprising finding, indicating that patients switched strategies with respect to their preoperative behavior, was consistently observed in 45 out of the 50 Ménière's patients during the whole postoperative period, up to 1 year. We concluded that there is a differential weighting of visual inputs for the fine regulation of posture in both healthy participants and Ménière's patients before surgical treatment. This differential weighting was correlated neither with age or sex factors, nor with the clinical variables at our disposal in the patients. It can be accounted for by a different selection of sensory orientation references depending on the personal experience of the subjects, leading to a more or less heavy dependence on vision. The change of sensory strategy in the patients who had undergone neurotomy might reflect a reweighting of the visual and somatosensory cues controlling balance. Switching strategy by means of a new sensory selection of orientation references may be a fast adaptive response to the lesion-induced postural instability.

Adult↗
PubMed1997

Three-dimensional MRI of hemifacial spasm with surgical correlation.

MRI was used to investigate 100 patients with hemifacial spasm, using 3D-FT T2-weighted (CISS) and contrast-enhanced 3D-FT T1-weighted (turbo-FLASH) sequences in all cases. MR angiography was performed in 54 patients, using 3D-MT FISP images. Decompression of the facial nerve through a retromastoid craniotomy was performed in all patients. Hemifacial spasm caused by tumours in the cerebellopontine angle was not included. Vascular contact with the facial nerve root-exit zone or at the internal auditory canal was present in 96 of 100 patients with hemifacial spasm. The vessel responsible was the vertebral artery (VA) in 18 cases, the posterior inferior cerebellar artery (PICA) in 23, the anterior inferior cerebellar artery (AICA) in 22, the VA and PICA in 24, VA and AICA in 3, PICA and AICA in 1, VA, PICA and AICA in 4, and a vein in 1 case. CISS images showed compressive vascular loops better than contrast-enhanced turbo-FLASH images alone. The sensitivity of MRI was high, since only one false-negative case was found among the 100 patients who underwent surgery.

Adult↗
PubMed1997

Hemifacial spasm: endoscopic vascular decompression.

Sixty patients with primitive hemifacial spasm were treated by means of a minimally invasive retrosigmoid approach in which endoscopic and microsurgical procedures were combined. Intraoperative endoscopic examination of the cerebellopontine angle showed that for 56 of the patients vessel-nerve conflict was the cause of hemifacial spasm. The most common offending vessel was the posterior inferior cerebellar artery (39 patients), next was the vertebral artery (23 patients), and last was the anterior inferior cerebellar artery (16 patients). Nineteen of the patients had multiple offending vascular loops. In one patient, another cause of hemifacial spasm was an epidermoid tumor of the cerebellopontine angle. For three patients, it was not possible to determine the exact cause of the facial disorder. Follow-up information was reviewed for 54 of 60 patients; the mean follow-up period was 14 months. Fifty of the patients were in the vessel-nerve conflict group. Forty of the 50 were free of symptoms, and four had marked improvement. The overall success rate was 88%, and there was minimal morbidity (no facial palsy, two cases of severe hearing loss).

Adult↗
PubMed1997

On the role of the olivocochlear bundle in hearing: 16 case studies.

Earlier we presented data (Scharf et al. (1994) Hear. Res. 75, 11-26) from a young patient (S.B.) who had undergone a vestibular neurotomy, during which the olivocochlear bundle (OCB) was severed. Those data are complemented by measurements on 15 other patients-some like S.B. with normal audiometric thresholds, none with a loss greater than 35 dB at experimental frequencies. Comparisons of performance for the same ear before and after surgery or between the operated and healthy ears do not provide evidence that the lack of OCB input impairs the following psychoacoustical functions: (1) detection of tonal signals, (2) intensity discrimination, (3) frequency selectivity, (4) loudness adaptation, (5) frequency discrimination within a tonal series, (6) in-head lateralization. Data on single-tone frequency discrimination are equivocal. These mostly negative results apply to listening both in the quiet and, where relevant, in noise. The only clear change in hearing after a vestibular neurotomy is that most patients detect signals at unexpected frequencies better than before. This change suggests an impaired ability to focus attention in the frequency domain. Although limited in scope, our finding that human hearing without OCB input is essentially normal agrees with much of the relevant literature on animal behavior and with the patients' self-reports.

Acoustic Stimulation↗
PubMed1996

Blunt injury to the internal carotid artery at the base of the skull: six cases of venous graft restoration.

PURPOSE: Blunt injuries to the internal carotid artery (ICA) at the base of the skull are uncommon but potentially dangerous lesions whose management remains unclear. We report a new surgical approach of the intrapetrosal portion of the ICA that was used in six patients with the help of an ear, nose, and throat surgeon. METHODS: During a 70-month period, seven consecutive patients (four women, three men; mean age, 35.7 years; range, 21 to 59 years) were admitted, six after a motor vehicle accident and one after a cervical manipulation. All patients had a neurologic deficit. An arteriographic scan revealed four unilateral ICA lesions: two false aneurysms, one tight stenosis, and one dissection; two cases of bilateral ICA dissection were mentioned, and one case of ICA dissection was associated with a contralateral ICA thrombosis. RESULTS: One patient died before surgery, and six patients underwent a unilateral venous graft restoration, reaching the vertical portion of the intrapetrosal ICA in two patients and the horizontal portion in four. A shunt was used in one patient. Failure to recognize the end of the ICA lesion was responsible for one postoperative asymptomatic graft thrombosis (17%), but this difficulty was overcome by using intraoperative angioscopy in the other patients. No deaths and no new strokes were noted during postoperative and midterm follow-up (mean follow-up, 34 months). Five postoperative facial pareses occurred and were totally regressive within 3 to 6 months in four patients; one total deafness was recorded. CONCLUSION: Venous graft restoration of traumatic ICA lesions at the base of the skull can safely be performed with such an approach, thus producing highly satisfactory results. Before undergoing surgery, the patient must be aware of the risk of facial and auditive disorders, which are generally temporary.

Accidents, Traffic↗
PubMed1996

[Results of treatment of hemifacial spasm by surgical and endoscopic neurovascular decompression. Analysis of 60 records].

The notion of a neurovascular conflict in the pathogenesis of hemifacial spasm is now well accepted based on evidence obtained from pre-operative imaging and per-operative videoendoscopy of the pontocerebellous angle. We operated 60 patients, 47 women and 13 men, age range 28-79 years, who had hemifacial spasms for 2 months to 30 years. Neurovascular decompression of the facial nerve via the retrosigmoid access was performed using a minimal invasive technique: limited access of short duration, microsurgery, endoscopic and electrophysiologic techniques, positioning of Teflon microsponges between the nerve and the vessels involved. Surgery led to 90% good long-term results with minimal morbidity limited to auditive sequellae in 3.3% of the cases. The site of compression was at the point where the facial nerve emerged in 95% of the cases. Arteries involved were the posteroinferior cerebellous artery (39 cases), the vertebral artery (23 cases) and the anteroinferior cerebellous artery (16 cases). In a third of the cases, the vascular conflict involved more than one vessel. The facial nerve should be isolated from any nociceptive contact to obtain definitive cure.

Adult↗
PubMed1996

[Neurinomas of the cochlear nerve].

Usually, schwannomas of the eight nerve arise from the vestibular nerve. Yet, the authors have operated from September 1993 to September 1995 three neuromas whose origin is certainly the cochlear nerve. Surgery was performed by retro-sigmoid approach magnified by endoscopic procedure of the cerebello-pontine angle before and after removing the tumor. We report here the cases and the literature is documented. Similar cases of observing cochlear neuromas at the moment of the procedure are exceptional. Because of more and more early diagnosis of these tumors, advances of microsurgery in ponto-cerebellar angle and endoscopic improvements in this area, observation of this kind of pathology could be more and more frequent.

Adult↗
PubMed1996

[Neuro-vascular decompression in hemifacial spasm: anatomical, electrophysiological and therapeutic results apropos of 100 cases].

Hemifacial spasm is a neurological disorder due to abnormal hyperactivity of the facial nerve. The most common cause of hemifacial spasm is a neuro-vascular conflict in the cerebellopontine angle between a vascular loop and the root of the facial nerve (96% of cases). Tumors are the cause of hemifacial spasm in only 1% of cases). The authors present their results in 100 patients who underwent microvascular decompression for essential hemifacial spasm between 1990 and 1995. They used microsurgical and endoscopic procedures by a minimal retrosigmoid approach in all cases. The most common offending vessels were the posterior inferior cerebellar artery (70%), the vertebral artery (41%) and the anterior inferior cerebellar artery (28%). An aberrant vein was found in 2 cases. There were 38% of multiple artery-nerve conflicts. Physiopathology of hemifacial spasm is explained by two principal theories: in the ephaptic theory, hyperactivity and an abnormal nervous impulse pathway are due to a short demyelinated area on the nerve trunk caused by the offending vessel, inducing short circuiting between adjacent nerve fibers. In the nuclear theory, hyperactivity of the facial nerve is due to an abnormal and automatic activity of the facial nerve nucleus itself, induced by the vessel. The authors used pre and postoperative electromyographic tests and intraoperative electromyographic tests. Their results tend to prove the nuclear theory. Ninety per cent of the patients had a good result, with a mean follow-up time of 30 months in 60 cases. In 82% of the cases, there was a total recovery after a single procedure. There was no mortality and no facial palsy. Hearing loss occurred in less than 5%.

Electromyography↗
PubMed1995

Evidence of a medial olivocochlear involvement in contralateral suppression of otoacoustic emissions in humans.

Otoacoustic emissions (OAEs) evoked by click stimuli were recorded in both ears of 20 normal human subjects, in the presence and absence of a contralateral masking broad band noise. No difference in the amplitude of OAE suppression was noted between the first tested ear and the second one. In addition, 20 pathological subjects were tested according to the same protocol. Ten of them belonged to a group of patients whose vestibular nerve was sectioned on one side to relieve incapacitating vertigo and thus represented a group in whom olivocochlear efferents were severed. A great reduction of suppression observed in the operated ear suggested that olivocochlear efferent fibers are necessary to obtain a full suppressive effect. Three of the pathological subjects were patients who had undergone a decompression of the facial nerve which necessitated the same surgical approach as vestibular neurotomy, but without any section of vestibular fibers. This surgical control group demonstrated that the surgical act by itself cannot explain the difference observed in the neurotomized group. Finally, seven of the pathological subjects were patients with Bell's palsy, which paralyses the facial nerve and abolishes the stapedial reflex. No suppression difference was observed between healthy ears and ears without stapedial reflex. Therefore, it appeared that the stapedial reflex was not involved in the contralateral suppression of EOAEs. However, as the tensor tympani muscle remained functional in these patients, its involvement in the suppressive effect cannot be excluded.

Adult↗
PubMed1995

[Microfibroendoscopy of the eustachian tube].

The development of extremely minute high performance optical fibers have made possible fibroscopic examination of the Eustachian tube. We have developed a microfibroendoscopic technique since 1987 to explore the Eustachian tube and the tympanic cavity without opening the tympanic membrane. This technique has been used in 125 patients with chronic otitis. The exploration is performed in the operating theatre during a tympanoplasty procedure. Patients are placed in supine position under general anaesthesia. Endoscopic exploration of the Eustachian tube has demonstrated that tube obstruction is very rare, encountered in only 2% of our cases. The major advantage of the technique is the direct antero-posterior visualization of the middle ear. Viewing the middle ear from this anterior view point, the surgeon can analyze regions unattainable with other techniques. The future challenge for this technique is to achieve the goal of non-invasive surgery of the middle ear.

Endoscopy↗
PubMed1995

Endoscopy of the cerebellopontine angle.

The authors present their experience of 191 patients from June 1990 to December 1993 with endoscopy of the cerbellopontine angle using a limited retrosigmoid approach. The advantages of endoscopy of the cerebellopontine angle are the simplicity and efficiency of the procedure, and less invasive surgery. The authors emphasize the importance of the endoscopic procedure: first in acoustic neuroma surgery to get more accurate information about the relationship between the tumour and the adjacent structures, and to control the lateral end of the internal auditory canal; second in hemifacial spasm or facial neuralgia surgery, intraoperative endoscopy is the key point giving a sure and safe way to recognize the offending vessels.

Cerebellopontine Angle↗
PubMed1995

[Current imaging of vasculo-neural conflicts in the cerebellopontine angle].

UNLABELLED: To demonstrate the high sensitivity of high definition MRI and particularly "Constructive Interference in Steay State" (Ciss) imaging sequence, in depicting neurovascular conflicts in the CP angle cistern, cisternographic imaging and high definition T1 weighed (Turbo flash), contrast enhanced imaging were used to investigate hemifacial spasm (72 patients) and tinnitus with abnormal BER (5 patients). The study was complemented with Angio MR in 25 patients. The results were compared with findings in a control group of 200 patients, and with the surgical observations in 57 operated cases. In hemifacial spasm, the morphology of the neurovascular conflict was determined, as well as the site of compression (lateral medullary fossa 38 cases; nerve 9; both 15 cases), and the vessel involved (VA 25 cases; PICA 16 cases; AICA 10 cases; VA and PICA 8 cases; VA and AICA 3 cases; lateral medullary vein 1 case). In tinnitus (5 cases), the AICA was involved in every case in the IAM. Among 57 operated cases, only one false negative was observed. In the asymptomatic control group, a nerovascular conflict was observed in 3, 5% of the cases only. CONCLUSION: CISS imaging is the single most efficient technique, but the combined used of the 3 types of imaging brings the highest diagnostic efficiency, for identifying a neurovascular conflict in the CPA cistern.

Adult↗
PubMed1995

Canal wall prosthesis--new devices.

In our experience, management of the troublesome mastoid cavity a "rehabilitation" of the middle ear, usually involves post canal wall reconstruction. The purpose of the long canal wall reconstruction is to restore the anatomy as perfectly as possible in order to induce satisfactory wound healing of both epidermal a mucosal layers. The numerous materials and different surgical procedures to date, demonstrate the difficulty of reconstruction of the ear canal. Over twenty years we have performed 386 cases using various materials: cortical bone, ear canal allograft, ceravital, porous and dense hydroxylapatite. More recently to improve the anatomical results we have used a new titanium prosthesis. The pros and cons of each device are discussed.

Biocompatible Materials↗