[Vibration-induced nystagmus: mechanism and clinical interest]. / Nystagmus induit par des vibrations: physiopathogénie et intérêt en clinique.

UNLABELLED: In 1973 Lücke described nystagmus induced by application of a vibrator on the mastoid process. Since that time, several Authors have applied the vibrator test in normal subjects or patients suffering from various well-characterized conditions. OBJECTIVE: Recognizing that results obtained with the vibrator test are sometimes in contradiction with those of other vestibular tests, our aim was to formulate an assumption regarding the genesis of induced nystagmus in an attempt to explain such contradictions. MATERIAL AND METHODS: We considered seven very different clinical situations. Each patient underwent a standard protocol including pendular and caloric tests as well as the vibrator test. We sought an assumption allowing, i) an interpretation of the characteristic features of nystagmus induced by the vibrator in any situation, ii) an understanding of the reasons why some vibrator test results do not correlate with those of other vestibular tests. RESULTS AND CONCLUSION: We assume that the vibrator stimulates phasic cells of the cupula and the vestibular maculae preferentially, if not exclusively. This assumption allows us to retain a very simple protocol for the vibrator test useful for routine clinical practice.

[Vestibular compensation. Clinical value of its dynamic study]. / La compensation vestibulaire. Intérêt clinique de son étude dynamique.

Vestibular compensation consists of all the processes of neurological reorganization that allow recovering balance after a unilateral vestibular lesion. According to its etiology, the peripheral lesion may be more or less severe, may evolve more or less rapidly, and be more or less reversible. Therefore, it will have a characteristic "pattern" in time, which enables us to classify the kinetic aspects of peripheral pathology. Vestibular compensation, which responds to these variations in the sensitivity of the posterior labyrinth, is a slowly progressive adaptation mechanism. This compensation will progressively reduce the musculotonic asymmetry affecting the postural muscles and the eye muscles, and it can therefore be studied on the basis of the velocity of the spontaneous nystagmus as measured in the dark. We can then define a "vestibular compensation rate" at a given moment. To achieve this, a diagram (E. UMER) is proposed to represent the lesion and the rate of vestibular compensation and to study their mutual relationships. The dynamic study of vestibular compensation and the measurement of its "time constant" than have threefold merits for diagnosis, prognosis and treatment.

Vestibular neurotomy by retrosigmoid approach: technique, indications, and results.

During the past 15 years, 96 retrosigmoid vestibular neurotomies have been used in the surgical management of incapacitating Meniere's disease for the control of vertigo and preservation of hearing. This posterior approach of the pontocerebellar angle gives the best view on the acousticofacial nerve bundle, through a 2 x 2 cm suboccipital craniotomy immediately behind the mastoid and sigmoid sinus. Then the vestibular nerve is easily identified, separated from the cochlear nerve and sectioned, the facial nerve not being at risk, as it lies much deeper. Actually, the majority of authors agree that vestibular neurotomy is the most effective surgical treatment in relieving disabling vertigo (96% of cases) with serviceable hearing, but few surgeons know that the retrosigmoid approach is simpler and more reliable than the middle fossa or retrolabyrinthine approaches, with a low incidence of complications. The purpose of this paper is to emphasize the routine use of the retrosigmoid approach.

[Anatomo-pathology of cholesteatoma]. / Anatomo-pathologie du cholestéatome.

The authors, from their own histopathological studies and from an overview of otological literature focus the controversial problems about the so-called disease cholesteatoma. The history of cholesteatoma has been marked out by pathologic data which, initially caused the cholesteatoma to be identified as a keratinized squamous tumor. This misnomer will however be retained because of it long-established usage. "Skin in the wrong place" in the middle ear summarizes this clinical entity. Electron microscopic observations provide arguments in favour of the migratory theory and the invasion of the epidermis from the bottom of the external ear canal into the middle ear cavity (identical fine morphology between skin and cholesteatoma, presence of Langerhans and Merkel cells, sharp junction between the advancing front of the cholesteatoma and the middle ear mucosa). Recent immunohistological techniques allow consideration of cholesteatoma as a self-induced inflammatory process in response to tissular and cellular conflicts. A cholesteatoma could be merely a non-healing wound process and a disease of epidermal growth control occurring in the middle ear space. The logical principles governing cholesteatoma surgery, suggested by these biological considerations, are: total removal of cholesteatoma matrix, prevention of cholesteatoma recurrence by a careful respect of the barrier separating the middle ear mucosa from the skin-lined bony external ear canal, maintenance of good healing conditions for both mucosa in a closed well-ventilated middle ear and epidermis in a harmonious anatomical external canal.

[Otospongiosis: different surgical technics, identical results. Why?]. / Otospongiose: techniques chirurgicales différentes, résultats identiques. Pourquoi?

Both platinectomy and platinotomy are currently used to treat otosclerosis surgically. Though the techniques are different from one another, especially by the new area ratio between tympanic membrane and stapes foot-plate, the results are similar. It should be clear that the simple "piston model" of the tympanic ossicular system cannot explain this results. If, for the seesaw mechanical view, a vibratory molecular system conducting acoustic energy is substituted, a pertinent explanation can be given for this result. Thus, understanding of the pattern motion of the tympanic ossicular system has to change drastically.

[Endoscopy of the eustachian tube. 1st evaluation]. / Endoscopie de la trompe d'Eustache. Premier bilan.

The authors present a novel, original method for exploration of the middle ear cavity using Eustachian tube endoscopy. The diameter of the fibre optic tube was only 0.9 mm, hence the term micro-endoscopy. This endoscopic procedure was used during surgery for chronic otitis, where there was evidence of tubal etiology which required confirmation. The preliminary results are presented.

[Retraction pockets, pathological entity?]. / Les poches de rétraction, entité pathologique?

Retraction pockets are not a pathological entity per se but take after various ear diseases, with which they share the same morphological eardrum alterations. The authors believe that any holistic evaluation of retraction pockets, as though these were forming a single group of like pathogenic origin, i.e., tubal dysfunction, would be artificial and raise therapeutic problems. The statistical analysis of the causes for retraction pocket formation provides little information. Otologists are still looking into chronic otitis media and cholesteatoma as a possible, long-suspected, unproved etiology. Electron microscopy and, more particularly, istological-enzymological analyses of mounts prepared by the authors have shown, in some cases, the anomalous presence, in the pocket, of Langerhans' cells, which the authors consider as strongly indicative of cholesteatoma. While confirming the clinical diagnosis, anatomopathological examination allows to differentiate poor-prognosis retraction pockets from benign ones. The pathogenesis of these pockets is still poorly understood. It is the authors' contention that tympanic invagination is more likely traceable to some biopathological/biochemical phenomenon than to occupational mechanical disorders involving the tube. The clinical characteristics of retraction pockets are the basis for their classification into three groups, according to their evolutional tendency. Thus, developing cholesteatomas bear a poor prognosis; sequelae of benign otitis are associated with small risk; lastly, there is a small group of pockets the evolution of which is hard to specify. The authors believe that such differentiation between retraction pockets is mandatory to have a clear picture of therapeutic indications, and to assess the various outcomes.

[Diagnostic and therapeutic problems in dissociated forms of Menière's disease]. / Problèmes diagnostiques et thérapeutiques au cours des formes dissociées de la maladie de Ménière.

The authors report the cases of 5 subjects who presented with incapacitating vertigo which was attributed to a dissociated form of Meniere's disease. They stress the difficulty, in these circumstances, in making a precise diagnosis which can only in fact be confirmed with the benefit of a longer follow up. They stress the value of systematically combining frequency analysis with measurement of maximal slow phase velocity during vestibular testing. This allowed better precision in terms of topographical diagnosis. All subjects underwent vestibular neurotomy via the retro-sigmoid approach. The procedure did not alter hearing and compensation occurred within the usual delay. The question therefore arises as to when is the best time to intervene in patients presenting with vertigo of peripheral origin with preserved hearing.

[Conditions necessary for a cure of cholesteatomatous chronic otitis]. / Les conditions de guérison de l'otite chronique cholestéatomateuse.

The authors present a homogeneous series of 750 cholesteatomas treated surgically between 1973 and 1984, 710 cases by a closed technique (94%) and 40 by an open technique. After dealing with the false problem of the choice between open technique and closed technique, the authors attempt to define the conditions required for successful treatment of cholesteatomatous chronic otitis, and on that basis justify their own therapeutic attitude. Excision of the cholesteatoma must be complete and as a single block, from the periphery to the point of origin of the epidermal matrix. Such excision is possible in the majority of cases without damage to the bony canal walls. The risk of residual cholesteatoma fell from 19% in 1978 to 8% in 1984. The prevention of cholesteatoma is based upon our basic knowledge of the disease. It requires avoiding damage to or repair of the osteo-membranous anatomical barrier which separate the two compartments, outer and middle, of the ear. This aim can now be better achieved by the use of tympanic homografts and recent techniques for repair of the bony external auditory canal. Recurrences (13%) are due to the ability of progression of the cholesteatoma but also, and above all, the imperfect surgery. Whilst it was long believed that complete eradication of cholesteatoma was impossible without destruction of part of the architecture of the ear, it is now known to be possible, and even represents one of the best methods for the prevention of recurrences.

[The fronto-supra-ethmoidal approach. Its value in cerebrospinal rhinorrhea]. / L'abord fronto-sus-ethmoïdal. Son intérêt au cours des rhino-liquorrhées.

A supra-ethmoidal approach was used to treat cerebrospinal fluid rhinorrhea secondary to anterior fractures of the base of the skull. After an internal orbital incision, the anterior wall of the frontal sinus is removed and the posterior wall of this sinus trephined in the internal region of its horizontal portion in order to expose the meninges covering the roof of the first ethmoidal space. Dissection is continued within the space towards the anterior extremity of the apophysis of the crista galli against which the fibrous band issuing from the anterior ethmoidal opening is sectioned. The dura mater is then separated from the cribriform plate of the ethmoid up to the jugum sphenoidale posteriorly, while progressively coagulating and sectioning the nerve and connective tissue network attached to the cribriform plate. This freeing of the dura mater exposes the meningeal fistula and allows its liberation from its bony adhesions. A fragment of epicranium removed from the frontal bone is spread between the dura mater and the cribriform plate in order to cover it completely. A drain is then introduced into the nasofrontal canal and the anterior wall of the frontal sinus replaced in position. The advantages of this technique are: the operation is simple, it allows good exposure of the fistula, and since the bony support of the ethmoid is not destroyed the meningeal opening can be easily obstructed.

[Vestibular neurotomy by the posterior retrosinus approach. Technics, results and indications]. / La neurotomie vestibulaire par voie postérieure rétro-sigmoïde. Technique, résultats et indications.

A posterior retrosinus approach was used for 50 vestibular neurotomies to treat patients with severe "Ménière's" disease. The pontocerebellar angle is approached by trephination of a 2 cm diameter opening immediately behind the mastoid and lateral sinus. The acoustic-facial nerve bundle lies 55 mm deep to the craniotomy opening. The vestibular nerve is separated from the cochlear and sectioned, the facial nerve not being at risk as it lies much deeper. Results after a minimum follow up of one year showed recovery from vertigo in 96 p. 100 of cases. Deafness, which was unchanged following surgery, did not appear to progress in most cases. Tinnitus was unchanged. Facial nerve lesions were never observed. The operation is a simple one (duration of 90 minutes) and is reliable, and vestibular neurotomy by the pontocerebellar angle approach appears to be most effective currently available method for treating severe cases of "Ménière's" disease. Decompression procedures provide results that are too inconstant, while neurectomy by a suprapetrous approach is a much riskier op eration than that which uses a posterior approach as described above.

[The jugular foramen, the inferior bulb of the jugular vein and their surgical approach]. / Le trou déchiré postérieur, le foramen jugulaire, le golfe de la veine jugulaire interne, et leur abord chirurgical.

Anatomical features of the sigmoid sinus and internal jugular vein and their connections are described. The jugular foramen is really only the opening of a bony canal between occipital and temporal bones, and is equivalent to a connective opening between the occipital vertebra and petrosal bone. The junction between the sigmoid sinus and internal jugular vein has the form and probably also the function of a siphon, but one in which the two arms are at right-angles. The jugular vein sinus has numerous vessels emptying into it, including some; condylar veins and inferior petrosal sinus, that are of high importance: valves are present at their orifices and the jugular sinus contains cords as in the cardiac cavities. The jugular vein sinus certainly plays a physiologic role in venous flow: a rigid-wall canal, the sigmoid sinus is followed by one with flexible, easily collapsible walls: the jugular vein. The latter is submitted to very high negative pressures that have to be compensated for by the sigmoido-jugular siphon in order to maintain cerebral vascular filling. Surgical approach to the jugular vein sinus is complicated by two factors: the facial nerve and hemorrhage. The facial nerve in its bony canal is situated immediately adjacent to the jugular sinus and must be displaced to reach the vein. The sinus is almost always approached for jugular glomus tumors, which are very hemorrhagic lesions. To prevent blood loss, the sigmoid sinus and then the external carotid are linked to the jugular vein.(ABSTRACT TRUNCATED AT 250 WORDS)

[Problems of hemostasis and excision technic in glomus jugulare tumors]. / Problèmes d'hemostase et technique d'exérèse des tumeurs du glomus jugulaire.

An artifice is proposed for controlling bleeding during excision of a glomus jugulare tumor. After ligature of the external carotid or ascending pharyngeal arteries, and of the sigmoid sinus, a balloon catheter is introduced into the internal jugular vein. The balloon is then placed at the level of the jugular vein sinus and distended, preventing bleeding from the inferior petrosal sinus and the condylar emissary veins. The operation is conducted in four stages, their order varying according to the extension of the lesion. The mastoid stage involves freeing of the sigmoid sinus and the third portion of the facial nerve. The cervical stage requires freeing of the VIIth nerve at its entry into the parotid, and of the external carotid and internal jugular arteries, and identification of the IXth, Xth, and XIth nerves. During the third cervicomastoid stage, the facial nerve is completely liberated and pushed upwards, and the jugular apophysis of the occipital resected. The last stage is that of preventive hemostasis and excision. The jugular sinus, external carotid artery and internal jugular vein are ligatured. The internal jugular vein is then catheterized with the balloon catheter, which is distended. The jugular vein sinus is opened, the afferent vein orifices clogged, and the lesion excised.