Archives of oto-rhino-laryngology最新文献

Evoked acoustic emissions (EAEs) and spontaneous acoustic emissions (SAEs) recordings hold some promise as a fast, objective and non-invasive audiological procedure, especially in children. However, accurate interpretation in the emission response must be based on the basic properties of the emissions present in a younger age group. In so doing, the properties of emissions were investigated in 49 ears from 26 children, whose ages varied between 2 days and 10 years. EAEs could be recorded in all normal ears, but the incidence of long-duration EAEs decreased with age. There were no statistically significant variations in recording the EAEs detection threshold with age. The incidence of SAEs also decreased with age.

The authors have used CT scans and MRI to study pathology in anatomical and radiological correlations of brain slices. The CT scan was particularly useful for studying structures at the skull base, although at the level of the posterior fossa such scans could visualize only those tumors that were larger than 8 mm. even after injection. The CT scan was found to be the most useful examination before surgery for facial neuralgia. In contrast MRI gave a precise cisternal course of the trigeminal nerve and its relations with vascular structures.

Epstein-Barr virus infected cultured epithelial cells from the human nasopharyngeal mucosa only, when the cells were maintained under conditions preventing terminal differentiation. The infection of these cells resulted in a marked cytopathology resembling that morphology induced in cell cultures by other members of the herpesvirus group.

We have reviewed the experiments done in our laboratory concerning various cochlear neuroactive substances. Data using chemical neuroanatomy and neurochemical techniques are described. They allow the identification and localization of neuroactive substances which could act as neurotransmitters and/or neuromodulators at the different types of synapses in the organ of Corti. Three hypotheses are presented: (1) the inner hair cells use glutamate as a neurotransmitter, but in addition to its excitatory properties, glutamate may also be involved in pathophysiological events affecting afferent auditory dendrites: (2) subpopulations of both the lateral and medial olivocochlear efferent systems can be differentiated by the neuroactive substances they may use: (3) the base and the apex of the cochlea can be distinguished on the basis of neurochemical data.

The authors present their current experience with stored bone grafts, using allografts shaped from the cortices of long bones for reconstructing the tympano-ossicular chain. The materials and the methods are described. The anatomical results have been good in 97% of the cases, while the functional results are as satisfactory as those obtained with bioceramics. In addition to ossiculoplasty, the bone allografts can also be used in otology for reconstructing large bony defects of the temporal bone.

Following Conley's work on facial nerve cross-over surgery in long-standing facial paralysis, we have reviewed five cases of paralysis of 2.5-7 years' duration. All had complete absence of electrical activity on preoperative EMG and ENG studies. In four of the five cases the facial nerve was not severely atrophic and a "cross-over" technique was feasible. Post-operatively, the results were electrically and clinically good to excellent. To foresee the results of facial nerve cross-over surgery, we have found that the degree of atrophy of the affected nerve at the time of reconstructive surgery is a more important factor than the time lapse since the beginning of the paralysis. Those results also seem better in younger patients. Our findings suggest that hypoglossal-facial cross-overs be considered even 3 years after a paralysis, mostly in younger patients, when the nerve is not severely atrophic. In some cases this technique can be complemented by muscular transfers or selected cosmetic surgery.

The authors have reviewed their clinical experiences with 92 cases of blepharoplasties treated during the past 10 years and discuss the principal approaches used, depending on the age of the patient, the amount of adipose tissue present, the degree of lower lid tarsal and muscle laxity present, and the quality of the skin excess encountered. On the upper eyelid, skin excision is combined with an orbicular muscle strip and in older patients a suspension of the lateral canthus. On the lower eyelid the transconjunctival approach is emphasized in young and or colored patients, using an undermined musculocutaneous flap in the classical technique. A good choice between these different approaches avoids the rare complications of ectropion and scleral show because the procedure used is considered to be a variable "geometric" operation.

In the majority of cases tinnitus has a high pitch and can be matched rather precisely to an objective high frequency sound. However, it is well known that tinnitus can be masked by different tones without any frequency selectivity. We wondered whether objective tones matched to tinnitus would show a more significant deterioration of frequency selectivity than could be expected from any associated hearing loss. Psychoacoustic tuning curves were obtained using simultaneous pure-tone masking and revealed a broadening of frequency selectivity. In cases of comparable bilateral hearing losses with unilateral tinnitus, the broadening associated with the tinnitus was particularly conspicuous. This broadening strongly suggests that tinnitus originates in the cochlea, although some involvement of central pathways may also occur. Tinnitus-induced broadening of frequency selectivity as a possible sign of cochlear origin deserves further consideration in future studies.

We have examined the function and fine structure of the mucociliary system of the eustachian tube in an experimental study of otitis media with effusion induced by X-ray irradiation. Functional examination demonstrated that the ciliary activity was diminished in such a condition, while morphological observations showed pathological findings including compound cilia, vacuolation of ciliated cells and expansion of intercellular space. These findings show that irradiation-induced otitis media with effusion results in impairment of the mucociliary system. As evidenced by these studies, the mucociliary system in the eustachian tube has an important role in the clearance of fluid produced in the tympanic cavity as well as affording improvement in this disease.

In children, cholesteatoma is closely related to dysfunction of the eustachian tube and evolves inside a malleable temporal bone. The importance of auditory and speech functions in such patients has caused us to use a very particular clinical philosophy. At the present time we have studied 154 cases of cholesteatomas in children under 15 years old. The following three points have been shown: the pathogenesis of a cholesteatoma can be of the primary type, secondary (due to an unfavorable extension of retraction pocket or to squamous cell migration) or even be iatrogenic; anatomical and clinical findings (with X-ray studies) predicate the treatment used; surgical treatment frequently requires a "second-look" operation.