Unilateral Atresia Research Articles

Congenital deformities of the middle and external ear.

Congenital deformities of the external and middle ears were shown by tomography in 246 patients. Surgical exploration has been undertaken at some time in many of these ears. The appearance of the tomograms and their significance were reviewed in the light of the operative findings and the authors' experience of congenital ear lesions. In nearly every case a middle ear cavity could be demonstrated although this varied from a normally aerated middle ear and mastoid in association with an isolated unilateral atresia of the external auditory meatus to a small slit-like hypotympanum in patients with craniofacial abnormalities. The ossicles were nearly always present but deformed. The typical appearances of the ossicles and the frequently aberrant pathways of the facial nerve are described.

Correction of congenital choanal atresia in children and adults.

AbstractCongenital choanal atresia occurs once in 7,000 to 8,000 births. The atresia is bony in most cases, more common in females, and more often right‐sided in patients with unilateral atresia. The incidence of associated congenital anomalies is relatively high. During the 25‐year period 1951 to 1976, 36 patients with choanal atresia were treated at the Mayo Clinic; 19 were females and 17 were males. The ages at the time of surgical treatment ranged from 1 day to 58 years. Twenty‐four patients had unilateral obstruction, and 12 had bilateral obstruction. Six patients (17%) had other associated congenital anomalies. Intranasal perforation and transpalatal correction were most commonly employed in children who were less than 8 years old, and transseptal correction was most often carried out in older patients. The nature of the stenting material and the age of the patient have important bearing on the outcome of the operation.Congenital choanal atresia is a bony or membranous closure of the posterior choana. It may be complete or incomplete and unilateral or bilateral. We wish to report on a series of children and adults who were treated for congenital choanal atresia at the Mayo Clinic during a 25‐year period and to describe a transseptal method of correction that may be performed concurrently with septal reconstruction and external nasal surgery in older children and adults.

Responses of neurons in the dorsal nucleus of the lateral lemniscus of cat to binaural tonal stimulation.

Responses of neurons in the dorsal nucleus of the lateral lemniscus of cat to binaural tonal stimulation.

Choanal Abnormalities

In reference to "Screening for Hidden Congenital Anomalies" (Pediatrics 41:147, 1968), Dr. Van Leeuwen found some cases of choanal stenosis and unilateral atresia and comments that there is little in the literature on the subject. Eight years ago I studied 500 neonates in an attempt to determine the frequency of choanal stenosis. I had a much higher incidence because I arbitrarily used a No. 8 catheter as the determining factor in the event that it could not be passed..

Binaural interaction in the cat superior olive S segment.

With the exception of low‐frequency characteristic frequency (CF) units, the ipsilaterally evoked discharge of the majority of S‐segment cells can be inhibited with simultaneous stimulation of the contralateral ear. The contralateral inhibitory CF is usually identical to the ipsilateral excitatory CF. The width of the contralateral inhibitory tuning curve is similar to the width of the ipsilateral excitatory tuning curve. Partial inhibition of the ipsilaterally evoked discharge increases the interspike intervals and increases the variability of the discharge. Inhibition, like excitation, is tonically acting. The contralateral inhibitory input with equally intense tones (measured in terms of decibels above threshold) is either about as effective as the excitatory input or less effective, rarely more effective. The primary factor determining the spike output from S‐segment cells is not the absolute intensity level of the stimulus but rather the relative intensity difference of the stimulus at the two ears. [Work supported in part by National Institutes of Health, U. S. Department of Health, Education, and Welfare.]

Some neural mechanisms in the inferior colliculus of the cat which may be relevant to localization of a sound source.

Some neural mechanisms in the inferior colliculus of the cat which may be relevant to localization of a sound source.

UNILATERAL ATRESIA OF THE INTERNAL AUDITORY MEATUS, CONFIRMED BY RADIOGRAPHY.

Labyrinthine anomalies constitute an unexplored field in the study of deafness. Only a very few pathological investigations of such cases have been published. These anomalies may consist in a total absence of the labyrinth, but this appears to be extremely rare, only two definite cases being on record (Saissy, 1819; Michel, 1863). Both were bilateral. A less common anomaly is a partial, visible defect of the labyrinthine skeleton, called Mondini's defect, in which the modiolus and septa of the superior cochlear coil are absent. This defect has been described in detail by Guffarth (1936) and Albrecht (1940) who considered it to be the pathological basis of dominant inherited deafness. It is represented by several examples in the “Ibsen-Macke-prang collection of temporal bones from deafmutes” (described by Mygind in 1893 and still kept at the University Ear Clinic, Rigshospitalet, Copenhagen). Special labyrinthine anomalies have recently been reported by Everberg (1960, 1961), who demonstrated, by polytomog...

Treatment of Complete Unilateral Bony Atresia of the Posterior Nares

Treatment of Complete Unilateral Bony Atresia of the Posterior Nares

Congenital malformation of the external ear and atresia of the auditory canal.

Bilateral atresia of the external auditory canal has long been a serious problem to the practicing otologist, and, through his efforts to restore some degree of hearing to the patient otherwise hopelessly deaf, many surgical procedures have been devised for its correction. Unfortunately, results of these procedures have been so unsatisfactory as to discourage attempts at surgical correction when the patient has one normal ear. We wish to report, however, a case of unilateral atresia associated with external ear deformity in which careful examination suggested to us the probable presence of a normally functioning acoustic mechanism. We were encouraged by this examination to undertake surgical procedure, which, in this case, yielded restoration of normal hearing and an improved cosmetic result. R. B. W., a white youth aged 19, was first seen by us on June 23, 1948, at which time he had acute otitis externa with marked swelling and occlusion

XXIV. Unilateral Atresia of the Auditory Canal without External Deformity: A Case

XXIV. Unilateral Atresia of the Auditory Canal without External Deformity: A Case