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At least 163 records · Page 9Linked to original sources
PubMed1987

Squamous cell carcinoma of the external ear: a review of 75 cases.

Squamous cell carcinoma of the external ear can be a potentially lethal lesion. Although it is the most common cancer involving the pinna, the variables that have the greatest impact on prognosis are still in question. We reviewed 75 cases of squamous cell carcinoma of the external ear to determine patterns of occurrence and treatment failure. Forty patients had adequate follow-up for determination of cancer control rates. Local control was successful with initial treatment in 85% of the cases. The incidence of lymph node metastases was 10%, whereas distant metastasis occurred in only one patient (2.5%). This series differs from others in that most patients were unselected and most of the lesions treated were early (less than 1 cm). The significance of positive margins after surgical excision is also analyzed.

Aged↗
PubMed2006

Chondroid syringoma of the external ear canal presenting as a cyst.

Chondroid syringoma of the external ear canal is a rare, usually firm or polypoid tumor, representing the cutaneous counterpart of pleomorphic adenoma of salivary glands. We report a very rare case of chondroid syringoma in a 40-year-old man who presented with a fluid-containing cyst in the external ear canal. Clinical and radiological examinations showed involvement of the whole external canal to the annulus. The cystic lesion was totally excised along with the overlying skin. The postoperative course was uneventful.

Adenoma, Pleomorphic↗
PubMed2003

[Effects of Burow's solution as an ear drop on Intractable chronic suppurative diseases of the external ear canal and middle ear].

OBJECTIVE: Burow's solution was developed by Karl August von Burow in the 19th century as an ear drop. Thorp et al. reported its excellent effect on chronic suppurative otitis media in 1998. We applied Burow's solution to intractable chronic purulent diseases of the external and middle ear in the 12 months from February 2001. SUBJECTS: Subjects were 25 ears of 21 patients--35-79 years old, 10 men's ears and 15 women's ears--whose disease has continued for an average of 3.78 years. Diseases and patients are as follows: 1) 11 ears with postoperative mastoid cavity problems, 2) 7 ears with chronic external otitis and chronic eczema of the external ear canal, 3) 7 ears with fungal otitis externa, 4) 6 ears with chronic otitis media with perforation, and 5) 2 ears of chronic granulated myringitis. METHOD: The solution was dropped into the ear canal once a day for 10 min or cotton balls soaked with the solution were applied to the canal wall. Criteria of efficacy were divided into cured, effective and unchanged. RESULTS: 8/11 ears with a cavity problem were cured (72.7%) and 3 ears showed treatment to be effective. All 7 ears with chronic external otitis and chronic eczema were cured. All 7 ears with fungal otitis externa were cured. 4/6 ears (66.6%) with chronic perforated otitis media were cured and 1 ear each showed treatment to be effective and 1 unchanged. Two chronic granurated myringitis were cured. Twenty of 25 ears (80%) were cured. Pre- and posttreatment audiometries showed almost the same. The cure appeared within 3 days to 3 weeks. The solution was not effective against mucoid secretion, cholesteatoma, or residual mastoid cells. The day after treatment, serous secretion appears temporarily. CONCLUSION: Burows's solution is seemed to be very effective and nonototoxic as an otic drop for treating suppurative ear diseases.

Acetates↗
PubMed1987

Changes in external ear position modify the spatial tuning of auditory units in the cat's superior colliculus.

This study examines the influence of external ear position on the auditory spatial tuning of single units in the superior colliculus of the anesthetized cat. Unit responses to broad-band stimuli presented in a free sound field were measured with the external ears in a forward symmetrical position or with one or the other ear turned 40 degrees to the side; the ears are referred to as contra- or ipsilateral with respect to the side of the recording site. Changes in the position of either ear modified the spatial tuning of units. The region of space from which a stimulus was most effective in activating a unit is referred to as the unit's "best area". Whenever the contralateral ear was turned to the side, best areas shifted peripherally and somewhat upward, roughly in proportion to the magnitude of the change in ear position. A turn of the ipsilateral ear to the side had more variable effects, but best areas generally shifted frontally. Best areas located between approximately 10 and 40 degrees contralateral when the ears were forward were least affected by changes in ipsilateral ear position. Changes in ear position also modified the maximum response rates of many units. Units with best areas located within approximately 20 degrees of the frontal midline when the ears were forward exhibited a pronounced decrease in responsiveness when either ear was turned. Units with more peripheral best areas tended to show no change or a slight increase in responsiveness. The influence of ear position on the directionality of the external ears was determined by mapping the cochlear microphonic response to tones or one-third-octave bands of noise before and after turning the ear. When the ears were forward, maximum interaural intensity differences (IIDs) were produced by high-frequency sound sources (greater than or equal to 20 kHz) located 20-40 degrees from the frontal midline and by lower frequency sources located further peripherally. The influence of ear position on the locations from which maximum IIDs were produced was similar to the influence of ear position on unit best areas. Changes in ipsilateral ear position had different effects on high- and low-frequency IIDs that were comparable with the effects of changes in ear position on frontally and peripherally located best areas, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Acoustics↗
PubMed1996

Sound source elevation and external ear cues influence the discrimination of spectral notches by the big brown bat, Eptesicus fuscus.

Measurements of external ear transfer functions in the echolocating bat Eptesicus fuscus have revealed a prominent spectral notch that decreases in center frequency (50 to 30-35 kHz) as elevation decreases [Wotton et al., J. Acoust. Soc. Am. 98, 1423-1445 (1995)]. To examine the influence of this notch, four Eptesicus were trained to discriminate between two sets of electronically generated artificial echoes. The negative (unrewarded) stimulus contained a test spectral notch at a specific frequency that varied from 30 to 50 kHz, while the positive (rewarded) stimulus contained no test notch. The vertical position of the loudspeakers delivering these simulated echoes was changed daily. When echoes were returned from an elevation at which the external ear introduced a spectral notch at the same frequency as the test notch, then the discrimination should have been difficult. The bats' performance conformed to this prediction: All bats discriminated the presence of a 35-kHz notch at all elevations except -10 degrees. As the frequency of the synthesized notch increased, the elevation at which bats could not perform the discrimination also increased. The movement of the bat's "blind spot" for the test notch of different frequencies followed the movement of the external ear notch at different elevations.

Animals↗
PubMed1993

Cannabis in the external ear.

ENT surgeons may well be asked to remove cannabis from the external ear where it has been lodged for various reasons. We report two cases and review four other cases we found in the literature to illustrate some of the difficulties. It is important that anyone working with people who abuse drugs are aware that cannabis can be concealed in the external ear.

Adult↗
PubMed1995

[The study of the modification of the natural resonance of the external ear following tympanoplasty].

The shape, position and amplitude of the natural resonance curve of external ear is related to sensation evoked in a subject by sound coming from the external environment. The involution of this curve varies from individual and is the sum of the effects provoked on the incident sound by the head, auricle and the conformation of canal (EEE = External Ear Effect). Natural amplification supplied by the system allows the individual to distinguish natural sound, whose being natural make them pleasant to hear. Any interventions that modifies the anatomy of the auricle and/or the canal activity alternates the REUR (Real Ear Unaided Response) to some degree. Restoration of basic anatomical conditions are choice of interventions which displace the curve only slightly allows a physiological sensation of sound to be maintained. Surgeon often neglect this little studied aspect preferring to evaluate this work in terms of quantity thus rather ignoring the quality of sound achieved.

Ear↗
PubMed1995

Embryology and anomalies of the external ear.

Malformations of the auricle are not uncommon and occur in 1 out of 12500 births. They can occur alone or can be associated with genetically determined syndromes. Most congenital malformations in the human occur during the third to twelfth weeks of embryonic life. During this period, the external ear is undergoing development and can be affected in many ways. There are three parts to the external ear: the auricle, the cartilaginous external auditory canal, and the bony external canal. The auricle (pinna) and the cartilaginous canal are closely related and probably develop from the same anlage. The bony canal is derived from the tympanic ring which is an incomplete cylinder of membranous bone. It must be clearly understood that, although this article is primarily concerned with the morphogenesis and dysmorphogenesis of the auricle, the rest of the external ear, specifically the external auditory canal, is developing simultaneously. Therefore, maldevelopment of the external canal and the auricle will frequently occur together.

Ear Canal↗
PubMed1986

The use of acoustical test fixtures for the measurement of hearing protector attenuation. Part II: Modeling the external ear, simulating bone conduction, and comparing test fixture and real-ear data.

This paper investigates two main features of the human head which influence the measured attenuation of circumaural and intraaural hearing protection devices (HPDs): the external ear and the different pathways of bone conduction. A theoretical model for the external ear shows that its influence on the insertion loss of HPDs, on the sensitivity level of headphones or earphones, and on the insertion gain of hearing aids, all can be described by one equation. While it is not necessary to simulate the eardrum impedance in order to measure the insertion loss of earmuffs and the sensitivity level of headphones with acoustical test fixtures (ATFs), the required accuracy of an ear simulator is more stringent when the same measurements are performed on intraaural devices. For the evaluation of HPDs, bone conduction plays an important role. We have developed a model to estimate HPD-dependent bone conduction effects. The model includes two bone conduction sources: one in the external ear and one in the middle ear. The model explains, for example, the occlusion effect of HPDs and the masking error at low frequencies due to physiological noise that arises when real-ear attenuation at threshold (REAT) measurements are made. Consequently, objectively measured insertion loss can now be used to predict REAT with improved accuracy. ATF and REAT data are compared using nine earmuffs and nine earplugs. In the majority of cases, the two sets of data agree well. Discrepancies are discussed.

Auditory Threshold↗