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Results for “TENSOR TYMPANI”

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PubMedDate not supplied

Suppressed sneezing as a cause of hearing loss and vertigo.

Two cases of inner ear injury caused by suppressed sneezing are described. One patient experienced vestibular symptoms in the form of reflexogenic vertigo that was relieved by surgical section of the tensor tympani tendon. The other patient had a sudden severe permanent sensorineural hearing loss. It is proposed that the aerodynamic pressure increase associated with suppressed sneezing is transmitted via the eustachian tube to cause an implosive fistula of either the round or oval window with injury to the membranous labyrinth.

Adult↗
PubMedDate not supplied

Middle ear muscle activity during speech in stapedectomized and laryngectomized subjects.

Middle ear muscle responses associated with speech production were observed in normal-hearing, stapedectomized, and laryngectomized subjects. Impedance changes associated with speech production were monitored by an electroacoustic impedance bridge simultaneously with vocal output. Results from stapedectomized subjects indicate that the tensor tympani muscle contracts prior to vocalization and is part of the neurological pattern of speech production. Data collected from laryngectomized subjects suggest that the presence of sensory fibers from the larynx is not a prerequisite for middle ear muscle activity during speech production.

Adolescent↗
PubMedDate not supplied

Observations on simultaneous perilymphatic motions and cochlear microphonics suppression.

Very low frequencies interfere in the intact cochlea with higher frequencies and suppress these depending on the vibration phase of the low-frequency sound. Physiological functions of the body, mediated, for example, by the eardrum or perilymph coupling with the cerebrospinal fluid, cause a low-frequency pressure modulation of the perilymph, which generates a synchronous perilymphatic motion resulting from the unevenly distributed compliances in the cochlea. This slow streaming causes a displacement of the entire basilar membrane, with as a consequence a postponement of the operating point of the mechanoelectrical transducer as a result of the pressure drop in the helicotrema and the narrow apical cochlear turn. In this contribution, interference phenomena are described, which are caused by spontaneous contractions of the tensor tympani muscle and by respiration-synchronous perilymphatic flow. These two test signals have trapezoidal and triangular impulse functions. In both cases, as suppression pattern of the cochlear microphonics level-time function, the second derivative of the pressure-time function was observed. The suppression is found to lie between 1 and 2 dB. It depends on the level of the suppressed sound and shows a compressive nonlinearity.

Acoustic Stimulation↗
PubMedDate not supplied

Effects of reflex middle-ear muscle contractions on cochlear responses to bone-conducted sound.

The effects of contralaterally elicited middle-ear muscle (MEM) reflexes on cochlear microphonic responses to air- and bone-conducted tones were examined in decerobrate cats. Stapedius effects on bone condn air conduction were almost identical in configuration and amplitude to those on air conduction at all frequencies. However, tensor tympani effects were more complex, the configuration of the bone-conduction effects varying with the location of the transducer on the skull and with frequency. The relative contributions of the two muscles to the effects of joint contractions varied markedly between animals. It is suggested that non-reflex MEM contractions associated with activity of the facial musculature might provide protection against masking of environmental sounds by the low-frequency bone-conducted sound generated by such activity.

Air↗
PubMed1987

[Position and position variations of the canal system of the temporal bone in frontal section].

Estimated are: 1. The axis of the internal acoustic meatus to the horizontal plane in adults and postnatal changes. 2. Eight coronal sections of the temporal bone have been selected to localize the canal systems and structures in the petrous part of the temporal bone and their variations. 3. Described are the different parts of the facial canal, the carotic canal, the auditive tube, the tensor tympani muscle, the major petrosal nerve, and its distances to the carotic canal, the cochlea, the internal acoustic meatus, the supra- and infracochlear cells, the fenestra vestibuli, the fossa jugularis, the canaliculus cochleae, the vestibulum and the semicircular canals. This report includes the development of the supravestibular and other mastoideal cells in the neighbourhood of the canal systems of the petrous bone and the vestibular aqueduct and sac. Estimated are also the distances between the different canal systems. 4. The investigations are discussed with our earlier researches and the results of other researchers and its diagnostic in clinical importance.

Adolescent↗
PubMedDate not supplied

Malleus handle probe: a middle ear diagnostic procedure.

Manual probing of the malleus handle (MH) of 477 patients suggests a protective middle ear reflex with a variable tonic contraction of the tensor tympani muscle (TTM). The degree and type of MH retraction suggests three stages of progressive middle ear inflammation. Prediction accuracy of 250 myringotomy findings was 60% with impedance audiometry and 92% with MH probing. Mechanical pressure gauge readings (grams) of 202 ears correlated with finger pressure estimations. The TTM tendons were sectioned in ten children with persisting otitis media with effusion (OME) and seven obtained benefit. The three diagnostic methods, pneumatic otoscopy, impedance audiometry and MH probing, assess similar and separate perimeters and are complementary. Malleus handle probing alone detects attic loculation of OME, 54 of 954 ears (5.6%). it extends the diagnostic range to the TTM activities.

Adolescent↗
PubMed1972

Spontaneous middle ear muscle activity in man: a rapid eye movement sleep phenomenon.

Changes in compliance of the tympanic membrane have been detected in normal human sleep, presumably due to spontaneous contraction of the stapedius and tensor tympani muscles of the middle ear. In the waking state, these muscles generally respond to loud sound (middle ear reflex). Middle ear muscle activity typically erupts before or at the onset of rapid eye movement (REM) sleep and persists throughout the REM period in a discontinuous pattern resembling that exhibited by rapid eye movements. Approximately 80 percent of all nocturnal middle ear muscle activity is contained in REM sleep. Half of the remaining 20 percent occurs in the 10-minute intervals just prior to the onset of REM sleep. Middle ear muscle activity is often associated with other phasic events such as momentary enhancement of electromyogram inhibition, apnea, and K complexes. Rapid eye movements and middle ear muscle activity, though significantly correlated in REM sleep, are not always simultaneous.

Adult↗
PubMed1986

The acoustic middle ear muscle reflex in albino rats.

The acoustic middle ear muscle reflex was studied in albino rats anesthetized with chloralose. The best frequency of the reflex and the threshold at this frequency were on average about 3 kHz and 57 dB SPL, respectively. The threshold increased as frequency increased above, and decreased below, the best frequency at a rate of about 20 dB/octave. Above about 12 kHz, the muscular response showed instability and habituation. Thresholds were similar between stapedius and tensor tympani reflexes and between ipsilateral and contralateral reflexes. The middle ear transmission loss due to the reflex was the greatest and nearly constant below about 1 kHz, where the loss was about 18 dB at the maximal stimulation. Above this frequency the loss decreased as frequency increased up to 20 kHz. Thus the reflex, unlike that in other animals, suppressed transmission over the whole range of reflex-eliciting frequencies. The transfer function of the reflex had a well damped low-pass characteristic with a cut-off frequency of about 20 Hz. From the above characteristics of the reflex, the role of the rat's tympanic muscles in improving ultrasonic hearing under ambient noises was suggested.

Animals↗
PubMed1988

Indications of a differentiated regulation of sound transmission by the middle ear muscles of the rat.

Measurement of the middle ear muscle reflex is an important tool in audiologic examination; however, the precise function of the tensor tympani and stapedius muscle is not fully understood. The function of the middle ear muscles in speech discrimination and noise-induced hearing loss is the main object of our study. Morphologic and enzyme-histochemical properties of the middle ear muscles of the rat indicate a complex, fine-tuned function of the middle ear muscles. Both middle ear muscles are merely composed of relatively small fast-twitch fibers. Almost all fibers possess an enzymatic profile that allows aerobic as well as anaerobic metabolism. The innervation of the muscles is extensive, and motor end plates are well developed. In a parallel study, middle ear muscle contraction (to be analyzed by electromyography) will be correlated with a change of the sound transmission characteristics of the middle ear (measured by the electrocochlear and brainstem auditory evoked responses). Preliminary results of the electrophysiologic measurements (electrocochleogram and brainstem auditory evoked response) are presented.

Acetylcholinesterase↗
PubMed1985

Number and distribution of stapedius motoneurons in cats.

Cell bodies of stapedius motoneurons were identified by retrograde transport of horseradish peroxidase (HRP) following injections into the stapedius muscle. Large injections were made in an attempt to label all stapedius motoneurons. To control for labeling of non-stapedial neurons resulting from spread of HRP, we determined the locations of brainstem neurons labeled by HRP applied to the facial nerve, the chorda tympani nerve, the auricular branch of the vagus nerve, the tensor tympani muscle, and the cochlea. In three cats analyzed in detail, 1,133-1,178 neurons projecting to the stapedius muscle were identified. Arguments are given which suggest that in these three cats all stapedius motoneurons were labeled. The labeled stapedius neurons may all be motoneurons because they all stain positively for acetylcholinesterase and have medium-coarse Nissl bodies. Most stapedius motoneurons were located around the motor nucleus of the facial nerve. Staphedius motoneurons were also found near the descending limb of the facial-nerve root, in the peri-olivary neuropil, and in the reticular formation with the ascending fibers of the facial-nerve root.

Animals↗
PubMed1988

Surgical anatomy of the anterior epitympanic space.

The structure of the anterior epitympanic space was examined in 16 temporal bones. The space showed three different structural types. In all three types the posterior boundary of the space was marked by a bony plate jutting downward and covered by a mucous membrane. No anterior boundary was found in type A (19%), the space being continuous to a widened eustachian tube orifice. In type B (31%), the space was anteriorly bounded by a mucosal fold that continued to the tensor tympani fold. In type C (50%), the space assumed the shape of a bulge extending into the bony structure and sealed at the bottom by the tensor fold. The ear surgeon is advised to be familiar with the structure of the anterior epitympanic space before intervening to remove cholesteatoma or create an anterior ventilation route.

Adult↗
PubMed1985

[Morphogenesis of the cranium of Cavia porcellus L. I: Introduction, classification and descriptive part].

The craniogenesis of Cavia porcellus has been investigated in 7 embryos of different ages. From the developmental stage of 36 mm CRL, a reconstruction of the chondrocranium is described. As there is still a gap in the tectum posterius, the foramen magnum is not closed posteriorly. The course of the notochord is retrobasilar at the beginning, more rostrally it runs intrabasilar. After ossification, the place where the notochord enters the basioccipital is marked by a cavity. This cavity is not identical with the posterior basicranial fenestra. The laminae alares build up strong paracondylar processes. The auditory capsule is connected with the occipital region only by the exoccipitocapsular commissure, but there is no supraoccipitocapsular commissure. The fossa subarcuata is pierced by a subarcuate foramen. The very short lamina parietalis is not in contact with the orbital wing as there is no orbitoparietal commissure. The processus recessus divides the perilymphatic foramen into fenestra rotunda and aquaeductus cochleae. The suprafacial commissure arises from the upper margin of the canalicular part of the auditory capsule, but it does not reach the superior surface of the cochlear part at this stage. The tegmen tympani is well developed. The foramen singulare is not yet separated from the inferior acoustic foramen. At the stage of 36 mm CRL there is no septum spirale cartilagineum. Mm. tensor tympani et stapedius are developed in the typical way. The auditory capsule is connected with the basal plate by the anterior basicochlear and the alicochlear commissures. The floor of the orbitotemporal region is incomplete, the temporal wings are small. The alicochlear commissure, the alar process, the anterior basicochlear commissure, and the basal plate surround the carotid foramen, but there is no blood vessel passing through it. The temporal wing is at the beginning of ossification and shows a fissura ovalis for the mandibular nerve. Although the hypophysial canal is still present, there are no structures passing through it. There is no foramen rotundum. The orbital wing is still cartilagineous. The basal plate and the pre- and postoptic roots border the optical foramen. The straight muscles of the eyeball are attached to the ala hypochiasmatica which projects from the postoptic root. The interorbital septum is absent. The ophthalmic artery, which instead of the obliterated internal carotid artery, contributes to the circulus arteriosus cerebri is well developed. There is no orbitonasal commissure . The epiphanial foramina are present.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1975

["Typical" and "atypical" damages of the organ of hearing from the administration of streptomycin].

Two areas of the damage localization in the organs of hearing after streptomycin use were found in the experiments with guinea pigs, i.e. (1) the Corti's organ of the lower part of the basal helix, the zone of perception of the maximum frequency sounds and (2) the tympanic muscles. Administration of streptomycin subcutaneously in a daily dose of 300 mg/kg for 50 days resulted in pronounced atrophic changes in the fibres of m. tensor tympani and some atony of m. stapedius. On the basis of the histological examination of the tympanic muscles after prolonged use of streptomycin and comparison of the periods of the tonus reduction in the skeletal muscles and Preier reflex after a single administration of streptomycin in maximum tolerating doses, it was concluded that streptomycin affected the state of the tympanic muscles as a myorelaxant. The atrophic changes in the tensor as a result of prolonged streptomycin use was due to chronic atony of the muscle. The decrease in the contraction capacity of the tensor must result in loosening of the drum membrane tension, impairement of the muscle activity coordination, decreased ability for elimation of the auditory ossicle fluctuation. Increased audibility limits within middle and low frequencies and noise in the ears during prolonged treatment of patients with streptomycin may be associated with chronic atony of the tympanic muscles and mainly tensor.

Animals↗
PubMed1992

[Anatomy of the auditory tube: CT scan and MRI aspect].

The auditory tube is a bony and cartilaginous canal which connects the middle ear to the nasopharynx. The bony portion (protympanum), explored by computed tomography, is cone shaped, with a posterior base. The main relations are: the intrapetrous carotid, the tensor tympani muscle, the middle cerebral fossa and temporo-mandibular joint. The fibrocartilaginous portion is explored by computed tomography and mainly by magnetic resonance. The fibrocartilaginous tube is posteromedial; its upper margin is curled outward to form the roof of the cartilaginous tube. Anterioly and Laterally, the auditory tube is closed by a fibrous membrane extending along the inferior surface of the auditory tube to form its floor. The auditory tube is in contact with two main muscle: the tensor veli palatini anterolateral and the levator veli palatini posterolateral and inferior. They are bounded by fascia: the intrapharyngeal fascia is medial, the pharyngo basilar fascia (salpingopharyngeal fascia of Trölstch, is between the tensor and levator veli palatini muscles; the fascia of Weber Liel is lateral to the tensor veli palatini. The auditory tube and its muscles form the lateral wall of the rhinopharynx and prevent the extension of a pathologic process to the para pharyngeal and infratemporal spaces.

Eustachian Tube↗
PubMed1975

Trisomy 18. A temporal bone report.

Since Edwards first described the trisomy 17-18 syndrome in 1960, the findings in the temporal bones of only four patients with this condition have been reported. They varied widely, ranging from a normal temporal bone, to severe malformations of both the middle and inner ear structures. This study describes the temporal bone findings in a patient with this syndrome. Many of the abnormalities described previously were present as well as the following unreported findings: complete bony atresia of the external canal, an aberrant tensor tympani muscle that did not insert into the malleus but rather attached to a dehiscent area in the Fallopian canal, wide short utricular and saccular ducts, and a widely patent cochlear aqueduct. There was also a developmental arrest of the membranous structures within the cochlea that probably occurred during the 12th week of fetal life.

Autopsy↗
PubMed1982

Ganglia and ganglion cells in the middle ear. Their presence in the human and the cat.

One hundred human and 100 cat temporal bones were studied for the presence of ganglia and/or ganglion cells. These structures were found at the following two main locations: (1) the promontory wall, both anterior to and below the stapes, and (2) the vertical portion of the facial nerve. In the cat, additional ganglion cells were found within the capsule of the musculus tensor tympani, proximal, medial, and lateral to muscle fibers. The consistent presence of ganglion cells in the mucoperiosteum suggests that they play important roles in the middle ear itself; their presence in the vertical portion of the facial nerve supports the concept that the parasympathetic innervation of the parotid gland is not exclusively via the ninth nerve and/or lends anatomical support to atypical facial pains.

Animals↗
PubMed1986

Metastatic seminoma of the temporal bone.

Temporal bone metastasis of classic testicular seminoma is extremely rare in the English literature. Except for a clinical case report of seminoma in the temporal bone, to our knowledge there is no temporal bone pathology report of secondary seminoma. In the left temporal bone of the present case, tumor cell infiltration was found in the external auditory canal, tympanic membrane, middle ear cavity, tympanic and mastoid mucosa, tensor tympani muscle, and so on.

Adult↗
PubMed1983

The anatomy of the eustachian tube in the rat: a macro- and microscopical study.

The rat eustachian tube (ET), from the nasopharyngeal orifice to the tympanal orifice, is about 4.5 mm long, of which the naso-medial membranous part (the nasopharyngeal orifice) measures about 1.5 mm and the occipito-lateral bony portion about 3 mm. The nasopharyngeal orifice is surrounded by two soft, lip-like, mucosal swellings--one ventral and one cranial--both easily mobile. The muscles related to the tubal opening mechanisms are the salpingopharyngeus, the tensor veli palatini and the levator veli palatini muscles. The salpingopharyngeus muscle originates partly from the cranial lip, whereas the palatal muscles originate partly from the ventral lip. The tympanal two thirds of the mucosal lining of the ET is cranially guided by a cartilage and incompletely framed by bony structures. The tympanal orifice is situated in the nasal part of the medial wall, well above the floor of the bulla. The tensor tympani muscle does not seem to take part in the opening and closing mechanisms of the ET. The mucosal lining of the ET consists of a respiratory epithelium with numerous glands in the lamina propria. It is suggested that the tubal muscles control the passage through the ET by moving the lip-like folds of the nasopharyngeal orifice. The anatomy of the rat ET is comparable to that described in Homo and it can be concluded that the rat ET might be a good model for studying the function of the human ET.

Animals↗