BACKGROUND AND OBJECTIVES: An essential part of the successful application of a cochlear implant is to adjust the stimulation levels to the patient's dynamic range. To test the subjective behavioral threshold (T-level) and the most comfortable loudness level (C-level), however, it may be troublesome or even impossible in very young children who are not able to perform such tasks appropriately. Therefore, utilization of objective measurements is important in children to estimate T- and C-levels. One of the objective measurements is the electrically evoked stapedial reflex (ESR) test. It has also been suggested that ESR may have applicability in confirming and quantifying electrical stimulation through a cochlear implant. The purpose of this study is to examine the feasibility of utilizing ESR to test device function during cochlear implant surgery and to predict ultimate behavioral T- & C-levels. MATERIALS AND METHODS: The ESR measurements were performed in 18 subjects during a cochlear implant surgery. Eight subjects received the Nucleus 22 multichannel cochlear implant (CI 22M) and 10 subjects received Nucleus 24 multichannel cochlear implant system (CI 24M). To test the ESRs, three electrodes, namely, apical electrode (E20), medial electrode (E12) and basal electrode (E5), were stimulated in each case. ESR thresholds were measured by visual observation of the stapedius muscle contraction in response to electrical stimulation delivered to the auditory nerve via a cochlear implant system. And the ESR thresholds were compared with the behavioral T- and C-levels in each electrode. RESULTS: ESRs were presented in 19/23 electrodes (82.6%) in subjects who received the CI 22M and 26/30 electrodes (86.7%) in subjects with CI 24M. The mean ESR threshold was the lowest in apical electrodes (E20) in both groups. In subjects with CI 22M, ESR thresholds were significantly correlated with behavioral T- and C-levels in apical electrodes (E20). In subjects with CI 24M, ESR thresholds were highly correlated with the C-levels in E5, E12, and E20. CONCLUSION: ESR provides an objective, accurate and rapid method to evaluate the device function during cochlear implant surgeries and in estimating T-/C- levels, which may be useful in the initial programming of younger children and the difficult-to-tests.
Child ; Cochlear Implantation* ; Cochlear Implants* ; Cochlear Nerve ; Electric Stimulation ; Electrodes ; Humans ; Muscle Contraction ; Reflex* ; Stapedius

OBJECTIVE: Compare the clinical characteristics and application value between elcetrically evoked stapedius responses and neural response telemetry. METHOD: Select number 1, 7, 11, 17, 22 electrodes from 21 cochlear implanting nucleus 24R cochlear implants, using NRT3.0 software provided by Cochlear corporation to test the threshold of elcetrically evoked stapedius responses and neural response telemetry during operation and subjective psychological physical test after operation repectively named elcetrically evoked stapedius responses threshold, electrically evokded compound aciton potentials threshold, and T-levels. Respectively study the correlations of ESRT, ECAP threshold, and T-levels. RESULT: The detection rates of ESRT, NRT, and T-levels were 96.19%, 93.33%, 100%. The mean thresholds of ESRT were 206.61 +/- 10. 74, 208.48 +/- 13.64, 205.52 +/- 14. 63, 203.76 +/- 12.97, 199.50 +/- 11.19; The mean thresholds of NRT were 184.11 +/- 6.35, 188.55 +/- 11.70, 187.00 +/- 12.29, 181.85 +/- 13.22, 179.00 +/- 10.50; The mean thresholds of T levels were 145.48 +/- 18.66, 148.62 +/- 8.22, 146.62 +/- 18.08, 142.52 +/- 13.11, 140.33 +/- 13.68. The mean thresholds of ESRT in each electrode were rather greater than that of T-levels. There is a high degree of consistency in the mean thresholds of ES RT, NRT and T-levels. The test time, test means, unilaterally detection rate during operation, ESR is better than NRT. All the electrodes were set as observation objects, the correlation of ESRT and NRT is 0.69, the correlation of NRT and T is 0.62, and the correlation of ESRT and T is 0.39. CONCLUSION The application of elcetrically evoked stapedius responses and neural response telemetry during operation can rapidly estimate wether the implant is in good condition and the pathway is normal. Rather than neural response telemetry, elcetrically evoked stapedi us responses is more flexible, convienient, accurate and visual, while it is more objective superiority after operation especially for young children for the former detector.
Child ; Child, Preschool ; Cochlear Implantation ; Evoked Potentials, Auditory ; Female ; Hearing ; Humans ; Infant ; Male ; Monitoring, Intraoperative ; methods ; Stapedius ; physiology ; Telemetry

Oculostapedial synkinesis following Bell's palsy, Ramsay Hunt syndrome and traumatic facial nerve paralysis is a rarely reported phenomenon. Oculostapedial synkinesis accompanying with hemifacial spasm also has been reported. We experienced a 51-year-old woman with persistent loud rumbling noise from her left ear related with voluntary left eye closure compatible with oculostapedial synkinesis after Bell's palsy. We objectively proved this oculostapedial synkinesis with impedance audiometry. The patient was successfully treated by transmeatal tenotomy of the left stapedius muscle tendon under local anesthesia.
Acoustic Impedance Tests ; Anesthesia, Local ; Bell Palsy* ; Ear ; Facial Nerve ; Female ; Hemifacial Spasm ; Herpes Zoster Oticus ; Humans ; Middle Aged ; Noise ; Paralysis ; Stapedius ; Synkinesis* ; Tendons ; Tenotomy

OBJECTIVETo investigate and measure the electrically evoked stapedius reflex threshold (ESRT) and the maximum comfortable level (MCL), the feasibility of using objective index of the fitting of speech processor was evaluated.

METHODSThe relationship of ESRT and MCL was conducted by measuring the ESRT and MCL of 28 Medel Combi 40 + cochlear implant users from August 2003 to April 2006.

RESULTSThe incidence of ESRT of 10 patient during operation was 78.3% (94/120), and the incidence 3 months after the operation was 82.5% (99/120). The incidence of ESRT in 3 patients with Large vestibular aqueduct syndrome was 47.2% (17/36). The ESRT and MCL of each electrode of those 28 patients after operation were compared, the result was shown as following: (1) 247 electrodes' MCL were greater than ESRT; (2) 14 electrodes' MCL were equal to ESRT; (3) 46 electrodes' MCL were smaller than ESRT. The average of ESRT after operation was (677.1 +/- 109.8) cu, the average of MCL was (732.3 +/- 114.8) cu. ESRT was smaller than MCL (t = 11.37, P < 0.05).

CONCLUSIONSThe cochlear implantations must be in normal working condition when ESR was positive. ESRT is a useful method to map the fitting of speech processor.

Adolescent ; Adult ; Auditory Threshold ; Child ; Child, Preschool ; Cochlear Implantation ; Cochlear Implants ; Female ; Humans ; Infant ; Male ; Reflex, Acoustic ; physiology ; Stapedius ; physiology ; Young Adult

Otologic complaints, including otalgia, tinnitus, vertigo, and hearing loss, are known to be related to temporomandibular disorders (TMDs). There have been several hypotheses regarding the clinical correlation between otologic complaints and TMDs, based on clinical phenomena with corresponding symptoms, the close neurological relationship between otic and masticatory structures, and anatomical features of the tympanic cavity and jaw joint. Function of the tensor tympani muscle seems to be crucial to understanding TMD-related otologic symptoms. The tensor tympani inserts into the handle of the malleus and it modulates sound transduction in situations of excessive noise. This muscle is innervated by the trigeminal nerve, like the masticatory muscles. Voluntary eardrum movement by pathological tensor tympani contraction results in various otologic symptoms. Thus, co-contraction of the tensor tympani with the masticatory muscle could be a possible cause of TMD-related otologic symptoms. The tensor tympani is rather unrelated to the acoustic reflex, in which the stapedius is strongly involved. The tensor tympani seem to be controlled by proprioceptive information from the trigeminal sensory nucleus. The peripheral innervation pattern of the tensor tympani and masticatory muscles is also supposed to be interconnected. The middle ear structure, including the malleus, incus, and tensor tympani, of mammals had been adapted for acoustic function and lacks the masticatory role seen in non-mammalian jawed vertebrates. The tensor tympani in non-mammals is one of the masticatory muscles and plays a role in the modulation of sound transduction and mastication. After the functional differentiation of the mammalian middle ear, the nervous connection of the tensor tympani with other masticatory apparatus still remains. Through this oto-stomatognathic vestige, the tensor tympani seems to contract unnecessarily in some pathological conditions of the TMD in which the masticatory muscles contract excessively. We hypothesized that the phylogenic relationship between the tensor tympani and masticatory apparatus is a significant and logical reason for TMD-related otologic complaints.
Acoustics ; Ear, Middle ; Earache ; Hearing Loss ; Incus ; Jaw* ; Joints ; Logic ; Malleus ; Mammals ; Mastication ; Masticatory Muscles ; Noise ; Reflex, Acoustic ; Stapedius ; Temporomandibular Joint Disorders ; Tensor Tympani* ; Tinnitus ; Trigeminal Nerve ; Tympanic Membrane ; Vertebrates ; Vertigo

There is little or no information about the distribution of elastic fibers in the human fetal head. We examined this issue in 15 late-stage fetuses (crown-rump length, 220-320 mm) using aldehyde-fuchsin and elastica-Masson staining, and we used the arterial wall elastic laminae and external ear cartilages as positive staining controls. The posterior pharyngeal wall, as well as the ligaments connecting the laryngeal cartilages, contained abundant elastic fibers. In contrast with the sphenomandibular ligament and the temporomandibular joint disk, in which elastic fibers were partly present, the discomalleolar ligament and the fascial structures around the pterygoid muscles did not have any elastic fibers. In addition, the posterior marginal fascia of the prestyloid space did contain such fibers. Notably, in the middle ear, elastic fibers accumulated along the tendons of the tensor tympani and stapedius muscles and in the joint capsules of the ear ossicle articulations. Elastic fibers were not seen in any other muscle tendons or vertebral facet capsules in the head and neck. Despite being composed of smooth muscle, the orbitalis muscle did not contain any elastic fibers. The elastic fibers in the sphenomandibular ligament seemed to correspond to an intermediate step of development between Meckel's cartilage and the final ligament. Overall, there seemed to be a mini-version of elastic fiber distribution compared to that in adults and a different specific developmental pattern of connective tissues. The latter morphology might be a result of an adaptation to hypoxic conditions during development.
Adult ; Capsules ; Cartilage ; Connective Tissue ; Ear Cartilage ; Ear Ossicles ; Ear, Middle ; Elastic Tissue ; Fascia ; Fetus ; Head ; Humans ; Joint Capsule ; Laryngeal Cartilages ; Ligaments ; Muscle, Smooth ; Muscles ; Neck ; Pterygoid Muscles ; Stapedius ; Temporomandibular Joint Disc ; Tendons ; Tensor Tympani