The relationship between round window and ear canal Cochlear microphonic.

Hypothesis: Cochlear microphonic recorded at ear canal (CM-EC) can be a substitute for the one recorded at round window (CM-RW). Background: Almost all clinics do not measure tone-burst evoked CM due to technical difficulty although it can provide more information than click evoked CM. Moreover, clinicians like the CM-EC more than that measured at CM-RW because CM-EC is non-invasive. There is difference between CM-RW and CM-EC, for example, CM-EC is less prominent than CM-RW, therefore, studying tone-burst evoked CM-EC and its relationship with CM-RW are highly significant and can promote the clinical application of CM-EC. Method: Nine guinea pigs were randomly allocated into three groups, group 1 was not exposed to noise, called normal control. group 2 and group 3 were exposed to the low- (0.5-2 kHz) and high-frequency band-noise (6-8 kHz) at 120 dB SPL for 1 h, respectively. It was difficulty to record low-frequency CM due to severe environmental interruption, in current study the recording technology of tone-burst evoked CM was optimized so that tone-burst evoked CM was measured across full speech frequency (0.5-8 kHz) in the presence of normal hearing and noise induced hearing loss (NIHL). Results: CM-RW and CM-EC were successfully recorded across speech frequency. Significant reduction in CM amplitude was observed at 0.5 and 2 kHz in group 2, at 6 and 8 kHz in group 3 as compared to group 1, p < .05, indicating that CM amplitude was sensitive to band-noise exposure. Significant correlation between CM-RW and CM-EC was also verified, p < .05. Conclusion: CM-EC is a useful objective test for evaluation of hearing function; the result of current study supports the clinical application of non-invasive CM-EC.

Optimizing the Measurement of 0.5-kHz Cubic Distortion Product Otoacoustic Emission.

BACKGROUND: The measurement of low-frequency cubic distortion product otoacoustic emission, for example, 0.5-kHz cubic distortion product otoacoustic emission, is often severely affected by background noise, and currently 0.5-kHz cubic distortion product otoacoustic emission is not commonly applicable in clinical setting. METHODS: The fundamental part of current study was the optimization of recording technology to reduce noise interference with the measurement of 0.5-kHz cubic distortion product otoacoustic emission and to establish the response patterns of cubic distortion product otoacoustic emission across speech frequencies from 0.5 to 8kHz in the presence of normal hearing and noise-induced hearing loss. RESULTS: After a series of optimization, a clinically applicable technology of measuring 0.5-kHz cubic distortion product otoacoustic emission was successfully completed via animal model. Cubic distortion product otoacoustic emission was recorded in 6 guinea pigs across speech frequencies from 0.5 to 8kHz before and after exposure to white bandnoise between 0.5 and 2 kHz. After noise exposure, significant reduction in the signal-to-noise ratio of cubic distortion product otoacoustic emission was found at 0.5 and 2 kHz, indicating our recording technology was sensitive and accurate. Other interesting finding was the reduction in cubic distortion product otoacoustic emiss ion-s ignal -to-n oise ratio at 4 and 6 kHz although the reduction was not statistically significant probably because of short exposure time. The result implied that the damaging effect induced by low-frequency noise exposure might spread upward to high-frequency region. CONCLUSIONS: Our recording technology was stable and reliable and had the great potentiality to be used in clinical setting.

A Review of Posterior Fossa Lesions.

Posterior fossa lesions can occur in patients of all ages. Patients present with subtle findings of hearing loss, tinnitus, headache, cranial neuropathies, imbalance, vertigo, nausea, and vomiting depending on the location and type of lesion. The presentation can be particularly insidious as the most common symptom is slowly progressive hearing loss. Posterior fossa lesions should be included in the differential diagnosis for patients with this presentation and appropriate audiologic testing and imaging should be performed. Management involves collaboration between multiple subspecialties and has evolved significantly over the years leading to increased patient involvement and improved outcomes.

Muscle-Nerve-Muscle Grafting for Facial Reanimation in Rats.

OBJECTIVE: Facial paralysis is a devastating condition leaving patients with a myriad of aesthetic and functional consequences. Muscle-nerve-muscle (MNM) neurotization is a reinnervation technique that involves implanting an autogenous nerve graft as a conduit between an innervated "donor" muscle and a denervated "recipient" muscle. We investigated the use of MNM reinnervation, alone or in combination with electrical stimulation (ES) and testosterone propionate (TP) in comparison to nerve reanastomosis (RE), on functional recovery following rat facial nerve injury. METHODS: Thirty-one male, Sprague-Dawley rats were assigned to groups: no graft (control), MNM grafting alone (MNM), MNM grafting with ES and TP (MNM+ES+TP), or RE. Harvested right facial nerve branches were used as the MNM graft. Functional recovery was assessed by behavioral observations and electromyographic recordings. RESULTS: The MNM grafting improved muscle tone and vibrissae movement. The ES+TP treatment further enhanced muscle tone as well as reduced recovery time for coordinated movement in a manner that is comparable to those of RE. Electromyographic recordings demonstrated electrical conductance across all MNM grafts. CONCLUSION: These data have important implications for patients with unilateral paralysis from facial or laryngeal nerve injury, particularly those who are not candidates for nerve reanastomosis.

Neoplastic causes of nonacute facial paralysis: A review of 221 cases.

We conducted a retrospective review to assess the clinical presentation of patients with tumor-related nonacute complete peripheral facial weakness or an incomplete partial facial paresis and to provide an algorithm for the evaluation and management of these patients. Our study population was made up of 221 patients-131 females and 90 males, aged 14 to 79 years (mean: 49.7)-who had been referred to the Facial Nerve Disorders Clinic at our tertiary care academic medical center over a 23-year period with a documented neoplastic cause of facial paralysis. In addition to demographic data, we compiled information on clinical signs and symptoms, radiologic and pathologic findings, and surgical approaches. All patients exhibited gradual-onset facial weakness or facial twitching. Imaging identified an extratemporal tumor in 128 patients (58%), an intratemporal lesion in 55 patients (25%), and an intradural mass in 38 (17%). Almost all of the extratemporal tumors (99%) were malignant, while 91% of the intratemporal and intradural tumors were benign. A transtemporal surgical approach was used in the 93 intratemporal and intradural tumor resections, while the 128 extratemporal lesions required a parotidectomy with partial temporal bone dissection. The vast majority of patients (97%) underwent facial reanimation. We conclude that gradual-onset facial paralysis or twitching may occur as a result of a neoplastic invasion of the facial nerve along its course from the cerebellopontine angle to the parotid gland. We caution readers to beware of a diagnosis of "atypical Bell's palsy."

Grading Facial Nerve Function Following Combined Static and Mimetic Surgical Techniques.

Objective To present a grading scale to assess the functional recovery of the facial nerve in patients who have undergone mimetic and static surgical techniques for facial reanimation. Study design This is a proposed new facial nerve grading system that will be demonstrated with specific case presentations. All patients underwent a variety of neural grafting, microvascular free-flap reconstruction, or surgical static procedures. Results The proposed facial nerve grading scale is one that has not been described previously in the literature and is applicable to a unique patient population. Its ease of use in this patient population will allow otolaryngologists to assess facial recovery accurately and quickly in cases where the facial nerve is not anatomically intact. Conclusion The proposed facial recovery grading scale provides an efficient means of grading facial recovery for a unique group of patients who previously could not be followed. The proposed scale is practical and easy to use in a clinical setting.

The Envoy Esteem implantable hearing system.

This article discusses the Envoy Esteem implantable hearing system, a completely implantable hearing device. The device is indicated for patients older than 18 years with stable moderate to severe sensorineural hearing loss and good speech discrimination. The device is placed through an intact canal wall tympanomastoidectomy with a wide facial recess approach. The implant is typically activated at 6 to 8 weeks postoperatively and usually requires several adjustments for optimal performance. The sound processor/battery lasts 4.5 to 9.0 years and can be replaced through a minor outpatient procedure.

Postlaryngectomy dysphagia masking as velopharyngeal insufficiency: a simple solution for an anterior neopharyngeal diverticulum.

Postlaryngectomy dysphagia is a common occurrence and can be a source of emotional distress that results in a decrease in quality of life among a patient population that is already exposed to considerable morbidity. One etiologic source that is less commonly reported as a source for postlaryngectomy dysphagia, and perhaps overlooked, is an anterior neopharyngeal diverticulum. Herein, we describe a postlaryngectomy dysphagia caused by a neopharyngeal diverticulum masking as velopharyngeal insufficiency of liquids. The liquid dysphagia was immediately relieved via transoral endoscopic approach using the Harmonic scalpel to resect and simultaneously coagulate the posterior wall.