Changes of Vestibulo-Ocular Reflex and Its Relation with Auditory functions in Chronic Renal Failure Patients Receiving Hemodialysis / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Sensorineural hearing loss and vestibular dysfunction are frequently found in patients receiving hemodialysis with chronic renal failure (CRF). However, the responsible etiologic factors, prevalence, relationship between auditory and vestibular dysfunction still remains unclear. The purpose of this study is to assess vestibular dysfunction and to investigate the relation between changes in vestibulo-ocul ar reflex (VOR) and auditory dysfunction in CRF patients receiving hemodialysis. MATERIALS AND METHODS: Thirty-five patients (70 ears) receiving hemodialysis with chronic renal failure were selected. Pure tone audiometry, monothermal caloric test, and velocity step rotation test were performed to assess the audio-vestibular function of the patients. Thirty normal controls were selected for comparison of vestibular function tests. RESULTS: Twenty-four (34%) out of 70 ears had pure tone average (PTA) of 25dBHL or more. The average peak velocity of caloric test and the value of slow cumulative eye position (SCEP) of velocity step test in the patient group were 18.7+/-10.5 d/sec and 376.9+/-170.0 degree, respectively. These values were significantly different from those of normal controls whose average peak velocity of caloric test and SCEP values of velocity step test were 25.3+/-6.0d/sec and 586.3+/- 207.3 degree, respectively(p<0.05). The results of caloric test and velocity step test in the patients with PTA of 25dBHI, or more were 10.2+/- 6.0 d/sec and 224.5+/-143.0 degree, respectively, while those of the patients with PTA of less than 25dBHL were 22.7+/-9.7 d/sec and 437.9+/-140.5 degree, respectively. These two groups showed a statistically significant difference(p<0.05). CONCLUSION: The patients under hemodialysis with CRF exhibited reduced vestibular function compared to normal control group.

Monitoring by ABR, TEOAE and DPOAE of Noise Induced Hearing Loss in Guinea Pig / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Noise-induced hearing loss (NIHL) is associated with the damage in outer hair cell (OHC). Otoacoustic emmision (OAE) is sensitive to the detection of damage in OHC. We intended to evaluate the usefulness of transient evoked OAE (TEOAE) and distortion product OAE (DPOAE) on early detection and monitoring of NIHL in guinea pigs. MATERIALS AND METHODS: Ten healthy guinea pigs were exposed to 90+/-3 dBA white noise 8 hours daily for 9 days. Daily measurements of auditory brainstem response (ABR), TEOAE and DPOAE were performed before the noise exposure and daily after the noise exposure. RESULTS: ABR threshold became poorer gradually until the 8th day of post noise exposure, and some recovery on the 9th day. Wave reproducibility on TEOAE demonstrated an abrupt decrement on the 6th post-exposure day, and a tendency of recovery from the 7th day. While the echo amplitudes in f2=2002 Hz and f2=4004 Hz showed similar pattern of change with ABR threshold, the echo amplitude of f2=6348 Hz showed marked decrease on the 5th day compared to two other frequencies (f2=2002 Hz, 4004 Hz). CONCLUSION: The results of this study suggest that wave reproducibility in TEOAE and echo amplitude in high frequency in DPOAE may have applicability for early detection and monitoring of NIHL.

A Case of Posterior Skull Base Adenocarcinoma Metastasized from The Prostate / 대한이비인후과학회지

Metastatic tumor of the skull base is uncommon. Diagnosis of the tumor is difficult without any associated evidence of another malignancy. It is distinguished from other benign or primary malignant tumor by rapid progression of symptoms, associated neurologic signs, and lytic or infiltrative lesion in imaging work-up study. Recently authors experienced one case of a posterior skull base adenocarcinoma metastasized from the prostate. Patient's initial complaints were hoarseness and aspiration due to vocal cord paralysis. He also complained of longstanding headache. On examination he had multiple cranial nerve paralyses of CN VII, VIII, X, XI, and XII. Radiologic study showed diffuse skull base lesion. Transmastoid biopsy revealed adenocarcinoma. With thorough examination a prostatic mass was found and proved to be the origin of the metastatic adenocarcinoma after transurethral biopsy. The patient was treated with "Flutamide".