The Relationship between Thresholds of Electrically Evoked Compound Action Potential and Speech Perception in Children with Cochlear Implants / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Neuropathology around the cochlea could create variation from site to site in physiological thresholds of cochlear implant users. This variability would be detrimental to speech recognition with a cochlear implant for a variety of reasons, including distortion of the place code and variation in the number of neurons. The purpose of this study is to examine the relationship between thresholds of electrically evoked compound action potential (ECAP) and speech perception in children implanted with the Nucleus Freedom devices. SUBJECTS AND METHOD: Fifty-seven children implanted with the Nucleus Freedom device participated in this study. ECAP thresholds were recorded using the automated neural response telemetry test protocol. We then calculated mean threshold and three metrics to assess across-site variation within subjects: 1) the variance of T levels for all tested sites, 2) the range of T levels (highest minus lowest) across all tested sites and 3) site-to-site variation. For each subject, these measures were compared with performance on tests of word recognition. RESULTS: There was considerable across-site (within-subject) and across-subject variability in thresholds. However, we found no significant correlation between speech recognition and across-site variation of thresholds as well as mean threshold levels. CONCLUSION: These data suggest that the ECAP measures of thresholds may not be an accurate predictor of speech perception ability.

Two Cases of Middle Ear Adenoma with Neuroendocrine Differentiation (Carcinoid Tumor) / 대한이비인후과학회지

Middle ear adenoma with neuroendocrine differentiation (carcinoid tumor) is a rare benign tumor of the tympanic cavity. Carcinoid tumor is generally derived from primitive stem cells in the gut wall but can be seen in other organs, including the lungs, mediastinum, thymus, liver, pancreas, bronchus, ovaries, prostate, and kidneys. This is unusual considering neuroendocrine cells have not been identified in normal or inflamed middle ear mucosa. Carcinoid tumor of the middle ear represents a class within the spectrum of adenomatous neoplasms. Immunohistochemical techniques have helped clarify that these tumors all share elements of neuroendocrine differentiation. Although histologic and biological similarities with middle ear adenoma exist, carcinoid tumor of the middle ear should be classified as a well-differentiated neuroendocrine carcinoma because the carcinoid tumor has higher rate of recurrence and incidence of metastasis than middle ear adenoma. Surgical management is the recommended treatment and long-term observation is necessary.

The Relationship between Electrically Evoked Compound Action Potential and Speech Perception in CI24RE Implant Users / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Since performance with a cochlear implant is negatively correlated with an individual's duration of deafness prior to implantation, neural survival may be an important factor in determining outcome. To date, studies relating physiological measures such as the threshold and growth of the electrically evoked potentials have not shown clear relationships to human speech perception abilities, although there are positive results correlating these measures to nerve survival in animals. The primary goal of this study was to determine the extent to which the growth functions of electrically evoked compound action potential (ECAP) are related with speech perception performance in recent CI24RE implant users and to investigate the relationship between ECAP growth function and performance according to more limited electrodes. SUBJECTS AND METHOD: We measured ECAP growth functions to biphasic pulses using reverse neural telemetry system in 21 CI24RE implant users. For each subject, the slope of the growth function was compared with speech perception tests. In addition, this measure was also evaluated for a more limited set of electrodes. RESULTS: Significant correlations have been found between the slope of ECAP growth functions and speech performance in CI24RE implant recipients. In addition, a relatively strong correlation has been found between the slope of ECAP growth function and performance on word recognition test in the group of basal electrodes. CONCLUSION: Effectiveness of the cochlear implant can be quite variable. These results show that ECAP measure may be useful in developing a test for predicting the outcomes of using the implant.

Retraction: The Relationship between Electrically Evoked Compound Action Potential and Speech Perception in CI24RE Implant Users / 대한이비인후과학회지

No abstract available.

A Case Report: Recurrent Intravenous Leiomyomatosis / 대한산부인과학회잡지

Intravenous leiomyomatosis is an uncommon uterine tumor characterized by the growth of histologically benign smooth muscle initially into venous channels within the broad ligament, intrauterine, and iliac vein, and can extend to inferior vena cava, and right side of the heart. Intravenous leiomyomatosis is always grossly visible as worm-like plugs within the involved vessels. A 41-year-old woman presented with lower abdominal mass, and she had undergone total abdominal hysterectomy and left salpingoophorectomy for leiomyoma of uterus. On pathological examination it was diagnosed as intravenous leiomyomatosis. 16 month later, She was admitted with lower abdominal mass on retroperitoneal cavity. The patient was successfully treated by resection of recurred mass and right salpingoophorectomy. A case of recurrent intravenous leiomyomatosis is presented with a brief review of literatures.