Objective measurement of subjective tinnitus using the acoustic change complex.

At present, there is no objective method for diagnosing subjective sensorineural tinnitus. Recently, the acoustic change complex (ACC) has been used to evaluate neural detection of sounds. Thus, the present study aimed to examine whether the ACC can reflect cortical detection and discrimination of sounds matched with tinnitus frequencies. We hypothesized that the ACC to change stimuli matched with tinnitus frequencies would be decreased in tinnitus patients because the tinnitus interferes with the perception of acoustic changes. To test the hypothesis, 96 ears of normal-hearing (NH) tinnitus patients and controls were tested. Among the tinnitus patients, 33 ears with a tinnitus frequency of 8 kHz constituted the tinnitus group, and the remaining 63 ears with no experience of tinnitus were allocated to the control group. For the 4 kHz non-tinnitus matched frequency, a subset of tinnitus (n = 17) and NH (n = 47) subjects was tested. The acoustic stimuli were pure tones with a total duration of 500 ms consisting of a 1 kHz tone in the first 250 ms and a second tone of either 8 kHz or 4 kHz in the latter 250 ms. The normalized amplitude of the ACC (naACC) was calculated separately for the amplitude of the N1'-P2' complex evoked by an 8 kHz or 4 kHz change stimulus and for the amplitude of the N1-P2 complex elicited by the initial 1 kHz background stimulus. Our results showed that the naACC to an 8 kHz stimulus in the tinnitus group was significantly smaller than those to 4 kHz and 8 kHz in normal controls. Additionally, in the tinnitus group, the naACC to 4 kHz was greater compared to 8 kHz. The receiver operating characteristic (ROC) curve analysis conducted for naACC to 8 kHz at UCL revealed a fair degree of diagnostic efficacy. Overall, our results indicated that the ACC to a change stimulus matched with the tinnitus frequency can provide an objective measure of frequency-specific tinnitus.

Transbuccal sonographic evaluation of the local extent of tumors of the tongue with pathological correlation.

PURPOSE: The object of this study was to evaluate the usefulness of preoperative transbuccal ultrasound (US) for the evaluation of tongue tumors. Thus, we evaluated the correlation between preoperative US measurements and postoperative pathologic measurements of tongue tumor size. METHODS: From January 2003 to March 2011, 29 patients with tongue tumors were evaluated. All patients underwent preoperative transbuccal US at 1 day before surgery. Preoperative US was compared with pathology findings, including specimen size. The maximum anterior-posterior (AP) diameter of the long axis of the tumor, the maximum width (WD), and the maximum thickness (TH) of the tumor were measured with US along with a pathologic evaluation of the specimens. RESULTS: The mean AP was 22 ± 1 mm; WD was 13 ± 6 mm, and TH was 10 ± 5 mm using US. The pathologic mean AP was 21 ± 12 mm; WD was 12 ± 6 mm, and TH was 9 ± 4 mm. The Spearman's correlation coefficients of the AP, WD, and TH were 0.905 (p < 0.001), 0.918 (p < 0.001), and 0.971 (p < 0.001), respectively. CONCLUSIONS: Transbuccal US is a useful tool for predicting tongue tumor extent.

Skull base osteomyelitis following a mastoidectomy.

Skull base osteomyelitis is a rare but life-threatening condition that is characterized by osteitis of the temporal bone and skull base. Although skull base osteomyelitis is recognized as a rare complication of malignant external otitis or middle ear infection, it may also occur following a mastoidectomy. We present a case of an 81-year-old woman who suffered severe otalgia with normal-looking EAC and tympanic membrane that developed six weeks following a canal wall up mastoidectomy. Otalgia was the only abnormal feature to suspect occurrence of skull base osteomyelitis.