Type III tympanoplasty with titanium total ossicular replacement prosthesis: anatomic and functional results.

OBJECTIVE: To evaluate anatomical and functional results using titanium prostheses in cartilage palisade tympanoplasties. STUDY DESIGN: Retrospective clinical study. Data were collected from patients' charts and clinical review. SETTING: Tertiary referral center. INTERVENTION: Cartilage tympanoplasty with titanium total ossicular replacement prosthesis after tympanoplasty or tympanomastoidectomy in patients operated on between July 1998 and February 2006. MAIN OUTCOME MEASURES: Anatomical results (closure of the perforation, rate of retraction pockets, recurrent cholesteatoma, and extrusion and re-perforation rates) were clinically evaluated. Pure-tone averages of air and bone conduction were analyzed. A postoperative air-bone gap (ABG) of 20 dB or less was taken to represent successful hearing.The hearing outcomes of canal wall up (CWU), canal wall down (CWD), primary and revision surgeries, and 2 groups of a short-term (<12 mo) or long-term (>24 mo) follow-up (f-u) were assessed and compared. RESULTS: Ninety-four cases were observed during the visiting period: 43 (45.7%) underwent primary procedures and 51 (54.3%) underwent revision surgeries. Closure of the tympanic membrane was achieved in 98.9%.Postoperative ABG was 20 dB or lower in 62 (66%) of 93 cases, between 11 and 20 dB in 33 cases (35%), and 10 dB or lower in 29 cases (31%).All cases undergoing CWU had a mean +/- SD postoperative ABG of 14.59 +/- 11.28 dB. There were no statistically significant differences (independent-samples t test, p = 0.5) between these patients and those receiving CWD surgery (15.95 +/- 10 dB).Thirty-eight (68%) of 56 CWD and 24 (64%) of 37 CWU cases achieved a postoperative ABG between 0 and 20 dB (chi = 0.08, p = 0.7, correlation = 0.031).Thirty-three (64.7%) of 51 who underwent revision surgeries and 29 (69%) of 42 who underwent primary procedures had a postoperative ABG between 0 and 20 dB. The difference between the groups was not significant (chi = 0.3, correlation = 0.058, p = 0.5).The mean ABG in the short f-u group was 12.38 +/- 7.34. There was no significant difference regarding long-term f-u after 24 months (11.76 +/- 8.9; Wilcoxon signed-rank test, p = 0.7).We compared the mean postoperative ABG in low hearing frequencies (500 and 1,000 Hz) and high hearing frequencies (2,000 and 4,000 Hz). A better sound transmission was achieved in high frequencies (10.32 +/- 10.6 versus 20.61 +/- 13.73 dB, respectively); the difference was statistically significant (p < 0.001, paired-samples t test). CONCLUSION: Our results suggest that tympanoplasty with titanium total ossicular replacement prosthesis reconstruction offers a stable improvement of the ABG less than 20 dB in 66% of cases, in both short-term and long-term f-u. There were no differences in the results between CWU and CWD or between primary and revision surgery. The titanium prosthesis achieves the best acoustical results for sound transmission at high frequencies (2,000 and 4,000 Hz).

Activation patterns of the primary auditory cortex in normal-hearing subjects: a functional magnetic resonance imaging study.

CONCLUSIONS: These results demonstrate that functional magnetic resonance imaging (fMRI) is an optimal tool to investigate the auditory cortex. The study suggests that there is a medio-lateral gradient of responsiveness to high frequencies medially and low frequencies laterally. The contralateral auditory cortex is more responsive than the ipsilateral cortex to tones presented monaurally. OBJECTIVES: To demonstrate the activation of the primary auditory cortex in normal-hearing subjects using fMRI and to examine the response and topographic location of activation in the human auditory brain to stimulation with two different frequencies in a large group of volunteers. SUBJECTS AND METHODS: Scanning was performed on a 1.5 Tesla MR with head gradient coils and a birdcage radiofrequency coil. Multiplanar echo-planar images were acquired in 32 subjects aged between 18 and 49 years. Two groups were defined, according to age (group A, 18 to <35 years old; group B, 35 to <50 years old). We studied normal-hearing subjects scanned while listening to auditory stimuli: narrative text in one volunteer and non-speech noise (pure tones 750 Hz and pure tones 2 KHz) in all subjects. RESULTS: For both tone frequencies, auditory activation was observed bilaterally across the supratemporal plane in 29 of the 32 subjects (90.62%) with a probability level of p<0.001. In Heschl's gyrus (HG) contralateral to the stimulated ear, the extent of activation was generally greater than in homolateral HG. There were no statistical differences in HG activation according to age or sex. The 750 Hz tone activated more voxels in the medial area of the transverse temporal gyrus (TTG) whereas the 2000 Hz tone activated more voxels in the lateral TTG.