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Biomedical subjects

Bruno Frachet

Publications and source records attributed to Bruno Frachet.

5 recordsLinked to original sources

Tongue mechanical characteristics and genioglossus muscle EMG in obstructive sleep apnoea patients.

The increased genioglossus muscle (GGm) activity seen in obstructive sleep apnoea syndrome (OSAS) may lead to increased fatigability or longer recovery time of the tongue. Maximal force, endurance, and recovery times of the tongue, electromyogram (EMG) absolute value, and EMG spectral analysis of the GGm obtained during submaximal contractions were compared in eight individuals without chronic snoring and eight OSAS patients. Endurance time values were not significantly different between the two groups (P = 0.40). Time to recovery of initial maximal force was significantly greater in the OSAS group (P = 0.01). Final EMG median frequency was significantly higher (P = 0.01) and the final low-frequency EMG component smaller in the OSAS patients (P = 0.02). Patients did not have changes in endurance time or fatigability but had longer recovery times and changes in spectral analysis variations. This functional investigation may be helpful in determining the presence of OSAS and the potential contribution of the tongue to pharyngeal obstruction.

Adult↗

A middle ear implant, the Symphonix Vibrant Soundbridge: retrospective study of the first 125 patients implanted in France.

OBJECTIVE: The Vibrant Soundbridge is an active semi-implantable middle ear implant for the rehabilitation of patients with a sensorineural hearing loss who are not able to derive adequate benefit from conventional hearing aids. A retrospective study was performed to assess the overall level of satisfaction of implanted patients and to investigate the potential determinants of postoperative success. STUDY DESIGN: A retrospective survey of audiological data from repeated measures and subjective data from self-assessment scales administered postoperatively was conducted to determine the degree of benefit and satisfaction for Vibrant Soundbridge implantees. SETTING: Twenty-one tertiary referral and teaching hospitals. SUBJECTS: The first 125 VSB implantees implanted in France between August 1997 and May 2001 were included in the study. RESULTS: No clinically significant change was observed for residual hearing postoperatively. Most patients (83%) reported they were either satisfied or very satisfied with the Vibrant Soundbridge. Analysis of correlation revealed a moderate correlation (Pearson coefficient r = 0.59) between the degree of benefit reported via the patient survey and the degree of benefit reported via the Glasgow Benefit Inventory. A moderate correlation (Pearson coefficient r = 0.66) was observed between speech comprehension scores in quiet for the preoperative unaided condition and the postoperative aided Vibrant Soundbridge condition. No correlation was observed between subjective reports of satisfaction postoperatively and performance on preoperative objective tests or patient characteristics. CONCLUSION: The results indicate a high level of satisfaction with the VSB as a treatment of sensorineural hearing impairment in patients with a wide range of characteristics. Preoperative scores for unaided speech comprehension tests in quiet may be a potential indicator of success on aided Vibrant Soundbridge speech comprehension tests postoperatively but do not reflect patient satisfaction with the device reported on self-assessment scales.

Adult↗

Genioglossal electromyogram during maintained contraction in normal humans.

Knowledge of the fatigability of the genioglossus muscle is of interest because this muscle prevents pharyngeal collapse, especially during sleep. In the present investigation, signs of fatigue in the genioglossus muscle were studied by measuring the tongue endurance using a force transducer and electromyographic (EMG) activity of the genioglossus muscle in eight nonapnoeic men. Mean absolute EMG values and spectrum analysis were calculated at three levels of submaximal effort. Median frequency and the force:mean absolute EMG value ratio were independent of force level (F = 0.37, P = 0.93; F = 0.35, P = 0.94, respectively) but dependent on effort duration (F = 52, P < 0.0001; F = 16, P < 0.0001). Force:mean absolute EMG value and logarithmic median frequency decreased linearly with respect to time and were similar at the three force levels when time was expressed as a percentage of total test time (F = 0.37, P = 0.93). The decrease in median frequency was ascribable to a larger increase in low- than in high-frequency components, as shown by the significant decrease in the high-frequency:low-frequency ratio (F = 27, P < 0.0001) with time. The method of investigation used in this study allowed detection of the behaviour of the tongue during fatigue and, therefore, should be useful in disorders where mechanical failure of the tongue is suspected, such as the sleep apnoea syndrome or in neuromuscular disorders.

Adult↗