Is drug-induced sleep endoscopy associated with better outcomes after soft tissue surgery for sleep apnea? A systematic review and meta-analysis.

OBJECTIVES: The aim was to estimate the effect of drug-induced sleep endoscopy (DISE) on surgical outcomes after soft tissue surgery for obstructive sleep apnea (OSA). DESIGN AND SETTING: Systematic review and meta-analysis. PARTICIPANTS: Adult patients with OSA and candidates for soft tissue surgery, with and without preoperative DISE, were included. MAIN OUTCOMES MEASURES: A systematic literature search of Medline, Web of Science, and Cochrane databases was performed from inception to December 31, 2021. Studies directly comparing patients with and without preoperative DISE were included. Success rate, change in apnea-hypopnea index (AHI), change in minimum SpO2 and change in Epworth Sleepiness Scale (ESS) score were extracted. Random-effect models were used to pool estimates. RESULTS: Seven out of 619 articles were included, representing 791 patients (389 in the DISE group and 402 in the no DISE group). DISE was neither associated with a higher success rate (pooled OR 1.34, 95% CI 0.69-2.59, p = 0.39) after soft tissue surgery for OSA, nor a significant change in AHI (-4.69 events/hour, 95% CI -11.10 to 1.72, p = 0.15), minimal SpO2 (mean increase of 2.02%, 95% CI -0.26 to 4.29, p = 0.08) and ESS (mean difference of 1.29, 95% CI -0.48 to 3.05, p = 0.15) when compared to patients without preoperative DISE. CONCLUSIONS: Soft tissue surgery does not give better results after DISE compared to when DISE is not performed. However, given the overall low level of evidence of included studies, future well-conducted studies should confirm or overturn these results and clarify the added value of DISE.

Surgical, clinical, and functional outcomes of transoral robotic surgery used in sleep surgery for obstructive sleep apnea syndrome: A systematic review and meta-analysis.

We investigated safety and efficacy of transoral robotic surgery (TORS) for base of tongue (BOT) reduction in obstructive sleep apnea syndrome (OSAS) patients. PubMed, Cochrane Library, and Scopus were searched. A meta-analysis was performed. Random effects models were used. Thirty-one cohorts met our criteria (1693 patients). The analysis was based mostly on retrospective studies. The summary estimate of the reduction of Apnea-Hypoxia Index (AHI) was 24.25 abnormal events per hour (95% CI: 21.69-26.81) and reduction of Epworth Sleepiness Scale (ESS) was 7.92 (95% CI: 6.50-9.34). The summary estimate of increase in lowest O2 saturation was 6.04% (95% CI: 3.05-9.03). The success rate of TORS BOT reduction, either alone or combined with other procedures, was 69% (95% CI: 64-79). The majority of studies reported low level of evidence but suggested that TORS BOT reduction may be a safe procedure associated with improvement of AHI, ESS, and lowest O2 saturation.

Is image interpretation in drug-induced sleep endoscopy that reliable?

PURPOSE: Previous studies have assessed drug-induced sleep endoscopy (DISE) as an interobserver reliable exam, with a learning curve effect. The objective was to check its assumed interobserver agreement and variability of between two groups of experienced and inexperienced French ENT physicians. METHODS: Prospective study. Seventy-six French ENT physicians (69 inexperienced in DISE and seven experienced) observed seven DISE videos. They were asked to determine the level(s), the configuration, and the degree of collapse, according to the VOTE classification. Specific and global agreements using the Fleiss' Kappa coefficient (k) were calculated. RESULTS: The interobserver agreement varied from poor to good in determining the level; the best agreement being found for the oropharynx (global agreement = 0.82 and k = 0.6 in the experienced group, global agreement = 0.87 and k = 0.7 in the inexperienced group), followed by the soft palate and the larynx; the worst agreement being found for the tongue base (k = 0.29 in the experienced group and k = 0.38 in the inexperienced group). The agreement for the configuration and the degree of collapse was moderate except for the tongue base where the concordance was poor. In both groups, agreement was at best good without any statistically significant difference between the two levels of experience groups. CONCLUSION: Even in a French ENT Sleep Experts group, DISE appears to be a technique with a limited interobserver agreement in the detection of obstructive sites, without any learning curve effect. In its current state, DISE interpretation may not be totally reliable.

Adult sleep apnea and tonsil hypertrophy: should pharyngoplasty be associated with tonsillectomy?

PURPOSE: Velopharyngoplasty and palatine tonsillectomy are at the very heart of the surgical treatment of obstructive sleep apnea syndrome (OSAS) care. In cases of major tonsil hypertrophy, we evaluated the relevance of associating soft palate surgery with palatine tonsillectomy, independent of the soft palate length. METHODS: We conducted a retrospective single-center study in OSAS patients with grade III or IV tonsils treated with tonsillectomy. Preoperative assessment included an upper airway examination performed while the patient was awake, a polysomnography and a drug-induced sedation endoscopy (DISE). Surgical efficacy was assessed on postoperative polysomnography. Success was considered when the postoperative apnea-hypopnea index (AHI) was less than 20 events/h with a 50% reduction. We compared palatine tonsillectomy efficacy alone (group A) and associated with soft palate surgery (group B). RESULTS: We analyzed 33 patients who had undergone surgery between December 2006 and May 2018. Their preoperative mean BMI and mean AHI were 27.3 ± 7.5 kg/m2 and 38.6 ± 21.4 events/h, respectively. The two groups (A, n = 18 and B, n = 15) were clinically comparable. The success rate was 72.2% in group A and 60% in group B. There was no statistically significant difference between the two groups (p > 0.1). CONCLUSIONS: According to this study, in our institution, in cases of major tonsillar hypertrophy, simultaneous soft palate surgery had no significant impact on the success rate, regardless of soft palate length. Associating soft palate surgery with palatine tonsillectomy does not seem mandatory to increase the success rate. LEVEL OF EVIDENCE: III. Retrospective comparative study.

European position paper on drug-induced sleep endoscopy: 2017 Update.

BACKGROUND: The first edition of the European position paper (EPP) on drug-induced sleep endoscopy (DISE) was published in 2014 with the aim to standardise the procedure, to provide an in-depth insight into the main aspects of this technique and to have a basis for future research. Since 2014, new studies have been published concerning new sedative agents or new insights into the pattern/levels of the obstruction depending on the depth of sedation. Therefore, an enlarged group of European experts in the field of sleep breathing disorders (SBD), including the most of the first DISE EPP main authors, has decided to publish an update of the European position paper on DISE, in order to include new evidence and to find a common language useful for reporting the findings of this endoscopic evaluation in adult population affected by SBD. METHODS: The authors have evaluated all the available evidence reported in the literature and have compared experience among various departments in leading European centres in order to provide an update regarding the standardisation of the DISE procedure and an in-depth insight into the main aspects of this technique. RESULTS: After the first European Position Consensus Meeting on DISE and its update, consensus was confirmed for indications, required preliminary examinations, where to perform DISE, technical equipment required, staffing, local anaesthesia, nasal decongestion, other medications, patient positioning, basics and special diagnostic manoeuvres, drugs and observation windows. So far, no consensus could be reached on a scoring and classification system. However, regarding this aim, the idea of an essential classification, such as VOTE with the possibility of its graded implementation of information and descriptions, seems to be the best way to reach a universal consensus on DISE classification at this stage. A common DISE language is mandatory, and attempts to come to a generally accepted system should be pursued.

Parafoveal and optic disc vessel density in patients with obstructive sleep apnea syndrome: an optical coherence tomography angiography study.

AIMS: To compare optic disc perfusion, radial peripapillary capillaries (RPC) and macular vascular density, between normal subjects and subjects with obstructive sleep apnea syndrome (OSAS) using spectral-domain OCT angiography (OCTA). METHODS: Sixteen eyes of patients with mild OSAS, 17 eyes with moderate OSAS, 20 eyes with severe OSAS on polygraphy and 28 controls were evaluated with OCTA RT XR Avanti (AngioVue software, Optovue Inc., Fremont, CA). Optic nerve head (ONH), RPC and macular vessel density were measured. Clinical data, visual field parameters, and Spectral Domain OCT evaluation (retinal nerve fiber layer (RNFL) thickness and ganglion cell complex (GCC) thickness) were recorded for all patients. RESULTS: ONH vascular flow (p = 0,396), RPC vascular density (automatized data "whole" p = 0,913, "peripapillary" p = 0,539, and segmented analysis with a topographic grid) and macular vascular density (foveal p = 0,484, parafoveal p = 0,491) were not significantly different between the four groups. FDT-Matrix™ and Humphrey 24/2 mean deviation were significantly lower in eyes with severe OSAS and were correlated to the apnea-hypopnea index. Retinal nerve fiber layer (RNFL) thickness, Cup/Disc ratio, rim area, and ganglion cell complex (GCC) were not significantly modified. CONCLUSIONS: OCTA did not detect reduced ONH, RPC, neither macular blood vessel density in eyes with OSAS. The precise mechanisms that link OSAS with optic nerve pathologies remain unclear: our study was not able to demonstrate a vascular impact by OCTA examination.

Are the obstruction sites visualized on drug-induced sleep endoscopy reliable?

PURPOSE: Drug-induced sleep endoscopy (DISE) has been claimed to be a reliable tool, improving surgical results in obstructive sleep apnea syndrome (OSAS). One means of assessing reliability would be to ablate only a part of the sites observed on endoscopy and find only partial success versus ablating all observed sites and finding resolution of apnea. METHODS: A retrospective study included 24 OSAS patients, operated on following awake clinical examination. DISE was performed prior to surgery. Overnight sleep study was performed before and after surgery. Two groups of patients were obtained: success (postoperative apnea-hypopnea index (AHI) <10 and >50 % reduction in preoperative AHI) and failure. Obstruction sites found on DISE and those ablated or left after surgery were compared between the two groups. RESULTS: Mean AHI fell from 30.9 ± 12.4/h to 13.7 ± 14.2/h after surgery. In eight of the 14 patients in the success group, DISE showed an obstruction site not treated by surgery. In six patients out of the ten patients in the failure group, all DISE sites were treated by surgery, which nevertheless was not effective. Four patients had retrovelar concentric obstruction. CONCLUSION: DISE could in some cases explain surgical failure. However, it also seems to show additional obstruction sites which do not need to be treated. Proper knowledge of pharyngeal fluid dynamics and mastery of the DISE technique would probably help us understand better some of the DISE findings.

Long-term results of surgical treatment of vocal fold nodules.

OBJECTIVES/HYPOTHESIS: To evaluate the long-term outcome of patients with vocal fold nodules treated by surgery alone, or by a combination of surgery and voice therapy and to identify factors associated with long-term recurrent dysphonia. STUDY DESIGN: Retrospective study. METHODS: All patients who had undergone surgery for vocal fold nodules in a tertiary care hospital between 1996 and 2006 were contacted. After giving their consent, they were evaluated by videostroboscopic examination of vocal fold nodules and by a subjective questionnaire including the Voice Handicap Index (VHI). RESULTS: Sixty-two out of 90 patients (69%) (60 women, 2 men with a mean age of 33 years) answered the questionnaire at a mean interval of 9.5 years after surgery. Recurrent dysphonia was observed in 19 patients (30%) at a mean interval of 5.2 years after surgery and new benign vocal fold lesions (nodules or Reinke's edema) were observed in 11 patients (18%). Absence of postoperative voice therapy was significantly associated with a higher recurrence rate (P = 0.02) (56% of recurrent dysphonia without voice therapy versus 22% with voice therapy). CONCLUSIONS: Postoperative voice therapy decreases the risk of recurrence. Vocal fold nodules can recur over a period of 5 years, consequently requiring follow-up for at least 5 years in clinical practice and in future prospective studies.

Snoring intensity after a first session of soft palate radiofrequency: predictive value of the final result.

OBJECTIVES/HYPOTHESIS: To determine whether snoring sound intensity measured after a first soft palate radiofrequency (RF) session for simple snoring helps predict the final result of the treatment. STUDY DESIGN: Observational retrospective study. METHODS: We conducted a retrospective review of 105 subjects presenting with simple snoring or mild sleep apnea. All patients underwent two to three sessions of RF-assisted stiffening of the soft palate. In addition, uvulectomy was performed in case of a long uvula, and two paramedian trenches were created in the presence of palatal webbing. Snoring sound intensity was evaluated by the bed partner after each session. RESULTS: Eighty-six men and 19 women were included in the study. Mean age was 51.7 ± 9.8 years, and mean body mass index was 24.7 ± 4.4 kg/m(2) . The mean apnea/hypopnea index was 6.6 ± 4.2/h. The mean snoring sound intensity, as evaluated on a 10-cm visual analog scale (VAS), decreased from 8.2 ± 1.5 to 3.5 ± 2.2 after all sessions (P < .0001). A score of 3 was determined as being a score that satisfied the bed partner. Two groups were formed according to the final snoring sound intensity, using 3 as a threshold. Both groups had similar preoperative characteristics, but the snoring sound intensity was significantly lower after the first session in the group with final score <3 (P = .01). Similarly, a VAS score >7 after the first session was associated with a final score <3 in 30% of the cases. CONCLUSIONS: Snoring sound intensity after the first RF session helps predict the final outcome of RF-assisted stiffening of the soft palate for simple snoring.

Sleep-disordered breathing: choosing the right cephalometric analysis.

PURPOSE: Cephalometry can be helpful for choosing the optimal treatment of sleep apnea. The presence or absence of maxillomandibular retrusion can contribute to the choice of treatment with an oral appliance or a skeleton-based or soft tissue surgery. To measure the position of the maxillomandibular complex, the analysis of Tweed has been cited most often. It uses dental landmarks. The analysis of Delaire relies on deeper skeletal points. The present study compared these 2 analyses for the diagnosis of maxillomandibular retrusion in a context of sleep-disordered breathing by determining the correlation between retrusion and the apnea-hypopnea index (AHI) for both methods. MATERIALS AND METHODS: A retrospective cohort study was conducted in a tertiary care university hospital. The population consisted of patients diagnosed with sleep-disordered breathing for whom polysomnographic and cephalometric data were available. Tweed and Delaire cephalometric analyses were performed for each case. The main outcome was the correlation between the degree of maxillomandibular retrusion and the AHI, as determined by Pearson coefficients. RESULTS: A total of 243 patients (42 females and 201 males) were included. For maxillary retrusion, the correlation coefficient with the AHI was -0.109 (P = .089) for Tweed and -0.160 (P = .012) for Delaire. For mandibular retrusion, the coefficient was -0.090 (P = .16) for Tweed and -0.201 (P = .002) for Delaire. Statistical significance was found only for the analysis of Delaire. CONCLUSION: The correlation between maxillomandibular retrusion and the AHI was better using the analysis of Delaire. If cephalometry is to be included in the workup of sleep-disordered breathing, the analysis of Delaire might be preferable.

Is snoring intensity responsible for the sleep partner's poor quality of sleep?

PURPOSE: This study aimed to determine if the intensity of breathing noise (including snoring) and/or the presence of abnormal breathing events (ABE) are factors that trigger arousal/awakening of a snorer's bed partner. METHODS: We conducted a prospective multicenter study investigating couples where the male had a chronic disturbing snoring. We simultaneously recorded the male's respiration and snoring and the female' sleep. We counted the number of arousals and awakenings during N2 sleep and randomly took nine of each. Then, for periods before, during, and after each arousal and awakening, we observed on the respiratory tracings what was happening in terms of breathing noise intensity and presence/absence of snoring and/or ABE. RESULTS: Thirteen couples were analyzed. The intensity of breathing noise and the presence/absence of snoring and/or ABE were comparable before and at initiation of arousal/awakening and between arousal and awakening. However, breathing volume intensity was lower and the presence of snoring and/or ABE was less frequent when the bed partner returned back to sleep from awakening compared to the other periods (p always <0.001). CONCLUSIONS: The intensity of breathing noise or the presence of ABE does not seem to be essential to trigger an arousal or an awakening. However, the persistence of noise or events may prolong the duration of wakefulness during the sleep period and could be one factor that explains the bothersome snoring.

Does propulsion mechanism influence the long-term side effects of oral appliances in the treatment of sleep-disordered breathing?

BACKGROUND: Mandibular advancement appliances (MAAs) can be used to treat sleep-disordered breathing, and differences in their designs have been thought to influence the occurrence of secondary effects. With bibloc devices, the lateral attachments producing mandibular propulsion can be inserted to generate traction or compression. We evaluated the clinical impact of this difference by comparing the long-term secondary effects and compliance of two devices. METHODS: One hundred sixty-two records of patients fitted with a traction-based or compression-based MAA before January 2008 were reviewed retrospectively for physical examination findings and cephalometry. Patients were sent a postal survey and contacted by phone 2 weeks later. They were offered a follow-up medical visit with repeat cephalometry. Main outcomes were long-term (> 2 years) secondary effects, compliance, or satisfaction. RESULTS: Of the patients who attended the follow-up visit, 48 had worn the MAA for > 2 years (16 traction based and 32 compression based), and nine for < 6 months (used as control subjects). Mean follow-up times for the traction and compression groups were 3.7 ± 1.2 years and 3.6 ± 1.2 years, respectively. No difference was found between the MAAs for subjective and objective side effects, except for greater early pain to the masticatory muscles (P = .02) and residual tongue pain (P = .04) in the compression group. However, pain intensity was low and clinical relevance was uncertain. No difference was found for compliance, satisfaction, and objective or subjective efficacy. CONCLUSIONS: This study suggests that traction-based appliances are similar to compression-based devices with regard to secondary effects and compliance.

The tongue-retaining device: efficacy and side effects in obstructive sleep apnea syndrome.

STUDY OBJECTIVES: The tongue-retaining device is a customized monobloc oral appliance used in the treatment of obstructive sleep apnea syndrome (OSAS). This study evaluated tongue-retaining device efficacy and its tolerance by patients with OSAS. METHODS: The charts of 84 apneic patients were retrospectively analyzed, and patients were contacted by telephone to answer an oral questionnaire. The median follow-up time was 5 years. RESULTS: Based on the apnea-hypopnea index, a complete or partial response was obtained in 71% of the cases. The mean apnea-hypopnea index decreased significantly from 38 to 14 (p < 0.001) with the tongue-retaining device. The subjective intensity of snoring decreased by 68% (p < 0.0001) and the Epworth Sleepiness Scale score decreased from 9 to 6 (p < 0.05). An age of more than 60 years associated with a mandibular protrusion distance inferior or equal to 7 mm was predictive of a nonresponse (odds ratio [OR]: 7.25; 95% confidence interval [CI]: 1.43-36.7; p < 0.02). The compliance rate, as determined by answers to the questionnaire, was 52% after 5 years of follow-up. Nasal obstruction was a negative predictor of good compliance (OR: 6.94; 95% CI: 0.28-0.79; p < 0.005), whereas patients with Class I occlusion were more compliant than patients with Class II or III occlusions (OR: 3.83; 95% CI: 1.00-2.81; p < 0.05). CONCLUSIONS: Tongue-retaining device performance tended to be similar to that of the mandibular advancement device. Thus, teams trained in tongue-retaining device fabrication and fitting may propose it as an alternative to continuous positive airway pressure, taking nasal obstruction into consideration as a contraindication.

Complications/adverse effects of maxillomandibular advancement for the treatment of OSA in regard to outcome.

OBJECTIVE: To evaluate adverse effects/postoperative complications and surgical response rate of maxillomandibular advancement for the treatment of severe obstructive sleep apnea syndrome. STUDY DESIGN: Case series with chart review. SETTING: Otolaryngology Head and Neck Surgery Department in a teaching hospital. SUBJECTS AND METHODS: A total of 59 consecutive severe sleep apnea patients underwent maxillomandibular advancement. Systemic complications were evaluated from medical charts. Functional adverse effects and cosmetic consequences were evaluated by questionnaires. The treatment outcome was assessed by polysomnography. RESULTS: Fifty patients were evaluated. They had a mean age of 46.4 +/- 9.0 years. No serious postoperative complication was observed. The most frequent local complication was mental nerve sensory loss. Most patients reported cosmetic changes. The mean apnea-hypopnea index decreased from 65.5 +/- 26.7 per hour to 14.4 +/- 14.5 per hour (P < 0.0001). Light-sleep stages were also decreased (P < 0.0001), whereas deep-sleep stages were increased (P < 0.001). CONCLUSION: Maxillomandibular advancement can induce local adverse effects and cosmetic changes, but they seem to be considered as secondary to the patients according to the surgical outcome.

Comparative study of four radiofrequency generators for the treatment of snoring.

OBJECTIVE: To compare the efficacy and safety of four radiofrequency generators (Ellman, Select Sutter, Coblator, Somnus) for the treatment of simple snoring. MATERIALS AND METHODS: Multicenter, randomized, prospective single-blind study on 120 selected patients with simple snoring (apnea/hypopnea index <10/h of sleep). Snoring sound intensity was measured on a visual analog scale and the partner's short-term satisfaction rate was evaluated after two treatment sessions maximum. Discomfort, pain, and medication intake were compared. RESULTS: Radiofrequency decreased the snoring sound intensity from 7.9 +/- 1.7 to 4.4 +/- 2.7 (P < 0.0001). The four radiofrequency generators had a statistically comparable efficacy. The Ellman generator caused less discomfort and required less anti-inflammatory drugs. CONCLUSION: Despite different technical characteristics, the four generators had a comparable efficacy with good safety. The Ellman generator induced the least discomfort.

Radiofrequency tongue reduction through a cervical approach: a pilot study.

OBJECTIVE/HYPOTHESIS: The objective of this prospective cohort study was to determine the feasibility, safety, and efficacy of radiofrequency tongue base reduction through a cervical approach in patients with obstructive sleep apnea syndrome (OSAS). METHODS: Patients with moderate to severe OSAS and predominant tongue base obstruction by physical examination were included at our institution from 1999 to 2003. A sonogram was obtained to identify the lingual arteries, and an electrode was inserted through the neck and into the tongue under fluoroscopic guidance. Adverse events were recorded as well as efficacy on snoring (visual analog scale), daytime sleepiness (Epworth score), and polysomnography. RESULTS: The 10 patients received a mean of 14,288 +/- 3,251 J per session. No cases of tongue palsy or infection occurred. During the first 7 days, mean pain score (0-10 scale) was 1.3 +/- 1.5. Snoring volume (0-10 scale) decreased from 6.2 +/- 2.3 to 3.9 +/- 2.6 (P = .017) and sleepiness (0-24 scale) from 8.7 +/- 5.6 to 4.7 +/- 3.3 (P = .011). The respiratory disturbance index (events/hour) decreased from 52.0 +/- 19.6 to 33.6 +/- 24.4 (P = .016). Mean minimal oxygen saturation (%) increased from 64.2 +/- 13.0 to 75.8 +/- 10.3 (P = .003). Sleep architecture improved although not significantly. CONCLUSION: Radiofrequency tongue base reduction through a cervical approach proved feasible and safe despite the large energy doses used. Fluoroscopic guidance enables to place the electrode at the desired site of treatment. Although OSAS improved in nine of 10 patients, greater efficacy might be achieved in patients with less severe OSAS at baseline. Studies are needed to correlate objective clinical efficacy with the dose per lesion site and the number of lesion sites per session.

Sleep disorders in childhood-onset myotonic dystrophy type 1.

Slowness, fatigue, and learning difficulties are common in young patients with myotonic dystrophy type 1. These features may indicate poor sleep quality. The aim of this study was to search for sleep disorders in this population. This prospective study used questionnaires, genetic testing, night-time polysomnography and multiple sleep latency tests to evaluate objective daytime sleepiness. Twenty-one patients were included. Mean age was 15.0+/-3.0. Age of onset of myotonic disorders was after birth and before 10 years old. Age of diagnosis was 12.0+/-2.9. Fatigue was reported by 76% of patients, while somnolence was present in 52%. Sleep was disturbed by numerous microarousals (mean 16.6+/-7.3/h of sleep) caused by abnormal respiratory events (6/21 patients) and/or periodic limb movements (8/21 patients). In young patients with DM1, complaints of fatigue and/or somnolence should lead to a polysomnography to look for sleep apnea syndrome and/or periodic limb movement, which were present in two-thirds of our population.

Radiofrequency in the treatment of craniofacial plexiform neurofibromatosis: a pilot study.

BACKGROUND: Neurofibromatosis type 1 manifests itself by the development of plexiform neurofibromas, with craniofacial deformities caused by bone alterations and soft-tissue infiltration. The medical treatment of this disease is disappointing, and the surgical management of these deformities calls for aggressive procedures. There is a strong risk of recurrence. METHODS: A pilot study was performed to test radiofrequency as a minimally invasive method with which to diminish the size of craniofacial neurofibromas either as an adjunct to craniofacial surgery (in cranio-orbital neurofibromas) or to avoid a visible scar in young patients (in infraorbital neurofibromas). Five patients ranging in age from 6 to 18 years were treated by three procedures 2 months apart using radiofrequency performed under local anesthesia or under sedation for the youngest patients. RESULTS: The tolerance of the treatment was excellent, with no major side effects and no pain in the postoperative course. A diminution of the size of the lesion was noted clinically in four patients and on computed tomography in two patients. A biopsy performed in one case illustrated the effect of the treatment. CONCLUSIONS: A partial diminution or stabilization of plexiform neurofibromas may be obtained using radiofrequency. This treatment is well tolerated. The best effect can be observed in the early stages of the disease. The optimal dose and frequency of the procedure require further study.

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.

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.