Simultaneous sleep study and nasoendoscopic investigation in a patient with obstructive sleep apnoea syndrome refractory to continuous positive airway pressure: a case report

<p>Abstract</p> <p>Introduction</p> <p>The standard treatment for obstructive sleep apnoea syndrome is nasal continuous positive airway pressure. In most cases the obstruction is located at the oropharyngeal level, and nasal continuous positive airway pressure is usually effective. In cases of non-response to nasal continuous positive airway pressure other treatments like mandibular advancement devices or upper airway surgery (especially bi-maxillary advancement) may also be considered.</p> <p>Case presentation</p> <p>We report the case of a 38-year-old Caucasian man with severe obstructive sleep apnoea syndrome, initially refractory to nasal continuous positive airway pressure (and subsequently also to a mandibular advancement devices), in which the visualization of the upper airway with sleep endoscopy and the concomitant titration of positive pressure were useful in the investigation and resolution of sleep disordered breathing. In fact, there was a marked reduction in the size of his nasopharynx, and a paresis of his left aryepiglotic fold with hypertrophy of the right aryepiglotic fold. The application of bi-level positive airway pressure and an oral interface successfully managed his obstructive sleep apnoea.</p> <p>Conclusion</p> <p>This is a rare case of obstructive sleep apnoea syndrome refractory to treatment with nocturnal ventilatory support. Visualization of the endoscopic changes, during sleep and under positive pressure, was of great value to understanding the mechanisms of refractoriness. It also oriented the therapeutic option. Refractoriness to obstructive sleep apnoea therapy with continuous positive airway pressure is rare, and each case should be approached individually.</p

The consolidation of implicit sequence memory in obstructive sleep apnea

Obstructive Sleep Apnea (OSA) Syndrome is a relatively frequent sleep disorder characterized by disrupted sleep patterns. It is a well-established fact that sleep has beneficial effect on memory consolidation by enhancing neural plasticity. Implicit sequence learning is a prominent component of skill learning. However, the formation and consolidation of this fundamental learning mechanism remains poorly understood in OSA. In the present study we examined the consolidation of different aspects of implicit sequence learning in patients with OSA. We used the Alternating Serial Reaction Time task to measure general skill learning and sequence-specific learning. There were two sessions: a learning phase and a testing phase, separated by a 10-hour offline period with sleep. Our data showed differences in offline changes of general skill learning between the OSA and control group. The control group demonstrated offline improvement from evening to morning, while the OSA group did not. In contrast, we did not observe differences between the groups in offline changes in sequence-specific learning. Our findings suggest that disrupted sleep in OSA differently affects neural circuits involved in the consolidation of sequence learning

An anisotropic elastoplastic model for soft clays

An anisotropic elastoplastic model for soft clays is presented. Experimental data from multistage drained triaxial stress path tests on Otaniemi clay from Finland provide support for the proposed shape of the yield curve and for the proposed relationship describing the change of yield curve inclination with plastic straining. Procedures are proposed for determining the initial inclination of the yield curve and the values of the two additional soil constants within the model. Comparisons of model simulations with experimental data demonstrate significant improvements in the performance of the new model over the Modified Cam Clay model. The remaining discrepancies are mainly attributable to the important role of destructuration in the sensitive Otaniemi clay

Efeitos da pressão positiva contínua em vias aéreas sobre os sintomas nasofaríngeos em pacientes com a síndrome da apnéia obstrutiva do sono Effects of continuos positive airway pressure on nasal and pharyngeal symptoms in patients with obstructive sleep apnea

INTRODUÇÃO: Sintomas nasofaríngeos são comuns em pacientes com a síndrome da apnéia obstrutiva do sono (SAOS) em tratamento com pressão positiva contínua em vias aéreas (CPAP). No entanto, sintomas nasofaríngeos são também comuns em pacientes com SAOS antes do início do tratamento. OBJETIVO: Determinar o impacto do tratamento com CPAP nasal sobre os sintomas nasofaríngeos em pacientes com SAOS. MÉTODO: Foram avaliados 35 pacientes (28 homens), com idade de 54 ±10 anos portadores de SAOS moderada a grave diagnosticada através de polissonografia. Os sintomas nasofaríngeos (espirros, coriza, prurido, obstrução, sangramento e ressecamento nasal e de garganta) foram quantificados através de questionário aplicado antes e depois de pelo menos 3 meses de tratamento com CPAP nasal. RESULTADOS: O índice de apnéia + hipopnéia foi de 50±25 eventos por hora. Ao menos um sintoma nasofaríngeo estava presente em 26 pacientes (74%) antes do tratamento. A obstrução nasal foi o sintoma mais comum, presente em 18 pacientes (51%). Dentre os pacientes inicialmente assintomáticos (n = 9), 78% apresentaram alguma reação nasofaríngea adversa com o tratamento. Em contraste, nos pacientes inicialmente sintomáticos, houve redução significativa da intensidade da obstrução, do ressecamento nasal e de garganta e do sangramento nasal após o tratamento. CONCLUSÃO: Sintomas nasofaríngeos são freqüentes em pacientes com SAOS. O uso de CPAP pode tanto desencadear sintomas nasofaríngeos em pacientes assintomáticos, como reduzir sua intensidade nos pacientes com sintomas prévios.<br>BACKGROUND: Nasal and pharyngeal symptoms are common in patients with obstructive sleep apnoea (OSA) treated with nasal continuous positive airway pressure (CPAP). However, these symptoms are common in OSA patients even before the treatment. OBJECTIVE: Determine the impact of nasal CPAP on nasal and pharyngeal symptoms in OSA patients. METHOD: Thirty-five adult patients (28 males), age 54±10 years old, with OSA diagnosed by polissonography. All patients answered to a questionnaire about the presence and quantification of sneezing, rhinorrhea, nasal pruritus, obstruction and bleeding, nasal and pharyngeal dryness. The questionnaire was answered before and after at least three months of CPAP therapy. RESULTS: The apnea-hypopnea index was 50±25 events per hour. Twenty six patients (74%) presented at least one naso-pharingeal symptom before treatment. Nasal obstruction was the most common symptom, being referred by 18 patients (51%). Among the patients that were initially assymptomatic (n=9), 78% developed adverse nasal reactions to CPAP. In contrast, among the patients that presented nasal symptoms before treatment, there was a significant reduction in nasal obstruction, nasal and throat dryness scores as well as nasal bleeding after CPAP therapy. CONCLUSION: Nasal na pharyngeal symptoms are frequent in OSAS patients. CPAP therapy may originate nasal symptoms in patients previously assymptomatic, as well as reduce the intensity of these symptoms in patients that are previously symptomatic