Brazilian Thoracic Association Consensus on Sleep-disordered Breathing.

Sleep is essential for the proper functioning of all individuals. Sleep-disordered breathing can occur at any age and is a common reason for medical visits. The objective of this consensus is to update knowledge about the main causes of sleep-disordered breathing in adult and pediatric populations, with an emphasis on obstructive sleep apnea. Obstructive sleep apnea is an extremely prevalent but often underdiagnosed disease. It is often accompanied by comorbidities, notably cardiovascular, metabolic, and neurocognitive disorders, which have a significant impact on quality of life and mortality rates. Therefore, to create this consensus, the Sleep-Disordered Breathing Department of the Brazilian Thoracic Association brought together 14 experts with recognized, proven experience in sleep-disordered breathing.

Prevalence of upper airway resistance syndrome in the São Paulo Epidemiologic Sleep Study.

OBJECTIVE: To establish the prevalence of upper airway resistance syndrome (UARS) according to different diagnostic criteria and evaluate its epidemiological characteristics in a representative sample of a large urban center. METHODS: This was a single-center evaluation involving volunteers from EPISONO, an epidemiological study focused on sleep disturbances and related factors in adults from São Paulo, Brazil in 2007. RESULTS: Considering the diagnostic criteria for UARS to be an apnea-hypopnea index of <5 events/h, minimum SpO2 ≥ 92%, the presence of airflow limitation during sleep for ≥5% of total sleep time, and daytime symptoms (sleepiness and/or fatigue), we observed a prevalence of the condition of 3.1% (4.4% in women and 1.5% in men). CONCLUSIONS: Although the diagnostic criteria for UARS, or even its existence as a syndrome, are still a subject of debate in the literature, the findings from this epidemiological study highlights UARS as a non-hypoxic sleep-disordered breathing condition with a significant prevalence in the general population, being more frequent among female young adults.

Brazilian Thoracic Association Consensus on Sleep-disordered Breathing / Consenso em Distúrbios Respiratórios do Sono da Sociedade Brasileira de Pneumologia e Tisiologia

ABSTRACT Sleep is essential for the proper functioning of all individuals. Sleep-disordered breathing can occur at any age and is a common reason for medical visits. The objective of this consensus is to update knowledge about the main causes of sleep-disordered breathing in adult and pediatric populations, with an emphasis on obstructive sleep apnea. Obstructive sleep apnea is an extremely prevalent but often underdiagnosed disease. It is often accompanied by comorbidities, notably cardiovascular, metabolic, and neurocognitive disorders, which have a significant impact on quality of life and mortality rates. Therefore, to create this consensus, the Sleep-Disordered Breathing Department of the Brazilian Thoracic Association brought together 14 experts with recognized, proven experience in sleep-disordered breathing.

RESUMO O sono é essencial para o adequado funcionamento de todos os indivíduos. Os distúrbios respiratórios do sono ocorrem em todas as faixas etárias, constituindo motivo frequente de consulta médica. O objetivo deste consenso foi atualizar os conhecimentos sobre os principais distúrbios respiratórios do sono tanto na população adulta quanto na pediátrica, com ênfase na apneia obstrutiva do sono. A apneia obstrutiva do sono é uma doença extremamente prevalente, porém frequentemente subdiagnosticada. Associa-se frequentemente a uma série de comorbidades, notadamente cardiovasculares, metabólicas e neurocognitivas, que impactam significativamente na qualidade de vida e na mortalidade. Por conta disso, o Departamento de Distúrbios Respiratórios do Sono da Sociedade Brasileira de Pneumologia e Tisiologia reuniu 14 especialistas com reconhecida e comprovada experiência em distúrbios respiratórios do sono para a elaboração deste documento.

Long term oral appliance therapy decreases stress symptoms in patients with upper airway resistance syndrome.

STUDY OBJECTIVES: To evaluate the long-term effects of a mandibular advancement device (MAD) on stress symptoms and cognitive function in patients with upper airway resistance syndrome (UARS) compared with placebo. METHODS: This study was a randomized placebo-controlled clinical trial. Thirty UARS patients were randomized into 2 groups: placebo and MAD groups. UARS criteria were the presence of sleepiness (Epworth Sleepiness Scale ≥ 10) and/or fatigue (Modified Fatigue Impact Scale ≥ 38) associated with an apnea-hypopnea index ≤ 5 events/h and a respiratory disturbance index > 5 events/h of sleep, and/or flow limitation in more than 30% of total sleep time. All patients completed the Rey Auditory-Verbal Learning Test, the Logical Memory test, the Stroop Color Test, the Trail Making Test, the Digit Symbol Substitution Test, and Inventory of Stress Symptoms. Cognition protocol was defined based on the most used neuropsychological tests in the literature. Evaluations were performed before and after 1.5 years of treatment. RESULTS: Mean adherence to placebo and to MAD was 6.6 ± 2.6 and 6.1 ± 2.4 h/night, respectively. Side effects reported by MAD group were minor and short-term. There was no statistically significant difference in Rey Auditory-Verbal Learning Test, Logical Memory test, Stroop Color Test, Trail Making Test, and Digit Symbol Substitution Test before and after 1.5 years of treatment in both groups. Inventory of Stress Symptoms score decreased at the alert phase and the resistance phase after 1.5 years of MAD treatment compared to the placebo. CONCLUSIONS: Mandibular advancement devices were effective in decreasing stress symptoms in UARS patients after 1.5 years of treatment. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Efficacy of Oral Appliance for Upper Airway Resistance Syndrome; URL: https://clinicaltrials.gov/ct2/show/record/NCT02636621; Identifier: NTC02636621.

Long-Term Oral Appliance Therapy Improves Daytime Function and Mood in Upper Airway Resistance Syndrome Patients.

Objectives: To evaluate the long-term effects of an oral appliance on clinical symptoms, respiratory sleep parameters, sleep quality, and sustained attention in patients with upper airway resistance syndrome (UARS) were compared with placebo. Methods: This study was a randomized placebo-controlled clinical trial. Thirty UARS patients were randomized in two groups: placebo and mandibular advancement device (MAD) groups. UARS criteria were presence of sleepiness (Epworth Sleepiness Scale ≥ 10) and/or fatigue (Modified Fatigue Impact Scale ≥ 38) associated with an apnea/hypopnea index ≤ 5 and a respiratory disturbance index (RDI) > 5 events/hour of sleep, and/or flow limitation in more than 30% of total sleep time. All patients completed the Pittsburgh Sleep Quality Index (PSQI), the Functional Outcomes of Sleep Questionnaire, the Beck Anxiety and Depression Inventories, underwent full-night polysomnography, multiple sleep latency test, and Psychomotor Vigilance Test (PVT). Evaluations were performed before and after 1.5 years of treatment. Results: RDI, number of respiratory effort-related arousal, percentage of total sleep time with flow limitation, and arousal index significantly decreased after 1.5 years of MAD treatment. PSQI total score improved, severity of depression symptoms decreased, and mean reaction time in the PVT, based on the first measurement taken at 8:00 am, significantly decreased (p = .03) at the end of the protocol. Conclusions: The MAD was effective in decreasing respiratory events in UARS patients. For UARS, 1.5 years of oral appliance therapy also improved sleep quality and sustained attention, and decreased the severity of depression symptoms. Clinical Trial: Efficacy of Oral Appliance for Upper Airway Resistance Syndrome: Randomized, Parallel, Placebo-Controlled Study, NCT02636621.

Upper Airway Resistance Syndrome Patients Have Worse Sleep Quality Compared to Mild Obstructive Sleep Apnea.

PURPOSE: To compare sleep quality and sustained attention of patients with Upper Airway Resistance Syndrome (UARS), mild Obstructive Sleep Apnea (OSA) and normal individuals. METHODS: UARS criteria were presence of excessive daytime sleepiness (Epworth Sleepiness Scale-ESS-≥ 10) and/or fatigue (Modified Fatigue Impact Scale-MFIS-≥ 38) associated to Apnea/hypopnea index (AHI) ≤ 5 and Respiratory Disturbance Index (RDI) > 5 events/hour of sleep or more than 30% of total sleep time with flow limitation. Mild OSA was considered if the presence of excessive daytime sleepiness (ESS ≥ 10) and/or fatigue (MFIS ≥ 38) associated to AHI ≥ 5 and ≤ 15 events/hour. "Control group" criteria were AHI < 5 events/hour and RDI ≤ 5 events/hour and ESS ≤ 9, without any sleep, clinical, neurological or psychiatric disorder. 115 individuals (34 UARS and 47 mild OSA patients and 34 individuals in "control group"), adjusted for age, gender, body mass index (BMI) and schooling years, performed sleep questionnaires and sustained attention evaluation. Psychomotor Vigilance Task (PVT) was performed five times (each two hours) from 8 a.m. to 4 p.m. RESULTS: UARS patients had worse sleep quality (Functional Outcomes of Sleep Questionnaire-FOSQ-and Pittsburgh Sleep Quality Index-PSQI: p < 0.05) and more fatigue than mild OSA patients (p = 0.003) and scored significantly higher in both Beck inventories than "control group" (p < 0.02). UARS patients had more lapses early in the morning (in time 1) compared to the results in the afternoon (time 5) than mild OSA (p = 0.02). Mild OSA patients had more lapses in times 2 than in time 5 compared to "control group" (p = 0.04). CONCLUSIONS: UARS patients have a worse sleep quality, more fatigue and a worse early morning sustained attention compared to mild OSA. These last had a worse sustained attention than controls.

Musculoskeletal Pain as a Marker of Health Quality. Findings from the Epidemiological Sleep Study among the Adult Population of São Paulo City.

BACKGROUND: We are witnessing the growth of urban populations, particularly in the developing world. São Paulo, the largest city in South America, continues to grow, and this growth is dramatically effecting the environment and human health. The aim of this study was to estimate the point prevalence of chronic pain in São Paulo city dwellers and to explore the influence of aspects related to urbanicity. METHODS: A two-stage cluster randomized sample included 1100 individuals of the city of Sao Paulo, representing the population proportionally in terms of gender, age and social classes in 2007. For this observational cross-sectional study, the household sample was interviewed using validated questionnaires for sociodemographic aspects, the Beck inventories for anxiety and depression, the WHOQoL-REF for quality of life, the Chalder Fatigue Scale. Musculoskeletal pain was defined as diffuse pain or pain located in the back, joints or limbs. Data regarding sleep complaints and polysomnography were obtained from the Epidemiologic Sleep Study conducted in São Paulo city in 2007. RESULTS: The prevalence estimate of chronic musculoskeletal pain was approximately 27%, with a female/male ratio of approximately 2.6/1. The predictors were being in the age-range of 30-39 years, low socioeconomic and schooling levels, obesity, sedentarism, fatigue, non-restorative sleep, daytime sleepiness, poor sleep quality, poor life quality, anxiety and depression symptoms. Psychological wellbeing was the main discriminator between responders with chronic musculoskeletal pain and the controls, followed by depression for the participants with poor psychological wellbeing, and fatigue, for the remaining ones. Insomnia syndrome was the third-level discriminator for those with fatigue, whereas sleep quality for those without fatigue. CONCLUSIONS: Musculoskeletal pain was frequently reported by São Paulo city dwellers and its correlates with psychological and sleep aspects are suggestive of a response to urbanicity. TRIAL REGISTRATION: ClinicalTrials.gov NCT00596713.

Treatment of upper airway resistance syndrome in adults: Where do we stand?

OBJECTIVE: To evaluate the available literature regarding Upper Airway Resistance Syndrome (UARS) treatment. METHODS: Keywords "Upper Airway Resistance Syndrome," "Sleep-related Breathing Disorder treatment," "Obstructive Sleep Apnea treatment" and "flow limitation and sleep" were used in main databases. RESULTS: We found 27 articles describing UARS treatment. Nasal continuous positive airway pressure (CPAP) has been the mainstay therapy prescribed but with limited effectiveness. Studies about surgical treatments had methodological limitations. Oral appliances seem to be effective but their efficacy is not yet established. CONCLUSION: Randomized controlled trials with larger numbers of patients and long-term follow-up are important to establish UARS treatment options.

Treatment of obstructive sleep apnea syndrome associated with stroke.

The association between sleep-disordered breathing and stroke has been a subject of increased interest and research. Obstructive sleep apnea (OSA) is an important risk factor for stroke incidence and mortality. Moreover, OSA is a common clinical outcome after stroke, directly influencing the patient's recovery. The treatment of choice for OSA is positive airway pressure (PAP) support and the PAP appliance is considered the most recommended clinical management for the treatment of patients with cardiovascular complications. However, the implementation of PAP in stroke patients remains a challenge, considering the increased frequency of motor and language impairments associated with the cerebrovascular event. In the present study, we reviewed the main findings describing the association between stroke and OSA treatment with continuous positive airway pressure. We also discussed the types of OSA treatment, the different options and indications of PAP treatment, PAP adherence and the clinical outcomes after treatment.

New insights on the pathophysiology of inspiratory flow limitation during sleep.

INTRODUCTION: Inspiratory flow limitation (IFL) is defined as a "flattened shape" of inspiratory airflow contour detected by nasal cannula pressure during sleep and can indicate increased upper airway resistance especially in mild sleep-related breathing disorders (SRBD). The objective of this study was to investigate the association between upper airway abnormalities and IFL in patients with mild SRBD. METHODS: This study was derived from a general population study consisting of selected individuals with apnea-hypopnea index (AHI) below 5 events/h of sleep, ("no obstructive sleep apnea" group) and individuals with AHI between 5 and 15 events/h ("mild obstructive sleep apnea" group). A total of 754 individuals were divided into four groups: group 1: AHI <5/h and <30 % of total sleep time (TST) with IFL (515 individuals), group 2: AHI <5/h and >30 % of TST with IFL (46 individuals), group 3: AHI: 5-15/h and <30 % of TST with IFL (168 individuals), and group 4: AHI: 5-15/h and >30 % of TST with IFL (25 individuals). RESULTS: Individuals with complains of oral breathing demonstrated a risk 2.7-fold larger of being group 4 compared with group 3. Abnormal nasal structure increased the chances of being in group 4 3.2-fold in comparison to group 1. Individuals with voluminous lateral wall demonstrated a risk 4.2-fold larger of being group 4 compared with group 3. CONCLUSION: More than 30 % of TST with IFL detected in sleep studies was associated with nasal and palatal anatomical abnormalities in mild SRBD patients.

Inspiratory flow limitation in a normal population of adults in São Paulo, Brazil.

STUDY OBJECTIVES: Inspiratory flow limitation (IFL) during sleep occurs when airflow remains constant despite an increase in respiratory effort. This respiratory event has been recognized as an important parameter for identifying sleep breathing disorders. The purpose of this study was to investigate how much IFL normal individuals can present during sleep. DESIGN: Cross-sectional study derived from a general population sample. SETTING: A "normal" asymptomatic sample derived from the epidemiological cohort of São Paulo. PATIENTS AND PARTICIPANTS: This study was derived from a general population study involving questionnaires and nocturnal polysomnography of 1,042 individuals. A subgroup defined as a nonsymptomatic healthy group was used as the normal group. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: All participants answered several questionnaires and underwent full nocturnal polysomnography. IFL was manually scored, and the percentage of IFL of total sleep time was considered for final analysis. The distribution of the percentage of IFL was analyzed, and associated factors (age, sex, and body mass index) were calculated. There were 95% of normal individuals who exhibited IFL during less than 30% of the total sleep time. Body mass index was positively associated with IFL. CONCLUSIONS: Inspiratory flow limitation can be observed in the polysomnography of normal individuals, with an influence of body weight on percentage of inspiratory flow limitation. However, only 5% of asymptomatic individuals will have more than 30% of total sleep time with inspiratory flow limitation. This suggests that only levels of inspiratory flow limitation > 30% be considered in the process of diagnosing obstructive sleep apnea in the absence of an apnea-hypopnea index > 5 and that < 30% of inspiratory flow limitation may be a normal finding in many patients.

The human leucocyte antigen DQB1*0602 allele is associated with electroencephelograph differences in individuals with obstructive sleep apnoea syndrome.

Human leucocyte antigen (HLA) DQB1*0602 allele, a well-known genetic risk factor for narcolepsy, has been associated with sleep parameters in healthy subjects. We aimed to assess the association of this allele with daytime sleepiness and altered sleep electroencephalogram characteristics in the general population and in patients with obstructive sleep apnoea syndrome (OSAS). Eight hundred and ninety-four individuals from the Epidemiologic Study of Sleep were genotyped for the HLA DQB1*0602 allele. Full-night polysomnography was performed, and daytime sleepiness was analysed according to the Epworth Sleepiness Scale. HLA-DQB1*0602 allele-positive and -negative subjects in the general population, as well as in patients with OSAS, exhibited similar sleep parameters and levels of daytime sleepiness. However, spectral analysis showed that allele-positive individuals with OSAS exhibited higher theta power during sleep Stage 1 (P < 0.05) in occipital derivations, and lower delta power during sleep Stages 1 and 2 (P < 0.01) compared with individuals negative for the allele, even after correction for potential confounders as age, sex, body mass index and European ancestry. No significant differences in the electroencephalogram variables were found in individuals without OSAS. The data highlight the HLA-DQB1*0602 as a potential genetic factor influencing sleep physiology in individuals diagnosed with OSAS.

[Pathophysiology of sleep-disordered breathing]. / Fisiopatologia dos distúrbios respiratórios do sono.

Sleep is a phase during which the respiratory system undergoes major changes. These changes lead to greater vulnerability and a greater risk of abnormalities, even in normal individuals. In the transition from wakefulness to sleep, there is commonly an increase in upper airway resistance and impairment of various protective responses and reflexes, which are efficient in promoting and maintaining upper airway patency during wakefulness. In individuals who present risk factors, such as anatomical abnormalities in the upper airway, these sleep-related changes cannot be efficaciously compensated, which increases the chances that sleep-disordered breathing will occur. Sleep-disordered breathing is characterized by a reduction in the size of upper airways, although the degree of the reduction varies. This reduction has multifactorial causes, which include anatomical abnormalities in the upper airway, alterations in the neuromuscular response and impairment of receptors in the upper airway. Upper airway functional and anatomical changes are likely to have genetic components, and, therefore, individuals exposed to certain environmental factors, such as allergies, have a greater chance of developing sleep-disordered breathing.

[Diagnostic criteria and treatment for sleep-disordered breathing: RERA]. / Critérios diagnósticos e tratamento dos distúrbios respiratórios do sono: RERA.

In polysomnography, RERA is defined as a respiratory parameter that indicates an arousal associated with a respiratory event and an increase in respiratory effort. Initially, RERA was described by means of esophageal manometry for the evaluation of respiratory effort. This greater respiratory effort occurs as a response to an increase in upper airway resistance, which is a factor present in the pathophysiology of sleep-disordered breathing, such as obstructive sleep apnea syndrome and upper airway resistance syndrome. Later, the use of a nasal pressure cannula was reported to be a reliable means of identifying airflow limitation and one that is more sensitive than is a thermistor. In addition, the nasal pressure cannula method has been used as a surrogate for esophageal manometry in the identification of periods in which upper airway resistance increases. Consequently, the American Academy of Sleep Medicine recommend the use of either method for the identification of RERA, which is defined by the flattening of the inspiratory curve, characteristic of airflow limitation. Although RERA has been identified and evaluated in current medical practice, it has yet to be standardized. Therefore, it is recommended that polysomnographic reports indicate which abnormal respiratory events were taken into consideration in the evaluation of the severity of sleep-disordered breathing.

Critérios diagnósticos e tratamento dos distúrbios respiratórios do sono: RERA / Diagnostic criteria and treatment for sleep-disordered breathing: RERA

Na polissonografia, RERA é definido como um parâmetro respiratório que indica um despertar associado a um evento respiratório e um aumento do esforço respiratório. Inicialmente, RERA foi descrito com o uso da manometria esofágica utilizada para avaliação do esforço respiratório. Esse maior esforço respiratório ocorre como resposta a um aumento da resistência da via aérea superior, aspecto presente na fisiopatologia dos distúrbios respiratórios do sono, entre esses, SAOS e SRVAS. Posteriormente, o uso de cânula de pressão nasal foi relatado como uma maneira confiável e mais sensível que o termistor para a identificação de eventos de redução do fluxo aéreo e também como um substituto da manometria esofágica para a identificação de períodos de aumento da resistência na via aérea superior. Consequentemente, a American Academy of Sleep Medicine recomenda o uso de um dos métodos para a identificação de RERA, que é definido por um padrão de achatamento da curva inspiratória, característico da limitação ao fluxo aéreo. Embora RERA seja identificado e avaliado na pratica médica, sua padronização ainda é necessária. Portanto, recomenda-se que os laudos de polissonografia indiquem quais eventos respiratórios anormais foram considerados na avaliação do grau de gravidade do distúrbio respiratório.

In polysomnography, RERA is defined as a respiratory parameter that indicates an arousal associated with a respiratory event and an increase in respiratory effort. Initially, RERA was described by means of esophageal manometry for the evaluation of respiratory effort. This greater respiratory effort occurs as a response to an increase in upper airway resistance, which is a factor present in the pathophysiology of sleep-disordered breathing, such as obstructive sleep apnea syndrome and upper airway resistance syndrome. Later, the use of a nasal pressure cannula was reported to be a reliable means of identifying airflow limitation and one that is more sensitive than is a thermistor. In addition, the nasal pressure cannula method has been used as a surrogate for esophageal manometry in the identification of periods in which upper airway resistance increases. Consequently, the American Academy of Sleep Medicine recommend the use of either method for the identification of RERA, which is defined by the flattening of the inspiratory curve, characteristic of airflow limitation. Although RERA has been identified and evaluated in current medical practice, it has yet to be standardized. Therefore, it is recommended that polysomnographic reports indicate which abnormal respiratory events were taken into consideration in the evaluation of the severity of sleep-disordered breathing.

Fisiopatologia dos distúrbios respiratórios do sono / Pathophysiology of sleep-disordered breathing

O sono representa uma fase na qual o sistema respiratório sofre importantes mudanças que levam a uma maior vulnerabilidade e maior chance de ocorrência de anormalidades, mesmo em indivíduos normais. Na transição da vigília para o sono, existe normalmente um aumento da resistência de via aérea superior e prejuízo de diferentes respostas e reflexos protetores, os quais são eficientes em promover e manter a patência da via aérea superior durante a vigília. Em indivíduos que apresentam fatores de risco, tais como anormalidades anatômicas em via aérea superior, essas mudanças associadas ao sono não conseguem ser compensadas de forma eficaz e, com isso, ocorre uma maior chance de ocorrer um distúrbio respiratório do sono. Os distúrbios respiratórios do sono são caracterizados por diferentes graus de diminuição do espaço das vias aéreas superiores. Essa diminuição tem causas multifatoriais, que incluem anormalidades da anatomia de via aérea superior, alteração da resposta neuromuscular e de alterações em receptores de via aérea superior. Provavelmente muitas alterações funcionais e anatômicas em via aérea superior são de característica genética, tornando o individuo com maior risco quando exposto a determinados fatores ambientais, tais como alergias, e a partir da combinação destes fatores haverá uma maior chance de desenvolver distúrbios respiratórios do sono.

Sleep is a phase during which the respiratory system undergoes major changes. These changes lead to greater vulnerability and a greater risk of abnormalities, even in normal individuals. In the transition from wakefulness to sleep, there is commonly an increase in upper airway resistance and impairment of various protective responses and reflexes, which are efficient in promoting and maintaining upper airway patency during wakefulness. In individuals who present risk factors, such as anatomical abnormalities in the upper airway, these sleep-related changes cannot be efficaciously compensated, which increases the chances that sleep-disordered breathing will occur. Sleep-disordered breathing is characterized by a reduction in the size of upper airways, although the degree of the reduction varies. This reduction has multifactorial causes, which include anatomical abnormalities in the upper airway, alterations in the neuromuscular response and impairment of receptors in the upper airway. Upper airway functional and anatomical changes are likely to have genetic components, and, therefore, individuals exposed to certain environmental factors, such as allergies, have a greater chance of developing sleep-disordered breathing.

Evaluation of the upper airway in obstructive sleep apnoea.

The evaluation of the upper airway (UA) includes the physical examination of pharyngeal structures and a number of imaging techniques that vary from the mostly used lateral cephalometry and computed tomography to more sophisticated methods such as tri-dimensional magnetic resonance image (MRI). Other complex techniques addressing UA collapsibility assessed by measurement of pharyngeal critical pressure and negative expiratory pressure however are not routinely performed. These methods provide information about anatomic abnormalities and the level of pharyngeal narrowing or collapse while the patient is awake or asleep. Data suggest that individual patients have different patterns of UA narrowing. So, the best method for evaluating obstruction during obstructive events remains controversial. In general, in clinical practice physical examination including a systematic evaluation of facial morphology, mouth, nasal cavity and the pharynx as well as simple imaging techniques such as nasopharyngoscopy and cephalometry have been more routinely utilized. Findings associated with obstructive sleep apnoea (OSA) are UA narrowing by the lateral pharyngeal walls and enlargements of tonsils, uvula and tongue. Additionally cephalometry identifies the most significant craniofacial characteristics associated with this disease. MRI studies demonstrated that lateral narrowing of UA in OSA is due to parapharyngeal muscle hypertrophy and/or enlargement of non adipose soft tissues. The upper airway evaluation has indubitably contributed to understand the pathophysiology and the diagnosis of OSA and snoring. Additionally, it also helps to identify the subjects with increased OSA risk as well as to select the more appropriate modality of treatment, especially for surgical procedures.