Magnetic resonance imaging of the upper airway structure of children with obstructive sleep apnea syndrome

Division of Pulmonary Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104-4399, USA.
American Journal of Respiratory and Critical Care Medicine (Impact Factor: 11.99). 09/2001; 164(4):698-703. DOI: 10.1164/ajrccm.164.4.2101127
Source: PubMed

ABSTRACT The anatomical relationships between lymphoid, bony, and other tissues affecting the shape of the upper airway in children with obstructive sleep apnea syndrome (OSAS) have not been established. We therefore compared the upper airway structure in 18 young children with OSAS (age 4.8 +/- 2.1 yr; 12 males and 6 females) and an apnea index of 4.3 +/- 3.9, with 18 matched control subjects (age, 4.9 +/- 2.0 yr; 12 males and 6 females). All subjects underwent magnetic resonance imaging under sedation. Axial and sagittal T1- and T2-weighted sequences were obtained. Images were analyzed with image-processing software to obtain linear, area, and volumetric measurements of the upper airway and the tissues comprising the airway. The volume of the upper airway was smaller in subjects with OSAS in comparison with control subjects (1.5 +/- 0.8 versus 2.5 +/- 1.2 cm(3); p < 0.005) and the adenoid and tonsils were larger (9.9 +/- 3.9 and 9.1 +/- 2.9 cm(3) versus 6.4 +/- 2.3 and 5.8 +/- 2.2 cm(3); p < 0.005 and p < 0.0005, respectively). Volumes of the mandible and tongue were similar in both groups; however, the soft palate was larger in subjects with OSAS (3.5 +/- 1.1 versus 2.7 +/- 1.2 cm(3); p < 0.05). We conclude that in children with moderate OSAS, the upper airway is restricted both by the adenoid and tonsils; however, the soft palate is also larger in this group, adding further restriction.

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    • "Kawashima 2000 [60] III À 15 with OSAS À 4.7 (range 3e5) y Cephalometry The study concluded that: 1) sleep apnea was often associated with mandibular retrognathia, 2) the lower incisors tended to exhibit a retrocline, 3) there were no significant differences in angular and linear measurements in the cranial base, and 4) the apneic children had a narrower epipharyngeal airway space. Arens 2001 [63] "
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    ABSTRACT: Obstructive sleep apnea syndrome in children is a manifestation of sleep-disordered breathing and associated with a number of complications. Structural narrowing of the upper airway in combination with inadequate compensation for a decrease in neuromuscular tone is an important factor in the pathogenesis. Adenotonsillar hypertrophy is the most important predisposing factor. However, many other causes of craniofacial defects may coexist. Additionally, the pathogenesis of narrowing is more complex in certain subgroups such as children with obesity, craniofacial malformations, Down syndrome or neuromuscular disorders. The diagnosis of obstructive sleep apnea is based on an overnight polysomnography. This investigation is expensive, time consuming and not widely available. In view of the major role of structural narrowing, upper airway imaging could be a useful tool for investigating obstructive sleep apnea and in establishing the site(s) of obstruction. Several radiological techniques (lateral neck radiography, cephalometry, computerized tomography, magnetic resonance imaging and post-processing of these images using computational fluid dynamics) have been used to investigate the role of structural alterations in the pathogenesis. We reviewed the literature to examine if upper airway imaging could replace polysomnography in making the diagnosis and if imaging could predict the effect of treatment with a focus on adenotonsillectomy. There is a limited number of high quality studies of imaging predicting the effect of treatment. To avoid unnecessary risks and ineffective surgeries, it seems crucial to couple the exact individual anatomical risk factor with the most appropriate treatment. We conclude that imaging could be a non-invasive tool that could assist in selection of treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.
    Sleep Medicine Reviews 08/2014; 21. DOI:10.1016/j.smrv.2014.08.001 · 9.14 Impact Factor
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    • "In selecting the indices referred to the air lumen we primarily relied on the experiences of previous authors who had tested their correlation with the results of PSG [1] [2] [3]. In regard to these indices we found the most significant differences from the statistical point of view between the two considered series. "
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    ABSTRACT: OBJECTIVE: Aim of our study was to identify anatomical risk factors involved in the development of pediatric OSAHS through a MRI-based case-control pilot study. METHODS: MRI exams of the head and neck of 40 children affected by OSAHS were retrospectively evaluated. 25 indices referring to the air lumen, soft tissues and craniofacial skeleton were measured. Subsequently, the same process of measurement of indices was performed on MRI exams of 40 controls. For each index, then, we calculated in both groups mean, standard deviation, standard error and t value. Comparing the two series we finally calculated the degree of significance of each difference between children with OSAHS and controls through the Student's t-test. RESULTS: Besides the expected and previously described differences of minimum retropharyngeal cross-sectional area (CSA), nasopharyngeal airway, combined upper airway volume, tonsillar and adenoid cross-sectional and volumetric indices, we found a higher midsagittal CSA of the soft palate and lower position of the hyoid bone, SNB angle and mandibular volume. CONCLUSIONS: Results from our study population, certainly limited in terms of number of patients and considered age range, showed that not only adeno-tonsillar hypertrophy is important in determining the clinical syndrome: soft palate enlargement and certain skeletal pattern can even assume greater importance in the genesis and in the progression of the obstruction. MRI proved to be an accurate technique in the evaluation of the prevalent risk factor in children affected by OSAHS, leading to the most appropriate surgical approach.
    International journal of pediatric otorhinolaryngology 10/2012; 77(1). DOI:10.1016/j.ijporl.2012.09.035 · 1.32 Impact Factor
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    • "In OSA, the episodes of airway obstruction can be related to increased airway collapsibility on account of mechanical and neuronal factors. The most common mechanical factor in children is hypertrophy of adenoids and/or tonsils narrowing the airway lumen [22]. Approximately 2% of otherwise healthy children have large tonsils and adenoids that mechanically obstruct airways [20] [23]. "
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    ABSTRACT: The global epidemic of childhood and adolescent obesity and its immediate as well as long-term consequences for obese individuals and society as a whole cannot be overemphasized. Obesity in childhood and adolescence is associated with an increased risk of adult obesity and clinically significant consequences affecting the cardiovascular and metabolic systems. Importantly, obesity is additionally complicated by obstructive sleep apnea (OSA), occurring in up to 60% of obese children. OSA, which is diagnosed using the gold standard polysomnogram (PSG), is characterised by snoring, recurrent partial (hypopneas) or complete (apneas) obstruction of the upper airway. OSA is frequently associated with intermittent oxyhemoglobin desaturations, sleep disruption, and sleep fragmentation. There is emerging data that OSA is associated with cardiovascular burden including systemic hypertension, changes in ventricular structure and function, arterial stiffness, and metabolic syndromes. Thus, OSA in the context of obesity may independently or synergistically magnify the underlying cardiovascular and metabolic burden. This is of importance as early recognition and treatment of OSA in obese children are likely to result in the reduction of cardiometabolic burden in obese children. This paper summarizes the current state of understanding of obesity-related OSA. Specifically, this paper will discuss epidemiology, pathophysiology, cardiometabolic burden, and management of obese children and adolescents with OSA.
    Journal of nutrition and metabolism 08/2012; 2012:134202. DOI:10.1155/2012/134202
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