Discussion
SDB in pediatric age differ both in the definition, diagnosis and treatment in relation to the adult. The child presents anatomical and functional peculiarities in the airway along with maturational characteristics from the point of view of sleep neurophysiology2.
Tonsillar hypertrophy is the main nasal and oropharyngeal anatomical pathogenesis´ factors of childhood OSA. Also included in the different factors that cause this pathogenesis are less frequent ones such as obesity, dental malocclusion or craniofacial malformations2.
The clinical manifestations of OSA are very varied depending on the severity, etiologies and the different degree of development, but the most frequent are snoring, evidence of nocturnal apnea, daytime hyperactivity or hypersomnolence, poor school performance and neurocognitive alterations1. In the case of CSAS, the symptoms are less florid and usually occur asymptomatically.
Although PSG and CRP are the diagnostic techniques of choice, it is important to know that other methods are also interesting. A brain MRI may be an important diagnostic tool for unexplained sleep disorders in nonsyndromic and syndromic children, and it should be considered in the context of an unexplained SDB, including OSA in the absence of adenotonsillar hypertrophy, persistent OSA following adenotonsillar, central sleep apnea, and nocturnal hypoventilation syndrome4.
In our case, the realization of a brain MRI showed a probable origin of the pathology. The malformation of Chiari type I is characterized by the existence of a decrease in the cerebellar tonsils that are located below the foramen magnum, associated with compressive phenomena of the brainstem and upper spinal cord. Ferré et al 2described that the most frequent clinical manifestations are usually occipitonucal headaches, dizziness and nocturnal respiratory disturbances, such as central apneas.
Adeno-tonsillectomy is the most frequent technique of treatment in children´s OSA, with an improvement in AHI of 75%1. Other non-surgical treatments would be the use of CPAP, weight loss, maxillary expansion and / or orthodontic and other methods aimed at eliminating the possible etiological trigger1. In the case of CSAS, it is important to identificate the underlying pathology. In Arnold Chiari malformation, it is usually decompressive neurosurgery5.
In summary, the Arnold Chiari malformation is a rare cause of central apneas in the pediatric patient, which requires an MRI study for diagnosis. It is important to assess these possible causes in a case of pediatric SAC. Also we think that it would be useful to carry out studies in Chiari malformation´s patients to evaluate respiratory alterations before and after surgery to determine whether surgery treats SDB.
Image 1 : PSG where multiple apneas of central origin are evident.
Image 2 : MRI of T2 sagittal brain showing a 9 mm decrease in cerebellar tonsils below the plane of the great hole compatible with Arnold Chiari type I malformation (red arrow), with association to cervical syringomyelia that extends from C5 until D9 (yellow arrow).