Anomalies of Nocturnal Gaz Exchanges in Patients With Down Syndrome

Recently, retrospective studies have shown that Down Syndrome children have a higher CO2 (carbone dioxide) sleep pressure than the general pediatric population. This increase does not seem to be always related to sleep apnea. The Investigators wish to confirm these results prospectively. The investigators hypothesize that this alveolar hypoventilation may be due to ventilatory control disorders caused by dysautonomia, but also to a decrease in the strength of the respiratory muscles within the framework of the global muscular hypotonia described in children with Down syndrome. .

47 Down syndrome patients age from 4 to 16 will be included. They will perform a medical visit at J0, then a measurement of gaz nocturnal exchanges at home within 1 month

Nocturnal gaz exchanges at patient's home BRIEF neuropsychological questionnaire VINELAND-II neuropsychological questionnaire Clinical OSA assessment Dysautonomia assessment

Percentage of total sleep time with a PtcCO2 in mmHg higher than 50; mean, maximum and minimum SpO2 in %

Number of patients with low mean, minimum and maximum SpO2 (oyxygen saturation) and/or % of Total sleep time spent with a PtcCO2 higher than 50 mmHg, higher than 20%, as measured by nocturnal gas exchange recordings.

Correlation between nocturnal PtcCO2 value and the existence of executive function and behavioral disorders assed by the Dysautonomia questionnaire

Correlation between nocturnal PtcCO2 value and the existence of executive function and behavioral disorders measured by Hand Grip assessment

Correlation between nocturnal PtcCO2 value and the existence of executive function and behavioral disorders measured by OSA (Obstructive Sleep Apnea) assessment questionnaire

Inclusion Criteria: Down syndrome patient without mosaicism Age 4 to 16 years Predominant French language in the living environment Exclusion Criteria: OAS diagnostic focused on an earlier polysomnography Methylphenidate treatment started before inclusion

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