PATIENTS AND METHOD:Eight children with congenital central hypoventilation syndrome (CCHS) (aged 3 to 16 years) underwent repeated polysomnographic recordings (sleep-EEG, induction plethysmography, PtcO2, PtcCO2, PACO2, FO2, SaO2, ECG) during spontaneous breathing and during therapy. The result led to individual therapeutic plans.RESULT:During NREM sleep a close relationship between increasing EEG-delta-activity and increasing PCO2 could be observed (PCO2 max. 107 mm Hg in NREM IV). A similar effect was seen during mechanical ventilation with decreasing spontaneous respiratory activity during increasing sleep depth (PCO2 max. 89 mm Hg in NREM IV). Associated with NREM I/II and REM sleep strong variations in spontaneous breathing with consecutive variations of blood gases were observed. Hyperventilation during REM sleep (PCO2 min. 20 mm Hg) could occur with continuous mechanical ventilation. A continuous blood gas monitoring improved home therapy since blood gas adapted control of mechanical ventilation was possible now. This caused a stabilization of blood gases in sleep.CONCLUSION:Patients with CCHS show a vigilance-dependent, enlarged variability of blood gases which should be considered in the management of home therapy. Continuous monitoring and blood gas adapted mechanical ventilation obtain a stabilization of acid-base balance during sleep. Preliminary data suggest a positive effect on sleep-wake quality and mental performance.

Unter dem Undine-Syndrom versteht man ein selten angeborenes, häufiger erworbenes Krankheitsbild, das auch als zentrales Hypoventilationssyndrom oder CHS bezeichnet wird. Da die erworbene Form eine weitgehend uneinheitliche Genese hat, wird hier nur die angeborene Form, das kongenitale zentrale Hypoventilationssyndrom (CCHS) behandelt. Die Wahrscheinlichkeit einer familiären Häufung wurde mit <5% angegeben. Aus der Koinzidenz eines Megacolon congenitum (MC) in über 20% der Fälle mit angeborener zentraler Hypoventilation einerseits und einer Koinzidenz heterozygoter Keimbahnmutationen im RET-Protoonkogen bei 20% der Patienten mit MC liegt ein genetischer Zusammenhang zwischen der Aganglionose des Darmes und der zentralen Hypoventilation nahe. Anhand von Langzeitbeobachtungen ließ sich bei 8 Kindern eine charakteristische vigilanzbezogene Hypoventilation und eine Unempfindlichkeit des Atmungssystems für CO2 im Wachsein wie im Schlaf nachweisen. Die Befunde decken sich mit Langzeitbeobachtungen im Tierexperiment nach Ausschaltung der CO2-Empfindlichkeit. Die Unempfindlichkeit für CO2, die mit einer mangelnden Empfindung für Atemnot einher geht, bleibt im Beobachtungszeitraum von bisher maximal 15 Jahren bestehen, während sich die Kinder bei optimaler atemtherapeutischer Versorgung weitgehend normal entwickeln. Eine Umstellung der Beatmung per Tracheostoma auf eine Maskenbeatmung mit Verschluß des Tracheostomas wurde insbesondere vor der Einschulung gut akzeptiert.

BACKGROUND:Children with congenital central hypoventilation syndrome (CCHS) have to be ventilated during sleep due to respiratory insensitivity to CO2. This long-term mechanical ventilation sometimes requires a tracheostomy during infancy, leading to increased risk of infections and of tracheal problems, and later on to stigmatization and restrictions in social life.PATIENTS AND METHOD:We therefore evaluated non-invasive mask ventilation in 4 children between 6 and 15 years of age, who had been ventilated via tracheal canula since early infancy under polysomnographic control.RESULTS:Best results were obtained with standard face masks in connection with pressure controlled timed ventilation. In 1 child we used a volume-controlled ventilator. The lack of dyspnea in these patients can worsen the acceptance of a face mask, which is more uncomfortable than a tracheal cannula. In 2 children we waited with the definite closure of the tracheostomy due to pavor-like symptoms and laryngeal closure during sleep and problems in acceptance of the mask, respectively. In the other 2 children we could demonstrate effective non-invasive mask ventilation during temporary tracheal closure for several nights. Therefore the tracheostomy was definitely closed. Long-term follow-up with home monitoring showed effectiveness of non-invasive ventilation in these cases.

Most information about the structures within the brain stem that modulate respiration and sleep are gathered from animal experiments. Therefore we examined 10 patients several weeks after an infarction of the brain stem by means of polysomnography and tested the chemosensitive drives of respiration. None of these patients complained about symptoms of sleep disordered breathing. In each case polysomnographic measurements and ventilatory response curves revealed pathologic findings. The respiratory response to CO2 was diminished or completely abolished in each patient. In some cases hypoventilation or disturbances of the respiratory rhythmicity could be seen. In several cases missing REM sleep, sleep fragmentation or the reduction of slow wave sleep were observed. The study indicates that on the base of results from animal research the comparison of morphological and pathophysiological data is helpful to gain a better understanding on the coupling of the respiratory system with sleep at the brain stem level as well as on the pathomechanism of sleep related breathing disorder.

4 children with congenital central hypoventilation syndrome (CCHS) now aged 6 to 9 years were studied for 1 to 8 years. In all patients CO2-response is missing, hypoxic drive is maintained. All patients required mechanical ventilation after birth. 1 patient is supported by controlled oxygen therapy during sleep since 9 months of age. 2 patients are IPPV-ventilated during sleep. 1 patient is pressure control ventilated with an oro-nasal mask since 6 years of age. All children showed phases of hypo- and hyperventilation (max. pCO2 107 mm Hg) depending on vigilance with respiratory acidosis in awake state and during sleep. These findings required ambulatory monitoring of home-therapy by a professional guard and continuous recording of pCO2 and pulseoximetry. These longtime data (max. pCO2 72 mm Hg) show that ambulatory monitoring and control of therapy is able to avoid extreme variation of blood gases and to stabilize acid-base regulation during sleeptime in patients with CCHS.