The urge to breathe comes from a physiological drive. Sensors inside and outside the brain are continuously monitoring the internal environment of our blood and effectively regulating daily oscillations in our breathing patterns. Breathing becomes faster and deeper when oxygen levels fall or carbon dioxide levels rise.
While we sleep we are at rest, our energy consumption is less, and our breathing slows. Throughout the night, our respiratory sensors continue monitoring the molecules in our blood, to protect us from having fatal events when we stop breathing. Sleep disordered breathing occurs in nearly every single patient with familial dysautonomia. When they fall asleep at night, their airways can collapse and/or their brain can fail to signal when it is time to breathe. This can lead to snoring, gasping, and sometimes long pauses in breathing. It is very common for patients to awaken in the morning, feeling unrested after frequent awakenings and lethargic.
Overtime, patients become accustomed to having high levels of carbon dioxide in their blood and develop daytime respiratory failure. Walking around with persistently high carbon dioxide levels (known as hypercapnia) blunts the desire to breathe.
A recent analysis of treating patients with FD with CPAP or BiPAP devices shows that this appears to be reversible. These devices, which restore normal breathing, cause a significant reduction in carbon dioxide levels during the day.
Researchers think that the physiological mechanism is resetting of the respiratory (chemo) sensors. CPAP or BiPAP are your back-up that mechanically support your breathing at night. They keep the airways open, ventilate the lung and essentially wash carbon dioxide out of the blood. They suspect that the sensors are being cleaned during sleep so that they work better during the day.
Read the paper here:
Kaufmann H, Norcliffe-Kaufmann L, Palma JA. Improvement of daytime hypercapnia with nocturnal non-invasive ventilation in familial dysautonomia. Clin Auton Res. 2019 Apr;29(2):255-256. doi: 10.1007/s10286-019-00590-3. Epub 2019 Jan 12. No abstract available. PMID: 30637592
This work was supported by the Familial Dysautonomia Foundation, Inc.