Ondine’s Curse and Respiratory Physiology

Each and every organ in our body needs energy to function. The process of generating energy in humans requires Oxygen, and generates Carbon Dioxide as a waste product. Blood collects this Carbon Dioxide, repleting the cell’s oxygen supply from its own supply. Then the blood returns to the heart and it is then distributed throughout the vessels of the lungs. The lungs take away the excess Carbon Dioxide and replete the Oxygen in the blood with the atmospheric Oxygen. This is a very simplified explanation of the basic functions of respiration.   

But have you ever thought of how amazing the process of respiration is? While you are reading this, your lungs are busy, keeping you alive. Even when you are asleep the respiration continues, since the body’s need for energy doesn’t cease just because you are not awake. But, unlike other vital functions in our body, like the beating of the heart or the filtering of the kidneys, we can control our respiration to an extent. You can decide on the rate and depth of respiration for an instance; try holding your breath and hyperventilating. But did you know that you can’t die by holding your breath? Even if you suppress the brain’s screams of ‘Breath now’, the reduced oxygen flow to your brain will cause you to faint, after which the respiration would resume automatically.   

After that brief explanation regarding this vast topic, I’m going to relate a story. This is a folk tale about two lovers to be precise. The story, titled Ondine’s Curse, is about a water nymph named Ondine, who fell in love with a mortal. If a water nymph, who is immortal, falls in love with a human, she will become a mortal, with its accompanying grievances like sickness, ageing and death. But the mortal, named Palemon, sweet talked Ondine into becoming his wife, pledging that his every waking breath would be a pledge of his love and faithfulness to her. But he went back on his words and cheated on Ondine after finding another woman. Ondine, devastated by his betrayal, cursed Palemon using his own words. He was to breathe only when he is awake and whenever he slept, he would ‘forget’ to breath.   

What does Ondine have to do with today’s article? A lot, since today we are talking about a condition called Ondine’s Curse, where the person stops breathing when he/she is asleep. Respiration is mainly involuntary, controlled by the brain stem. This includes starting inspiration when the body’s carbon dioxide levels are high and the oxygen levels are low, preventing the lungs from over inflating, coordinating the time and depth of respiration among other things. But, the cerebral cortex, which is the part of the brain which makes conscious or voluntary decisions, also has a say in it. What happens in Ondine’s curse, otherwise called ‘Central Hypoventilation Syndrome’, is that the ‘involuntary’ part of the brain fails to act, so the voluntary control is what sustains breathing. The cerebral cortex is at rest during sleep, and thus, without voluntary control, the patient may stop breathing. Do I need to explain what the result will be?  

The objective of this article isn’t to worry you of the perils of Ondine’s Curse, since, this condition (Fortunately) is extremely rare. And with the advancement of medicine, these patients can now sleep without the fear of death with the assistance of mechanical ventilation. But hopefully, it will inspire our readers to explore more of the thousands of interesting stories disguised in the form of medical jargon. When I first heard the story, narrated by one of our lecturers, I also got an appreciation for the sense of humour of the scientists who discover these conditions, who we imagine to be hardcore geeks, but in reality, are everyday humans, just like you and I!