Locked-In Syndrome is officially the most terrifying condition I have learned about so far. In my opinion, it is worse than any form of cancer. It is worse than leprosy. It is worse than flesh-eating bacteria, or Huntington's Chorea, or Broca's Aphasia. It is worse than having all of your limbs surgically amputated. It is worse than being paralyzed from the neck down. Locked-In Syndrome results from strokes to the ventral pons - the shaded region labeled 11 in the diagram above. For clarification, the pons is part of your brainstem - see Region 5 in the midsagittal cross-section below:
When blood supply to the ventral pons is cut off long enough for the cells there to die, you lose all motor function except a select few movements. While there is some variability in severity of conditions, this often means no unassisted breathing, no swallowing, no facial expressions, no eye movements - NOTHING. From what I have read, eye movements are the most commonly retained ability, but even with that, sometimes the only movement retained is of both (in some cases only one) eyelid.
The worst part is that people with this condition can still feel everything. If their eye is dry because they haven't blinked, it will itch and burn like it would for you or me. If they have some saliva trickling down their throat into their lungs, they will feel the need to cough but won't be able to. If they contract pneumonia from not having their lungs get sufficient ventilation (or from never being able to cough up bacteria), the pain and discomfort will be every bit as real and constant for them as it would be for anyone else with pneumonia, but they won't be able to do anything. And unless someone notices that they are able to move their eyelid in a non-random manner and works out a method of communication so that they can speak one excruciatingly slow letter at a time, they will have no way to tell anyone about their pain or discomfort.
It is reading about conditions like this in class (and then searching about real people who have them) that makes me feel horribly ashamed for the minor complaints to which I so regularly give voice. Who am I to complain about feeling tired because I stayed up too late studying, or because I feel sore the day after moving furniture? Sometimes perspective like that which is provided by Locked-In Syndrome is like a slap to the face. I have nothing to complain about, and vast mountains for which I should be eternally grateful. We all do. No matter what our situation is, it can't possibly be as bad as being stuck in a bed, unable to communicate with the world around us, while still feeling like you did the day before - remembering what it is like to move and laugh and talk and hold hands and swim and drive and run and kiss, all the while knowing that you will never do any of that again. Knowing that you will just lie there every day for the rest of your life. Until some bacterial infection gets overlooked, you contract pneumonia and can't fight it off, and you die drowning in your own pulmonary pus. I can't imagine a worse form of torture than that...