Narcolepsy and the Stages of Sleep

Have you ever known anyone to fall asleep right in the middle of a conversation?  As in, speaking coherently one second and then WHAM - snoring the next?   Even if the person has had a full-night's rest?  



Thus far, I have only known one Narcoleptic and throughout the duration of our acquaintance never had the above experience occur - although her roommates did often hint about a umm... surprise event that happened over a long group trip from Montreal to Boston.    The person in question was apparently driving the car at the time. 


Nacrolepsy tends to be a bit misunderstood in the public mind, sometimes conceived of as a type of mental illness or a psychological problem.  

In truth, it once again devolves back down to Genetics: HLA-DQB (insert really long number).

Without going into the nitty gritty of it all (because you may as well read a textbook), a few general points of interest can be made.

• Narcoleptics can't really control nor fight off the "oncoming" snore as it were, in the same manner a person with epilepsy can't hold back a seizure. 

• Narcolepsy generally starts to manifest around Puberty to one's Mid-Twenties.  This little tidbit is actually important when one considers that the ratio of REM (Rapid-Eye Movement)/Non-REM sleep that each human receives changes around this critical time period.  I've seen an estimate of 50% REM in infancy/childhood to 25% in adolescence/adulthood.

• An interesting CoMorbidity is cataplexy, which is a temporary abrupt loss of muscle tone brought about by the stimulation of a person's emotions. So for example, if I were to make you Cry or Laugh, you would got through the emotion and then suddenly receive a manifestation - ranging from a mild weakness to the slackening of one's jaw to even total collapse.  Cataplexy has been seen to manifest in Narcoleptic patients prior to or after an episode.

But what is incredibly intriguing to me at least, is that the Narcoleptic can actually enter into REM sleep immediately  without going through the Stages of Sleep.   Heck technically, they can even undergo REM while awake, which leads to some interesting reports where the person in question is incapable of telling the difference between an ongoing hallucination and reality.


The Stages of Sleep

I've often found that people tend to think that going to sleep and waking up works like an On/Off situation - somewhat similar to the way a person might unplug their toaster oven.

Nothing could be further from the truth though.

Sleep (like Pain) is governed by a complicated set of neurobiological circuitry associated with the Reticular Formation - its a portion of the brain that runs through the Middle of the Brainstem between the midbrain to the medulla.

ie: That  Blue Thing.



So i think the takeaway point here is that as opposed to the "On/Off" light-switch model of sleep, what we think is going on rather is a bunch of homeostatic mechanisms making a concerted effort either Keep you Awake Or Keep you Asleep.  There is no total cessation of neuronal activity - that would probably actually be Death wouldn't?

Strap an EEG onto a person's head and once can actually track the changes in a person's electrical activity in the brain while he or she is starting to fall asleep.

Non-REM sleep comprises the majority of these stages..

Stage 1 is Slow Wave Sleep

Stage 2 is "true" Sleep

Stage 3 is Deep/Delta Slow Wave Sleep

 Now for those familiar with biology or physiology, what happens here isn't completely unexpected.  Your ParaSympathetics (Rest/Digest) turn on, your heart rate goes down, your muscles relax, and your oxygen consumption is low.

In terms of Dreaming - usually if a person is currently on one of these stages of sleep, those are the periods when one wakes up and doesn't remember their dream.  There isn't a consistent story or set of images associated with the dreams.

And then about 90 minutes into your trip to the dreamland,  a person enters Stage 4 REM Sleep.  

This is where all the very peculiar stuff begins.

• "Paradoxical Sleep": If you were to take an EEG of a person wide awake and a person in REM sleep they would look the same. 

• During REM - your Sympathetic (Fight or Flight) response switches on!    In fact, REM Sympathetic stimulation can be greater than when one is awake undergoing the most extreme physical activity.

• Yet REM is also the time period when a person experiences Dreams that Sorta Make Sense.  Dreams that have clear-cut images and associated storylines.  

One last interesting tidbit.   While "Bad dreams" do occur during REM, True Nightmares belong to the domain of Non-REM.  

I'm sure some of us have had either first or second hand experience with Pavor Nocturnus , latin for "Night Terrors" which afflict children in the midst of their sleep - only for them to wake up and not remember the thing that had them tossing and turning or screaming at the top of their lungs.

There is an adult version of this as well, dubbed Incubus

the name of which is taken from the old belief that demons or witches in the night would sometimes come to one's bedside and torment the sleeper with bad dreams accompanied by respiratory issues and paralysis.

Sweet Dreams....

Dr. Thomas Willis, the Oxford Boys, and The Discovery of the Brain

  

It may come a surprise to most people, but once upon a time no one really cared much about the Brain. 

We already have it on good authority that even the famed ritual mummifiers of ancient Egypt, those early masters of the anatomical arts, would often yank out the poor organ and toss it in the trash heap while preserving more valuable viscera like the Liver, the Lungs, Stomach, the Intestines and above all the Heart.

It wasn't until about the 17th century that someone actually paid close attention to the workings of the brain - a physician by the name of Thomas Willis.  His discovery was not made in isolation, for he was surrounded by some of the best and brightest of his age - names like John Locke (mostly known for his political writings - incidentally also a physician), the scientist Robert Boyle (come on Chemists.. Boyle's Law Ring a Bell?), as well as polymath and architect Christopher Wren who built St. Paul's Catherdral in the heart of London.

And they worked all this out while Trapped in Oxford..... because of a Raging Civil War between the supporters of the Stuart Monarchy versus the increasingly radicalized "puritanical" Round-Hounds, so called because they had short hair, that would eventually support the commoner-general Oliver Cromwell's act of regicide and declaration of Commonwealth.

So you've got one crazy explosive political situation that also happens to overlap with an increasingly strident sectarian debate about the nature of religion, society, and morality (translation: Lots of People Running Around Trying to Re-Write the Rules by Which Society worked) on top of what Dr. Willis and his friends were trying to accomplish.

Want a good quick read about the subject?  Check out the book up top, Soul Made Flesh by the science journalist Carl Zimmer.  I promise you, if you like situations such as the one described above, the book will be a very easy read.

But a few relevant things to chew on for those who don't have the time:

This was really the first case in history where a concerted effort was made by the think-tank par excellence of the era to actively investigate the workings of the Mind and the "mechanical aspects" of the Brain.  

At the heart of the tale lays this mere son of a local farmer, whose dissections exposed the Great Nerve Tracts to and from the Brain as well as the very basics of Neuroanatomy.

And yes..  Thomas Willis is where we get the name for the "Circle of Willis" - the arterial supply to the brain below.

This was also the time period when Willis, Locke, et al. did what every good Empiricist does - Experiment....by strapping down Dogs to dissecting tables and opening them up to explore things like the circulation of the blood, the effects of removing certain organs from the body, etc. etc.

Sounds pretty bad right?  But the information they gathered is essentially Knowledge that we in our modern era take for granted.

This was the dawning of a new age, a "Neurocentric" age that displaced older notions of the Heart as the Seat of our Preceptions and Cognitions. 

This was the Birth of Neuroscience.

About the Brain....from the Father of Medicine himself.

“Men ought to know that from nothing else but the brain come joys, delights, laughter, and sports, and sorrows, griefs, despondency, and lamentations.   And by this, in an especial manner, we acquire wisdom and knowledge, and see and hear and know what are foul and what are fair, what are bad and what are good, what are sweet, and what are unsavory.  …And by the same organ we become mad and delirious, and fears and terrors assail us. …  All these things we endure from the brain.”

-On the Sacred Disease, Hippocrates, 5^th Century BC