Psychological sleep disorders: Pathology review

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Case study0:00–0:47

A 31 year old male named Hercules comes to the clinic complaining of excessive daytime sleepiness over the past year. Despite getting a regular 7 to 9 hour sleep every night, this has recently started to interfere with his job since he keeps dozing off at his desk during meetings or even while talking on the phone.
Hercules is also concerned because he sometimes has very vivid dreamlike sensations right before falling asleep, like seeing other people in the room on further questioning.
Hercules also mentions that when he gets really nervous or excited about something, he feels as if he cannot move his legs and might even fall down past medical history and physical examination are both unremarkable.

Pathophysiology0:47–2:29

Based on the initial presentation, Hercules seems to have some form of sleep disorder. Many of us can have trouble falling asleep or may sleep too much from time to time, usually because of stress or a temporary illness.
But when sleep problems become a regular occurrence and interfere with daily life, that's a sign of a sleep disorder for your exams.
Remember that sleep disorders are usually caused by factors that interrupt the sleep cycle, which is a period of sleep that lasts about 90 minutes and is divided into four stages.
The first three stages make up non rem or NR em sleep, which stands for non rapid eye movement. So usually during non rem sleep, our eyes don't move much or at all.
However, keep in mind that the voluntary muscles of the body may still be active. Nrem.
Sleep accounts for roughly 80% of the sleep cycle. And across the three stages of nrem, we move from very light sleep during stage one to very deep sleep.
In stage three, this is followed by stage four, which is known as rapid eye movement or rem sleep. And accounts for the last 20% of the sleep cycle during rem sleep.
The eyes dart around really fast and this is where dreaming occurs and memories are consolidated during rem sleep, the voluntary muscles of the body are paralyzed probably to prevent people from acting out their dreams.
Now, rem sleep is then followed again by non rem sleep. And over the course of the night, there are four or five of these sleep cycles.
Ok. Now, for your test, the most high yield sleep disorders include sleep terror disorder, enuresis and narcolepsy.

Sleep terror disorder2:29–3:43

Let's start with sleep terror disorder for your exams. Remember that this is typically triggered by stress or fatigue fever or sleep deprivation and is most common in Children.
So, in sleep terror disorder, individuals partially wake up during deep sleep or stage three of nrem sleep and suddenly start screaming or crying.
And this turns on the sympathetic nervous system which can lead to mydriasis or dilated pupils, tachycardia or rapid heart rate, tachypnea, or rapid breathing and sweating.
What's extremely high yield is that individuals usually return to sleep right afterwards. And the next day, they have no recollection of the episode for your exams.
Make sure you're able to set sleep terrors apart from nightmares which typically occur during rem sleep and individuals wake up right away and the next day they are able to recall the episode.
Ok. Now, because sleep is disrupted, people with sleep terror disorder often feel chronically fatigued, which can lead to distress and impairment in a person's life.
Good news is that sleep terror disorder is typically self-limited and tends to resolve spontaneously by puberty. So no treatment is needed.
Next is enuresis also commonly known as bedwetting where individuals repeatedly urinate on themselves while asleep for your exams.

Enuresis3:43–5:26

Remember that in order to make a diagnosis, this needs to occur at least twice a week for at least three consecutive months in someone older than five years of age to be considered a disorder.
It's also important to rule out other disorders that could have the same presentation such as urinary tract infections and structural urologic abnormalities.
And this can be done with laboratory tests such as urinalysis and urine culture as well as imaging test such as abdominal x-rays and ultrasound.
Regarding treatment most Children outgrow their bed wetting successfully by the time they reach puberty, if the enuresis persists, they are usually treated using behavioral modification techniques.
These consist mostly of restricting fluid consumption in the evening as well as changing nighttime toileting habits by encouraging the child to void at scheduled times, especially before bed.
Adults can also help Children avoid shame and embarrassment via positive reinforcement by rewarding certain positive behaviors like going to the toilet.
If these don't work, individuals may use a bedwetting alarm and have the child sleep on a special pad that sets off the alarm when it becomes wet.
Refractory cases may consider taking a medication like desmopressin, which is an analog of the antidiuretic hormone or a DH.
An alternative is imipramine, a tricyclic antidepressant. However, for your test, remember that imipramine is usually avoided due to its severe side effects including cardiotoxicity, convulsions and coma.

Narcolepsy5:26–8:38

Ok. The last high yield sleep disorder is narcolepsy.
Normally in the lateral hypothalamus. There is a special group of neurons that produce the neurotransmitters, orexins ak A hypocretin while we're awake, orexins have an excitatory effect that promotes wakefulness across the day.
Keep in mind that Orexin production stops at night to promote sleep. Now, for unknown reasons in individuals with narcolepsy, an autoimmune process kills off nearly all the Orexin producing neurons during puberty.
As a result, there's a lack of erections which presents with four key symptoms. The first one is excessive daytime sleepiness.
Despite adequate sleep at night to the point where people with narcolepsy can have brief sleep episodes where they doze off and fall asleep with little warning at any time or place.
Most often, these sleep episodes occur during periods of quiet or boredom such as when sitting down in class or while working on the computer.
But they can also happen during activities like walking or driving. In which case, it can be life threatening.
The second major symptom is cataplexy, which is unique for narcolepsy and refers to sudden episodes of muscle weakness that can be triggered by strong positive or negative emotions such as laughter or intense anger.
Most often cataplexy affects only the face and neck. But severe episodes can cause total body weakness or paralysis, causing the person to slump to the ground, unable to move for a minute or two.
Even though they are awake and conscious, the third symptom is sleep paralysis, which is the complete inability to move for a few seconds to minutes immediately after waking up or right when falling asleep.
Now remember that during rem sleep, the voluntary muscles of the body are paralyzed. This paralysis generally subsides before we wake up.
But occasionally we regain consciousness before the paralysis has worn off. And with narcolepsy, this occurs pretty frequently.
In addition, episodes of sleep paralysis can be even more frightening when they are accompanied by hypnopompic hallucinations.
The fourth and final key symptom are vivid hallucinations which may occur when falling asleep. In which case, they're called hypnagogic hallucinations or upon awakening, which are called hypnopompic hallucinations.
And that's extremely high yield for your exams. Commonly reported hallucinations include seeing a threatening stranger or animals in the bedroom.
Now, unlike the other two sleeping disorders, narcolepsy is a long term disorder that can't be cured. However, there are some treatment options aimed at improving the individual's quality of life.
This includes sleep habits like having a strict and regular sleeping schedule with brief naps throughout the day. Some individuals may also benefit from treatment with stimulant medications like dextro amphetamine, sulfate or modafinil that can be used during the day to help manage daytime sleepiness.
Whereas sodium oxidate AK A gamma hydroxybutyrate or G HB can be used at nighttime to help improve sleep. All right.

Review8:38–9:30

As a quick recap, sleep terror disorder usually affects Children and episodes can be triggered by stress fever or lack of sleep.
Individuals partially wake up during nr em sleep and start screaming or crying. But the next day, they have no recollection of the episode with enuresis, individuals who are older than five years of age repeatedly urinate on themselves while asleep at least twice a week for at least three consecutive months.
And it's important to rule out underlying disorders like urinary tract infections or structural urologic abnormalities. Finally, in narcolepsy, there's a lack of orexin, a neurotransmitter that normally promotes a state of wakefulness as a result, individuals present with excessive daytime sleepiness, cataplexy, sleep paralysis, and hypnogogic or hypnopompic hallucinations.

Summary9:30–10:00

Ok. Back to our case, Hercules is a 31 year old man that comes to the clinic complaining of excessive daytime sleepiness despite adequate sleep during the night.
This combined with the vivid dreams right before falling asleep, which is a description of hypnagogic hallucinations should immediately make you think of narcolepsy.
The final clue is that Hercules experiences episodes of cataplexy as he cannot move his legs when he gets really nervous or excited about something, which is unique for narcolepsy.