Neuroscience: Sleep & Sleep Disorders (TEST)

Here are the objectives: Define sleep, parasomnias, insomnia, and narcolepsy. Describe the anatomy and physiology of sleep (stages of sleep). Describe the patterns of sleep according to age. List good sleep hygiene routines. Identify sleep disorders. (Include insomnia and narcolepsy) Explain the importance of sleep.

What is the definition of sleep?

a state of reduced mental and physical activity in which consciousness is altered and certain sensory activity is inhibited

What is the suprachiasmatic nucleus (SCN)?

clusters of thousands of cells that receive information about light exposure directly from the eyes and control the behavioral rhythm

What is the hypothalamus’ role in sleep?

contains groups of nerve cells that act as control centers affecting sleep and arousal

What does the SCN do?

sends signals to the pineal gland increasing the production of the hormone melatonin, once the lights go down

What is Stage 1 of Non-REM Sleep?

Stage 1 sleep (change over from wakefulness to sleep) 

• short period (5% of total sleep) 

• light sleep

• slow eye movements

• muscles relax with occasional twitches  

What is Stage 2 of Non-REM Sleep?

• Longer stage (45%)

• Deeper sleep

• The heartbeat and breathing slow, and muscles relax even further

• Body temperature drops 

What is Stage 3 of Non-REM Sleep?

• It takes about 25% of total sleep.

• Deepest sleep people need to feel refreshed in the morning.  

• It may be difficult to be awakened

What is REM Sleep?

• It occurs every 90 minutes 

• The eyes move rapidly from side to side behind closed eyelids.  

• Breathing becomes faster and irregular, and your heart rate and blood pressure increase to near waking levels

• Most of dreaming occurs during REM sleep 

• Your arm and leg muscles become temporarily paralyzed, which prevents you from acting out our dreams.  

• REM sleep decreases in elderly

What is a parasomnia?

• sleep disorder that involves unusual and undesirable physical events or experiences that disrupt your sleep

• can occur before or during sleep or during arousal from sleep

What are characteristics of parasomnias?

• Abnormal movements

• Talking and express emotions or do unusual things

What are non-REM parasomnias?

• People are not completely awake or aware during these events

• People usually don’t remember or only partially remember the event the next day

• Occur between 5 and 25 years of age

• Non-REM parasomnias often occur in people who have a family history of similar parasomnias

What are sleep terrors (non-REM)?

• Usually brief

• crying, screaming

• common in younger children

What is sleepwalking (somnambulism) (non-REM)?

• Sleepwalkers get out of bed, move about with the eyes wide open, but they are asleep. 

• Mumbling or sleep talking.

• Performing complex activities (driving, playing a musical instrument, or move furniture)

• It can lead to injuries

What is Nocturnal lagophthalmos?

• sleeping w/ eyes open

• causes →

What is Nightmare Disorder? (REM sleep)

• Vivid dreams that cause feelings of fear, terror and/or anxiety

• People may feel a threat to their survival or security

• People are able to describe their dream in detail

• Trouble falling back to sleep. 

• More likely to occur if the person is under stress or experience a traumatic event, illness/fever, extreme tiredness or after alcohol consumption

What are Lucid Dreams (REM sleep)?

• A lucid dream occurs when a person is asleep but aware that they are dreaming.

• A person can take control of their dream’s narrative to some degree, essentially guiding and directing the course of their dream.

• There is a recognition that what is happening is not real and that it is taking place within a dream

What is Recurrent Isolated Sleep Paralysis (REM Sleep)?

• Inability to move the body or limbs during sleep. 

• Scientists think the paralysis might be caused by an extension of REM sleep – a stage in which muscles are already in a relaxed state. 

• It happens before falling asleep or while waking up. 

• Episodes last seconds to a few minutes and are distressing, usually causing anxiety or fear. 

• Sleep paralysis can be stopped if a person’s bed partner speaks or touches them

What is REM Sleep Behavior Disorder (RSBD) (REM Sleep)?

• People act out, vocalize (e.g., talk, swear, laugh, shout), or make aggressive movements (e.g., punching, kicking, grabbing) as a reaction to a violent dream

• This sleep disorder is more common among older adults

•  Many people with this disorder have neurodegenerative disease, such as Parkinson’s disease, Lewy body dementia, or stroke

What is insomnia?

• having trouble falling or staying asleep.

• When people don’t sleep enough, it can cause sleep deprivation, that keeps people from functioning at their best.

How is insomnia classified?

• Acute (short-term)

  Chronic (long-term, known as insomnia disorder)

• Primary insomnia (it happens on its own, even when a person has time and the right environment to do so.).

  Secondary insomnia (it is a symptom of another condition or circumstance, such as changes in work schedule, life events)

What causes secondary insomnia?

• Family history (genetics)

• Medical conditions (minor infections or injuries, acid reflux, or Parkinson’s disease, and conditions that affect your circadian rhythm)

• Anxiety or depression

• Life circumstances

• Life changes (jet lag, sleeping in an unfamiliar place or adjusting to a new work schedule, moving to a new home)

• Habits and routine (taking naps, consuming caffeine)

What are the 3 main ways people have trouble sleeping?

• Initial (sleep onset) insomnia

• Middle (maintenance) insomnia

• Late (early waking) insomnia

What are the daytime effects of insomnia?

• Feeling tired, unwell or sleepy

• Delayed responses, such as reacting too slowly when you’re driving

• Trouble remembering things

• Slowed thought processes, confusion or trouble concentrating

• Mood disruptions, especially anxiety, depression and irritability

• Other disruptions in your work, social activities, hobbies or other routine activities

What is the treatment for insomnia?

• Developing and practicing good sleep habits (also known as sleep hygiene)

• Medications that help you fall or stay asleep (especially ones that aren’t habit-forming or that might otherwise affect your sleep)

• Mental healthcare

What is Narcolepsy?

• Condition where the brain can’t control the ability to sleep or stay awake. 

• People with this condition often fall asleep during the day.

• Going into the REM stage shortly after falling asleep

• This condition is serious and disruptive

• Patients usually respond well to treatment

What are the symptoms of Narcolepsy?

• Excessive daytime sleepiness

• Sudden muscle weakness (cataplexy)

• Sleep-related hallucinations

• Sleep paralysis

What is cataplexy?

• sudden muscle weakness

• Not every one with narcolepsy experiences this symptom

• People with cataplexy will have sudden muscle weakness, similar to how your body blocks movements during REM sleep

What are other symptoms of Narcolepsy?

Automatic movements. People with narcolepsy can often fall asleep, but may keep moving parts of their body like their hands

Amnesia or forgetfulness. It’s common for people with this condition to not remember what they were doing right before falling asleep.

Sudden outbursts around sleep attacks. A person with narcolepsy may suddenly speak up and say something (usually words or phrases that are nonsensical or unrelated to what’s happening around them). When someone with narcolepsy does this, it might startle them back to being fully awake, but most people who do this also don’t remember doing it

What causes Narcolepsy?

• loss of orexins - a neurotransmitter crucial for regulating wakefulness and suppressing REM sleep

• certain viral and bacterial infections

• damage to hypothalamus

What are similarities/differences with insomnia and Narcolepsy?

Similarities:

• Feeling tired throughout the day

• Forgetfullness/trouble remembering things

• Keeps people from functioning best they can

Differences:

• Insomnia - trouble falling/staying asleep

• Narcolepsy - can’t control ability to sleep or stay awake

What are good sleep hygeine routines?

1. Setting a schedule of waking up and going to bed at the same time everyday

2. Exercising 20-30 minutes a day a few hours before bed

3. Avoiding caffeine, nicotine, and alcohol before bed

4. Relaxing and creating a comfortable room without lights and TVs

5. Laying in bed awake can make you stay awake longer, so reading a book until you feel tired can also help

What is the pattern of sleep as you age?

1. Infants sleep 16-18 hours everyday - it’s essential for growth and brain development

2. Children and teens need about 9.5 hours of sleep

3. Adults need around 7-9 hours

4. Over 60, sleeping is typically shorter, lighter, and you wake up more often, which can sometimes be from medications that they’re taking