What is Sleep? Little movement—walking, talking, writing, etc., usually preclude a judgment of sleep. A stereotypic posture — usually we are lying down when we are asleep, and with rare exception, it is safe to say that people who are, for example, standing on their hands, are not asleep. A reduced response to stimulation — we do not respond to low intensity sounds, touches, etc., which we would be aware of instantly during wakefulness. Reversibility — we know that we can readily awake from sleep, which distinguishes it from coma or death.

Sleep is Heterogeneous

5 Copyright © 2004 Allyn and Bacon

Divisions of Sleep Stages REM sleep: A period of desynchronized EEG activity during sleep, at which time dreaming, rapid eye movements, and muscular paralysis occur. Non-REM sleep: All stages of sleep except REM sleep. Slow-wave sleep: Stage III and Stage IV of Non-REM sleep, characterized by slow, high amplitude (Delta Waves) synchronized EEG activity. 6

Sleep is Cyclical

Neurobiology of Sleep Sleep is NOT simply the diminished function of waking systems. Sleep is an active physiological process requiring the co-ordination of a slew of neurotransmitters and “sleep factors” acting simultaneously at different areas of the brain.

9 Activation of GABA neurons in PONS Decreases activity in NE (Locus Ceruleus) and Serotonin (Raphe Nuclei) systems Increases ACh release (Pontine Nuclei) Activates glutamate neurons in Pons Glutamate neurons activate Glycine neurons in the Medulla Glycine neurons fire onto and inhibit motor neurons in the Spinal Cord causing sleep paralysis Deactivates rhythmic synchronous firing patterns in Thalamus causing asynchronous waves of REM sleep in cortex

Sleep Disorders

Categories of Sleep Disorders Dyssomnias Problem with quantity, quality or timing of sleep. Parasomnias Relatively normal quality, quantity and timing of sleep, but something odd happens during sleep itself or during the times when the patient is falling asleep or waking up.

Dyssomnias Insomnia Not enough sleep is usually the presenting complaint (for at least a month). Usually as a result of an Axis I or II or general medical condition (rarely shows up by itself). MUST evaluate the cause of the Insomnia for proper treatment decisions. If no other Axis I, II or III disorders are made then it’s: Primary Insomnia

Dyssomnias Primary Hypersomnia Presenting complaint is that they sleep too much. Usually fall asleep quickly and sleep late the next day. Frequently complain of being chronically tired and sleepy during the day (may take naps) Sleep 9+ hours/day

Dyssomnias Narcolepsy Four major symptoms (do not have to have all of them): Sleep attacks Irresistible urge to fall asleep. Cataplexy Sudden bilateral loss of muscle tone Hallucinations (usually visual) Hypnagogic or hypnopompic Sleep paralysis Sensation of being awake, but unable to move, speak or even breathe adequately Associated with anxiety and fear of dying (lasts < 10 mins)

Narcolepsy REM sleep intrusions Uncommon, chronic, largely hereditary disorder that is difficult to manage & requires lifelong treatment. No gender differences. Onset is usually in puberty – always before age 30. Slow steady progression of symptoms Can lead to depression, impotence, work problems, accidents Not related to a general medical condition or substances/medications Treatment: Stimulants (e.g. Ritalin)

Breathing-Related Sleep Disorder Low oxygen levels in blood Causes insomnia or hypersomnia Symptoms Alveolar hypoventilation syndrome Sleep apnea (relatively common) Obstructive Central Use Axis III to specify which medical condition

Circadian Rhythm Sleep Disorder Circadian comes from about one day (circa = approximately; dia = day) Presenting problem: sleep-wake cycle is off NOTE: this cycle is not constant through the lifespan Two major types of Circadian Rhythm Sleep Disorder Jet Lag Type Shift Work Type

Dyssomnia NOS Complaints of clinically significant insomnia or hypersomnia related to the environment (e.g. airlines, trains, lights) Restless legs syndrome Sleep deprivation sleepiness.

Parasomnias These are problems that encroach on sleep but don’t cause insomnia or hypersomnia. Example Nightmares vs. Sleep apnea Scary vs. causing sleepiness during the next day

Nightmare Disorder Nightmares occur during REM sleep Those that occur during childhood have no pathological significance. Nightmares are very common – when does it become a disorder? Vivid nightmares sometime precede a psychosis. However most Nightmares are normal a reaction to stress

Sleep Terror Disorder Usually affect children (not pathological) Occur during non-REM sleep (most common early during the night). Attack lasts 5-15 minutes and ends with the individual going back to sleep. In adults the disorder is rare and usually coincides with another Axis I disorder (anxiety?) or a personality disorder.

Sleepwalking Disorder Usually occurs during first third of the night (non-REM sleep) Some purposeful behavior is not uncommon (dressing, eating, using bathroom) but facial expression is blank and speech is either non-existent or garbled. Usually have amnesia regarding incident Incident can last from a few seconds to 30 minutes. Hard to reawaken (not dangerous) 1-5% of children, <1% of adults

Parasomnia NOS Sleep paralysis\ Bruxism Sleep-related cluster headaches

Sleep disorders related to another Mental Disorder Depression Anxiety disorders Adjustment disorders Somatization disorders Cognitive Disorders Manic/Hypomanic Episodes Schizophrenia