Sleep and sleep disorders Definition Sleep is an

Sleep and sleep disorders.

Definition Sleep is an ACTIVE process. It is a reversible state of unresponsiveness to stimuli of the outside world and to responses within the brain which underlie perception.

Sleep Architecture Normal sleep has 2 essential phases : - Non rapid eye movement sleep (NREM) strong reduction of physiological functioning. movement sleep (REM). y active brain with physiological ly levels similar to awake state.

: EEG shows the following In the awakening state : Alpha waves (9 to 10 Hz ) = Alpha activity REM sleep= S (Synchronized) sleep 75 - 80%) stage 1 : Law amplitude Theta waves (3 to 7 Hz ) with vertex sharp waves = initiation to sleep(5%) stage 2 : Sleep spindles + triphasic k complex = Light sleep (50% )

SWS) = Deep sleep ( stages 3 & 4 ) (15 -20%) stage 3 : Delta waves represent 20%- 50% (½- 1 Hz with amplitude greater than 75 m. V ) = Stage 4 : Delta waves more than 50%. In stages 3 &4(deep sleep) nocturnal enuresis sleep walking & night terrors may occurs Most of stage 4 occurs in 1 st third of the night.

REM sleep D (Desynchronized ) sleep Law amplitude mixed frequencies (Theta &Beta waves) Sawtooth waves – rolling of eyes – Law amplitude. Most of REM sleep occurs in the last third of night. 1 st episode occurs after a latency of 90 minutes and is the shortest (less than 10 minutes) later REM lasts from 15 to 40 minutes (4 to 5 episodes)

Features of non-REM sleep · ►· ►· ► reduced recall of dreaming if woken reduced complexity of dreams increased parasympathetic activity upward ocular deviation with few or no eye movements abolition of tendon reflexes decreased heart rate decreased systolic blood pressure decreased respiratory rate decreased cerebral blood flow penis not usually erect

Features of REM sleep ► ► ► · · · increased recall of dreams if woken increased complexity of dreams increased sympathetic activity transient runs of conjugate eye movements maximal loss of muscle tone increased heart rate increased systolic blood pressure increased respiratory rate increased cerebral blood flow occasional myoclonic jerks penile erection or increased vaginal blood flow increased protein synthesis (in rat brains)

Neuroanatomy of sleep Wakefulness : -Reticular formation -Thalamic Nuclei (intra laminar & midline) -Subthalamus -Hypothalamus SWS : -Raphe Nuclei of Brain stem (sleep promotion) -Thalamic Nuclei (non specific) - Hypothalamus

Neurophysiology of sleep Neurotransmitters of wakefulness: -Acetyl. Choline (cortex) -Noradrenaline (cortex) -peptides -Histamine -Corticotrophin releasing hormone -Thyrotrophin releasing hormone -Vasoactive intestinal polypeptide -ACTH & TRH

Neurotransmitters of SWS: - GABA acting to reduce sensory output to inhibit motor activity ) -Alpha-melanocyte secreting hormone - Somatostatin

► The monoaminergic model of the sleep-wake cycle ► · n. REM sleep is associated with serotonergic neuronal activity, originating in the raphe complex ► · REM sleep is associated with noradrenergic neuronal activity, originating in the locus coerulus ► The cellular model of the sleep-wake cycle pontine gigantocellular tegmental fields (nucleus reticularis pontis caudalis) – ► acetylcholine – is responsible for causing the onset of REM sleep; these are known as the ‘on cells’ ► ► ► these cells are inhibited by the dorsal raphe nuclei (5 -HT) and the locus coeruleus (NA); known as the ‘off cells’

SLEEP – WAKE CYCLE During sleep : All decrease Corticosteroids-catecholamine- reflexes- cardiac output peripheral BP gastric acid , metabolic , heart, respiratory rates , cerebral blood flow & brain GH & Prolactin are secreted During REM : Thermoregulation stops (No shivering or sweating)=POIKILOTHERMIC CONDITION Near paralysis of all muscles

Classification of sleep disorders Dysomnias 1 - DIMS - disorders of initiating and maintaining sleep a) Psychophysiological insomnia - transient and persistent b) DIMS associated with psychiatric disorder c) DIMS associated with drug and alcohol abuse d) Other conditions: i) restless leg syndrome

2 - DOES - disorders of excessive somnolence a) Psychophysiological DOES - transient and persistent b) DOES associated with psychiatric disorder c) DOES associated with drug and alcohol abuse d) Sleep apnea e) Narcolepsy f) Idiopathic CNS Hypersomnia g) Other medical conditions

Dysfunction associated with sleep, the sleep stages, and partial arousals (the Parasomnias) a) Sleep walking b) Night terrors c) Sleep related enuresis d) Dream anxiety attacks (nightmares) e) Sleep-related epilepsy f) Bruxism g) Head banging (a. k. a. jacatio capitis nocturnis) h) Body rocking i) Sleep paralysis j) Painful nocturnal penile erections ►

. Disorders of the sleep-wake cycle ► a) transient - jet lag or shift work ► b) persistent - people who frequently change their ► cycle e. g. business men

Insomnia ► Epidemiology 50 % lifetime prevalence ► more common in: ► · · · females the elderly unemployed separated lower socioeconomic class ► Neurological causes ► Psychiatric Illness · 40 % have a concurrent psychiatric disorder

Restless Leg Syndrome Deep sensation of creeping inside the calves sitting or lying down , not painful Interferes with sleep and falling asleep - Peak middle age - 5% of population -

Excessive daytime sleepiness Aetiology : 1 - Insufficient night sleep 2 - Pathological causes : -Obstructive sleep apnea -Narcolepsy -Drug effect -Kleine – Levin syndrome - Depression

Obstructive sleep apnea 2% of population – males –third are obeselate middle age Aetiology: Airways obstructed by fatty tissues leading to cessation of respiration many times per night CP : LOUD SNORING (95%) DAYTIME SLEEPINESS(90%) unrefreshed sleep morning headache& confusion, enuresis

Narcolepsy · characterized by excessive sleepiness associated with REM sleep phenomena such ► as: ► ► ► ► 1. Cataplexy a) sudden temporary episodes of paralysis with muscle tone, precipitated by strong emotion b) occurs in most cases 2. Sleep paralysis a) a transient and generalized inability to move or speak during the transition between sleep and wakefulness b) typically occur while falling asleep c) the paralysis is flaccid, and usually complete d) episodes usually last only a few seconds, and less than one minute 3. Hypnagogic hallucinations a) occur while falling asleep

The Kleine – Levin syndrome mmon (100 cases) affect young men ( onset in early adolescence ), self limiting , remission occurs spontaneously before 40 -Period of hypersomnia ( one or several weeks ) -Alternating with periods of normal sleep Marked by withdrawal from social activities, return to bed at first opportunity , apathy , confusion irritability, loss of sex inhibition, delusions , or hallucinations.

Parasomnias 1 - Abnormality of REM sleep ►· Nightmares an awakening from REM sleep to full consciousness with detailed dream recall ► · usually occur in the 1 st third of nocturnal sleep ► · causes: ► · frightening experiences during the day ► · PTSD ► · fever ► · psychotropic drugs ► · alcohol detoxification

Abnormality of n. REM sleep 1 - Night terror disorder ►· sometimes familial ► · begins and ends in childhood ► · child awakes terrified and may scream, and usually appears confused ► · occurs in stage 3 -4 sleep ► · usually occur in the 1 st third of nocturnal sleep ► · there is little or no dream recall

(2 - Sleep walking (somnambulism · an automatism occurring during deep non-REM sleep (stages 3 and 4), usually in ► the early part of the night ► · affects 1 % of the population ► · M>F ► · associated with enuresis ► · most common between the ages of 5 and 12 years ► · 15 % of this age group sleepwalk at least once ► · may be familial ► · possibly due to an abnormality of deep sleep – subject goes from deep sleep to ► wakefulness ►

Circadian Rhythm sleep disorders Circadian means following 24 Hours rhythm Pacemaker of this rhythm is the Suprachiasmatic Nucleus ( SCN) TYPES OF DISORDERS : Transient : jet lag or shift work Persistent : in some jobs

The effects of drugs on sleep

Alcohol Biphasic effect : - In the first half of night : decrease sleep onset latency ( promotes sleep initiation ) , increase deep sleep , decrease REM sleep - In the second half : rebound increase in REM sleep Chronic use : disruption of all stages of sleep Withdrawal : decrease total sleep time & n. REM sleep

Sleep and psychiatric illness ► 1. Depression a) reduced stage 3 and 4 b) reduced REM latency c) REM occurs earlier in night ► 2. schizophrenia a) reduced slow wave sleep b) reduced REM ► 3. Anxiety a) increased stage 1 and 2 b) reduced effecieny of sleep ► 4. Panic disorder a) increased sleep latency

► 5. Alcoholism a) increased delta b) increased REM sleep c) increased alpha activity ► 6. Alzheimer’s disease a) increased sleep b) fragmentation c) reduced sleep efficiency

Sleep and Age As we get older : -We have more difficulty in initiating sleep - We awaken more often -We take more time to fall back to sleep -we fall asleep frequently during the day Studying sleep is by using polysomnography in Sleep Lab

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► ► ► ► · · · disturbance of sleep continuity more time awake increased sleep fragmentation early morning wakening disturbance in the sleep architecture · · · decreased slow wave sleep disturbance in REM sleep shortened REM latency more REM activity (higher % in first ½ of the night) higher REM density sleep deprivation (esp. deprivation of REM sleep) has a beneficial effect on mood in depressed patients ►· ► antidepressants destroy REM sleep - there is a rebound of REM sleep on discontinuation