Sleep and Sleep Disorders Dr. Y R Bhattarai TMU

Normal sleep Measured by eletroencephalogram (EEG) Sleep is made up two physiological stages. Measured by eletroencephalogram (EEG) Non-rapid eye movement (NREM) sleep Stage characterized by Slowing of the EEG rhythms High muscle tone Absence of eye movements Brain is inactive while the body is active

REM sleep Rapid eye movement (REM) sleep Spontaneous rapid eye movement Dreaming Body movement is absent Sexual arousal Brain is active and body is inactive heart rate, blood pressure, respiration are variable

NREM and REM sleep Awake (stage 0) : alpha waves (8-12cps, low voltage)‏ NREM sleep : increasing depth Stage 1: very light sleep, transition from wakefulness to sleep, drowsy reduced alpha activity Stage 2: medium depth of sleep, occupies about half the night in adults. EEG shows sleep spindles and k complexes DELTA SLEEP Stage 3: deeper sleep than stage2 Stage 4: very deep stage of sleep. REM sleep: Dream sleep. EEG is active mimicking that of the wakening stage. low voltage, mixed frequency with sawtooth waves.

Sleep cycles NREM and REM sleep alternate cyclically throughout the night. Start with NREM 80 minutes followed by REM 10 minutes Cycles repeat 3-6 times per night Sleep latency: time needed before you actually fall asleep. Typically less than 15 minutes. Increased in many disorders like insomnia.

Neurotransmitters of sleep Serotonin: initiates sleep Acetylcholine: linked to REM sleep. Increased during sleep Norephinephrine: linked to REM sleep. Decreased during sleep Dopamine: linked to arousal and wakefulness. Increased during sleep

Chemical effects on sleep Benzodiazepines: suppresses stage 4 and when used chronically, increases sleep latency Alcohol intoxications: suppresses REM Alcohol and barbiturate withdrawal: REM rebound. Major depression: increased REM time, multiple awakenings and early morning awakening.

Question? How many hours do we need for sleep per night?

Sleep requirements Neonates: 16-18hrs/24 hrs 1year: 12hr 10year: 10hr From infancy to old age Total sleep time decreases REM percentage decreases Stage 3 and 4 tend to vanish

A case….. While studying for an important exam, Michael, a third year college student has been unable to sleep for the past several days. At night he lies awake and imagines himself doing poorly on the exam and failing medical school. During the day, he is tired and frequently falls asleep during his classes. Provisional diagnosis?

Sleep Disorders Disorders of initiating and maintaining sleep: insomnia Disorders of excessive somnolence: hypersomnia Parasomnias like night terrors, nightmares and sleepwalking.

Insomnia A disorder characterized by difficulties in initiating or maintaining sleep. Most common sleep complaint 15% of people have chronic insomnia. Brief insomnia is most often associated with anxiety: examination Persistent insomnia is most difficulty in falling asleep. Chronic insomnia if insomnia persists for more than 6 months

Risk factors Situational stressors : job problem, marital discord; study pressure. Aging: the older the age, the lesser the sleep Drugs: caffeine, alcohol, withdrawal from some drugs Psychiatric disorders (especially in women): depression, etc Sex: more common in females.

Physical & psychiatric symptoms Predominant complaint is difficulty in initiating or maintaining sleep Affects the patient’s level of functioning Frequent yawning and tiredness during the day

Treatments for insomnia Psychotherapy: change the cognition Medication: Benzodiazepine: reduce time in Delta sleep They should be considered for a short period of time If used for prolonged time, rebound insomnia occurs.

Treatment for insomnia... Behavioral intervention strategies Progressive relaxation techniques Biofeedback : muscle feedback, relaxation training Sleep restriction Stimulus control Hot bath several hours before bed

Treatment for insomnia....‏ Sleep hygiene techniques Regular sleep-wake schedule Reduced light and noise Eliminate caffeine, smoking, alcohol Cool room Exercise during the day Reduce activity at night Avoiding daytime naps

Differential diagnosis Medical: CNS lesions, endocrine diseases, aging, alcohol, diet, medications Psychiatric: anxiety, tension, depression etc

Hypersomnia Excessive sleepiness Complaint in narcolepsy and sleep apnea syndrome

Narcolepsy Sleep attack: fall sleep while doing something, last 15 minutes for a period of greater than 3 months This is an abnormality of REM sleep.

Physical and psychiatric symptoms Sleep attack: most common symptom Cataplexy: a sudden loss of muscle tone, often initiated by an intense emotion Sleep paralysis: unable to move a muscle when awake and conscious Hypnogogic and hypnopompic hallucinations: visual or auditory hallcinations may precede sleep or occur during the sleep attack. Report falling asleep quickly at night.

Treatment Forced naps at a regular time of day is usually the treatment of choice If medications need to be prescribed, psycho stimulants are preferred. If cataplexy are present, antidepressants like TCAs are preferred.

Case… An overweight man reports having difficulties in his marriage because of his snoring at night. During the day, he reports feeling tired. What's the provisional diagnosis?

Sleep apnea Disorder characterized by the cessation of airflow at nose or mouth during sleep. Each apneic episodes usually last longer than 10 seconds. Characterized by loud snore followed by a heavy pause Physical and psychiatric presenting symptoms Excessive sleepiness during the day Loud snoring at night Decreased attention span Complain of being tired during the day time. Decreased memory Hyperirritability

Treatment for sleep apnea Behavioral intervention: sleep position training,weight loss, exercise, and alcohol reduction Mechanical intervention: clear the airway Surgery Sometimes progesterone, the respiratory stimulants, can be given.

Sleep disorders common to children Enuresis (bed- wetting)‏ Sleepwalking disorder Sleep terror disorder: no memory of the event Nightmares: memory of the event upon awakening. Sleep talking

When we are sleeping… An active disengagement from our environment; Shut out sensory input; Cease to be aware of the outer world; Brain waves change; Eye movement slow; Dream; Memory close…

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