Sleep and Sleep Disorders Lecture

Introduction to Sleep

• Definition: Temporary state of decreased consciousness, characterized by:
  • Reduced wakefulness
  • Inhibition of sensory information
  • Lowered muscle activity
• Functions:
  • Regenerates energy and restores tissues
  • Promotes memory formation through consolidation

Circadian Rhythm

• Regulated by Melatonin:
  • Secreted by the pineal gland in low light
  • Decreases wakefulness, promotes sleep
• Cortisol:
  • Peaks in the morning, increasing alertness

Sleep Cycle

• Cycle Duration: Approximately 90 minutes, with 4-6 cycles per night
• Stages:
  • Beta waves: Awake state
  • Alpha waves: Drowsy, in-between state
  • Theta waves: Stage 1 (light sleep)
  • Sleep spindles & K complexes: Stage 2 (full absence of consciousness)
  • Delta waves: Stages 3 & 4 (deep sleep)

REM Sleep

• Characteristics:
  • Rapid Eye Movement
  • Brain activity resembles wakefulness
  • Associated with dreaming
  • Muscle paralysis (except for breathing and eye movement)

Sleep Disorders

Insomnia

• Definition: Difficulty sleeping (falling asleep, staying asleep, waking early)
• Prevalence: Affects 30% occasionally, 5% chronic
• Risk Factors: Age, gender, psychiatric disorders
• Treatment:
  • Cognitive Behavioral Therapy for Insomnia (CBTi)
  • Hypnotic medications as last resort

Obstructive Sleep Apnea (OSA)

• Characteristics: Episodes of apnea due to airway obstruction
• Symptoms: Fatigue, headaches, possible insomnia
• Risk Factors: Snoring, high BMI, male gender
• Treatment: CPAP machine

Restless Leg Syndrome (RLS)

• Symptoms: Urge to move legs, worsens with rest
• Causes: Often idiopathic or related to iron deficiency
• Treatment: Lifestyle changes, medications like gabapentin

Circadian Rhythm Disorders

• Common in: Shift workers, frequent travelers
• Symptoms: Excessive daytime sleepiness, insomnia
• Treatment: Sleep hygiene, melatonin, light exposure

Parasomnias

Sleepwalking

• Characteristics: Performing activities while in deep sleep
• Common Activities: Walking, cooking

Nightmare Disorder

• Occurs in: REM sleep
• Association: Often linked with trauma

Sleep Terrors

• Occurs in: Non-REM sleep
• Symptoms: Distress without memory of dream

Sleep Paralysis

• Occurs in: Transition between REM and wakefulness
• Symptoms: Inability to move, hallucinations

REM Sleep Behavior Disorder

• Characteristics: Acting out dreams due to lack of muscle paralysis
• Treatment: Melatonin, safety precautions

Narcolepsy

• Symptoms: Excessive daytime sleepiness, cataplexy, sleep paralysis
• Treatment: Sodium oxybate, modafinil

Conclusion

• Importance of sleep for physical and mental health
• Assessing sleep patterns can improve quality of life

This lecture provides an overview of sleep and its disorders, emphasizing the importance of understanding and treating sleep-related issues for overall well-being.