61. Disorders in sleep and wakefulness – insomnia.

DISORDERS IN SLEEP AND WAKEFULNESS – HYPERSOMNIA AND INSOMNIA

Hypersomnia

• Hypersomnia is a condition in which you feel excessive sleepiness during the day
• Hypersomnia can be:

1. Primary hypersomnia

• Occurs with no other medical conditions present
• The only symptom is excessive fatigue

2. Secondary hypersomnia

• Result of conditions that cause fatigue or insufficient sleep

Etiology of hypersomnia

1. Primary hypersomnia

• Idiopathic

2. Secondary hypersomnia

• Sleep apnea
• Parkinson’s disease
• Kidney failure
• Chronic fatigue syndrome

Symptoms of hypersomnia

• Constant tiredness
• Low energy
• Irritability
• Anxiety
• Loss of appetite

Insomnia

• Insomnia is characterised by chronic dissatisfaction with sleep quantity or quality that is associated with difficulty falling asleep, frequent nighttime awakenings with difficulty returning to sleep, and/or awakening earlier in the morning than desired
• The sleep difficulty occurs at least 3 nights per week, and present for at least 3 months

Pathophysiology of insomnia

• Insomnia may occur due to some neurobiological changes in the sleep-wake regulation mechanisms:
• Misalignment of the circadian process leading to phase delays or advances
• Delayed or advanced melatonin secretion
• Dysfunction of the homeostatic process
• Maladaptive behaviours reducing the homeostatic process
• The hyperarousal model of insomnia describes an increased activation of cognitive-emotional, behavioural, and autonomous processes during waking and sleeping hours
• Increased number of arousals during REM sleep
• Increased activity of the pituitary-adrenal axis
• Increased metabolic rate
• Increased body temperature
• Increased heart rate