Parasomnia is a category of sleep related / sleep behavior disorders characterized by disturbance of sleep. Parasomnias usually involve sleep experiences that affect physical or verbal behavior. Parasomnia sleep behavior disorders may involve any abnormal movement, behavior, emotion, perception and dream (nightmares) during sleep.Parasomnia can occur in any stage of sleep or the transition between sleep-wake stage.

NREM & REM Sleep Stages

The experience of sleep can be divided into two phases – NREM (Non Rapid Eye Movement) or REM (Rapid Eye Movement) sleep. Parasomnia disorders can occur in either of these two phases.NREM sleep is the transition phase, from wakefulness to ‘deep sleep’ and then into the dream stages of sleep (REM sleep). NREM sleep and has 4 distinct stages known as stage 1 to stage 4. and is then followed REM sleep which is the period during which dreams and nightmares may occur. A  natural sleep cycle consists of many episodes of NREM sleep followed my REM sleep in a single night’s sleep.

Types of Sleep Behavior Disorders – NREM & REM Parasomnias

Parasomnias include a wide range of sleep related behavior occurring at different stages of NREM and REM sleep.

• Night terror disorder (sleep terrors or pavor nocturnus)
• Sleepwalking (somnambulism)
• Sleep talking  (somniloquy)
• Nightmares
• Confusion arousals
• Rhythmic movement disorder (jactatio capitis nocturna)
• Sleep bruxism (jaw clenching that may cause clicking jaw or TMJ dysfunction)
• Sleep paralysis
• Restless legs syndrome (RLS)
• Periodic Limb Movement Disorder
• Nocturnal Leg Cramps
• Sleep enuresis (bedwetting)
• Sleep related painful or impaired penile erections