Confusional arousals, also known as sleep drunkenness or sleep inertia, are partial or incomplete awakenings from sleep, during which people are confused and disoriented. Episodes are brief, between 1 and 10 minutes long, and can include small hand movements like picking at bedding, but don’t include gross motor activity like standing or walking.
People experiencing a confusional arousal won’t remember the episode later. These arousals are considered NREM parasomnias because they arise out of deeper, non-rapid-eye-movement sleep. Confusional arousals can sometimes evolve into sleepwalking, sleep-related eating disorder (SRED) or another NREM parasomnia.
Symptoms of Confusional Arousals
Confusional arousals involve brief periods of arousal after at least two hours of sleep, usually during the first third of the night. During these arousals, people may:
Show confusion, disorientation and slowed thinking
Perform fine motor activity, but not gross motor activity
Respond inappropriately to people and things in the room
Have amnesia of the event afterward
How Common are Confusional Arousals?
Like other NREM parasomnias, confusional arousals are more common in people who spend more time in NREM sleep. Young children experience more confusional arousals, which are usually outgrown after age 5. Prevalence in young adults 15-24 is 6 percent; rates drop to 1 percent for adults over 65.
What Causes Confusional Arousals?
Disorders of arousal, including confusional arousals, are influenced by genetics. Medications or substances that deepen sleep, including alcohol, can make confusional arousals more likely. Factors that disturb sleep, including travel, stress, anxiety, periodic limb movement disorder and obstructive sleep apnea, also increase the risk of experiencing confusional arousals.
Physicians usually diagnose confusional arousals in a clinical setting after reviewing a patient’s medical history and sleep patterns. When symptoms point to another sleep disorder, like restless legs syndrome or sleep apnea, a doctor may order an an overnight polysomnogram. This sleep study monitors heart, brain and lung activity overnight, and may help determine if an underlying sleep disorder is causing the arousals.
When these arousals result from another sleep disorder like sleep apnea, treating the underlying condition will often resolve the arousals. Confusional arousals themselves are generally harmless and don’t require treatment. When your child or bed partner experiences a confusional arousal, reassure him, but don’t wake him; he will soon return to sleep. Improving the sleep environment and helping your loved one avoid stress and anxiety can lead to more restful sleep for you both.