Causes

Isolated sleep paralysis is more likely to happen during the first two hours of sleep. Not getting enough sleep or sleeping on the back may cause more frequent episodes.

Though this condition may occur with narcolepsy, many people who do not have narcolepsy have isolated sleep paralysis. It is common in adults and is also seen in children.

Most people with isolated sleep paralysis do not have any mental health problems. However, these episodes seem to occur more often in people with:

• Anxiety disorders
• Bipolar illness
• Depression
• Post-traumatic stress disorder

Rarely, it runs in families.

Symptoms

People with isolated sleep paralysis have episodes that last from a few seconds to 1 or 2 minutes in which they are unable to move or speak.

• These spells end on their own or when the person is touched or moved.
• Rarely, the person may have dream-like sensations or hallucinations, which may be scary to them.

Exams and Tests

If you do not have other symptoms of narcolepsy, there is usually no need to perform sleep studies.

Alternative Names

Sleep paralysis - isolated

References

ChokrovertyS. Sleep and its disorders. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann Elsevier; 2008:chap 72.

Mahowald MW. Disorders of sleep. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 429.

Update Date: 5/22/2012

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.