Diagnosing Night Terrors

Night terrors are a rare parasomnia (unwanted and abnormal sleep behavior), occurring in an estimated 15% of children and 2% of adults. In general, they are not dangerous, although extremely volatile or active episodes can injure the affected person or the person trying to wake them up. They can, however, be indicative of underlying issues, from hyperthyroidism to obstructive sleep apnea. Diagnosing night terrors can be important largely because of what’s causing them. Here’s a look at how night terrors are diagnosed. 

Before Diagnosis

Night terrors are fairly easy to identify from home. Particularly in children, it may seem as if they’ve woken from a nightmare, but there are a few characteristic differences. Nightmares occur during the rapid eye movement (REM) stage of sleep, while the brain is extremely active, the eyes dart about beneath the eyelids, and the rest of the body is virtually paralyzed. Additionally, bits of imagery can often be recalled from a nightmare. Night terrors, however, occur during the slow-wave sleep phase of the non-REM sleep stage. Thus, the body is free to flail about; you may also notice screaming, crying, or sitting up and staring with a look of utter fear. Upon waking (which will probably be extremely difficult -- and may even be detrimental), the individual will likely be confused about what’s going on and appear disoriented, with no memory of the event. 

Preparing for the Doctor

If you’re particularly concerned about the development of night terrors, there are a few things you can do to get ready for the doctor visit. Keep a sleep diary for about 2 weeks, detailing times, major changes or stresses, and specific symptoms -- even those that seem unrelated to the night terrors. Include bedtime routine information, quality of sleep (if possible), and anything that might interfere with sleep. Bring any medications taken, as well as a list of questions you want to ask. 

Diagnostic Criteria

The Diagnostic and Statistical Manual of Mental Disorders, 5th edition, lists the following criteria for diagnosing sleep terrors:

  • Abrupt and recurrent awakenings with a scream
  • Intense fear with physiological evidence (increased heart rate, respiration, and perspiration)
  • Unconsolable
  • Amnesia following the event
  • Impairment or distress of general functioning is clinically significant, and
  • Nothing else causes the events.

Preparing for a Sleep Specialist

Your family doctor may recommend you (or your child) to a sleep specialist for specific testing. A polysomnogram, or sleep study, involves spending the night in a special lab, so you can be monitored in your sleep. This can help discover issues like obstructive sleep apnea, and you can discover a more accurate sleep stage during which these are occurring. While the latter aspect assumes a night terror will occur during the polysomnogram, since strange environments can impact their presence, it isn’t necessarily unlikely that it will happen. 

What to Expect from the Polysomnogram

During the polysomnogram, specialists will monitor different aspects of your physiology. Sensors can record blood oxygen levels, how fast your heart beats, your rate of respiration, and how much movement occurs in your eyes and appendages (particularly the legs). Sensors can also measure brain wave activity, allowing your physician to determine which parts of the brain are active during a night terror. 

Once you have an official diagnosis, you can take steps towards managing whatever is causing the sleep terrors. If there is nothing definitive, the best course of action may be to attempt to change your sleeping habits. Make sure you’re getting plenty of sleep, avoid anything that can interfere with the quality of sleep (such as caffeine), and try to find ways to relax or manage stress (such as meditation) before bed. This will help you get deeper sleep faster and longer, and hopefully limit episodes of night terrors.