Exams and Tests

• A sleep log identifies the sleep-wake cycles in a person's normal environment, and it allows subjective assessment of alertness over a 2-week period. In keeping a sleep log, a person is asked to maintain a sleep diary describing the previous night's sleep. Data from the sleep diary may help to minimize distortions in sleep information recalled some time later while in the health care provider's office. Sleep logs can also be used for self-monitoring and as an addition to behavioral treatment.
  
  
• Imaging studies, such as CT scan and MRI, may be done to evaluate for neurodegenerative diseases.
  
  
• A multiple sleep latency test allows for objective measurement of sleepiness. This test is indicated when the clinical history is suggestive of narcolepsy.
  
  
• The Epworth Sleepiness Scale is based on a questionnaire that rates a person's responses to 8 situations on a scale of 0-3 based on whether the situation was likely to be associated with dozing behavior. Although controversy exists as to what score constitutes abnormal sleepiness, a total score above 10 generally warrants investigation.
  
  
• Actigraphy is done with the help of an Actigraph. An Actigraph is a small, motion-sensing device worn on the nondominant wrist, generally for 1 week. Actigraphy is based on the premise that a person's wrist motion decreases during sleep. This allows an overall measure of sleep-wake cycles over time.