Glossary
NREM-REM Sleep Cycle (synonymous with Sleep Cycle)–These cycles occur during sleep which starts with the first phase namely, NREM sleep episode and the second , which is the REM sleep episode. This NREM-REM phase constitutes one cycle with the duration of 90 minutes in adults. In a 6.5 -8.5 hours of total sleep period of adults, there are nearly 4-6 cycles of NREM-REM sleep.NREM Sleep (Non-Rapid Eye Movement, Non-REM) – This includes all the sleep stages that are not a part of REM sleep, characterized by a reduction in the intensity of brain waves and psychological functions. During this state, rapid eye movements and twitches cannot be noticed.
REM Sleep (Rapid Eye Movement Sleep) – This is the phase during sleep where the victim is dreaming and parallely portraying rapid eye movements with closed eyelids. This phase of sleep is associated with heavy or irregular breathing, faster autonomic activity, erratic heart rate and twitching of muscles.
REM Sleep Episode – This is the REM sleep portion in the NREM-REM sleep cycle. The REM sleep episodes range from 4-6 during the complete sleep period. The events occurring early during this sleep cycle last couple of minutes while those that occur in the later REM phases are longer ranging between 20- 60 minutes.
Restlessness– Continuous movements of the body during sleep causing the victim to be disturbed is deemed as a state of restlessness.
Sleep hygiene– Involves the positive changes in the lifestyle targeted to improve sleep pattern.
