Sleepwalking occurs when a person appears to be awake and moving around but is actually asleep. Sleepwalkers have no memory of their actions. Sleepwalking most often occurs during deep non-REM sleep (stages 3 and 4 sleep) early in the night. It can occur during REM sleep in the early morning. This disorder is most commonly seen in children aged six to twelve; however, sleepwalking can occur among younger children, the elderly, and adults. Sleepwalking appears to run in families. Contrary to what many people believe, it is not dangerous to wake a person who is sleepwalking. The sleepwalker simply may be confused or disoriented for a short time upon awakening. Although waking a sleepwalker is not dangerous, sleepwalking itself can be dangerous because the sleepwalker is unaware of his or her surroundings and can bump into objects or fall down.
Confusional arousals usually occur when a person is awakened from a deep sleep during the first part of the night. This disorder, which also is known as excessive sleep inertia or sleep drunkenness, involves an exaggerated slowness upon awakening. People experiencing confusional arousals react slowly to commands and may have trouble understanding questions that they are asked. In addition, people with confusional arousal often have problems with short-term memory.
Rhythmic movement disorders
Rhythmic movement disorder occurs mostly in children who are one year old or younger. A child may lie flat, lift the head or upper body, and then forcefully hit his or her head on the pillow. Rhythmic movement disorder, which also has been called "head banging," also can involve movements such as rocking on hands and knees. The disorder usually occurs just before a person falls asleep.
Sleep talking is a sleep-wake transition disorder. Although it usually is harmless, sleep talking can be disturbing to sleep partners or family members who witness it. Talk that occurs during sleep can be brief and involve simple sounds, or it can involve long speeches by the sleeper. A person who talks during sleep typically has no recollection of the actions. Sleep talking can be caused by external factors including fever, emotional stress or other sleep disorders.
Nocturnal leg cramps
Nocturnal leg cramps are sudden, involuntary contractions of the calf muscles during the night or periods of rest. The cramping sensation may last from a few seconds to 10 minutes, but the pain from the cramps may linger for a longer period. Nocturnal leg camps tend to be found in middle-aged or older populations, but people of any age can have nocturnal leg cramps. Nocturnal leg cramps differ from restless legs syndrome as the latter usually does not involve cramping or pain. The cause of nocturnal leg cramps is not known. Some cases of the disorder can occur without a triggering event, while other causes of leg cramps may be linked to prolonged sitting, dehydration, an overexertion of the muscles, or structural disorders (such as flat feet). Muscle-stretching, exercise, and adequate water intake may help prevent leg cramps.