The continuous recordings of brain activity that led to the discovery of REM (rapid eye-movement) sleep were not done until 1953, partly because the scientists doing the tests were concerned about wasting paper!
Periodic Limb Movements in Sleep (PLMS) is a symptom that is commonly associated with another type of sleep disorder known as Restless Leg Syndrome (RLS). However, PLMS is a separate condition and RLS need not be present.
Although the problem itself does not seem to cause or aggravate any other medical conditions, the frequent limb movements can cause a disruption in a person’s sleep. In fact, it can lead to significant insomnia, which can have adverse affects. It is for this reason that PLMS is considered a sleep disorder.
Symptoms are few but they are obvious. As the name implies, the lower limbs of individuals with this disorder move, often repetitively, for varying periods of time. These movements, which are characterized as either sudden jerks, or twitches, or a flexing of the foot upwards, occur while the affected individual is asleep. These types of limb movements occur in episodes that can last just a minute or they can last for many hours. Once an episode stops, however, …