People experience restless legs syndrome (RLS) in many different ways, but all sufferers describe very unpleasant “creepy, crawly” sensations that occur in the legs when they are sitting or lying still, especially at bedtime. RLS can be very painful, but the pain is unlike that of a leg cramp. RLS is also different from the feeling of a limb having “fallen asleep” when the blood supply is cut off, and from the “pins and needles” or burning sensation sometimes experienced by those with peripheral neuropathy. The pain and unpleasant feelings of RLS appear most often in the calves and can be temporarily relieved by stretching and moving the legs. Restless legs syndrome occurs primarily during waking hours, although it can affect one's ability to fall asleep. The constant need to stretch or move the legs to eliminate the uncomfortable or painful feelings often prevents a person with RLS from falling asleep. Extreme tiredness during the day can be one result, which may bring about the inability to participate in normal activities or carry out regular duties.
Periodic limb movement disorder (PLMD), formerly known as nocturnal myoclonus, is another disorder that affects the limbs and the ability to sleep at night and function normally during the day. While the movements of RLS are a voluntary response to uncomfortable feelings in the limbs when a person is awake, the movements of PLMD occur most often when a person is asleep and are involuntary, or not consciously controlled. PLMD often results in excessive daytime sleepiness.
PLS and PLMD are often treated with dopamine, or dopamine-like drugs, which are the same drugs used to treat Parkinson's disease. These drugs include pramipexole (Mirapex), ropinirole (Requip) and L-dopa (Sinemet). Benzodiazepines, such as clonazepam, or opiates, such as codeine, are also sometimes used.