PLMD is repetitive cramping or jerking of the legs during sleep, PLMD is also considered a sleep disorder, because the movements often disrupt sleep and lead to EDS. PLMD is often linked with restless legs syndrome (RLS), but they are not the same thing. RLS is a condition involving strange sensations in the legs while awake and an irresistible urge to move the limbs to relieve the sensations. At least 80% of people with restless legs syndrome have PLMD, but the reverse is not true. PLMD can occur at any age. Like many sleep disorders, PLMD is more common in middle-aged and older people. Sleep study is the way to detect PLMD