Periodic limb movement during sleep is a very identified sign in RLS patients. It is found that 80–89% of RLS patients have excessive PLMS than same aged people (Montplaisir et al., 1997). PLMS is not very specific for RLS since it is a frequent condition among adults aged over 45 years (Hornyak et al., 2007). When PLMS present in a pattern different than expected for age excluding the states of other disease or medication, PLMS can support the diagnosis of RLS.