Restless Legs Syndrome 411
Diagnostic Features
Restless legs syndrome (RLS) is  a sensorimotor, neurological sleep disorder characterized
by a desire to move the legs or arms, usua lly associated with uncomfortable sensations
typically described as creeping, crawling, tingling, burning, or itch ing (Criterion A). The
diagnosis of RLS is based primarily on patient self-report and history. Symptoms are
worse when the individual is at rest, and freq uent movements of the legs occur in an effort
to relieve the uncomfortable sensations. Sympto ms are worse in the evening or night, and
in some individuals they occur only in the ev ening or night. Evening worsening occurs in-
dependently of any differences in activity. It is important to differentiate RLS from other
conditions such as positional discom fort and leg cramps (Criterion D).
The symptoms of RLS can delay sleep onset and awaken the individual from sleep and
are associated with significant sleep fragmentation. The relief obtained from moving the
legs may no longer be apparent in severe ca ses. RLS is associated with daytime sleepiness
and is frequently accompanied by significant clinical distress or functional impairment.
Associated Features Supporting Diagnosis
Periodic leg movements in sleep (PLMS) can serve as corroborating ev idence for RLS, with
up to 90% of individuals di agnosed with RLS demonstratin g PLMS when recordings are
taken over multiple nights. Periodic leg mo vements during wakefulness are supportive of
an RLS diagnosis. Reports of difficulty initiating and maintaining sleep and of excessive
daytime sleepiness may also support the diagnosis of RLS. Additional supportive features
include a family history of RLS among first- degree relatives and a reduction in symptoms,
at least initially, with dopaminergic treatment. 
Prevalence