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Review ArticleDiagnosis and Management of Restless Legs SyndromeIntroductionRestless Legs Syndrome (RLS) was first described in 1672and rediscovered by KA Ekbom in 1945 1 who extensivelystudied this disorder and contributed important findingswhich are still relevant today. The international RLS StudyGroup (IRLSSG) published a set of criteria to establish adiagnosis of this frequent sensorimotor disorder. 2,3Clinical features, definition and diagnosis of RLSRLS is a neurological sleep disorder characterised by analmost irresistible urge to move the limbs which is mostoften but not necessarily accompanied by uncomfortablesensations in the legs. RLS symptoms are evoked by restand are worse in the evening or night. The arms may alsobe involved. RLS occurs predominantly in the evening orduring the night and has a profound impact on sleep. Inaddition to difficulty initiating sleep, many RLS patientshave problems maintaining sleep with frequent awakeningsor short arousals resulting in poor sleep efficiency.Diagnostic criteria for RLS are characterised by fouressential criteria (Table 1). To make a definite diagnosis ofRLS, all four diagnostic criteria must be established.The following supportive features have been establishedwhich are not necessary to make the diagnosis of RLS butwhich may, especially in doubtful cases, help to diagnoseor exclude RLS.Positive family historyA positive family history is present in more than 50% ofRLS patients.Positive response to dopaminergic treatmentSeveral controlled studies have shown that most patientswith RLS have a positive therapeutic response todopaminergic drugs. Based on clinical experience, morethan 90% of patients report a relief of their symptomswhen treated with these agents.Periodic limb movements in sleep (PLMS)PLMS are reported to occur in 80 to 90% of patients withRLS. However, PLMS also commonly occur in other disordersand in the elderly. A PLMS index (number ofPLMS per hour of sleep) of greater than 5 is consideredpathologic, although data supporting this feature is verylimited. The occurrence of PLM during nocturnal periodsof wakefulness (PLMW) is considered to be more specificfor RLS. Thus the presence of a high number of PLM issupportive for RLS but the absence of PLM does notexclude RLS.In addition to the essential and supportive criteria theprogressive clinical course with intermittent symptoms inthe beginning, the presence and character of sleep disturbancesand the normal physical examination in primarycases are other features of RLS that may be helpful fordiagnosis. 3Table 1: Essential diagnostic criteria of the International RLS Study Group [76]EpidemiologyThe prevalence of RLS in the general population liesbetween 5 and 10%, women are affected twice as often asmen. 4 Most individuals suffer from primary RLS whichshows a familial association in more than 50%. An autosomal-dominantmode of inheritance has been shown. 5Genome-wide studies have been conducted to map genesthat play a role in the vulnerability to RLS. So far linkagewas found to a locus on chromosome 12q, 6 14q 7,8 and 9p. 9While most RLS cases may be idiopathic, RLS is oftenlinked to other medical or neurological disorders. Themost important associations of RLS are with end-stagerenal disease or iron deficiency. RLS may also developduring pregnancy or intensify secondary to treatmentwith various drugs such as dopamine antagonists, typicaland atypical neuroleptics, metoclopramide, or antidepressantssuch as tri- and tetracyclic antidepressants, serotoninreuptake inhibitors and lithium. Although supportingdata are limited, peripheral neuropathies may be associatedwith RLS. 10TreatmentPharmacological therapy should be limited to thosepatients who meet the specific diagnostic criteria and sufferfrom clinically relevant RLS symptoms. Several factorslike the frequency and severity of symptoms, the temporalappearance of symptoms, the kind of sleep disturbancesand the degree to which RLS interferes with the quality oflife influence treatment strategies. Dopaminergic agentsare considered the first-line treatment in RLS, 11 after secondaryRLS associated with low iron or ferritin levels hasbeen excluded. Even raising ferritin levels from the lowernormal range frequently improves RLS symptoms.L-dopaL-dopa/benserazide (Restex® and Restex® retard) was thefirst drug licensed for RLS in September 2000 in twoEuropean countries, Germany and Switzerland. Doses of50/12.5 to 100/25mg standard L-dopa / DDI improve RLSsymptoms about one hour after drug intake resulting inan improved quality of sleep. In correlation to the plasmahalf-life of L-dopa (1–2 hours) the beneficial effectdecreases and RLS may persist in the second half of thenight. If so, an additional application of slow release L-dopa/DDI (100/25mg given in combination with standardL-dopa/benserazide one hour prior to or at bedtime) is recommended. In general, L-dopa is best used inpatients with mild RLS. In patients with sporadic RLS, L-dopa can be given on demand. Tablets are generally takenat bedtime, perhaps supplemented by a dose earlier in theday to control evening or daytime symptoms.In more severely affected patients RLS symptoms maynot be adequately controlled for the whole night evenwith the combination of standard and sustained releasepreparations.1. An urge to move the legs, usually accompanied or caused by uncomfortable and unpleasant sensations in the legs. (Sometimesthe urge to move is present without the uncomfortable sensations and sometimes the arms or other body parts are involved inaddition to the legs).2. The urge to move or unpleasant sensations begin or worsen during periods of rest or inactivity, such as lying or sitting.3. The urge to move or unpleasant sensations are partially or totally relieved by movement, such as walking or stretching, at least aslong as the activity continues.4. The urge to move or unpleasant sensations are worse in the evening or night than during the day or only occur in the evening ornight. (When symptoms are very severe, the worsening at night may not be noticeable but must have been previously present).Dr Karin Stiasny-Kolster, is aNeurologist and heads the RLS outpatientclinic and neurological sleeplaboratory at the Department ofNeurology of Phillips University inMarburg, Germany. Her researchinterests include restless legs syndromeand sleep disorders associatedwith neurodegenerative disorders.Dr Aline Metz is a Neurologist atthe Department of Neurology ofPhillips University in Marburg,Germany. Her research interestsinclude Parkinson’s disease andrestless legs syndrome.Professor Wolfgang Oertel isDirector of the Department ofNeurology at the University ofMarburg. He has been opinionleader in the diagnosis and treatmentof RLS for more than 15years and was founder of the RLSresearch group in Germany. Hewas principal investigator in placebo-controllednational and multinationalclinical trials in RLS andinvolved in the conception anddesign of studies for EMEA orFDA approval. He is speaker of theGerman RLS Patient Register,which was founded by the GermanMinistry for Education andResearch (BMBF).Correspondence to:Dr Karin Stiasny-Kolster,Department of Neurology,University of Giessen andMarburg,Rudolf-Bultmann-Str. 8,35037 Marburg,Email: Stiasny@med.uni-marburg.deACNR • VOLUME 5 NUMBER 6 • JANUARY/FEBRUARY 2006 I 7