ABSTRACT
Even though recognition of restless legs syndrome (RLS) by the medical community is not yet proportionate to its prevalence in the general population,1
RLS was a syndrome reported as early as 1672 by Willis,2 and well defined clinically by Ekbom in 1945 and 1960.3,4 RLS may either occur as a primary disturbance, frequently familial and not associated with other neurological or systemic illnesses, or secondary to other pathological conditions such as peripheral neuropathy, uremia, and pregnancy.5 Landmark but serendipitous discoveries, such as its association with periodic limb movements in sleep (PLMS)6 and the discovery of the therapeutic effects of levodopa,7 were later followed by more systematic approaches aimed at the definition of the clinical diagnostic criteria,8,9 at measuring the degree of clinical severity,10 and of quality of life (QoL).11,12 Accordingly, the essential diagnostic criteria for RLS9 include the following: an urge to move the legs usually accompanied or caused by uncomfortable and unpleasant sensations in the legs; the urge to move or unpleasant sensations begin or worsen during periods of rest or inactivity, such as lying or sitting; the urge to move or unpleasant sensations are partially or totally relieved by movement, such as walking or stretching, at least as long as the activity continues; and the urge to move or unpleasant sensations are worse in the evening or night than during the day or only occur in the evening or night. Supportive clinical features include a positive family history, response to dopaminergic therapy, and periodic limb movements during wakefulness or sleep. The International Restless Legs Syndrome Study Group (IRLSSG) rating scale for severity10 rates symptoms over 10 items with a score ranging from 0 (none) to 4 (very severe symptom) experienced by the patient for the most recent 2-week period; RLS symptoms are defined as moderate to severe when a score of at least 15 is reached. Recently, diagnostic criteria for the
PLMS have also been made available.13 These efforts have brought about previously lacking clinical instruments useful for epidemiological studies and clinical trials, at least for the adult population with RLS, and facilitated the recognition and assessment of the significant effects of RLS upon sleep, cognitive function, and memory and psychomotor performance. Here, the clinical features of RLS will not be tackled, and the reader is directed to more general works;5,14 we shall instead deal first with the consequences of RLS on the function of sleep, and the attendant mood disruption. We shall afterwards summarize the effects of RLS upon cognitive performance and more generally upon QoL. Such a way of dealing with the subject at hand is not meant to imply definite causal relationships between pain, disturbed sleep, mood depression, and finally cognitive defects and poor QoL. All of these clinical features associated with RLS could indeed represent intrinsic properties of the RLS brain or mind.
