An update on restless legs syndrome (Willis-Ekbom disease): clinical features, pathogenesis and treatment

PURPOSE OF REVIEW

In recent years, there have been a number of advances in the field of restless legs syndrome (RLS) or Willis-Ekbom disease (WED). Here, we review recent studies pertaining to the diagnosis and clinical features, pathogenesis, and treatment of RLS/WED.

RECENT FINDINGS

Recent studies have added a temporal dimension to RLS/WED epidemiology by examining both the incidence and persistence rates in different populations. Diagnostic criteria have been modified to increase sensitivity, and new guidelines take into account recently published studies of different drug classes.

SUMMARY

Recent epidemiological findings have shown that RLS/WED is a common neurological disorder that affects up to 5% of the adult population in Western countries. In moderate and severe cases, RLS/WED has a strong impact on sleep and quality of life and can involve an increased cardiovascular risk. Diagnosis is made clinically by confirming the presence of the five essential criteria. However, in difficult cases objective tests such as the multiple suggested immobilization test (m-SIT) can be used. The pathophysiology is partially known, with several risk polymorphisms (BTBD-9 (BTB (POZ) domain containing 9), MEIS-1 (Meis homeobox 1), protein tyrosine phosphatase, receptor type, D, and others) playing an important role, along with dopaminergic and iron dysfunctions. The disorder frequently requires long-term treatment with low-dose dopamine agonists or α2δ ligands. Dopamine agonists are usually effective but the main complication, RLS/WED augmentation, can arise.

A novel locus for restless legs syndrome on chromosome 13q

BACKGROUND

Restless legs syndrome (RLS) is a sensorimotor disorder in which affected individuals suffer from uncomfortable sensations and an urge to move their lower limbs; it occurs mainly in resting situations during the evening or at night. Multiple chromosomal loci have been mapped for RLS through family-based linkage analysis, and genome-wide association studies but causative mutations have not been identified yet.

METHOD

We identified an RLS family from the eastern part of central Turkey which has 10 patients suffering from this syndrome. Whole genome linkage analysis was performed in family members who consented for study (9 affected and 2 unaffected).

RESULTS

A theoretical maximum logarithm of the odds score of 3.29 was identified at chromosome 13q32.3-33.2. This result shows strong genetic linkage to this locus.

CONCLUSIONS

We demonstrated a genetic linkage at chromosome 13 in a RLS family. Further investigation in this linkage area may reveal a causative gene leading to RLS phenotype and may illuminate the pathogenesis of this disease. This study supports the genetic heterogeneity in the pathogenesis of this syndrome.

Genomic medicine and neurological disease

"Genomic medicine" refers to the diagnosis, optimized management, and treatment of disease--as well as screening, counseling, and disease gene identification--in the context of information provided by an individual patient's personal genome. Genomic medicine, to some extent synonymous with "personalized medicine," has been made possible by recent advances in genome technologies. Genomic medicine represents a new approach to health care and disease management that attempts to optimize the care of a patient based upon information gleaned from his or her personal genome sequence. In this review, we describe recent progress in genomic medicine as it relates to neurological disease. Many neurological disorders either segregate as Mendelian phenotypes or occur sporadically in association with a new mutation in a single gene. Heritability also contributes to other neurological conditions that appear to exhibit more complex genetics. In addition to discussing current knowledge in this field, we offer suggestions for maximizing the utility of genomic information in clinical practice as the field of genomic medicine unfolds.