Restless legs syndrome in subjects with a knee prosthesis: evidence that symptoms are generated in the periphery

OBJECTIVE:

There are no data adressing the prevalence of restless legs syndrome in subjects who have knee prosthesis. Therefore, we conducted a cross-sectional survey of subjects who underwent knee prosthesis surgery.

METHOD:

A total of 107 subjects (30 male, 77 female) were interviewed over the telephone regarding restless legs syndrome symptoms. If the patients exhibited symptoms of the syndrome, we conducted face-to-face interviews. Lastly, a therapeutic test with pramipexole was proposed for each subject.

RESULTS:

In our cohort, 7 males (23%) and 30 females (39%) had restless legs syndrome. Of these, 6 males and 23 females were submitted to face-to-face-interview. Of the males, 5 (83%) had restless legs after the knee surgery- exclusively in the operated leg- and reported no family restless legs history. One man had a prior case of bilateral restless legs syndrome, a positive family history and claimed exacerbation of symptoms in the operated leg. Among the females, 16 (69%) had restless legs prior to surgery. A total of 10 female patients reported bilateral symptoms, with fewer symptoms in the operated leg, while 6 displayed a worse outcome in the operated leg. The 7 females (31%) without restless legs prior to surgery and without a family history experienced symptoms only in the operated leg. All subjects responded favorably to the pramipexole therapeutic test.

CONCLUSION:

Our results suggest that secondary unilateral restless legs syndrome may ensue from knee prosthesis surgery and that the symptoms are generated in the peripheral nervous system.     

Determination of bismuth in pharmaceutical products using methyltriphenylphosphonium bromide as a molecular probe by resonance light scattering technique

A method for the determination of bismuth in pharmaceutical products using methyltriphenylphosphonium bromide as a molecular probe based on the resonance light scattering (RLS) technique was developed. In the presence of Tween-20, bismuth reacts with a large excess of I(-) to form [BiI(4)](-), which further reacts with methyltriphenylphosphonium bromide (MTPB) to form an ion-association compound. This resulted in a significant enhancement of RLS intensity and the appearance of the corresponding RLS spectral characteristics. The enhanced RLS intensity was directly proportional to the concentration of Bi(III) in the range of 0.001-1.50 microg/ml for the system. The detection limit was 0.98 ng/ml. The characteristics of RLS spectra of the complex, the optimum conditions and the influencing factors were investigated. The method has high selectivity and was applied to the determination of Bi(III) in pharmaceutical products with satisfactory results, which were in agreement with those of the official method and atomic absorbance spectrometry (AAS).     

Suggestive evidence for linkage for restless legs syndrome on chromosome 19p13

Five loci for restless legs syndrome (RLS) on chromosomes 12q, 14q, 9p, 2q, and 20p (RLS1-RLS5) have been mapped in RLS families, with a recessive in the first and autosomal-dominant mode of inheritance in the latter cases. Investigations of further RLS families showed evidence for genetic locus heterogeneity. We have conducted a genome-wide linkage analysis in a large RLS family of Italian origin with 12 affected members in 3 generations using 5,861 single nucleotide polymorphisms (SNP, 6K Illumina). Linkage analysis was performed under an autosomal-dominant model with a complete penetrance, an allele frequency of 0.003 and a phenocopy rate of 0.005. The genome-wide scan resulted in suggestive evidence for linkage on chromosome 19p with maximum multipoint logarithm of the odds score of 2.61 between markers rs754292 and rs273265. The locus was replicated in a family-based association study in a set of 159 trios of European origin. This study provides evidence for a further RLS locus, thus supporting the picture of RLS as a genetically heterogenous complex trait.     

Clinical efficacy of ropinirole for restless legs syndrome is not affected by age at symptom onset

ObjectiveTo determine whether clinical response to the dopamine agonist, ropinirole, in the treatment of primary restless legs syndrome (RLS), depends upon the age-at-onset of RLS symptoms.MethodsPooled data from four 12-week, randomized, double-blind, placebo-controlled studies of ropinirole in patients with moderate-to-severe primary RLS were analyzed post hoc. The relationship between age-at-onset and response to treatment, based on change from the baseline International Restless Legs Syndrome Study Group (IRLSSG) rating scale (the International Restless Legs Scale [IRLS]) total score and the proportion of responders (rated ‘much’/‘very much’ improved) on the Clinical Global Impression–Improvement (CGI-I) scale, was explored.ResultsThe range of age-at-onset of RLS symptoms was 2–75 years. No relationship was observed between the age-at-onset of RLS symptoms and baseline IRLS total score (correlation r = −0.06), and between dose administered at Week 12 last observation carried forward (LOCF) and age-at-onset (r = −0.04). The age-at-onset by treatment interaction was non-significant (P = 0.952 for the IRLS and P = 0.716 for the CGI-I scale), indicating there was no significant relationship between age-at-onset and the magnitude of ropinirole treatment effect.ConclusionsThese data suggest that ropinirole provides effective relief of symptoms, regardless of age at RLS symptom onset.     

Incidence and Outcomes of Positive Bubble Contrast Study Results After Transcatheter Closure of a Patent Foramen Ovale

Objectives

The aim of this study was to assess the incidence of persistently positive results on agitated saline contrast injection after patent foramen ovale (PFO) closure, the underlying mechanism, and management.

Restless legs syndrome: a common disorder in patients with rheumatologic conditions

OBJECTIVES: To review the symptoms, differential diagnosis, and treatment of the restless legs syndrome (RLS), and its relevance within rheumatologic practice. METHODS: Review of the scientific literature on RLS to summarize symptom presentation, burden, diagnosis, treatment, and association with rheumatologic conditions. RESULTS: RLS is a sensorimotor neurological disorder characterized by an irresistible urge to move the legs, usually accompanied or caused by unpleasant sensations within the legs. These sensations are sometimes described as achy or painful. They may cause sleep disruption and impair quality of life. RLS may be primary, of unknown etiology, with a likely genetic basis, or secondary, provoked by other conditions. Secondary RLS often improves when the underlying condition is treated or resolves. Since RLS is common in rheumatologic disorders such as rheumatoid arthritis or Sj?gren's syndrome, rheumatologists need to be familiar with the condition. Primary care physicians may misattribute RLS symptoms to other conditions and refer patients to specialists for treatment. Since RLS symptoms can be similar to, and mistaken for, symptoms in rheumatologic diseases, patients may be referred to rheumatologists. Therefore, it is important that rheumatologists be able to recognize, differentiate, diagnose, and treat RLS. CONCLUSIONS: The clinical diagnosis of RLS is based on 4 essential diagnostic criteria related to the urge to move that characterizes this disorder. Beyond good sleep hygiene and behavioral measures, dopaminergic agents are first-line treatments for primary RLS. Anticonvulsants, opioids, and sedative/hypnotics may also have a role in management.     

Family-based association study of the restless legs syndrome loci 2 and 3 in a European population.

Three loci for the restless legs syndrome (RLS) on chromosomes 12q, 14q, and 9p (RLS1, RLS2, and RLS3) have been mapped, but no gene has been identified as yet. RLS1 has been confirmed in families from three different populations. We conducted a family-based association study of 159 European RLS trios. The subjects were genotyped using microsatellite markers evenly covering the candidate regions on chromosomes 14q and 9p with an average intermarker distance of 1.1 cM. Transmission disequilibrium tests were used to analyze the data, and empirical P values were estimated by permutation testing. On chromosome 14q, a significant association (empirical P = 0.0033) was found with a haplotype formed by markers D14S1014 and D14S1017 when analyzing all families. On chromosome 9p, no significant association in the sample of all families and only marginally significant associations were detected, with a haplotype involving markers D9S1846-D9S171 in a subset of South European trios and with a haplotype at D9S156-D9S157 in a subset of Central European trios (P = 0.0086 and 0.0077, respectively). These results represent the first confirmation of these loci in a mixed European population. Variable results observed in families of different ethnic groups further corroborate the genetic complexity of RLS.     

Controlled withdrawal of pramipexole after 6 months of open-label treatment in patients with restless legs syndrome.

Although dopamine agonists are becoming first-line therapy for restless legs syndrome (RLS), few reports describe treatment periods exceeding 12 weeks. Here, 150 RLS patients who had responded to pramipexole during a 6-month run-in period (mean dose, 0.50 mg) were randomly assigned to receive placebo or continue receiving pramipexole at an individually optimized dose of 0.125 to 0.75 mg/day for a further 3 months. Patients switched to placebo reached the primary endpoint (a predefined worsening on both the Clinical Global Impressions-Global Improvement scale and the International RLS Study Group Rating Scale) significantly more often than patients who continued to receive pramipexole (85.5% vs. 20.5%; P < 0.0001). They also reached the primary endpoint faster, in 5 versus 42 days to a Kaplan-Meier survival estimate of 0.85 and 7 versus > 84 days to an estimate of 0.5. Over the total 9 months, clinician and patient ratings of symptoms, sleep, and quality of life identified no decline in pramipexole's benefit or tolerability. The great majority of adverse events (AEs) were mild or moderate, and of expected types. Augmentation was considered an AE, but in this population of responders it did not occur.