This is the first nationwide extensive series of CTX reported in Spain. The higher number of cases in some areas suggests a possible founder effect. Spinal forms had a less severe prognosis. A delayed diagnosis could contribute to the lack of significant response to treatment.

Patients with ET showed impaired motor performance, at least in some tasks, such as rapid repetitive finger movements (finger tapping and frequency) and visual reaction time (impairment was not related with tremor severity). This probably means that patients with ET have some degree of bradykinesia.

No abstract

Several biochemical, neuropathological, and experimental data suggest a possible role of nitric oxide (NO) in the pathophysiology of restless legs syndrome (RLS). Two single nucleotide polymorphisms (SNPs) neuronal nitric oxide synthase (nNOS or NOS1) gene (rs7977109 and rs693534) have been found to be associated with the risk for RLS in Germans, although only one of them (rs7977109) remained as significant after multiple comparison tests. The aim of our study was to replicate the possible association between these SNPs and risk for RLS in the Spanish population. We studied the allelic and genotype frequencies of the SNPs rs7977109 and rs693534 in 205 patients with RLS and 328 healthy controls using TaqMan genotyping. The rs7977109 and rs693534 genotypes and allelic frequencies did not significantly differ between patients with RLS and controls and were unrelated with the age at onset of RLS, gender, ferritin levels, and response to dopaminergic or gabaergic agents. The rs7999109GA genotype was overrepresented in RLS patients with positive family history of RLS, and in patients with symptomatic response to clonazepam. The results of our study suggest that these two NOS1 SNPs are not related to the overall risk for RLS in the Spanish population.

Several neurochemical, neuropathological, neuroimaging, and experimental data, suggest that iron deficiency plays an important role in the pathophysiology of restless legs syndrome (RLS). Heme-oxygenases (HMOX) are an important defensive mechanism against oxidative stress, mainly through the degradation of heme to biliverdin, free iron, and carbon monoxide. We analyzed whether HMOX1 and HMOX2 genes are related with the risk to develop RLS.We analyzed the distribution of genotypes and allelic frequencies of the HMOX1 rs2071746, HMOX1 rs2071747, HMOX2 rs2270363, and HMOX2 rs1051308 SNPs, as well as the presence of Copy number variations (CNVs) of these genes in 205 subjects RLS and 445 healthy controls.The frequencies of rs2071746TT genotype and rs2071746T allelic variant were significantly lower in RLS patients than that in controls, although the other 3 studied SNPs did not differ between RLS patients and controls. None of the studied polymorphisms influenced the disease onset, severity of RLS, family history of RLS, serum ferritin levels, or response to dopaminergic agonist, clonazepam or GABAergic drugs.The present study suggests a weak association between HMOX1 rs2071746 polymorphism and the risk to develop RLS in the Spanish population.