OBJETIVO: Temos frequentemente observado que infantes que apresentam choro excessivo e agitação ou cólicas noturnas têm pais com Síndrome de Pernas Inquietas. Nosso objetivo foi determinar se estes infantes são mais propensos a terem pais com a Síndrome de Pernas Inquietas. MÉTODOS. Foram entrevistadas 67 famílias com infantes e crianças em busca de uma história de choro excessivo e agitação durante os primeiros 4 meses de vida. Seus pais foram investigadas para Síndrome de Pernas Inquietas. RESULTADOS: Dentre os 134 pais entrevistados, 39 (29%) tinham doença Willis-Ekbom. Entre as 96 crianças avaliadas 37 (38%) apresentaram choro excessivo e agitação. Destas, 28 (76%) apresentaram pelo menos um dos pais com Síndrome de Pernas Inquietas. Entre as 59 crianças sem choro excessivo e agitação, apenas 14 (23, 7%) apresentaram pelo menos um dos pais com a Síndrome de Pernas Inquietas. A associação entre os eventos (crianças de pais com ou sem Síndrome de Pernas Inquietas) foi medida pelo coeficiente phi (0,510), indicando uma associação mais do que trivial. As crianças com choro excessivo e agitação mostraram-se mais propensas a ter pelo menos um dos pais com a doença Willis-Ekbom (75,7 vs. 27,7, “Odds Ratio” = 10, com intervalo de confiança de 95%, 3,82-26,15). CONCLUSÃO: A evidência gerada por este estudo não é suficiente para concluir que o choro infantil excessivo e agitação é equivalente a um diagnóstico provável da doença Willis-Ekbom parental. No entanto, eles fornecem informações, bem como a motivação necessária para empreender estudos mais extensos sobre bebês com choro excessivo e agitação.

OBJECTIVE: We have frequently observed that infants presenting with excessive crying and fussing, or colic at night have parents with Restless Legs Syndrome. Our objective was to determine if these infants are more likely to have parents with Restless Legs Syndrome (Willis-Ekbom Disease). METHODS: We interviewed 67 families with infants and children, in search of a history of excessive crying and fussing during their first four months of life. Their parents were investigated for Restless Legs Syndrome. RESULTS: Among the 134 interviewed parents, 39 (29%) had Restless Legs Syndrome. Among the 96 children, 37 (38%) presented excessive crying and fussing. Of these, 28 (76%) had at least one parent with Restless Legs Syndrome. Among the 59 children without excessive crying and fussing only 14 (24%) had at least one parent with Restless Legs Syndrome. The association between events (children of parents with vs. without Restless Legs Syndrome) was measured by the phi coefficient (0.510), indicating a more than trivial association. The estimated association was 75.7 vs. 27.7, Odds Ratio = 10 at 95% confidence interval, 3.82-26.15). CONCLUSION: Children with excessive crying and fussing were more likely to have at least one parent with Restless Legs Syndrome. The present evidence is insufficient to conclude that infantile excessive crying and fussing is equivalent to a a probable diagnosis of parental Restless Legs Syndrome. However, they provide information as well as the necessary motivation to undertake more extensive studies of infants with excessive crying and fussing.

Data collected from medical literature indicate that dopaminergic agonists alleviate Restless Legs Syndrome symptoms while dopaminergic agonists antagonists aggravate them. Dopaminergic agonists is a physiological regulator of thyroid-stimulating hormone. Dopaminergic agonists infusion diminishes the levels of thyroid hormones, which have the ability to provoke restlessness, hyperkinetic states, tremors, and insomnia. Conditions associated with higher levels of thyroid hormones, such as pregnancy or hyperthyroidism, have a higher prevalence of Restless Legs Syndrome symptoms. Low iron levels can cause secondary Restless Legs Syndrome or aggravate symptoms of primary disease as well as diminish enzymatic activities that are involved in dopaminergic agonists production and the degradation of thyroid hormones. Moreover, as a result of low iron levels, dopaminergic agonists diminishes and thyroid hormones increase. Iron therapy improves Restless Legs Syndrome symptoms in iron deprived patients. Medical hypothesis. To discuss the theory that thyroid hormones, when not counterbalanced by dopaminergic agonists, may precipitate the signs and symptoms underpinning Restless Legs Syndrome. The main cause of Restless Legs Syndrome might be an imbalance between the dopaminergic agonists system and thyroid hormones.