The duration of the cortical silent period is not abnormal in Restless Legs Syndrome/Willis-Ekbom Disease.
OBJECTIVE
To compare the duration of the cortical silent period (CSP) measured in a hand muscle in subjects with primary Restless Legs Syndrome (RLS/WED) and controls, using four different methods of analysis.


METHODS
The CSP to transcranial magnetic stimulation of the dominant motor cortex was assessed in the abductor digiti minimi of 33 subjects with RLS/WED and 24 controls. CSP duration was measured by an automated and three visually-guided methods.


RESULTS
There were significant differences between absolute values of CSP duration according to the method of analysis. However, irrespectively of the method used for CSP assessment, no differences were found between measurements performed in subjects with RLS/WED and subjects from the control group.


CONCLUSIONS
Absolute values of CSP durations analyzed by different methods should not be directly compared, because significantly different results can be obtained from the same data set.


CONCLUSIONS
The CSP assessed from a hand muscle is unlikely to be a biomarker of primary RLS/WED. Our results highlight the importance of standardizing the definition of CSP onset and offset, as well as of describing in detail the methodology chosen to record and measure CSP duration, in order to enable comparisons between studies.
Hospital Israelita Albert Einstein, Edifício Josef Féher (Bloco A), 2° subsolo, Av. Albert Einstein, 627/701, São Paulo, SP, Brazil CEP: 05652-900. Electronic address: joselisa@gmail.com.
Joselisa Péres Queiroz
JPQ
de Paiva
Hospital Israelita Albert Einstein, Edifício Josef Féher (Bloco A), 2° subsolo, Av. Albert Einstein, 627/701, São Paulo, SP, Brazil CEP: 05652-900. Electronic address: samircm@gmail.com.
Samir Câmara
SC
Magalhães
Universidade Federal de São Paulo, Departamento de Neurologia e Neurocirurgia, Rua Claúdio Rossi, 394, São Paulo, SP, Brazil CEP: 01547-000. Electronic address: gilmarunifesp@yahoo.com.br.
Gilmar Fernandes
GF
do Prado
Hospital das Clínicas da Faculdade de Medicina, Departamento de Neurociências e Ciências do Comportamento, Divisão de Neurologia, Hospital das Clinicas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil CEP: 14.048-900. Electronic address: eckeli.alan@yahoo.com.br.
Alan Luiz
AL
Eckeli
Neurocenter of Southern Switzerland, LBN - Laboratory for Biomedical Neurosciences, 6900 Lugano, Switzerland. Electronic address: alain.kaelin@eoc.ch.
Alain
A
Kaelin-Lang
Hospital Israelita Albert Einstein, Edifício Josef Féher (Bloco A), 2° subsolo, Av. Albert Einstein, 627/701, São Paulo, SP, Brazil CEP: 05652-900; Hospital das Clínicas da Faculdade de Medicina, Departamento de Neurologia e Núcleo de Apoio à Pesquisa em Neurociência Aplicada (NAPNA), Universidade de São Paulo, São Paulo, SP, Brazil CEP: 05403-010. Electronic address: adriana.conforto@gmail.com.
Adriana Bastos
AB
Conforto
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009119:Muscle Contraction / Q000502:physiology*; D012148:Restless Legs Syndrome / Q000473:pathology*; D012189:Retrospective Studies; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
Cortical silent period; Methods; Restless Legs Syndrome; Transcranial magnetic stimulation; Willis-Ekbom Disease