Session Information
Date: Tuesday, June 21, 2016
Session Title: Restless legs syndrome and other sleep disorders
Session Time: 12:30pm-2:00pm
Location: Exhibit Hall located in Hall B, Level 2
Objective: To assess the intrinsic diagnostic values of F waves parameters in diagnosis of RLS/WED.
Background: Restless legs syndrome, also known as Willis-Ekbom Disease (RLS/WED), is a frequent condition, though its pathophysiology is not completely understood. The diagnosis of RLS/WED is based on on clinical criteria and the only instrumental tool, the suggested immobilization test [1], may lead to non-univocal results. Recently, neurophysiological parameters related to F-wave duration have been proposed as a diagnostic aid [2].
Methods: 15 women affected by primary RLS/WED and 17 age- and sex- matched healthy subjects were consecutively enrolled. They underwent a complete electroneurographic evaluation, including nerve conduction studies (NCS) and F-wave parameters, namely amplitude, duration (FWD) and the ratio between FWD and duration of the corresponding compound muscle action potential (FWD/CMAPD).
Results: No subject showed alterations of the NCS. However, FWD and FWD/CMAPD of both upper and lower limbs were significantly longer in patients compared to controls. Tibial FWD/CMAPD best discriminated RLS/WED patients from controls. A cut-off of 2.06 yielded to a sensitivity of 69.2%, a specificity of 94.1%, a Positive Predictive Power of 90%, a Negative Predictive Power of 80% (AUC= 0, 817; 95% CI= 0.674- 0.959). The combination of ulnar OR tibial FWD/CMAPD increases the sensitivity (85.7%) while slightly decreasing the specificity (87.5%, PPV: 85.7%, NPP: 87.5%).
Conclusions: Lower limbs FWD/CMAPD ratio may represent a supportive diagnostic tool, especially in cases of evening lower leg discomfort of unclear interpretation. References: [1] Montplaisir J, et al. Immobilization tests and periodic leg movements in sleep for the diagnosis of restless leg syndrome. Mov Disord. 1998;13(2):324–9. [2] Isak B, et al. A neurophysiological approach to the complex organisation of the spine: F-wave duration and the cutaneous silent period in restless legs syndrome. Clin Neurophysiol. 2011;122(2):383–90.
To cite this abstract in AMA style:
P. Congiu, M.L. Fantini, G. Milioli, P. Tacconi, M. Figorilli, G. Gioi, B. Pereira, F. Marrosu, L. Parrino, M. Puligheddu. Specificity and sensitivity of F-waves parameters in diagnosis of RLS/WED [abstract]. Mov Disord. 2016; 31 (suppl 2). https://www.mdsabstracts.org/abstract/specificity-and-sensitivity-of-f-waves-parameters-in-diagnosis-of-rlswed/. Accessed June 15, 2025.« Back to 2016 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/specificity-and-sensitivity-of-f-waves-parameters-in-diagnosis-of-rlswed/