Abstract
The Suggested Immobilization Test (SIT) was developed as an objective diagnostic tool to quantify motor restlessness periodic limb movements during wakefulness (PLMW) associated with Restless Legs Syndrome (RLS). Limited research has explored the relationship between discomfort and pain associated with motor activity in RLS during the SIT. Twenty-five RLS patients and ten control participants completed the International Restless Legs Syndrome Study Group Severity Scale and the SIT with bilateral recordings of tibialis anterior EMG (PLMW index), as well as pain and discomfort visual analogue scales every 5 min for the 60-min SIT. The discomfort score had the ability to discriminate between RLS and control participants (P = 0.0001); however, the PLMW index did not (P = 0.67). The RLS patients also exhibited greater discomfort and pain in the latter half of the SIT (P < 0.05) compared to the initial phase of the SIT and compared to controls. Despite rating significant levels of discomfort, the majority of the RLS patients did not exhibit PLMW possibly suggesting a disconnect between the sensory and motor components of RLS. These sensory and motor features may be independent and as such presentation of PLMW during the SIT may not be a reliable objective measure of RLS.
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References
Allen RP, Picchietti DL, Garcia-Borreguero D, et al. Restless legs syndrome/Willis-Ekbom disease diagnostic criteria: updated international restless legs syndrome study group (IRLSSG) consensus criteria—history, rationale, description, and significance. Sleep Med. 2014;15:860–73. https://doi.org/10.1016/j.sleep.2014.03.025.
Allen RP, Earley CJ. Restless legs syndrome: a review of clinical and pathophysiologic features. J Clin Neurophysiol. 2001;18:128–47. https://doi.org/10.1097/00004691-200103000-00004.
Trenkwalder C, Hening WA, Walters AS, et al. Circadian rhythm of periodic limb movements and sensory symptoms of restless legs syndrome. Mov Disord. 1999;14:102–10.
Montplaisir J, Boucher S, Nicolas A, et al. Immobilization tests and periodic leg movements in sleep for the diagnosis of restless leg syndrome. Mov Disord. 1998;13:324–9. https://doi.org/10.1002/mds.870130220.
Michaud M, Paquet J, Lavigne G, et al. Sleep laboratory diagnosis of restless legs syndrome. Eur Neurol. 2002;48:108–13.
Michaud M, Lavigne G, Desautels A, et al. Effects of immobility on sensory and motor symptoms of restless legs syndrome. Mov Disord. 2002;17:112–5. https://doi.org/10.1002/mds.10004.
Aksu M, Demirci S, Bara-Jimenez W. Correlation between putative indicators of primary restless legs syndrome severity. Sleep Med. 2007;8:84–9. https://doi.org/10.1016/j.sleep.2005.12.001.
Winkelmann J, Wetter TC, Collado-Seidel V, et al. Clinical characteristics and frequency of the hereditary restless legs syndrome in a population of 300 patients. Sleep. 2000;23:1–6. https://doi.org/10.1093/sleep/23.5.1b.
Bentley AJ, Rosman KD, Mitchell D. Can the sensory symptoms of restless legs syndrome be assessed using a qualitative pain questionnaire? Clin J Pain. 2007;23:62–6. https://doi.org/10.1097/01.ajp.0000210948.11805.69.
Stiasny-Kolster K, Magerl W, Oertel WH, et al. Static mechanical hyperalgesia without dynamic tactile allodynia in patients with restless legs syndrome. Brain. 2004;127:773–82. https://doi.org/10.1093/brain/awh079.
Bachmann CG, Rolke R, Scheidt U, et al. Thermal hypoaesthesia differentiates secondary restless legs syndrome associated with small fibre neuropathy from primary restless legs syndrome. Brain. 2010;133:762–70. https://doi.org/10.1093/brain/awq026.
Hening W, Allen R, Earley C, et al. The treatment of restless legs syndrome and periodic limb movement disorder. Am Acad Sleep Med Rev Sleep. 1999;22:970–99. https://doi.org/10.1093/sleep/22.7.970.
Montplaisir J, Boucher S, Poirier G, et al. Clinical, polysomnographic, and genetic characteristics of restless legs syndrome: a study of 133 patients diagnosed with new standard criteria. Mov Disord. 1997;12:61–5. https://doi.org/10.1002/mds.870120111.
Pelletier G, Lorrain D, Montplaisir J. Sensory and motor components of the restless legs syndrome. Neurology. 1992;42:1663–6. https://doi.org/10.1212/WNL.42.9.1663.
Michaud M, Poirier G, Lavigne G, Montplaisir J. Restless legs syndrome: scoring criteria for leg movements recorded during the suggested immobilization test. Sleep Med. 2001;2:317–21. https://doi.org/10.1016/S1389-9457(00)00072-1.
Garcia-Borreguero D, Kohnen R, Boothby L, et al. Validation of the multiple suggested immobilization test: a test for the assessment of severity of restless legs syndrome (Willis-Ekbom disease). Sleep. 2013;36:1101–9. https://doi.org/10.5665/sleep.2820.
Allen RP, Barker PB, Horska A, Earley CJ. Thalamic glutamate/glutamine in restless legs syndrome increased and related to disturbed sleep. Neurology. 2013;80:2028–34. https://doi.org/10.1212/WNL.0b013e318294b3f6.
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Funding provided by the University of the Witwatersrand Medical Faculty Research Endowment fund. Many thanks to Raffaele Ferri for his statistical suggestions.
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Kerr, S., Bentley, A., Dafkin, C. et al. Disconnect between sensory and motor features of restless legs syndrome during the suggested immobilization test. Sleep Biol. Rhythms 17, 203–207 (2019). https://doi.org/10.1007/s41105-018-00202-z
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DOI: https://doi.org/10.1007/s41105-018-00202-z