Comments on: “Efficacy and Safety of Pregabalin for Restless Legs Syndrome in Korean Adults: A Randomized, Double-Blind, Placebo-Controlled Trial”

We read with great interest the recent article by Sunwoo et al. 1 titled "Efficacy and Safety of Pregabalin for Restless Legs Syndrome in Korean Adults: A Randomized, Double-Blind, Placebo-Controlled Trial." The authors deserve credit for their rigorous methodology, clearly defined inclusion criteria, and use of validated instruments to assess symptom severity and treatment responses.The described study makes an important contribution to the literature on pharmacological interventions for restless leg syndrome (RLS).However, we would like to highlight two key methodological limitations concerning sleep-related outcomes and the trial duration.RLS is known to disrupt both the onset and maintenance of sleep due to unpleasant limb sensations.While the study demonstrated that newly diagnosed RLS patients experienced longer sleep latency and more-frequent disturbances compared with controls, these outcomes were assessed solely using self-report measures. 2revious research 1 employing polysomnography has identified strong associations between RLS, periodic limb movements, and sleep disruption.Objective tools such as polysomnography and actigraphy are essential for accurately capturing these sleep disturbances, since relying exclusively on subjective measures will not reliably reveal how pregabalin affects nocturnal symptoms and the sleep architecture.Objective evaluations provide critical insights into sleep continuity, periodic limb movements, and other physiological parameters that subjective self-reports alone cannot adequately capture.Future investigations incorporating objective sleep assessments would strengthen the clinical relevance of the described findings and clarify the treatment efficacy, particularly for nighttime symptoms.The second major limitation is the 12-week trial duration.Short-term studies inherently cannot evaluate long-term effects for a chronic condition such as RLS, especially augmentation, which is a known complication of dopaminergic and certain nondopaminergic treatments.For example, a long-term trial found that 5 (2.1%) of 235 patients treated with pregabalin for 40-52 weeks developed augmentation, compared with 12 (5.3%) of 225 patients receiving pramipexole at 0.25 mg/day (p=0.08) and 18 (7.7%) of 235 patients receiving pramipexole at 0.5 mg/day (p=0.001). 2 Such findings emphasize the importance of performing extended follow-ups to capture augmentation and other delayed adverse effects.Longer-duration trials lasting 6-12 months would allow for more-comprehensive evaluations of the long-term efficacy, safety, tolerability, adherence, and delayed complications of pregabalin, thereby providing a clearer understanding of its role in RLS management.The authors have made valuable contributions to this field, and we anticipate that future research making the additional observations described herein would further improve the understanding of the efficacy and safety of pregabalin for RLS.