Lumbar central spinal stenosis (LCSS) is a common degenerative spinal disorder characterized by narrowing of the spinal canal, resulting in chronic low back pain, leg pain, and neurogenic claudication. Restless legs syndrome (RLS) is frequently observed in patients with lumbar spinal disorders and may contribute substantially to sleep disturbance and reduced quality of life. Although lumbar interlaminar epidural steroid injection (LIESI) is widely used to alleviate pain and improve functional status in patients with LCSS, its effect on RLS symptoms has not been adequately investigated.

The aim of this prospective observational study is to evaluate the effect of lumbar interlaminar epidural steroid injection on restless legs syndrome symptoms in patients with lumbar central spinal stenosis. Adult patients with symptomatic moderate-to-severe lumbar central spinal stenosis who have persistent pain despite conservative treatment and who also report symptoms consistent with restless legs syndrome will be enrolled. Participants will undergo standard fluoroscopy-guided lumbar interlaminar epidural steroid injection as part of routine clinical care.

Restless legs syndrome severity, pain intensity, disability, and sleep quality will be assessed before the procedure and at 3 weeks and 3 months after treatment using the International Restless Legs Syndrome Rating Scale (IRLS), Numeric Rating Scale (NRS), Modified Oswestry Disability Index (MODI), and Pittsburgh Sleep Quality Index (PSQI), respectively. The primary outcome is the change in IRLS score from baseline to 3 months. Secondary outcomes include changes in pain intensity, disability, and sleep quality following treatment.

This study aims to provide evidence regarding the relationship between epidural pain treatment and restless legs syndrome symptoms in patients with lumbar central spinal stenosis.

Lumbar central spinal stenosis (LCSS) is one of the most common causes of chronic low back and leg pain in older adults. Degenerative narrowing of the spinal canal may lead to compression of neural structures, resulting in pain, neurogenic claudication, sensory symptoms, functional impairment, and reduced quality of life. Lumbar interlaminar epidural steroid injection (LIESI) is a frequently performed minimally invasive treatment option for patients with symptomatic LCSS who do not achieve adequate relief with conservative treatment modalities.

Restless legs syndrome (RLS) is a sensorimotor disorder characterized by an urge to move the legs, usually accompanied by unpleasant sensations that worsen during rest and improve with movement. Several studies have suggested an association between lumbar spinal disorders and secondary RLS symptoms. Chronic pain, neural irritation, inflammatory mediators, sleep disturbance, and impaired mobility may contribute to the development or worsening of RLS in patients with lumbar spinal stenosis. However, data regarding the effect of epidural steroid injections on RLS symptoms remain limited.

The purpose of this prospective observational study is to evaluate the effect of lumbar interlaminar epidural steroid injection on restless legs syndrome symptoms in patients with lumbar central spinal stenosis. Adult patients with moderate-to-severe lumbar central spinal stenosis confirmed by magnetic resonance imaging (MRI), persistent low back and leg pain despite conservative treatment, and symptoms consistent with restless legs syndrome will be enrolled. All participants will receive fluoroscopy-guided lumbar interlaminar epidural steroid injection as part of routine clinical care. No additional intervention beyond standard treatment will be performed for research purposes.

Baseline demographic and clinical characteristics, including symptom duration, pain intensity, disability level, sleep quality, and radiological severity of spinal stenosis, will be recorded. Outcome assessments will be performed before the procedure and at 3 weeks and 3 months after treatment. Restless legs syndrome severity will be assessed using the International Restless Legs Syndrome Rating Scale (IRLS). Pain intensity will be measured using the Numeric Rating Scale (NRS), disability using the Modified Oswestry Disability Index (MODI), and sleep quality using the Pittsburgh Sleep Quality Index (PSQI).

The primary objective is to determine whether lumbar interlaminar epidural steroid injection is associated with improvement in RLS symptom severity at 3 months compared with baseline. Secondary objectives include evaluating changes in pain intensity, disability, and sleep quality following treatment. The findings of this study may improve understanding of the relationship between lumbar spinal stenosis, chronic pain, and restless legs syndrome, and may help identify additional clinical benefits of epidural steroid injection beyond pain relief alone.

Inclusion Criteria:

Age between 18 and 75 years Ability to understand the study procedures and provide written informed consent Moderate or severe lumbar central spinal stenosis confirmed by magnetic resonance imaging (MRI) Chronic low back and leg pain attributed to lumbar central spinal stenosis Symptoms of restless legs syndrome Pain intensity ≥4 on the Numeric Rating Scale (NRS) Symptom duration ≥3 months Persistent symptoms despite conservative treatment and maximum tolerated medical therapy Planned fluoroscopy-guided lumbar interlaminar epidural steroid injection as part of routine clinical care -

Exclusion Criteria:

Radicular pain limited to a single nerve root distribution Vascular claudication History of peripheral vascular disease Previous lumbosacral spine surgery Polyneuropathy or lower extremity entrapment neuropathy Local or systemic infection Rheumatologic disease Neurodegenerative disease Diabetes mellitus Moderate to severe chronic kidney disease Ankylosing spondylitis or rheumatoid arthritis Epidural steroid injection within the previous 6 months Foraminal stenosis causing dynamic or postural radiculopathy Current use of antidepressant, sedative, or hypnotic medications Iron deficiency anemia Vitamin B12 deficiency Known history of restless legs syndrome or family history of restless legs syndrome Failure to receive maximum tolerated medical therapy

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Adult patients aged 18 to 75 years with moderate-to-severe lumbar central spinal stenosis confirmed by magnetic resonance imaging (MRI), chronic low back and leg pain refractory to conservative treatment, and symptoms consistent with restless legs syndrome who are scheduled to undergo fluoroscopy-guided lumbar interlaminar epidural steroid injection as part of routine clinical care.