Restless Legs Syndrome

^aListed salts supply approximately 200 mg of elemental iron daily.
^bAs the hydrochloride salt.
^cAs the mesylate salt.

Authors and Disclosures

Melody Ryan, Pharm.D., is Associate Professor, Department of Pharmacy Practice and Science, University of Kentucky College of Pharmacy, Lexington, and Department of Neurology, University of Kentucky College of Medicine (UKCM).

John T. Slevin, M.D., is Professor, Department of Neurology, UKCM, and Staff Neurologist, Department of Veterans Affairs Medical Center, Lexington.

Appendix A: Diagnostic criteria for restless legs syndrome

Essential diagnostic criteria

• A symptomatic urge to move the legs, usually accompanied or caused by uncomfortable or unpleasant sensations in the legs. Descriptive terms include but are not limited to the following: ants crawling, jittery, pulling, worms moving, electric current, pain, the gotta moves, burning, heebie-jeebies, tearing, throbbing, tight feeling, grabbing sensation, itching bones, crazy legs, fidgets.

• The symptom complex begins or worsens during periods of rest or inactivity.

• The symptom complex is partially or totally relieved by movement.

• The symptom complex is at its worst or only occurs in the evening or night.

Supportive clinical features

• Family history

• Response to dopaminergic therapy

• Periodic limb movements (while asleep or awake)

Associated features

• Natural clinical course of the disorder

• Sleep disturbance

• Typically normal neurologic examination

Appendix B: Evaluation methods used in restless legs syndrome studies

Rating scales

• The Clinician Global Impression-Improvement scale is a rating system in which the clinician assigns a score from 1 (very much improved) to 7 (very much worse). It is not specific to restless legs syndrome (RLS).

• The International Restless Legs Syndrome scale is a 10-item scale with scores ranging from 0 (best) to 40 (worst). Items assess the intensity and frequency of the primary features of RLS, associated sleep problems, and the impact of RLS on mood and daily functioning. Patients' RLS can be classified as mild (1-10), moderate (11-20), severe (21-30), or very severe (31-40).^[8]

• The Medical Outcomes Study Sleep Scale has been validated in the general population but is not specific to RLS. Patients self-rate sleep disturbance, sleep adequacy, daytime somnolence, sleep quantity, respiratory impairments, and snoring. The score on each item ranges from 0 to 100.^[9]

• The Pittsburgh Sleep Quality Index is a 19-item questionnaire to assess sleep quality and sleep disturbances. Patients score between 0 (best) and 21 (worst).

• The Restless Legs Syndrome Quality of Life questionnaire is a validated 18-item questionnaire. Ten items are used to calculate an overall life impact score ranging from 0 (lowest quality of life) to 100 (best quality of life). The remaining items assess employment, work, and sexual interest.^[10]

• The Short Form-36 is a well-validated, 36-item questionnaire. Quality of life is assessed in the domains of physical function, social function, role disturbances resulting from physical and emotional problems, mental health, energy and vitality, pain, and general health perception. It is not specific to RLS.

• Sleep diaries are used daily to document the time the patient sleeps and subjective sleep quality.

• The Standardized Sleep Inventory Schlaf-Fragebogen, part A, is a 22-item questionnaire that assesses sleep patterns and mood.

Clinical tests

• Actigraphy is a method of counting movements during sleep. An activity meter is placed around the ankle. While not as detailed as polysomnography, actigraphy can be performed in the patient's home and is more economical.

• Polysomnography is almost always performed in a sleep laboratory. Electroencephalography, surface electromyography (EMG), and video recordings of sleep are performed over one or more nights. From these data, a number of criteria can be derived: the total number of periodic limb movements of sleep (PLMS), PLMS index (number of PLMS per hour), PLMS arousal index (number of PLMS associated with arousal per hour), total number of arousals, sleep efficiency, and sleep latency (time for an individual to go to sleep).^[8]

• The suggested immobilization test assesses RLS symptoms while the patient is awake. EMG surface electrodes are placed on the legs, and the patient is instructed to sit on the bed with eyes open and legs outstretched without moving. The patient indicates RLS sensations during the test.^[8]