| Disorder | Comment |
| Neurological disorders with "urge to move" | |
| Neuroleptic-induced akathisia | Looks like severe RLS but affects the whole body, not just the limbs. Less circadian pattern and less relief from movement. Entire body rocking often seen. Associated with dopamine antagonists. |
| Hypotensive akathisia | Feeling of restlessness, brought on by sitting still, which may be localized in legs; should not occur while lying down but might be relieved by movement; occurs in patients with orthostatic hypotension. |
| Volitional movements, foot tapping, leg rocking | Occurs in subjects who fidget, especially when bored or anxious, but usually not associated with sensory symptoms, discomfort, or conscious urge to move. Symptoms do not bother the subject, usually lack a circadian pattern, and do not cause sleep disturbances. Probably a type of psychic restlessness, very common. |
| Painful legs and moving toes | Feet involved more than in RLS. Movement is truly involuntary, no circadian pattern. Usually a continuous slow writhing. |
| Isolated leg stereotype | Fast (>3 Hz) rhythmic plantar flexion/dorsiflexion movements oscillating around ankle, but sometimes involving other parts of the leg. Usually a tremor phenotype, but not considered a true tremor. It is easily suppressed and is almost always seen only while sitting. The condition is common, not considered pathologic, and may be an alerting activity. Overlaps with foot tapping/leg rocking. |
| Orthostatic tremor | Fine leg tremor manifest by a sense of poor balance while standing, but not while walking. Therefore, patients cannot stand still but need to walk. Unlike RLS, there are no symptoms while sitting or lying down and no circadian pattern. |
| Disorders without "urge to move" | |
| Nocturnal leg cramps | Leg cramps or charley horse cramps that come on at night and are relieved with stretching or walking. Experienced as an unusually painful muscular contraction, often involving the calf muscles. Unlike RLS, sensations are sudden onset, short duration, usually palpable contractions, no urge to move. |
| Arthritis, lower limb pain | Discomfort centered mostly in joints, increased with movement. Unlike RLS, does not have prominent circadian pattern, does not respond to dopaminergics, usually no PLMS. |
| Positional discomfort | Often comes on with prolonged sitting or lying in the same position, but usually relieved by a simple change in position, unlike RLS, which often returns when change of position, movement, or walking is not continued, no circadian pattern. |
| Vascular disorders | |
| Vascular claudication | Pain in the legs. Usually worse with walking or movement and usually relieved by prolonged rest, often best in a lying position. Unlike RLS, no urge to move, no circadian pattern, usually no sleep disturbances. |
| Varicose veins | May have discomfort in legs, some relief with massage or inactivity. |
| Pain disorders | |
| Myelopathy, radiculopathy | Dysesthesias and pain in the legs, frequently one-sided, often radicular, with atrophic changes of musculature. Although symptoms can be initiated by sitting or lying down and improve with movement, there is no urge to move the legs, no response to dopaminergic therapy. |
| Painful peripheral neuropathy | Sensory symptoms commonly reported as numbness, burning, and pain; more superficial than RLS, no urge to move. Complete and persistent relief is not obtained while walking or during sustained movement. |
| Isolated leg pain | Undiagnosed leg pain or ache in the muscle may be seen without other explanation. The examination and evaluation is normal. This is often worse at night and may improve with movement but there is no true urge to move. |
| Congestive heart failure | Nighttime pain in the lower limbs that spreads to the lumbosacral area, causing sleep disturbances; no urge to move. Attributed to nocturnal engorgement of the lumbar veins causing transient lumbar stenosis. |
| Fibromyalgia | Multiple, alternating, varied complaints in muscle groups and joints; sometimes leg-accentuated but mostly whole body affected. Frequent sleep disturbances, but no circadian pattern, no relief from movement. |
| Sleep-related disorders | |
| Periodic limb movements of sleep | Diagnosis made by sleep laboratory assessment, positive response to dopaminergic therapy. No urge to move or dysesthesias while awake. Sleep disturbance and complaints of daytime fatigue and sleepiness may be present. |
| Hypnic jerks | Involuntary muscle (myoclonic) twitch that occurs while falling asleep. Described as an electric shock or falling sensation, which can cause movements of legs and arms. Occurs once or twice per night, common. |
