What is the Difference Between RLS and PLMD

The key difference between RLS and PLMD is that RLS (Restless Leg Syndrome) causes an uncontrollable urge to move the legs, arms, or both, especially when a person is sitting or lying down. On the other hand, PLMD (Periodic Limb Movement Disorder) involves repetitive movements of the arms, legs, or both that occur specifically during sleep.

Movement disorders are a group of conditions associated with the nervous system that result in either increased movements or reduced movements. The movements in these disorders may be voluntary or involuntary. Therefore, restless leg syndrome (RLS) and periodic limb movement disorder (PLMD) are two types of movement disorders.

CONTENTS

1. Overview and Key Difference
2. What is Restless leg syndrome (RLS)
3. What is Periodic Limb Movement Disorder (PLMD)
4. Similarities – RLS and PLMD
5. RLS vs. PLMD in Tabular Form
6. Summary – RLS vs. PLMD

What is Restless leg syndrome (RLS)?

Restless leg syndrome (RLS) is also called Willis-Ekbom disease. This condition results in an uncontrollable urge to move legs or arms, generally due to an uncomfortable sensation. It usually occurs in the evening or nighttime when sitting or lying down. However, in this condition, the movement of the legs temporarily eases down the unpleasant feeling or sensation. The main symptom of this disorder is the urge to move. The other characteristics may include sensations that begin while resting, relief with movement, worsening of symptoms, generally in the evening, and leg twitching at night times. RLS is caused by an imbalance of the brain chemical dopamine due to heredity or pregnancy-related complications. Moreover, the risk factors for this condition include peripheral neuropathy, iron deficiency, kidney failure, spinal cord conditions, and Parkinson’s disease.

RLS can be diagnosed through medical history, physical examination, neurological examination, blood test, and sleep study. Furthermore, RLS can be treated through medications that increase dopamine in the brain (rotigotine and pramipexole), drugs affecting calcium channels such as gabapentin, gabapentin enacarbil, and pregabalin, muscle relaxants and sleep medications, and opioids like tramadol, codeine, oxycodone, and hydrocodone.

What is Periodic Limb Movement Disorder (PLMD)?

Periodic limb movement disorder (PLMD) is a disease condition that results in repetitive limb movements (cramping or jerking) during sleep. These movements can often disrupt sleep. The symptoms of PLMD may include daytime fatigue or sleepiness, insomnia, leg or arm twitches or jerks every 20 to 40 seconds during sleep, frequent awakenings, and problems with sleep onset. PLMD is caused by abnormalities in the regulation of nerves traveling from the brain to the limbs and due to other factors like diabetes, iron deficiency, spinal cord tumor, spinal cord injury, sleep apnea, narcolepsy, uremia, anemia, medication (neuroleptics and other antidopaminergic agents), and withdrawal from sedative medications such as barbiturates or benzodiazepines. Moreover, risk factors for PLMD include diabetes, uremia, spinal cord conditions or injuries, iron deficiency, and family history.

PLMD can be diagnosed through travel history, habits, and lifestyle, detailed physical examinations, blood tests, urine tests, and sleep lab testing. Furthermore, PLMD is treated by taking iron supplements, avoiding caffeine, like chocolate, coffee, tea, and soft drinks, and taking medications like benzodiazepines, dopaminergic agents, anticonvulsant agents, and GABA agonists.

What are the Similarities Between RLS and PLMD?

• RLS and PLMD are two different types of movement disorders.
• Both disorders can disrupt nighttime sleep.
• Heredity may play a main role in both these disorders.
• Both disorders can be diagnosed through physical examination, blood tests, and sleep studies.
• They are mainly treated through medications.

What is the Difference Between RLS and PLMD?

RLS causes an uncontrollable urge to move the legs, arms, or both, especially when a person is sitting or lying down. On the other hand, PLMD involves repetitive movements of the arms, legs, or both that occur specifically during sleep. Thus, this is the key difference between RLS and PLMD. Furthermore, RLS is caused by an imbalance of the brain chemical dopamine due to heredity or pregnancy-related complications. On the other hand, PLMD is caused by abnormalities in the regulation of nerves traveling from the brain to the limbs and due to other factors like diabetes, iron deficiency, spinal cord tumor, spinal cord injury, sleep apnea,  narcolepsy, uremia, anemia, medication (neuroleptics and other antidopaminergic agents) and withdrawal from sedative medications such as barbiturates or benzodiazepines.

The infographic below presents the differences between RLS and PLMD in tabular form for side-by-side comparison.

Summary – RLS vs. PLMD

Movement disorders are a group of neurological conditions that generally result in abnormal movements. They cause increased (like spasms, jerking, or shaking), reduced, or slow movement. RLS and PLMD are two different types of movement disorders. RLS causes an uncontrollable urge to move the legs or arms due to an uncomfortable feeling. On the other hand, PLMD causes leg or arm twitches or jerks every 20 to 40 seconds during sleep. So, this summarizes the difference between RLS and PLMD.

Reference:

1.“Restless Legs Syndrome.” Mayo Clinic, 1 Mar. 2022.
2. “Periodic Limb Movement Disorder.” – Statpearls – NCBI Bookshelf.

Image Courtesy:

1. “RLS sleep patterns diagram – en” By RLS-Schlafmuster.png: Markus Muellerderivative work: — Editor at Large • talk – RLS-Schlafmuster.png (CC BY-SA 3.0) via Commons Wikimedia