Restless Legs Syndrome Differential Diagnosis Table

Restless Legs Syndrome Differential Diagnosis Table:

Restless legs syndrome (RLS) is a condition that causes an urge to move the leg, its uncomfortable sensation of tingling and itching, it usually occurs during relaxing times especially in the evening or during sleep and gets better with movement.
The pathophysiology of restless legs syndrome is not known but may be related to insufficient dopamine in the basal ganglia, which is responsible for movement. A lot of conditions can cause restless leg syndrome such as diabetes, iron deficiency anemia, and kidney disease.
There’s no cure for restless legs syndrome, but medication can help relieve the symptoms.
Diagnosis of restless legs syndrome is made by the criteria established by the International Restless Legs Syndrome Study Group; other neurological and blood tests may be used to exclude other conditions.

How to Distinguish Restless Legs Syndrome from Other Diseases

Distinguish Periodic Limb Movement Disorder (PLMD) from Restless Legs Syndrome (RLS) – Diagnosis

Periodic limb movement disorder (PLMD) is described as an involuntary movement of a body part, more commonly the lower extremities, during sleep that happens every 20 to 40 seconds. The patients are usually unaware of the disease, but a bed partner can confirm it. RLS and PLMD commonly happen together, and most people diagnosed with RLS have PLMD as well.

• The most common diagnostic tool for PLMD is polysomnography or a sleep study, which is a test used for the diagnosis of any abnormalities during sleep and appears as electromyographic activity.

“Periodic limb movement disorder commonly occurs because of an underlying condition like a spinal cord problem or maybe because of medications such as antidepressants or antihistamines.”

Distinguish Sleep-Related Leg Cramps from Restless Legs Syndrome (RLS) – Diagnosis

Sleep-related leg cramps, although known as nocturnal leg cramps, are a disorder causing muscle tightening in the leg, especially in the calf and thighs during sleep. It’s often painful and lasts from several seconds to several minutes.

• There’s no specific diagnostic test for sleep-related leg cramps; usually, physical examination and history are used to distinguish it from other diseases.

“Sleep-related leg cramps and restless legs syndrome may look alike, but one major difference between them is that in sleep-related leg cramps, the leg cramps, and it feels painful while in restless legs syndrome, there’s only an urge to move the extremity.”

Distinguish Diabetes Mellitus from Restless Legs Syndrome (RLS) – Diagnosis

Diabetes mellitus is a chronic metabolic disease that results from insufficient insulin in your body, resulting in increased blood sugar. It has two types; type 1, which is genetic and affects patients from a young age, and type 2, which affects patients from age 40 or above. A common complication of diabetes is diabetic neuropathy in which high blood sugar for a long time results in damaging nerves causing symptoms like numbness and pain in the feet.

• The diagnosis of diabetes is usually confirmed by blood tests like fasting blood glucose more than 126 mg/dl or HbA1c more than 6.5%.
• Diagnosis of diabetic neuropathy depends initially on a history of diabetes and a series of nerve tests like nerve conduction tests or electromyography are needed to confirm the diagnosis and prognosis of the condition.

Distinguish Iron Deficiency Anemia from Restless Legs Syndrome (RLS) – Diagnosis

Iron deficiency anemia is a condition caused by low iron in the blood, which leads to a decrease in oxygen supply in the blood and to tissues. This results in fatigue and sometimes muscle cramps or pain. Iron deficiency anemia itself can cause restless legs syndrome.

• Iron deficiency anemia is diagnosed based on serum levels of hemoglobin (in males: < 13mg/dl – in females < 11mg/dl), ferritin (in males: <30 ug/L – in females: <14 ug/L), and transferrin (<20%).

“Since iron deficiency anemia can cause restless legs syndrome, initial blood iron level should be considered. If low, treatment with iron supplements may help improve symptoms if iron deficiency is the main cause of symptoms.”

Distinguish Peripheral Neuropathy from Restless Legs Syndrome (RLS) – Diagnosis

Peripheral neuropathy is a condition that affects the peripheral nerves (outside the brain and spinal cord). This leads to a tingling sensation, pain, and discomfort in the legs or hands. A lot of diseases and drugs can result in peripheral neuropathy.
Based on initial physical examination and symptoms, the doctor will usually order various tests to know the underlying problem.

• Nerve tests like nerve conduction test (electromyograph) are usually needed to determine and monitor electrical activity in the nerves.
• Imaging tests like CT or MRI may be needed also to exclude herniation or other problems that cause a block or damage in the nerves.
• Other blood tests like blood glucose level may be needed to determine if it’s a diabetic neuropathy.

Distinguish Rheumatoid Arthritis from Restless Legs Syndrome (RLS) – Diagnosis

Rheumatoid arthritis is a chronic autoimmune disorder that causes the body’s immune system to attack healthy tissues of joints and organs, resulting in joint pain and swelling, and it may progress to joint and bone erosion.

• Rheumatoid factor is the most specific marker of rheumatoid arthritis; it’s produced during attacks of the immune system to healthy tissue.
• Anti-cyclic citrullinated peptide (anti-CCP) is another marker that can be used. Most people with rheumatoid arthritis will have anti-CCP positive, but some patients may not have it.
• Other blood tests like CRP and ESR, which are inflammatory markers, may help in diagnosis and during flare-ups of the disease.
• Imaging tests like CT scan and MRI are usually used to monitor the prognosis of the disease and the extent of joint inflammation and damage.

Distinguish Varicose Veins from Restless Legs Syndrome (RLS) – Diagnosis

Varicose veins are a condition that affects veins, especially veins in the leg. The valves in the vein that are responsible for the flow of blood to the heart become weakened and can’t function, causing the vein to become twisted. This may result from old age, obesity, or standing too long, which is the most common cause.

• Duplex varicose veins is the most specific test for diagnosis; it visualizes dilated veins and helps to know the extent of the disease.
• Doppler ultrasound is used, and it helps to know blood flow inside the vein.
• Physical examination by identifying the characteristic spider veins, which appear as bluish veins, usually helps identify the disease immediately.

Distinguish Fibromyalgia from Restless Legs Syndrome (RLS) – Diagnosis

Fibromyalgia is a chronic condition that causes pain throughout the body; the exact cause of this condition is unknown, but the pain stimuli become amplified, sometimes occurring after physical stress.

• Widespread pain index is currently used for diagnosis; if the patient has pain for the past 3 months with specific areas in the body.
• Tender point exam was also previously used, in which the doctor examines 18 points in the body to see the extent of pain.
• Other blood tests for other several conditions like thyroid hormone, rheumatoid, or vitamin D will need to be done to exclude other diseases.
• X-ray or other imaging tests may also be needed to exclude other conditions.

“There’s no specific diagnostic test for fibromyalgia; the diagnosis usually depends on exclusion criteria and guidelines of the American College of Rheumatology.”

Important Red Flags in Restless Legs Syndrome

Restless legs syndrome is a lifelong condition, although it’s not a severe or life-threatening condition. But it can affect a patient’s quality of life.
Restless legs syndrome is a hard condition to live with; it can lead to anxiety and depression.
The most common red flag that affects a patient’s life is the inability to sleep at night, which can lead to dizziness, drowsiness, and sometimes can lead to a change in mood and impaired memory.
Although it’s not treatable, it’s important to seek a doctor to prevent the prognosis of the disease and its effect on a patient’s quality of life.