Why do I get leg discomfort?
There is a broad range of medical problems that can lead to leg discomfort and pain. There are many ways to divide up these causes, but in sleep medicine, the first concern is if the leg discomfort happens mainly in the daytime, nighttime, or both day and night. Leg discomfort that happens in the daytime, is almost always due to an underlying medical problem and not a sleep disorder.
Medical problems that can lead to leg discomfort can include electrolyte disorders (abnormal amounts of sodium, potassium and vitamins- especially vitamin D), endocrine disorders (diabetes, thyroid disease), arthritis (knee and ankle pain), nerve disorders or neuropathies, back injuries, poor blood flow (vascular disease, vasculitis) and muscle diseases (myopathies). Blood clots (deep venous thrombosis or DVT) following travel, injury, surgery, or hormonal medications can also cause leg discomfort. Bone pain from small fractures (stress fractures) or cancers (sarcomas) can cause pain. It is important to describe the onset and location of the pain as best as you can to your physician so that they can help you. For example, burning pain is more likely neuropathy, pain when exercising is more likely vascular. Shooting pains are usually due to injury or nerve damage.
Leg pain that happens when resting or sleeping, or leg pain that happens exclusively at night is more often due to a sleep disorder, the most common ones are discussed next.
What are nocturnal leg cramps?
These are frequently referred to as a “Charley Horse.” This is a leg cramp that is characterized by a muscle spasm, causing part of the leg to become stiff and painful. It usually lasts only a few minutes but can recur. These are usually relieved by gentle stretching of the muscle and may benefit from the use of quinine water (found in tonic water, seltzer, and ginger ale).
What is restless leg syndrome?
Unlike leg cramps, this type of leg discomfort between the ankle and knee always starts when someone is immobilized, from prolonged sitting or when first reclining in bed. It can vary from a creeping and tugging sensation up to cramping and discomfort. It is significantly relieved by moving (usually getting out of bed and walking around) and can return when returning to bed. It does run in families and usually occurs after the age of fifty, although it can be seen in younger people as well. It is felt to be linked to dopamine receptors and a lack of dopamine in the basal ganglion of the brain leads to difficulty controlling leg movements. It can also be triggered by pregnancy, low ferritin (iron, which is needed for the body to effectively use dopamine), and vitamin D. However, thyroid disease, kidney disease, anemia and other vitamin deficiencies can also lead to this syndrome.
Can medications make my restless legs symptoms worse?
Yes. Alcohol, caffeine, and certain medications can affect the dopamine level in your body and subsequently make restless legs worse. These medications are once that act directly on the brain (i.e., antipsychotics and antidepressants), medications to treat nausea, calcium-channel blockers, and some antihistamines.
Is there a treatment for restless legs disorder?
If a cause for restless legs can be identified, then that is targeted for treatment, such as iron deficiency or stopping an aggravating medication. If no cause can be immediately identified, then medications are used to increase the balance of dopamine in the brain and to relax the muscles. There are several medications specifically approved by the FDA for restless legs, which include: pergolide, pramipexole and ropinirole. The most common side effects of these medications include daytime drowsiness, low blood pressure, and an increased risk of melanoma (skin cancer). All patients should use sunscreen and have any skin lesions or growths checked by a Dermatologist (skin doctor). Medications similar to those used to treat Parkinson’s can also be used, as well as medications that are used for anxiety and sedation, pain medications (including medications used for seizures), and central agents, such as clonidine.
The timing and dosing of medications used to treat restless legs may need to be adjusted, as symptoms may worsen or occur more frequently over time.
What if I have restless legs during my pregnancy?
During pregnancy, restless legs may become much worse. Treatments during pregnancy are usually limited to iron, vitamins, and if severe or debilitating oxycodone. Thankfully, these symptoms usually completely resolve in 1-2 months following delivery.
Why do I kick my bed partner?
There are two common sleep disorders that may lead to kicking during sleep. One happens in association with dreaming and is called REM Behavior Disorder. The other more common disorder, called Periodic Limb Movement Syndrome (or PLMS), usually happens outside of “dream” or REM sleep. With PLMS, the person doing the kicking may even be completely unaware that they are having these events. The leg movements are usually characterized by bending the ankle and flexing the foot and usually happen in clusters. They are short and repetitive movements, which can happen for short periods of time, or continue all night long. They may be disruptive both for the person kicking (leading to unrestful sleep and daytime sleepiness) and to the person on the receiving end. The evaluation and treatment for periodic limb movement disorder is similar to that for Restless Legs Syndrome, with the exception that PLMS can also be caused by sleep apnea.
What if my child complains of leg discomfort “growing pains”?
Children, as well as adults, can suffer from Restless Legs Syndrome as well as other leg disorders; including disorders of growth (bone or joint), nerves (motor tics) and even leg movements related to attention deficit and hyperactivity disorder (ADHD). Restless Legs Syndrome more commonly occurs in kids whose parents have had Restless Legs as well. Treatment in children is usually more focused on finding the underlying cause than medications.
What tests are done in people with leg discomfort or increased leg movements?
All patients with abnormal leg movements will usually have routine blood work that screens for anemia, electrolytes, renal function, thyroid function, iron, and vitamin D deficiency. An evaluation of the medications taken may be helpful, as some medications that block dopamine (antipsychotics- used for treatment of hallucinations) can lead to leg restlessness and discomfort. People with sleep related symptoms often undergo polysomnography (sleep study) to determine if their leg discomfort is related to sleep apnea. If the symptoms are in the daytime, a SIT or suggested immobilization test may be performed to evaluate the severity of your symptoms. This test will require you to sit still on a bed for an hour while awake and will check for excessive leg movements.
Some patients may have leg discomfort that is due to other medical conditions and will frequently be seen by additional specialists. A Vascular Surgeon can further assess arterial and venous blood flow to the legs to see if this is a source of the discomfort. This is frequently done by testing the pulses (placing a Doppler ultrasound and blood pressure cuff on the limbs and measuring blood flow). Another physician who evaluates people with leg discomfort is a Neurologist (brain or nerve doctor). This doctor may perform testing to look for nerve or muscle disorders (EMG- electromyography and NCV- nerve conduction velocity), imaging of the brain and spine (CT scan or MRI), or brainwave evaluation for seizures by EEG (electroencephalography, monitors placed on the scalp). Rarely, similar symptoms are accompanied by pain in one part of the leg. If this exists, imaging of the leg may be performed to look for cancer (sarcoma).