Restless Leg Syndrome Part 3 of 8
How is restless legs syndrome diagnosed?
Currently, there is no single diagnostic test for RLS. The disorder is diagnosed clinically by evaluating the patient's history and symptoms. Despite a clear description of clinical features, the condition is often misdiagnosed or under-diagnosed.
In 1995, the International Restless Legs Syndrome Study Group identified four basic criteria for diagnosing RLS:
(1) a desire to move the limbs, often associated with paresthesias or dysesthesias,
(2) symptoms that are worse or present only during rest and are partially or temporarily relieved by activity,
(3) motor restlessness, and
(4) nocturnal worsening of symptoms.
Although about 80 percent of those with RLS also experience PLMD, it is not necessary for a diagnosis of RLS. In more severe cases, patients may experience dyskinesia (uncontrolled, often continuous movements) while awake, and some experience symptoms in one or both of their arms as well as their legs. Most people with RLS have sleep disturbances, largely because of the limb discomfort and jerking. The result is excessive daytime sleepiness and fatigue.
Despite these efforts to establish standard criteria, the clinical diagnosis of RLS is difficult to make. Physicians must rely largely on patients' descriptions of symptoms and information from their medical history, including past medical problems, family history, and current medications. Patients may be asked about frequency, duration, and intensity of symptoms as well as their tendency toward daytime sleep patterns and sleepiness, disturbance of sleep, or daytime function.
If a patient's history is suggestive of RLS, laboratory tests may be performed to rule out other conditions and support the diagnosis of RLS. Blood tests to exclude anemia, decreased iron stores, diabetes, and renal dysfunction should be performed. Electromyography and nerve conduction studies may also be recommended to measure electrical activity in muscles and nerves, and Doppler sonography may be used to evaluate muscle activity in the legs. Such tests can document any accompanying damage or disease in nerves and nerve roots (such as peripheral neuropathy and radiculopathy) or other leg-related movement disorders. Negative results from tests may indicate that the diagnosis is RLS. In some cases, sleep studies such as polysomnography (a test that records the patient's brain waves, heartbeat, and breathing during an entire night) are undertaken to identify the presence of PLMD.
The diagnosis is especially difficult with children because the physician relies heavily on the patient's explanations of symptoms, which, given the nature of the symptoms of RLS, can be difficult for a child to describe. The syndrome can sometimes be misdiagnosed as "growing pains" or attention deficit disorder.
What Restless Leg Syndrome is
How is restless legs syndrome treated?
Although movement brings relief to those with RLS, it is generally only temporary. However, RLS can be controlled by finding any possible underlying disorder. Often, treating the associated medical condition, such as peripheral neuropathy or diabetes, will alleviate many symptoms. For patients with idiopathic RLS, treatment is directed toward relieving symptoms.
For those with mild to moderate symptoms, prevention is key, and many physicians suggest certain lifestyle changes and activities to reduce or eliminate symptoms. Decreased use of caffeine, alcohol, and tobacco may provide some relief. Physicians may suggest that certain individuals take supplements to correct deficiencies in iron, folate, and magnesium. Studies also have shown that maintaining a regular sleep pattern can reduce symptoms.
Some individuals, finding that RLS symptoms are minimized in the early morning, change their sleep patterns. Others have found that a program of regular moderate exercise helps them sleep better; on the other hand, excessive exercise has been reported by some patients to aggravate RLS symptoms. Taking a hot bath, massaging the legs, or using a heating pad or ice pack can help relieve symptoms in some patients. Although many patients find some relief with such measures, rarely do these efforts completely eliminate symptoms
Physicians also may suggest a variety of medications to treat RLS. Generally, physicians choose from dopaminergics, benzodiazepines (central nervous system depressants), opioids, and anticonvulsants.
Dopaminergic agents, largely used to treat Parkinson's disease, have been shown to reduce RLS symptoms and PLMD and are considered the initial treatment of choice. Good short-term results of treatment with levodopa plus carbidopa have been reported, although most patients eventually will develop augmentation, meaning that symptoms are reduced at night but begin to develop earlier in the day than usual. Dopamine agonists such as pergolide mesylate, pramipexole, and ropinirole hydrochloride may be effective in some patients and are less likely to cause augmentation.
Benzodiazepines (such as clonazepam and diazepam) may be prescribed for patients who have mild or intermittent symptoms. These drugs help patients obtain a more restful sleep but they do not fully alleviate RLS symptoms and can cause daytime sleepiness. Because these depressants also may induce or aggravate sleep apnea in some cases, they should not be used in people with this condition.
For more severe symptoms, opioids such as codeine, propoxyphene, or oxycodone may be prescribed for their ability to induce relaxation and diminish pain. Side effects include dizziness, nausea, vomiting, and the risk of addiction.
Anticonvulsants such as carbamazepine and gabapentin are also useful for some patients, as they decrease the sensory disturbances (creeping and crawling sensations). Dizziness, fatigue, and sleepiness are among the possible side effects.
Unfortunately, no one drug is effective for everyone with RLS. What may be helpful to one individual may actually worsen symptoms for another. In addition, medications taken regularly may lose their effect, making it necessary to change medications periodically.