Periodic Limb Movement Disorder

The Difference between Periodic Limb Movement Disorder (PLMD) and Restless Leg Syndrome (RLS)

Periodic limb movement disorder should firstly be distinguished from restless leg syndrome. While both disorders cause movement of a patient’s arms and or legs, periodic limb movement disorder occurs involuntarily, only while the patient is sleeping, while restless leg syndrome has voluntary effects that can strike during a patient’s waking hours. In fact, patients with restless leg syndrome can feel an uncomfortable urge to fidget their legs during the daytime—for example, at work or while sitting for a long time—while many patients with periodic limb movement disorder may not even know that they have the condition, as it displays no symptoms while the patient is wake (except for scars, injuries or soreness caused indirectly by the nighttime limb movement).

Patients with periodic limb movement disorder move their limbs during the first couple of stages of sleep, before deep cycles kick begin. A patient may feel the after-effects of these limb movements the next day in the form of excessive tiredness or fatigue as a result of those restless hours, during which a patient’s limbs may move a few times per minute. Falling asleep and staying asleep may also be problematic for patients with periodic limb movement disorder.

Diagnosing Periodic Limb Movement Disorder

It is actually quite difficult for a person to diagnose himself or herself with periodic limb movement disorder because the symptoms display themselves while the patient is asleep. Because of this, typically a patient’s family member or roommate detects the disorder. Unfortunately, the characteristics of each PLMD patient’s symptoms vary widely, so it is very difficult to generalize about the condition. The best way to diagnose periodic limb movement disorder is to undergo a polysomnogram (PSG or sleep study), during which the patient will stay overnight at a special sleep center to allow sleep experts to monitor the brainwaves and observe the patient’s physical way of sleeping. Although a single cause of PLMD has not been determined, periodic limb movement disorder is usually a sign that a patient has another medical condition—most oftentimes Parkinson’s disease, a brain disorder that causes affected individuals to shake and lose control of physical functions like walking and simple hand-eye coordination.

Treating Periodic Limb Movement Disorder

Since periodic limb movement disorder is often a sign of an underlying medical condition, the symptoms of period limb movement disorder will usually go away with regular treatment of that condition. For example, many PLMD patients are treated for their symptoms with the same medications prescribed to patients diagnosed with Parkinson’s disease. Unfortunately, these medications must be taken regularly for a long period of time, as they simply control symptoms. There is not an official cure for Parkinson’s disease yet. Small changes in a PLMD patient’s diet and lifestyle, such as exercising regularly and avoiding caffeine may also help control limb movement at night. Talk to a sleep expert about the different types of medication available to control muscle movement at night before you commit to one.