Diagnosis of PLMD/RLS
PLMD Diagnosis
A sleep partner may observe the occurrence of periodic limb movements, which often affect the partner before the patient knows of his or her behavior. In other cases, however, the diagnosis is made by a sleep technician during an overnight polysomnogram, which records sleep and the bioelectrical processes that govern it. This test is often used to assess the cause of excessive daytime sleepiness, such as PLMD and obstructive sleep apnea.
RLS Diagnosis
The diagnosis of RLS is based on the patient's description and personal history of his or her affliction. Because it presents no external secondary symptoms, RLS can be difficult to identify. There are studies designed to quantify the effects of RLS, though these are used mostly for research purposes. For example, a Suggested Immobilization Test, or Forced Immobilization Test, is performed while the patient either voluntarily keeps his or her legs motionless or while the legs are immobilized with a stretcher. The limb movements are then monitored with an EMG. In both PLMD and RLS, a complete examination to exclude secondary causes is warranted.
Furthermore, it is necessary to distinguish PLMD from other more serious types of nocturnal movement, such as seizure. Nocturnal seizures present problems for patients because they can cause injury and are indicative of disorders that require specialized treatment. Also, iron and calcium deficiencies often produce symptoms that mirror RLS, such as leg cramping and tenderness.
