Periodic Limb Movement Disorder Workup

Updated: Aug 03, 2021
  • Author: Deepak K Gupta, MD; Chief Editor: Selim R Benbadis, MD  more...
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Laboratory Studies

Because anemia, uremia, hyperglyecemia, and iron deficiency can lead to a secondary form of periodic limb movement disorder (PLMD), laboratory screening studies should be obtained to rule out such metabolic abnormalities.

A urine drug screen may be appropriate.


Sleep Study

Definitive diagnosis of periodic limb movement disorder (PLMD) requires polysomnography. [20] Obtaining a sleep study to evaluate for PLMD, obstructive sleep apnea (OSA), and other underlying sleep disorders may be especially useful in patients with generalized and persistent fatigue, including those with diagnosed depression and in whom antidepressant therapy has been ineffective. [21] Observation in a sleep laboratory allows documentation of the movements and rapid diagnosis.

Periodic leg movements in sleep (PLMS) are a common symptom in restless legs syndrome and are a frequent finding in polysomnography. An elevated number of PLMS are defined as PLMD.

Variability from night to night occurs in both adults and children with documented PLMD. [22]



Other Tests

The Stanford PLM automatic detector (S-PLMAD) is a robust, automated leg movement detector used to score periodic limb movement functions. According to one study, the S-PLMAD works well in controls and sleep disorder patients. [23]

Additional testing, such as cerebrospinal fluid (CSF) analysis or magnetic resonance imaging (MRI) of the brain, may be warranted if the patient history and clinical presentation are suggestive of pathologies such as sporadic Creutzfeldt-Jakob disease or fatal familial insomnia, as sleep disturbances including periodic limb movement disorder (PLMD) are common features of these conditions. [24]