Periodic Limb Movement Disorder Clinical Presentation

Updated: Nov 10, 2017
  • Author: Wayne E Anderson, DO, FAHS, FAAN; Chief Editor: Selim R Benbadis, MD  more...
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Periodic limb movement disorder (PLMD) is characterized by periodic episodes of repetitive limb movements during sleep, which most often occur in the lower extremities. These movements may cause awakening during the night resulting in excessive daytime sleepiness. Often, the presenting complaint is poor sleep or unexplained insomnia and daytime somnolence. [6] Researchers report that sleep changes induced by periodic limb movements during sleep are associated with decreased physical and psychological fitness on awakening. [7]

Leg movements associated with PLMD are stereotyped and involve one or both limbs. The movement simulates triple flexion with leg flexion, ankle dorsiflexion, and great toe extension; it lasts approximately 2 seconds and thus is not consistent with the rapid jerk that defines true myoclonus. The periodicity ranges from 20-40 seconds with a variable duration. The movements are said to occur mainly in non–rapid eye movement (REM) sleep.

Occasionally, a bed partner may provide the history of limb movements.

Nozawa and colleagues studied arousal index and movement index in periodic limb movement disorder and noted that the sleep-wake disorders associated with periodic limb movement relate to threshold of awakening. [8]

Growing evidence suggests a link between restless legs syndrome and periodic limb movement or sleep disorder. Picchietti et al provide evidence supporting the concept that periodic limb movement disorder may be a marker for an RLS genotype. [9]

The patient history may include ADHD. Walters et al provide an association between ADHD and sleep movement disorders including periodic limb movement disorder. [10]