title: Periodic leg movements in sleep in elderly patients with Parkinsonism and Alzheimer's disease.
abstract: BACKGROUND
  Periodic leg movements in sleep (PLMS) are non-epileptiform, repetitive movements of the lower limbs that have been associated with apparent dopamine deficiency. We hypothesized that elderly patients with a disease characterized primarily by dopamine depletion (Parkinsonism) would have higher rates of PLMS than age-matched controls or a different neurodegenerative condition not primarily involving a hypodopaminergic state, Alzheimer's disease (AD).
  
  
  METHODS
  We compared rates of PLMS derived from in-laboratory overnight polysomnography in patients with Parkinsonism (n = 79), AD (n = 28), and non-neurologically impaired, community-based controls (n = 187).
  
  
  RESULTS
  Patients with Parkinsonism not receiving levodopa had significantly higher rates of PLMS than did patients with Parkinsonism receiving levodopa as well as higher rates than seen in AD and controls. Other medications did not appear to exert the pronounced effect of levodopa on PLMS in this Parkinsonian patient population. The symptom of leg kicking was reported more frequently in Parkinsonism and was associated with higher rates of PLMS. Caregiver reported leg kicking was unrelated to PLMS in AD.
  
  
  CONCLUSIONS
  Results are broadly compatible with a dopaminergic hypothesis for PLMS in Parkinsonism. The clinical significance of the negative findings in patients with AD requires further investigation.
authors.affiliation: Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA. dbliwis@emory.edu
authors.forename: D L
authors.initials: DL
authors.lastname: Bliwise
authors.forename: L M
authors.initials: LM
authors.lastname: Trotti
authors.forename: J A
authors.initials: JA
authors.lastname: Yesavage
authors.forename: D B
authors.initials: DB
authors.lastname: Rye
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000150:complications*; D004576:Electromyography; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology; D020734:Parkinsonian Disorders / Q000150:complications*; D017286:Polysomnography; D011569:Psychiatric Status Rating Scales; D012111:Residence Characteristics; D012148:Restless Legs Syndrome / Q000175:diagnosis* / Q000209:etiology*; D012720:Severity of Illness Index