title: Transcranial sonography in idiopathic REM sleep behavior disorder and multiple system atrophy.
abstract: OBJECTIVE
  We investigated preclinical abnormalities as revealed by transcranial sonography (TCS) in patients with idiopathic rapid eye movement sleep behavior disorder (iRBD) compared with those revealed in patients with multiple system atrophy (MSA) or Parkinson's disease (PD) and in normal controls.
  
  
  METHODS
  Twenty-two patients with iRBD, 21 patients with MSA, 22 patients with PD, and 21 normal controls were included in this study. All participants underwent one night of video-polysomnography monitoring, and the sleep parameters were analyzed using Polysmith software and by visual analysis. TCS was performed following a standardized procedure. The echogenicity of the substantia nigra and basal ganglia were evaluated.
  
  
  RESULTS
  A greater proportion of PD patients were found to have substantia nigra hyperechogenicity (86.4%) when compared to iRBD patients (31.8%), MSA patients (23.8%), and normal controls (4.8%) (P < 0.001). Fourteen MSA patients (66.7%) and 11 iRBD patients (50.0%) had hyperechogenicity in the basal ganglia, whereas hyperechogenicity in the basal ganglia was less frequent in PD patients (18.2%) and normal controls (9.5%) (P < 0.001). Poor sleep efficiency, less stage II sleep time, and more periodic leg movements were found in MSA and PD patients, whereas iRBD patients had almost normal sleep.
  
  
  CONCLUSIONS
  Some iRBD patients had basal ganglia hyperechogenicity that was similar to that observed in MSA, which may represent another possible convert direction. The present study further confirmed iRBD as a prodromal stage of synucleinopathy. TCS could detect subclinical changes and thus might provide useful markers for identifying individuals at increased risk for developing a synucleinopathy.
authors.affiliation: Department of Neurology and, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Neurology and, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Xue
authors.affiliation: Department of Neurology and, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Shuhong
authors.initials: S
authors.lastname: Jia
authors.affiliation: Department of Senior Official Ward, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Department of Neurology and, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Qiao
authors.affiliation: Department of Neurology and, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Chunlei
authors.initials: C
authors.lastname: Hou
authors.affiliation: Department of Neurology and, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Wei
authors.affiliation: Department of Neurology and, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Zheng
authors.affiliation: Department of Neurology and, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Rong
authors.affiliation: Department of Neurology and, China-Japan Friendship Hospital, Beijing, China.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Jiao
mesh_terms: D000368:Aged; D001479:Basal Ganglia / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000000981:diagnostic imaging*; D010300:Parkinson Disease / Q000000981:diagnostic imaging*; D017286:Polysomnography; D062706:Prodromal Symptoms; D020187:REM Sleep Behavior Disorder / Q000000981:diagnostic imaging*; D013378:Substantia Nigra / Q000000981:diagnostic imaging; D017585:Ultrasonography, Doppler, Transcranial
keywords: Parkinson's disease; multiple system atrophy; polysomnography; rapid eye movement sleep behavior disorder; transcranial sonography