title: Longitudinal study of regional cerebral blood flow in elderly patients with idiopathic rapid eye movement sleep behavior disorder.
abstract: OBJECTIVE
  Single photon emission computed tomography (SPECT) studies showed that regional cerebral blood flow (rCBF) abnormalities in idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) are similar to those seen in Parkinson's disease (PD) and dementia with Lewy bodies (DLB). The aim of the present study was to assess the longitudinal rCBF changes in patients with iRBD using repeated SPECT.
  
  
  METHODS
  Nine patients with iRBD (7 men and 2 women; mean age 71.1 ± 3.2 years) underwent baseline and follow-up SPECT studies (a mean interval of 22.8 ± 9.2 months).
  
  
  RESULTS
  A decrease in rCBF was found in bilateral parietotemporal and occipital areas at the first and second SPECT. Compared with the first SPECT, the second SPECT showed a decreased rCBF in the medial portions of the parietooccipital lobe with a significant decrease in rCBF of the right posterior cingulate. None of the patients showed any neurological deficits, including extrapyramidal and cerebellar signs, visual hallucinations, and neuropsychological impairments during the study.
  
  
  CONCLUSIONS
  These findings suggest that longitudinal measurements of rCBF can show the presence of progressing neurodegenerative process in iRBD. Longitudinal SPECT study can be used to monitor the progression of degenerative process in patients with iRBD, even though there were no evolving neurological and neuropsychiatric impairments.
authors.affiliation: Department of Geriatric Medicine, Tokyo Medical University, Tokyo, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Sakurai
authors.forename: Haruo
authors.initials: H
authors.lastname: Hanyu
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Inoue
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Kanetaka
authors.forename: Masaki
authors.initials: M
authors.lastname: Nakamura
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Miyamoto
authors.forename: Taeko
authors.initials: T
authors.lastname: Sasai
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Iwamoto
mesh_terms: D000368:Aged; D002560:Cerebrovascular Circulation / Q000502:physiology*; D018450:Disease Progression; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D017286:Polysomnography; D011379:Prognosis; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis / Q000503:physiopathology*; D012039:Regional Blood Flow / Q000502:physiology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
keywords: follow up; rapid eye movement sleep behavior disorder; regional cerebral blood flow; single photon emission computed tomography; synucleinopathy