Reduced striatal dopamine transporters in idiopathic rapid eye movement sleep behaviour disorder. Comparison with Parkinson's disease and controls

Brain. 2000 Jun;123 ( Pt 6):1155-60. doi: 10.1093/brain/123.6.1155.

Abstract

Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by complex behaviour during REM sleep. The aetiology of this disorder is still unknown, but a recent study showed an association between RBD and Parkinson's disease. We therefore studied striatal postsynaptic dopamine D2 receptor density with [123I](S)-2-hydroxy-3-iodo-6-methoxy-(1-ethyl-2-pyrrolidinylmethyl ) benzamide ([123I]IBZM) and the striatal presynaptic dopamine transporter with (N)-(3-iodopropene-2-yl)-2beta-carbomethoxy-3beta-(4-chlorop henyl) tropane ([123I]IPT) using single-photon emission computed tomography (SPECT) in patients with idiopathic RBD. We compared the [123I]IPT-SPECT results of five patients with polysomnographically confirmed idiopathic RBD with the [123I]IPT-SPECTs of seven age- and sex-matched controls without a history of sleep disorders, and of 14 patients with Parkinson's disease (Hoehn and Yahr stage I). All RBD patients had significantly reduced striatal [123I]IPT binding compared with the controls (RBD: right, 2.94 +/- 0.32, left, 3.03 +/- 0.41; controls: right, 4.41 +/- 0.17, left, 4.34 +/- 0.21; P = 0.003), but significantly higher striatal [123I]IPT binding compared with the striatum contralateral to the symptomatic body side of the Parkinson's disease patients (Parkinson's disease: ipsilateral, 3.17 +/- 0.36, P = 0.298; contralateral, 2.51 +/- 0.31, P = 0.019). Uptake of [123I]IBZM was not significantly different in the RBD group compared with the controls. This study demonstrates that [123I]IPT-SPECT is a useful diagnostic tool in RBD and that reduced striatal dopamine transporters may be a pathophysiological mechanism of idiopathic RBD. (Results are given as mean +/- standard deviation.)

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Benzamides
  • Carrier Proteins / metabolism*
  • Corpus Striatum / chemistry
  • Corpus Striatum / metabolism*
  • Corpus Striatum / physiopathology
  • Dopamine Antagonists
  • Dopamine Plasma Membrane Transport Proteins
  • Eye Movements / physiology
  • Humans
  • Iodine Radioisotopes / pharmacokinetics
  • Membrane Glycoproteins*
  • Membrane Transport Proteins*
  • Middle Aged
  • Nerve Tissue Proteins*
  • Parkinson Disease / diagnostic imaging
  • Parkinson Disease / metabolism*
  • Parkinson Disease / physiopathology
  • Presynaptic Terminals / chemistry
  • Presynaptic Terminals / metabolism
  • Pyrrolidines
  • Receptors, Dopamine D2 / metabolism
  • Sleep Wake Disorders / diagnostic imaging
  • Sleep Wake Disorders / metabolism*
  • Sleep Wake Disorders / physiopathology
  • Sleep, REM / physiology*
  • Tomography, Emission-Computed, Single-Photon
  • Tropanes / pharmacokinetics

Substances

  • Benzamides
  • Carrier Proteins
  • Dopamine Antagonists
  • Dopamine Plasma Membrane Transport Proteins
  • Iodine Radioisotopes
  • Membrane Glycoproteins
  • Membrane Transport Proteins
  • Nerve Tissue Proteins
  • Pyrrolidines
  • Receptors, Dopamine D2
  • Tropanes
  • N-(3-iodopropen-1-yl)-2-carbomethoxy-3-(4-chlorophenyl)tropane
  • 3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide