title: Reduced striatal dopamine transporters in idiopathic rapid eye movement sleep behaviour disorder. Comparison with Parkinson's disease and controls.
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.)
authors.affiliation: Department of Neurology, University of Munich, Germany. eisen@nefo.med.uni-muenchen.de
authors.forename: I
authors.initials: I
authors.lastname: Eisensehr
authors.forename: R
authors.initials: R
authors.lastname: Linke
authors.forename: S
authors.initials: S
authors.lastname: Noachtar
authors.forename: J
authors.initials: J
authors.lastname: Schwarz
authors.forename: F J
authors.initials: FJ
authors.lastname: Gildehaus
authors.forename: K
authors.initials: K
authors.lastname: Tatsch
mesh_terms: D000328:Adult; D000368:Aged; D001549:Benzamides; D002352:Carrier Proteins / Q000378:metabolism*; D003342:Corpus Striatum / Q000737:chemistry / Q000378:metabolism* / Q000503:physiopathology; D018492:Dopamine Antagonists; D050483:Dopamine Plasma Membrane Transport Proteins; D005133:Eye Movements / Q000502:physiology; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009419:Nerve Tissue Proteins; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D017729:Presynaptic Terminals / Q000737:chemistry / Q000378:metabolism; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D012893:Sleep Wake Disorders / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D012895:Sleep, REM / Q000502:physiology*; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes / Q000493:pharmacokinetics
chemical_list: D001549:Benzamides; D002352:Carrier Proteins; D018492:Dopamine Antagonists; D050483:Dopamine Plasma Membrane Transport Proteins; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D014326:Tropanes; C087210:N-(3-iodopropen-1-yl)-2-carbomethoxy-3-(4-chlorophenyl)tropane; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide