title: Normal striatal D2 receptor binding in idiopathic restless legs syndrome with periodic leg movements in sleep.
abstract: Dopaminergic treatment is very effective in restless legs syndrome (RLS) and periodic leg movements in sleep (PLMS). However, neuroreceptor imaging studies that addressed altered striatal dopaminergic function have given controversial results. In this present study, 14 patients with idiopathic RLS (iRLS) and PLMS with a good response to dopaminergic and non-dopaminergic treatment and ten healthy sex- and age-matched controls were investigated off-medication by using 123I-IBZM and SPECT. RLS symptoms and sleep disturbances were evaluated using three nights of polysomnography, the Pittsburgh Sleep Quality Index, and the International RLS Study Group (IRLSSG) rating scale. The patients presented with sleep disturbances, a high PLMS index (56.2 +/- 33.1 per h), and severe RLS symptoms during SPECT (IRLSSG rating scale 23.1 +/- 8.0), and showed no significant differences in striatal to frontal IBZM binding to D2 receptors compared to controls (ratio striatum/frontal cortex, right side 1.60 +/- 0.10 vs 1.63 +/- 0.08, P = 0.35, NS; left side 1.61 +/- 0.11 vs 1.63 +/- 0.08, P = 0.51, NS). These findings show normal function of striatal D2 receptors in successfully treated patients with iRLS and PLMS. Dopaminergic and non-dopaminergic pretreatment does not appear to change striatal D2 receptor binding as compared to healthy controls. Structures other than striatal D2 receptors are discussed as possible causes of the treatment effects in RLS.
authors.affiliation: Department of Clinical Neurology, University of Vienna, Vienna General Hospital, Austria. gotthard.tribl@univie.ac.at
authors.forename: G G
authors.initials: GG
authors.lastname: Tribl
authors.forename: S
authors.initials: S
authors.lastname: Asenbaum
authors.forename: S
authors.initials: S
authors.lastname: Happe
authors.forename: R M
authors.initials: RM
authors.lastname: Bonelli
authors.forename: J
authors.initials: J
authors.lastname: Zeitlhofer
authors.forename: E
authors.initials: E
authors.lastname: Auff
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism; D000927:Anticonvulsants / Q000627:therapeutic use; D001549:Benzamides / Q000493:pharmacokinetics; D003342:Corpus Striatum / Q000000981:diagnostic imaging* / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020189:Nocturnal Myoclonus Syndrome / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism*; D011759:Pyrrolidines / Q000493:pharmacokinetics; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D012148:Restless Legs Syndrome / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism*; D012720:Severity of Illness Index
chemical_list: D000927:Anticonvulsants; D001549:Benzamides; D018492:Dopamine Antagonists; D011759:Pyrrolidines; D019275:Radiopharmaceuticals; D017448:Receptors, Dopamine D2; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide