Spinocerebellar ataxia type 1, 2, and 3 and restless legs syndrome: striatal dopamine D2 receptor status investigated by [11C]raclopride positron emission tomography.
In spinocerebellar ataxias (SCAs), up to 30% of patients complain of restless legs syndrome (RLS). In primary RLS, a putative role of the dopaminergic system has been postulated. To assess dopaminergic function in SCA1, 2, and 3, dopamine D(2) receptor binding potential (BP) was assessed by [(11)C]raclopride positron emission tomography in 10 SCA patients, 4 of whom suffered from RLS as demonstrated by polysomnography. BP was compared to 9 age-matched control subjects. In 2 SCA patients, striatal BP was clearly reduced (<2 SD below the mean of controls). However, there were no significant group differences between SCA and controls, largely owing to a significantly higher variance of striatal BP in SCA. BP was negatively correlated with disease duration. The fit suggests an increased BP in early stages, followed by a moderate decline in all quantified regions (caudate, dorsal putamen, ventral striatum) presumably reflecting a progressive loss of D(2) receptors. RLS in SCA was not accompanied by a significant reduction of D(2) receptor availability in the striatum. This missing correlation may point to an extrastriatal origin of RLS.
Reimold
Matthias
M
Department of Nuclear Medicine, University of Tübingen, Germany.
Globas
Christoph
C
Gleichmann
Marc
M
Schulze
Michael
M
Gerloff
Christian
C
Bares
Roland
R
Machulla
H-J
HJ
Bürk
Katrin
K
D000328:Adult; D000067696:Ataxin-1; D000067699:Ataxin-3; D000067528:Ataxins; D002250:Carbon Radioisotopes; D003342:Corpus Striatum / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D005838:Genotype; D006801:Humans; D017827:Machado-Joseph Disease / Q000000981:diagnostic imaging* / Q000235:genetics / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics; D009460:Neurologic Examination; D009687:Nuclear Proteins / Q000235:genetics; D009778:Occipital Lobe / Q000000981:diagnostic imaging / Q000503:physiopathology; D017286:Polysomnography; D049268:Positron-Emission Tomography; D020891:Raclopride; D017448:Receptors, Dopamine D2 / Q000502:physiology*; D012097:Repressor Proteins / Q000235:genetics; D012148:Restless Legs Syndrome / Q000000981:diagnostic imaging* / Q000503:physiopathology; D020754:Spinocerebellar Ataxias / Q000000981:diagnostic imaging* / Q000235:genetics / Q000503:physiopathology
C000593749:ATXN1 protein, human; D000067696:Ataxin-1; D000067528:Ataxins; D002250:Carbon Radioisotopes; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D017448:Receptors, Dopamine D2; D012097:Repressor Proteins; D020891:Raclopride; C092341:ATXN3 protein, human; D000067699:Ataxin-3