Presynaptic dopaminergic function in patients with restless legs syndrome: are there common features with early Parkinson's disease?
The cause of restless legs syndrome (RLS) is unknown, but an involvement of the dopaminergic system and a possible relation to Parkinson's disease (PD) is suggested by the positive response to dopaminergic treatment. We imaged the striatal dopamine transporter with [(123)I] N-(3-iodopropen-2-yl)-2beta-carbomethoxy-3beta-(chloro-phenyl) tropane ([(123)I]IPT) and single-photon emission computed tomography (SPECT) in 28 RLS patients, and compared the results with transporter binding in 29 patients with early PD and 23 age-matched controls. No difference in IPT binding was found between RLS patients and controls. IPT binding was correlated significantly with age in RLS patients and controls, whereas there was no relation with the duration of symptoms or severity of RLS. PD patients presented significant lower presynaptic IPT binding ipsi- and contralateral to the affected body side compared with RLS patients or controls. We found no common characteristics between RLS patients and patients with early PD detectable by dopamine transporter SPECT. Our results do not strengthen an identical pathophysiologic pathway between RLS and PD on the level of nigrostriatal presynaptic terminal function.
Linke
Rainer
R
Department of Nuclear Medicine, University of Munich, Munich, Germany. rainer.linke@med.uni-muenchen.de
Eisensehr
Ilonka
I
Wetter
Thomas-Christian
TC
Gildehaus
Franz-Josef
FJ
Pöpperl
Gabriele
G
Trenkwalder
Claudia
C
Noachtar
Soheyl
S
Tatsch
Klaus
K
D000368:Aged; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D003937:Diagnosis, Differential; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010300:Parkinson Disease / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology; D011699:Putamen / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D019275:Radiopharmaceuticals; D017661:Receptors, Presynaptic / Q000378:metabolism*; D012148:Restless Legs Syndrome / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon
D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D019275:Radiopharmaceuticals; D017661:Receptors, Presynaptic; D004298:Dopamine