Normal IPT and IBZM SPECT in drug-naive and levodopa-treated idiopathic restless legs syndrome

Fourteen drug-naive and 11 levodopa-treated patients with idiopathic restless legs syndrome (RLS), and 10 controls age-matched to each RLS group separately were examined with polysomnography (PSG), [I-123]-(N)-(3-iodopropen-2-yl)-2 beta -carbomethoxy-3 beta-(4-chlorophenyl) tropane (I-123-IPT) SPECT, and [I-123]-(S)-2-hydroxy-3-iodo-6-methoxy-[(1-ethyl-2-pyrrolidinyl)methyl] benzamide (I-123-IBZM) SPECT. Drug-naive and levodopa-treated patients with RLS and controls showed similar striatal dopamine transporter and dopamine D-2-receptor binding, the latter declining with age. The authors conclude that striatal dopamine transporter and receptor density is normal in drug-naive and levodopa-treated patients with RLS.