An FDOPA PET study in patients with periodic limb movement disorder and restless legs syndrome

The authors investigated nine drug-naive patients with periodic limb moveme nt disorder and restless legs syndrome (PLMD-RLS) and 27 healthy controls w ith PET using 6-[F-18]fluoro-L-dopa (FDOPA). In the patients, the FDOPA upt ake (K-i(occ)) in the caudate nucleus was 88% and in the putamen 89% of the control mean values. This equal affection of the caudate and the putamen d iffers, for example, from the dopaminergic dysfunction in Parkinson's disea se, which affects the putamen earlier and more severely than the caudate. T he current results indicate mild nigrostriatal presynaptic dopaminergic hyp ofunction in PLMD-RLS.