Computerized movement analysis and beta-CIT-SPECT in patients with restless legs syndrome

Considering the positive effect of dopaminergic treatment on Restless Legs Syndrome (RLS), it has been suggested that the cause of RLS may be linked to central dopaminergic dysfunction. As problems of alternating movements can result from a failure in the dopaminergic system, we used a movement analysis system to analyse this and in-parallel, performed [123I]beta-CIT-SPECT to investigate signs of dopaminergic dysfunction in patients with RLS. In 10 patients with idiopathic RLS, we conducted a three-dimensional computerized ultrasound-based movement analysis before a single dose of levodopa (L-dopa) was given and 90 minutes after the L-dopa challenge. In 6 of the 10 RLS patients, the striatal dopamine transporter system was studied with [123I]beta-CIT-SPECT. We did not observe any significant change in the movement pattern with the computerized movement analysis and no significant effect of L-dopa on the movement. We did not detect any significant differences between patients and normal controls regarding beta-CIT-signals in putamen or caudate nucleus, respectively. There was, however, a slight but significant change regarding the relative [123I]beta-CIT-SPECT binding in the putamen vs. the caudate nucleus. We conclude that the methods used could not detect any definite signs of changed central dopaminergic function in patients with RLS.