Sleep disorders in Machado-Joseph disease: a dopamine transporter imaging study

Sleep disorders, especially restless legs syndrome (RLS) and rapid eye movement sleep behavior disorder (RBD), are common in spinocerebellar ataxia type 3 or Machado-Joseph disease (MJD), and a possible underlying dopaminergic dysfunction is implicated. This study assessed the relationship between sleep disorders in MJD and dopamine transporter (DAT) densities.

Twenty-two patients with MJD and twenty healthy subjects were enrolled in this study. MJD patients underwent clinical sleep evaluation and polysomnography. SPECT with [(99m)Tc]-TRODAT-1, was performed in all subjects.

DAT densities were significantly reduced in MJD group when compared to controls. No significant correlation was found between DAT densities and RLS or RBD in MJD.

Our study failed to demonstrate a clear correlation between sleep disorders and DAT densities in MJD patients, hence suggesting that extrastriatal and non-presynaptic dopamine pathways could be implicated in MJD-related sleep disorders.