Transcranial brain sonography was performed in a sample of Parkinson's disease and Machado-Joseph disease patients, and findings then correlated with the presence and severity of restless legs syndrome.
There was a continuum of substantia nigra echogenicity among groups (Parkinson's disease versus Machado-Joseph disease versus controls) and sub-groups (Parkinson's disease with and without restless legs syndrome versus Machado-Joseph disease with and without restless legs syndrome) as well as a statistically significant negative correlation between restless legs syndrome severity and substantia nigra echogenicity (p < 0.001).
These preliminary observations demonstrate that the severity of RLS may be influenced by nigral iron load reflected by substantia nigra echogenicity in different neurodegenerative movement disorders.