I read with great interest the article by Piccini et al1 in the Archives They suggest that periventricular hyperintensities on proton density—weighted and T2-weighted magnetic resonance images in patients with Parkinson's disease may represent a marker for a clinical subtype with severe disease. I would like to make some comments.
• In the figures, proton density—weighted and T2-weighted magnetic resonance images are inverted. However, I think that this inversion is probably due to a typing error.
• In one of their patients (Figure 2), the proton density—weighted axial magnetic resonance image demonstrates mild periventricular hyperintensities and also a crescentic bilateral (predominating on the right) extracerebral lesion, with signal intensity different from that of cerebrospinal fluid.
Do these lesions represent subdural effusions or dural thickening? Are they also a possible marker for disease severity? The article by Piccini et al should be supplemented, with specific