Nigral degeneration was symmetrical and correlated with disease duration and motor and cognitive handicap.18In another Brazilian cross-sectional case-control study19involving 84 patients with five different SPG subtypes analyzed with high-resolution brain T1 and diffusion tensor image, the authors showed that the SPG11 group had the most widespread pattern of brain abnormalities. Here, SPG11 is linked to hereditary spastic paraplegia.