GRN and cerebellar ataxia: Signs of corticobasal syndrome (CBS), including cortical sensory loss, limb apraxia, and alien limb phenomenon, are slightly more common in carriers of GRN pathogenic variants than are signs of progressive supranuclear palsy (PSP), such as neck rigidity, impaired eyelid function, supranuclear gaze palsy, dystonia, pseudobulbar palsy, and ataxia [161].