| Supporting features |
| Orofacial dystonia |
| Disproportionate antecollis |
| Camptocormia (severe anterior flexion of the spine) and/or Pisa syndrome (severe lateral flexion of the spine) |
| Contractures of hands or feet |
| Inspiratory sighs |
| Severe dysphonia |
| Severe dysarthria |
| New or increased snoring |
| Cold hands and feet |
| Pathologic laughter or crying |
| Jerky, myoclonic postural/action tremor |
| Non-supporting features |
| Classic pill-rolling rest tremor |
| Clinically significant neuropathy |
| Hallucinations not induced by drugs |
| Onset after age 75 years |
| Family history of ataxia or parkinsonism |
| Dementia (on DSM-IV) |
| White matter lesions suggesting multiple sclerosis |
