Table 2.
Overlapping clinical features between PSP and CBS and the frequency of the reported pathologies
| PSP | CBS | |
|---|---|---|
| Cognitive impairment | Frontal dysexecutive, early | Frontal dysexecutive, late |
| Speech | Dysarthria, early | Dysarthria, late; apraxia of speech |
| Language | Fluent perserverative | Nonfluent (PNFA) |
| Saccades | Normal latency but slow velocity and decreased amplitude (hypometric) | Delayed latency but normal velocity and amplitude (non-hypometric) |
| Motor phenotype | Typically symmetric akinesia with axial-predominant rigidity, but lateralized featuresa may predominate | Typically lateralized features, but symmetric akinesia with axial-predominant rigidity may predominate |
| Common pathologies (approx. frequency) | PSP, 80% | CBD, 35% |
| CBD, 10% | AD, 20% | |
| FTLD-Tau, 10% | PSP, 15% | |
| FTLD-TDP, 15% | ||
| FTLD-Tau, 15% |
a
Lateralized motor features mostly apply to unilateral dystonia or myoclonus; lateralized cognitive features mainly apply to unilateral ideomotor apraxia, cortical sensory signs, or visual neglect.