Some characteristic clinical features are used for the differential diagnosis, this manifestations include early and severe postural instability, falls in the first year of onset, abnormal eye movements, autonomic dysfunction, cerebellar signs and upper motor neuron signs. The PPS respond poorly to antiparkinsonian medications and have a worse prognosis than does PD. In spite of these suggestive features, not all PD patients have the same progression, in some cases it is impossible to separate typical PD from PPS, especially at the early stage. In this context, biological markers must be of great usefulness for the differential diagnosis of these entities.