Findings that exclude MSA:
(1) onset of symptoms at < 30 years of age
(2) family history for the same condition
(3) hallucinations not due to medication
(4) systemic disorder or medication that can explain all of the clinical findings
(5) dementia
(6) focal cortical dysfunction (alien limb, parietal lobe dysfunction, aphasia, etc)
Findings favoring the diagnosis of progressive supranuclear palsy:
(1) prominent limitation of upward gaze
(2) any limitation of downward gaze
(2) prominent slowing of vertical saccades
Findings favoring the diagnosis of Parkinson's disease:
(1) good response to levodopa therapy
