Table 1.

Characteristics of ocular motor abnormalities in PD-related disorders

Diagnosis	SI	Horizontal saccades	Vertical saccades	Smooth pursuit	Blepharospasm or eyelid apraxia
PD	+	Hypometric	Hypometric	Mild	Very rare
PSPS	++	Slowed, late	Slowed, early	Severe	Common
CBS	+	Delayed	Impaired, late	Mild	Common
MSA	+	Hypometric	Hypometric	Moderate	Rare

PD: Parkinson’s disease, SI: saccadic intrusions, PSPS: progressive supranuclear palsy syndrome, CBS: corticobasal syndrome, MSA: multiple systemic atrophy.