Analysing of the diagnostic value of oculomotor markers in progressive supranuclear palsy and subtypes with video oculography

Progressive Supranuclear Palsy (PSP) is a neurodegenerative disease characterized by supranuclear vertical gaze paralysis, symmetric akinetic axial rigidity, postural instability, and frontal cognitive impairments, affecting a wide spectrum, and considered a tauopathy with heterogeneous clinical features. In this study, we aimed to determine the sensitivity and specificity of video oculographic (VOG) parameters in differentiating PSP from idiopathic Parkinson's disease (iPD) and to determine the diagnostic utility of these markers in defining various PSP subtypes. In this prospective cross-sectional study, patients with probable PSP, as well as control groups of patients with iPD and healthy controls were included. Parameters such as oculomotor functions, slow pursuit, horizontal and vertical reflex saccades, and self-paced saccades were evaluated. Brain Magnetic Resonance Imaging (MRI) was used as a supportive diagnostic parameter. Significant differences were observed in VOG parameters between PSP patients and iPD and control groups. In the evaluations of vertical saccades, it was observed that the latency and peak velocities of reflex saccades were particularly impaired in PSP patients. In the subtype analysis, no significant difference was found between PSP-Richardson syndrome (PSP-RS) and PSP-parkinsonism (PSP-P). MRI provided confirmatory results for the diagnosis of PSP. In conclusion, VOG is a valuable non-invasive method with high sensitivity and specificity for the early diagnosis of PSP and differentiation from other parkinsonism types, capable of guiding targeted therapeutic approaches.