Progressive Supranuclear Palsy Rating Scale total score to assess disease severity in participants with PSP features. Higher scores indicate worse impairment.

Tinetti gait and balance test score to assess gait and balance performance. Lower scores indicate worse gait and balance function.

Berg Balance Scale score to assess balance function. Lower scores indicate worse balance.

Hoehn and Yahr stage to assess Parkinsonian disease stage. Higher stages indicate more advanced disease.

Non-Motor Symptoms Questionnaire total score to assess non-motor symptom burden. Higher scores indicate greater non-motor symptom burden.

Scales for Outcomes in Parkinson's Disease-Autonomic total score to assess autonomic dysfunction. Higher scores indicate worse autonomic symptoms.

Sniffin' Sticks 16-item olfactory identification score to assess olfactory function. Higher scores indicate better olfactory performance.

Wexner constipation score to assess constipation severity. Higher scores indicate worse constipation symptoms.

Parkinson's Disease Questionnaire-39 total score to assess health-related quality of life. Higher scores indicate worse quality of life.

Eating Assessment Tool score to assess swallowing difficulty. Higher scores indicate worse swallowing symptoms.

Rapid Eye Movement Sleep Behavior Disorder Screening Questionnaire total score to assess REM sleep behavior disorder symptoms. Higher scores indicate worse symptom burden.

Pittsburgh Sleep Quality Index total score to assess sleep quality. Higher scores indicate worse sleep quality.

17-item Hamilton Depression Rating Scale total score to assess depressive symptoms. Higher scores indicate worse depressive symptom severity.

Hamilton Anxiety Rating Scale total score to assess anxiety symptoms. Higher scores indicate worse anxiety symptom severity.

Montreal Cognitive Assessment score to assess global cognitive function. Higher scores indicate better cognitive performance.

Mini-Mental State Examination score to assess global cognitive function. Higher scores indicate better cognitive performance.

Frontal Assessment Battery score to assess frontal executive function. Higher scores indicate better executive performance.

Oxyhemoglobin level measured by near-infrared spectroscopy during postural and motor testing as a quantitative indicator of brain functional response.

Deoxyhemoglobin level measured by near-infrared spectroscopy during postural and motor testing as a quantitative indicator of brain functional response.

Total hemoglobin level measured by near-infrared spectroscopy during postural and motor testing as a quantitative indicator of brain functional response.

Mean systolic blood pressure measured by 24-hour ambulatory blood pressure monitoring. Units: mmHg.

Mean diastolic blood pressure measured by 24-hour ambulatory blood pressure monitoring. Units: mmHg.

Mean heart rate measured by 24-hour ambulatory blood pressure monitoring. Units: beats per minute.

Tremor frequency measured by tremor analysis as a quantitative indicator of tremor characteristics.

Tremor amplitude measured by tremor analysis as a quantitative indicator of tremor severity.

Timed Up and Go (TUG) test duration derived from wearable device-based assessment to evaluate mobility and functional movement performance.

Unified Parkinson's Disease Rating Scale Part III motor score estimated using machine vision-based video assessment to quantify motor impairment.

Prespecified structural MRI-derived quantitative measure, such as regional brain volume or cortical thickness, assessed to characterize disease-related neuroanatomical changes.

Prespecified resting-state functional MRI quantitative measure, such as functional connectivity within a predefined brain network, assessed to characterize disease-related functional brain changes.

Prespecified diffusion tensor imaging quantitative parameter, such as fractional anisotropy or mean diffusivity in a predefined tract or region of interest, assessed to characterize microstructural changes.

Quantitative susceptibility mapping value measured in a prespecified brain region to assess iron-related imaging changes.

Neuromelanin-sensitive magnetic resonance imaging signal intensity measured in a prespecified brain region to assess disease-related imaging changes.

Standardized uptake value ratio measured by tau PET/MR in a prespecified brain region using a prespecified tau tracer to assess tau-related signal.

Standardized uptake value ratio measured by dopamine transporter PET/MR in a prespecified brain region to assess dopaminergic terminal integrity.

Standardized uptake value ratio measured by FDG PET/MR in a prespecified brain region to assess regional glucose metabolism.

Mean cerebral blood flow velocity measured during postural testing using continuous cerebral blood flow monitoring and transcranial Doppler ultrasonography to assess hemodynamic changes associated with postural challenge.

Heart rate measured during postural testing using continuous hemodynamic monitoring performed together with transcranial Doppler ultrasonography to assess autonomic and hemodynamic responses to postural challenge.

Quantitative speech parameter measured during standardized speech assessment performed in a sound-controlled room to evaluate speech-related changes associated with Parkinsonism.

Quantitative parameter derived from 64-channel high-density electroencephalography to assess neurophysiological changes associated with disease progression.

Quantitative parameter derived from respiratory sleep monitoring to assess sleep-related physiological abnormalities during follow-up.

Quantitative parameter derived from paired transcranial stimulation to assess cortical excitability and related neurophysiological changes.

Quantitative level of a prespecified blood biomarker measured in biospecimens collected during follow-up to assess biological changes associated with disease progression.