Parkinson's disease laterality: a ¹¹C-PE2I PET imaging study

Area of Science:

• Neurology
• Neuroscience
• Radiology

Background:

• Idiopathic Parkinson's disease (PD) typically presents with asymmetric striatal dopaminergic deficits and motor symptoms.
• Understanding the evolution of this asymmetry in moderate-stage PD is crucial for disease management and research.

Purpose of the Study:

• To characterize the longitudinal trend of asymmetry in striatal dopamine transporter (DAT) density and motor symptoms in moderate-stage PD.
• To investigate whether dopaminergic degeneration asymmetry diminishes or persists as the disease progresses.

Main Methods:

• A 19-month longitudinal study involving 27 moderate-stage PD patients.
• Positron Emission Tomography-Computed Tomography (PET-CT) imaging using 11C-PE2I to quantify striatal dopamine transporter (DAT) binding potential (BPND).
• Clinical assessments using the Movement Disorders Society Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS-III).

Main Results:

• Changes in striatal 11C-PE2I BPND over time were more pronounced on the ipsilateral (more affected) side compared to the contralateral side, indicating a reduction in DAT asymmetry.
• MDS-UPDRS-III motor scores did not show significant differences between the most and least affected body sides, suggesting motor asymmetry was maintained.
• The study observed a decrease in the asymmetry of striatal dopaminergic degeneration in moderate-stage PD.

Conclusions:

• Striatal dopaminergic transporter asymmetry tends to become less prominent in moderate-stage Parkinson's disease.
• Despite reduced dopaminergic asymmetry, motor symptom asymmetry is maintained in moderate-stage PD patients.
• These findings highlight a potential dissociation between neurochemical degeneration and clinical presentation asymmetry in PD progression.