Brain Structure Deviations in Patients with Parkinson Disease without Dementia Using Normative Modeling

Area of Science:

• Neuroscience
• Neurology
• Radiology

Background:

• Parkinson disease (PD) diagnosis without dementia presents inconsistent cortical alteration findings.
• Understanding these alterations is crucial for early diagnosis and symptom management.

Purpose of the Study:

• To investigate cortical structural deviations in patients with PD without dementia.
• To explore the relationship between cortical alterations and motor/non-motor symptoms in PD.

Main Methods:

• Utilized life span brain charts to derive individualized centile scores for brain structure in 225 PD patients.
• Compared PD patient data with 451 healthy controls (HC) and performed correlation analysis between cortical thickness and symptoms.

Main Results:

• Nearly half (44.11%) of cortical regions showed negative deviations in PD patients, with the inferior temporal cortex most affected.
• Patients exhibited negative deviations in gray matter and positive deviations in cerebrospinal fluid (CSF) volume, with no significant white matter volume changes.
• Cortical thickness correlated with gait freezing severity but not cognitive function.

Conclusions:

• Cortical changes in PD without dementia are heterogeneous, characterized by widespread negative deviations in gray matter.
• Structural alterations include reduced gray matter, increased CSF volume, and preserved white matter volume.
• Reduced cortical thickness is associated with more severe gait freezing in PD patients.