Unveiling MRI markers for Parkinson's Disease: GABAergic dysfunction and cortical changes

Area of Science:

• Neuroscience
• Radiology
• Biochemistry

Background:

• Parkinson's disease (PD) is a neurodegenerative disorder.
• Early diagnosis of PD, especially early-onset PD (EOPD), remains challenging.
• Investigating neurotransmitter and structural brain changes may reveal diagnostic biomarkers.

Purpose of the Study:

• To examine basal levels of gamma-aminobutyric acid (GABA) in the sensorimotor cortex (SMC).
• To assess cortical gyrification in PD patients.
• To identify potential imaging biomarkers for PD, including EOPD.

Main Methods:

• Fifty PD patients (10 EOPD, 40 late-onset PD [LOPD]) and 52 healthy controls (HC) were studied.
• GABA-edited 1H Magnetic Resonance Spectroscopy (MRS) of the SMC and 3D T1-weighted MRI were performed.
• GABA levels and local gyrification index (LGI) were quantified.

Main Results:

• Significant negative correlations were found between GABA/Cr, LGI, and PD likelihood.
• Lower GABA levels were observed in the SMC of both EOPD and LOPD patients compared to HC.
• A logistic regression model using GABA/Cr and transversetemporal LGI showed high predictive value (AUC).

Conclusions:

• GABAergic dysfunction is implicated in PD pathogenesis.
• Alterations in GABA levels and cortical morphology may serve as potential biomarkers.
• These markers could aid in the preclinical diagnosis and progression monitoring of PD, including EOPD.