Apathy in Parkinson's Disease: EEG Microstate Characteristics

Area of Science:

• Neuroscience
• Neurology
• Psychiatry

Background:

• Apathy is a common neuropsychiatric symptom in Parkinson's disease (PD), characterized by reduced goal-directed activity and emotional flattening.
• The underlying pathophysiology of apathy in PD remains incompletely understood.
• This study investigates the electroencephalography (EEG) microstate correlates of apathy in idiopathic Parkinson's disease.

Purpose of the Study:

• To identify correlations between EEG microstates and apathy in Parkinson's disease patients.
• To differentiate brain activity patterns between apathetic and non-apathetic PD groups.

Main Methods:

• Patients with idiopathic Parkinson's disease were classified as apathetic or non-apathetic based on the Apathy Evaluation Scale.
• Clinical, motor, demographic, and neuropsychometric evaluations were performed.
• Spontaneous EEG data were recorded and analyzed using microstate analysis.

Main Results:

• No significant differences in clinical or motor functions were found between apathetic and non-apathetic groups.
• Apathetic patients performed worse on executive function and memory tests.
• EEG analysis revealed increased duration and coverage of Microstates B and E, and decreased frequency of Microstate D in the apathetic group.
• Increased transitions were observed from Microstate A to B, and from C to E and G in apathetic patients.

Conclusions:

• Altered EEG microstate dynamics, including increased Microstates B and E and decreased Microstate D, along with specific transition patterns, may reflect changes in large-scale brain circuit activity or functional connectivity in Parkinsonian apathy.
• Microstate E alterations might be fundamental to changes associated with the Default Mode Network in Parkinsonian apathy.