Sex differences in Parkinson disease-associated episodic memory and processing speed deficits

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Cognitive dysfunction is a common non-motor symptom in Parkinson disease (PD).
• Existing data suggests cognitive impairment may be more severe in males with PD, but specific cognitive domains require further investigation.

Purpose of the Study:

• To investigate sex-specific differences in cognitive function, specifically episodic memory and processing speed, in individuals with Parkinson disease.
• To address the incomplete data regarding cognitive sex differences in Parkinson disease.

Main Methods:

• 167 individuals diagnosed with PD (56 female) were assessed.
• Episodic memory evaluated using California Verbal Learning Test and Wechsler Memory Scale.
• Processing speed assessed using Wechsler Adult Intelligence Scale.
• Multivariate analysis of covariance used to analyze sex-specific differences.

Main Results:

• Males with PD performed significantly worse than females in verbal and visuospatial recall.
• A trend for poorer performance in males with PD was observed in the processing speed task (coding).

Conclusions:

• Females with PD demonstrated superior verbal episodic memory compared to males, consistent with prior research.
• Females with PD also outperformed males in visuospatial episodic memory, a novel finding unique to this disease.
• Cognitive deficits in males with PD may be linked to frontal lobe dysfunction, suggesting a potential disease subgroup susceptible to frontal lobe deterioration.