Cognitive Functioning in Toxic Oil Syndrome Survivors: A Case-Control Study Four Decades After the Epidemic

Area of Science:

• Neuroscience
• Epidemiology
• Toxicology

Background:

• Toxic oil syndrome (TOS) is a food-borne epidemic from 1981 caused by adulterated rapeseed oil.
• Long-term cognitive effects of TOS remain poorly understood over 40 years post-exposure.

Purpose of the Study:

• To investigate the long-term cognitive consequences of TOS.
• To explore the role of fatigue and mood symptoms in mediating cognitive deficits in TOS survivors.

Main Methods:

• A case-control study comparing 50 TOS survivors with 50 matched healthy controls.
• Comprehensive neuropsychological assessment, fatigue, anxiety, depression, and quality of life questionnaires.
• Multivariate regression and structural equation modeling to analyze cognitive performance and mediating factors.

Main Results:

• TOS survivors showed poorer performance in attention, executive function, processing speed, and global cognition.
• Cognitive differences were not significant after adjusting for fatigue, depression, anxiety, and medication use.
• Affective symptoms, especially fatigue, substantially mediated the relationship between TOS and cognitive performance.

Conclusions:

• The cognitive profile in TOS survivors suggests subcortical dysfunction and impaired neural connectivity.
• Findings indicate potential long-lasting white and gray matter alterations in TOS survivors.
• Mood and fatigue symptoms are crucial for evaluating cognition in TOS survivors, highlighting enduring neurobiological effects.