Long-term effects of postearthquake distress on brain microstructural changes

Area of Science:

• Neuroscience
• Psychiatry
• Trauma Studies

Background:

• Stressful events significantly impact brain structure and function.
• Previous research indicated short-term white matter integrity (WMI) changes post-earthquake, with some regions showing pre-existing vulnerability and others acquired distress markers.

Purpose of the Study:

• To investigate the long-term (1-year) effects of a major earthquake on white matter integrity (WMI).
• To explore the relationship between WMI changes and psychological distress following the disaster.

Main Methods:

• Longitudinal analysis of white matter integrity (WMI) using diffusion tensor imaging (DTI) in 25 subjects 1 year after the Japanese earthquake.
• Correlation analysis between WMI metrics (Fractional Anisotropy - FA) and psychological measures of post-earthquake distress.

Main Results:

• Significant long-term WMI alterations were observed in the right anterior cingulate cortex (Cg), bilateral uncinate fasciculus (Uf), left superior longitudinal fasciculus (SLF), and left thalamus.
• Differential changes in FA suggest synaptic enhancement and shrinkage as long-term effects.
• Correlation between WMI changes in the right anterior Cg and left Uf with psychological distress measures indicates temporal WMI alterations in distressed individuals.

Conclusions:

• Long-term WMI changes, including synaptic modifications, occur after significant stressful events like earthquakes.
• Dynamic WMI changes may predict a better prognosis for psychological distress.
• Persistently reduced WMI could be a marker for cognitive dysfunction and anxiety disorder development.