Brain imaging techniques applied to chronically solvent-exposed workers: current results and clinical evaluation

Area of Science:

• Neuroscience
• Occupational Health
• Toxicology

Background:

• Neuroimaging techniques like cerebral blood flow (CBF), SPECT, CAT, and MRI yield inconclusive results for solvent-exposed workers and toxic encephalopathy patients.
• Chronic neurotoxicity from solvent exposure requires critical review concerning neuroimaging findings.

Purpose of the Study:

• To critically review current knowledge on chronic neurotoxicity of solvent exposures.
• To evaluate the utility of neuroimaging techniques in assessing solvent-induced brain changes.

Main Methods:

• Computed Axial Tomography (CAT) scans were performed on 86 house/construction painters, 82 spray painters, and 81 non-painters.
• Data were controlled for confounding variables including age, alcohol consumption, and prior disease.
• Correlation analyses were conducted between exposure, CAT parameters, and neuropsychological test results.

Main Results:

• CAT measurements revealed no abnormal diffuse brain atrophy in solvent-exposed painters compared to non-painters, even after controlling for confounders.
• No consistent, biologically plausible exposure-effect relationship was found between solvent exposure and brain atrophy.
• Neuropsychological test results did not significantly correlate with CAT parameters; age showed a strong dependency.

Conclusions:

• Long-term exposure to solvents at concentrations not exceeding permissible occupational limits does not lead to increased brain atrophy.
• Current neuroimaging techniques provide limited evidence for structural brain damage from occupational solvent exposure within regulated limits.
• Age is a significant factor influencing brain structure, independent of solvent exposure.