Chronic Neuropsychological and Neurological Impairment Following Acute Exposure to a Solvent Mixture of Toluene and Methyl Ethyl Ketone (MEK)

Abstract

A 38 year-old laborer experienced solvent intoxication during each of two spray paintings of a dump truck and other heavy equipment in an enclosed, unventilated garage. The paint base consisted primarily of toluene and methyl ethyl ketone. Nausea, headaches, dizziness, respiratory difficulty and other symptoms began after exposures. Over the next several days he developed impaired concentration, memory loss and cerebellar signs including an intention tremor, gait ataxia and dysarthria. MRI of the brain and EGG early in the work-up were normal, although later MRIs demonstrated fluid collection over the left parietal area. Examination by a toxicologist and neurologist revealed likely toxic encephalopathy with dementia and cerebellar ataxia. Three formal neuropsychological assessments over 2 1/2 years quantified cognitive, motor and behavioral changes. Despite similar findings in chronic exposure to these solvents, lasting sequelae following acute exposure have not been widely reported.

KEY WORDS:

• organic chemicals
• depressive disorder
• toluene
• methyl ethyl ketone
• butanones
• poisoning
• human
• central nervous sytem