Obstructive sleep apnoea syndrome caused by prolonged occupational exposure to organic solvents

History and admission findings: A 52-year-old man working in a chemical lab orytory was referred with the possible diagnosis of toxic encephalopathy. F or 17 years he had been exposed to high concentrations of perchlorethyline and n-butanol vapours which every day had caused acute symptoms of organic solvent intoxication. Current complaints were autonomic nervous system symp toms, loss of concentration and memory, and fatigue in the second half of t he day. The patient was obese but in good general condition. Investigations: Neuropsychiatric examination confirmed the reported loss of concentration and planning ability at work. The polysomnogram indicated an increased number of largely obstructive apnoea attacks. Diagnosis, treatment and course: As the patients had an obstructive type of sleep apnoea treatment consisted of positive pressure ventilation at night and weight reduction, The occupational exposure to organic solvents was th e likely cause. Conclusions: As the symptoms of encephalopathy and sleep apnoea syndrome ov erlap, the latter should be considered before an encephalopathy is diagnose d. Because a rare cause of the sleep apnoea syndrome is prolonged and marke d occupational exposure to organic solvents this should be asked about in t aking the history. If indeed there has been occupational exposure, it shoul d cease at once and be reported.