Prognosis of symptoms in patients with diagnosed chronic organic solvent intoxication

The profile and prognosis of symptoms of 87 patients (mean age 38.6 years) in whom a chronic organic solvent intoxication due to tri- or perchloroethylene or mixtures of solvents had been diagnosed 3-9 years earlier were examined by means of an interview. Both at the time of diagnosis and upon reexamination, the most common symptoms were abnormal fatigue, memory disturbances and headache. Also dizziness, sleep disturbances, sensory symptoms in the extremities, mental depression, concentration difficulties, psychic irritability, emotional lability, tremor and nausea were present in over 60% of patients at the time of diagnosis. Upon reexamination, 52% of the intoxication patients with no other contributing neurological disease felt that their overall subjective condition was better than at the time of diagnosis, 21% felt that it was worse, and 27% reported no change. Most of the individual symptoms had more often changed for the better than for the worse; the differences were statistically significant with regard to abnormal fatigue, headache, dizziness, sleep disturbances, nausea, and emotional lability, whereas memory disturbances had changed in the opposite direction. Younger persons, who had had a longer follow-up period and without regular check-ups at the Institute of Occupational Health seemed to have better prognosis at the group level. Due to the great variation between the individuals, the prognosis was, however, impossible to predict in individual cases.