Background: The toxic oil syndrome (TOS) is an autoimmune disease caused by the ingestion of aniline-denatured rapeseed oil. The carpal tunnel syndrome (CTS) is an entrapment neuropathy due to the median nerve entrapment, which is associated with both occupational activities and autoimmune diseases. The objective of this work was to know the frequency and characteristics of CTS in TOS patients.
Patients and methods: Between December 1977 and July 2000, 744 TOS patients were evaluated. The inclusion criteria were: the clinical records for patients diagnosed between May 1981 and November 1997; and for patients diagnosed between December 1997 and July 2000, symptoms with the classical or likely pattern according to the Katz's hand diagram and one of the following findings: a) abnormal electromyogram, and b) hypalgesia in the median nerve territory and positive Tinel and/or Phalen signs.
Results: A total of 70 patients (63 women, 90%) were diagnosed; 48 of them had been diagnosed before 1997 and 22 subsequently. The mean age of patients was 47.6 (20-78) years. In 36 patients (51.4%), a bilateral CTS was present. Fifty-six patients (81.4%) had a diagnostic EMG, and 31 (44.2%) were obese, 13 (18.6%) diabetic, and 4 (6%) had hypothyroidism. Most of these cases (48; 68.6%) were housewives.
Conclusions: TOS patients have a high frequency of CTS; therefore, this condition must be suspected in patients with associated obesity and diabetes mellitus.