Carpal canal size was examined as a risk factor associated with carpal tunnel syndrome in the workplace. Seven of 14 electricians had symptomatic carpal tunnel syndrome. On measuring cross-sectional areas by CT, affected workers had a cross-sectional area of 1.75 +/- 0.21 cm2; control values were 2.53 +/- 0.15 cm2 (p less than 0.05). Individuals with a subclinical syndrome had an area of 1.83 +/- 0.22 cm2, similar to the symptomatic group. Wrist circumference was not a predictor of smallest carpal canal area. Unusual bony and soft tissue structures within the carpal canal were easily identified with CT.

An epidemic of urinary retention among workers in a polyurethane manufacturing plant was discovered in the spring of 1978. The most severely affected workers had neurogenic bladders confirmed by cystometrograms and mild sensory peripheral neuropathy. A survey of the plant disclosed increased incidence of urinary retention, muscle weakness, paresthesia, insomnia, and sexual dysfunction in exposed workers. A catalyst containing dimethylaminopropionitrile was identified as the probable causative agent, and after its removal no new cases occurred.