[Toxic polyneuropathy in shoe-industry workers. A longitudinal electromyographic study (author's transl)].

A longitudinal electromyographic study was carried out on fifteen shoe-industry workers (one man and fourteen women) affected with toxic polyneuropathy. The mean values of age, duration of exposure and lenght of the follow-up period were 23.2 years, 4.2 years and 12.2 months, respectively. Twelve subjects (80%) had a sensory-motor involvement of both upper and lower limbs; in the remainder, only the latter were affected. From a clinical standpoint, the polyneuropathy was classified as mild in seven subjects (46.6%), moderate in four (26.7%) and severe in four. On the basis of electromyographic criteria (maximal motor nerve conduction velocity; features of voluntary contraction tracings; existence of spontaneous activity recorded in different points of the same muscle), the polyneuropathy could be defined as mild in two patients (13.3%), moderate in three (20%) and severe in 10 (66.7%). In eight subjects (53.3%) the electromyographic abnormalities disappeared completely, through a gradual improvement in six and alternative phases of improvement and worsening in two. As for the remainder patients (7, viz. 46.6%), improvement and worsening in two. As for the remainder patients (7, viz. 46.6%), four showed a reduction of their electromyographic abnormalities, whereas no significant changes occurred in the last three. The obtained results are discussed and the following conclusions drawn: 1. the lower limbs are mostly affected, both clinically and electromyographically; 2. the clinical symptoms do not parallel the electromyographic findings; 3. the course of the disease appears to be independent of the initial electromyographic pattern; 4. recovery appears to occur in most instances within approximately eighteen months since the onset of symptoms, generally without significant residual deficit. Finally, the role of electromyography in the diagnosis and the follow-up study of the observed toxic polyneuropathy is underlined.