Clinical and electromyographic examinations of patients with tremor after chronic occupational lead exposure.

Tremor is considered to be a clinical sign of patients with chronic lead exposure. However, the type of tremor and its pathophysiological mechanisms are controversial. The aim of this study was to examine the clinical and electromyographic characteristics of tremor in patients with chronic lead exposure. Twenty-three men, 27-49 years old, participated in the study. The tremor activity was detected using surface electrodes from a pair of antagonistic hand muscles. Serum lead concentrations were measured on the day of examination. Our results revealed 12 Hz postural and kinetic tremor, with characteristics of enhanced physiological tremor. Different pathophysiological mechanisms might be responsible for the enhanced physiological tremor of patients with chronic lead exposure. In conclusion, the tremor of patients with chronic lead exposure is an enhanced physiological one. It is probable that this tremor could be influenced by beta-blockers, known to influence the enhanced physiological tremor in anxiety. This will be of benefit for patients disturbed by persistent tremor.