Impaired energy-dependent processes underlie acute lead neuropathy

The mechanisms of lead neuropathy remain unexplained. A 48-year-old painter presented after undertaking a 3-week project of paint removal without the use of a protective mask. Two weeks later, he developed fasciculations, weakness, and muscle wasting. Nerve conduction studies demonstrated a motor neuropathy. A high serum lead level was identified, leading to a diagnosis of acute lead neuropathy.

To investigate the pathophysiology, nerve excitability studies were undertaken acutely and in convalescence. Studies were undertaken at baseline and after the induction of limb ischemia.

Prominent abnormalities of excitability were noted, including a rightward shift of stimulus-response curves, reduction in depolarizing threshold electrotonus, and increased refractoriness. These changes became more severe with limb ischemia, and there was abolition of the superexcitable period and increased refractoriness.

We identified prominent changes in nerve excitability in lead neuropathy. The results suggest that there is impairment of axonal energy-dependent processes in lead neuropathy.