Electroneurographic investigations of misonidazole polyneuropathy.

13 patients with malignant tumors were treated by the radiosensitizer misonidazole (Ro 07-0582), total dosage 20-29 g. The electrophysiological investigations showed (1) an early increase of distal latency, the motor nerve conduction velocity (NCV) of the peroneal nerve and the NCV of the sural nerve remaining normal or only signlty reduced, and in a few cases a marked reduction of the compound action potential or of the nerve action potential (NAP), indicating a primary axonal neuropathy; (2) greater changes in the parameters of sensory nerves (n. suralis) than of motor nerves; (3) the distal latency is a good indicator of subclinical neuropathies; (4) the electrophysiological parameters showed a normalization 6 months after the end of therapy. The mechanisms possibly responsible for the misonidazole neuropathy are discussed.