Oxaliplatin-induced hyperexcitability of the peripheral nerves

Oxaliplatin is associated with two distinct forms of neurotoxicity leading to sensory symptoms. Sensory axonal neuropathy is correlated with cumulative doses and length-dependent damage of the distal nerves. Acute transient neurotoxicity occurs within hours of oxaliplatin infusion as a consequence of hyperexcitability of the peripheral nerves. We describe a patient with acute reversible symptoms of cold-induced paresthesias and myokymia following each treatment. At the same time nerve conduction studies and needle EMG disclosed two hallmarks of peripheral nerve hyperexcitability - repetitive muscle action potentials in response to a single motor nerve stimulus and myokymic and neuromyotonic discharges. These results highlight the need for careful planning of electrophysiological studies in patients with oxaliplatin since amplitude reduction of the sensory nerve action potential is a common finding in cancer patients and may be misleading.