The effect of height on paclitaxel nerve damage

Dying-back neuropathies result in sensory loss and motor signs in the distal distribution of the longest nerves of the body. It would be expected, therefore, that taller individuals with dying-back neuropathies would tend to have worse nerve damage than shorter individuals. This hypothesis was tested in patients receiving high dose paclitaxel. Nerve conductions and quantitative sensory tests were obtained in 21 breast cancer subjects, prior to and 20-40 days after 725 mg/m(2) paclitaxel administered intravenously over 24 h. Despite the uniform dose of paclitaxel, there was a wide variation in post minus pre-paclitaxel changes. Analysis by linear regression showed that decrease of peroneal nerve compound muscle action potential amplitude was significantly greater in taller subjects (P=0.004), and increase in cold detection threshold was greater in taller subjects (P=0.02). No correlation with height was found for paclitaxel drug clearance, maximum concentration, and area under the curve. Decrease in sural sensory nerve action potential amplitude and increase in vibration detection threshold did not correlate with height. In summary, the wide variation of changes seen in neurophysiological tests suggests that multiple factors are involved in determining the severity of neuropathy. Nerve length is probably one of these factors. To determine whether the effect of height is clinically important would require additional study with a larger number of subjects and longer clinical follow-up.