The motor response to sequential apomorphine in parkinsonian fluctuations

Fifteen patients with Parkinson's disease and levodopa-induced motor fluctuations, were studied with repeated injections of apomorphine using two protocols to explore possible changes in the duration of motor response. One involved different interdose intervals; in the other, doses were given when the motor effects induced by the previous dose had just worn off. No significant change in the duration of motor response to sequential subcutaneous apomorphine with either protocol was found. The results suggest that rapid changes in receptor sensitivity during repeated intermittent dopaminergic stimulation do not contribute to the pathogenesis of Parkinsonian motor fluctuations.