Function of dopamine receptors in young‐onset parkinson's disease: Prolactin response

Abstract

The basal levels of prolactin (PRL) and their changes after i. v. thyrotropin releasing hormone (TRH) administration after bromocriptine (BCT) pretreatment (BCT/TRH test) were monitored in 12 patients with young‐onset Parkinson's disease (PD) (before 40 years of age) and 10 patients with older‐onset PD (after 40 years of age), as well as in two groups of healthy subjects (10 persons in each), age‐matched with older‐onset (control A) and young‐onset (controlB) parkinsonians. The basal PRL levels were normal in both groups of patients. When given after BCT, TRH induced a significantly lower PRL increase in older‐onset parkinsonians than in controls. This response was even more blunted in young‐onset patients, being significantly more attenuated than in older‐onset PD patients. Copyright © 1993 Movement Disorder Society