DIMINISHED SEROTONIN-MEDIATED PROLACTIN RESPONSES IN NONDEPRESSED STROKE PATIENTS COMPARED WITH HEALTHY NORMAL SUBJECTS

Background and Purpose-The purpose of this study was to use hormonal r esponsiveness to d-fenfluramine (d-FEN) challenge as a measure of cent ral serotonin (5-HT) function in a comparative evaluation of serotoner gic abnormalities between stroke patients and healthy elderly normal s ubjects to test the hypothesis that stroke may be associated with dimi nished serotonergic functioning. Methods-Eight nondepressed medically stable stroke patients and 12 healthy volunteers completed a single-bl ind, placebo-controlled, fixed-order, crossover design challenge test with 30 mg of oral d-FEN. Baseline prolactin (PRL) and cortisol (CORT) and hormonal responses to d-FEN and placebo were measured at hourly i ntervals over a 4-hour period. Cardiovascular responses (pulse and blo od pressure) and behavioral responses were also recorded at the same t ime points.Results-The 2 groups were comparable in demographics, body weight, plasma drug concentration, and behavioral and CORT responses. A 3-way ANOVA for repeated measures showed group differences for basel ine adjusted PRL responses (change of scores from baseline). Peak PRL responses (maximal PRL change from baseline scores after treatment wit h d-FEN) in nondepressed stroke patients were attenuated compared with healthy elderly subjects, suggesting diminished serotonergic responsi veness in stroke patients. Conclusions-The demonstrated serotonergic h ypofunctioning poststroke may contribute to the high incidence of depr essive disorders in stroke patients. Serotonergic agents may have a ro le in augmentation of stroke recovery.