The synaptic significance of metoclopramide induced dyskinetic-dystonic head and neck movements in pregnancy.

Two young, pregnant women presenting dyskinetic-dystonic crises limited to head and neck (HNDD) due to metoclopramide (MP) were observed. Evidence has been brought for the specific extrapyramidal effect of dyskinetic-dystonic head and neck movements induced by MP in young females. The synaptic action of MP differs from that of the generally accepted dopamine receptor blocking neuroleptics such as the phenothiazines. Concomittant quasi opposing neuroleptic and nonneuroleptic like effects of this drug can not support the mechanism of dopamine receptor blockade as the explanation of the synaptic effect. The concept of "dopamine receptor imbalance" may explain the synaptic action of the metoclopramide.