Letter: Metoclopramide and facial dyskinesia

Serum dopamine beta hydroxylase activity and metoclopramide provocative test in torsion dystonia

A familial study of 13 Ashkenasy Jewish patients suffering from torsion dystonia (TD) of various origin, was carried out using clinical observation and determination of serum dopamine-beta-hydroxylase (DBH) activity. None of the following criteria: Jewish origin, dominant trait, slow progression and axial topography are specific for an elevated serum DBH activity. A significantly high serum DBH activity was found in TD patients and their relatives compared with controls, particularly in the childhood onset group. Intravenous injection of 20 mg Metoclopramide (MP) did not change serum DBH activity in 12 patients and 17 relatives. In one patient with symptomatic dystonia and two of her maternal relatives (from different fathers) serum DBH activity increased after i.v. injection of MP. In these three cases the serum DBH activity doubled and tripled. It is suggested that the MP induced elevation of serum DBH activity in relatives of TD patients indicates a genetic disposition.

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.

Tardive dyskinesia associated with metoclopramide

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