[Dopamine beta hydroxylase. Value and limits of its study in neurology]

Plasma dopamine-beta-hydroxylase was studied in 96 subjects, 33 of them controls and 63 of them patients (Parkinson's disease, chronic chorea, torsion dystonia, postural tremor and epilepsy). Only the epileptics showed a significant decrease in the average level of dopamine-beta-hydroxylase activity in comparison with the controls. During the cold test, DBH did not vary except in one case. On the other hand, during epileptic attacks, DBH activity underwent considerable fluctuations. Therefore, except in special pathological conditions, such as epileptic attacks, measurement of plasma or serum DBH activity is of limited value for neurological pathology and is not a good indication of the activity of the sympathetic nervous system.