Serum Dopamine-β-Hydroxylase Activities in the Various Disorders with Symptoms of Dizziness or Vertigo

Abstract

Serum dopamine-β-hydroxylase (DBH) activities were examined in 110 patients complaining of dizziness or vertigo. The enzyme was measured by the photometric assay method of Nagatsu and Udenfriend.The mean serum DBH activity of 17 patients was 16.1±8.3 units and there was no significant difference from findings in the normal controls (18.2±6.7 units).Dizziness and vertigo were often complained of by patients with cerebrovascular diseases, particularly thrombosis of the posterior cerebral artery or vertebro-basilar insufficiency, as well as other neurological diseases such as spino-cerebellar degeneration, normal pressure hydrocephalus, cerebellar hemorrhage, cerebellar tumor, Parkinson's disease, essential tremor, amyotrophic lateral sclerosis etc.Computed tomography (CT) of the brain was performed on 71 patients. Serum DBH activities in the patients with normal CT scan findings exhibited no significant change, while activities in patients with CT findings of cerebral atrophy, cerebellopontine atrophy and localized low density areas exhibited comparatively low values.In the dysautonomic patients with dizziness or vertigo, the serum DBH activities exhibited wide varieties, but there were 5 with values under 5 units.No significant change was seen on the enzyme activity during attacks of vertigo or after the caloric test, in the same individual.