NEUROTRANSMITTERS IN CSF OF IDIOPATHIC ADULT-ONSET DYSTONIA - REDUCED5-HIAA LEVELS AS EVIDENCE OF IMPAIRED SEROTONERGIC METABOLISM

While several radiological findings point towards the basal ganglia as a possible anatomical site of the lesion in dystonia patients the bio chemical basis of the disorder is still unknown. 5-Hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) levels - the respective met abolites of serotonin and dopamine - were measured in lumbar cerebrosp inal fluid (lCSF) of 15 patients with idiopathic adult-onset focal dys tonia and in lCSF of 11 controls. 100 mu l lCSF were analyzed for 5-HI AA and HVA by reversed-phase HPLC with electrochemical detection. 5-HI AA levels were significantly reduced in dystonia patients (11.4 mu g/m l) compared to controls (18.4 ng/ml) (p < 0.02). HVA levels in dystoni a patients (30.3 ng/ml) were below control values (41.6 ng/ml) but thi s finding did not reach statistical significance. Decreased lCSF level s of 5-HIAA suggest an impaired serotonin metabolism in patients with idiopathic adult-onset dystonia. This observation may provide a bioche mical basis for a more specific pharmacotherapy in dystonia patients.