[Clinical course and CSF monoamine metabolism in neuroleptic malignant syndrome--a study of nine typical cases and five mild cases].

In nine typical cases and five mild cases of neuroleptic malignant syndrome (NMS), homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA) and noradrenaline (NA) and 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) levels in the cerebrospinal fluid (CSF) were assayed both during the active phase of NMS and after recovery. Compared with levels in normal control subjects, the levels of HVA were significantly lower in the active phase of typical NMS. This finding supports the central dopamine blockade theory of NMS pathophysiology. In addition, the levels of HVA were significantly decreased after recovery from typical NMS. This suggests that there may be a decreased dopamine metabolism in patients susceptible to NMS. The levels of 5-HIAA in the active phase of typical NMS and after recovery were also significantly lower than those in normal control group, suggesting a relationship between the development of NMS and a disturbance of serotonin metabolism. In mild cases, the levels of HVA and 5-HIAA in the active phase of NMS and after recovery were not different from those in normal control subjects. This suggests that there may be a difference in dopamine and serotonin metabolism between typical cases and mild cases. In both cases, the levels of NA in patients with active NMS were significantly higher than in normal subjects, and were within a normal range after recovery. The levels of MHPG were significantly increased in the active phase of typical NMS and had a tendency to increase in the active phase of mild cases, compared with levels in normal control subjects. The levels of MHPG after recovery in both cases were not different from those in normal control subjects. These findings are a result of increased sympathetic activity in active NMS. However, these findings are also observed in other disorders and probably reflect the physical stress caused by NMS.