Concentrations of Neurotransmitters in Ventricular and Lumbar Cerebrospinal Fluid in Patients with Normal Pressure Hydrocephalus

For several years concentrations of neurotransmitters and their metabolites in lumbar cerebrospinal fluid have been used for diagnostic purposes or to elucidate the pathophysiology of disorders in the central nervous system. In patients with normal pressure hydrocephalus (NPH) it would also be of interest to investigate a possible relationship between pathological features in NPH and concentrations of neurotransmitter substances in CSF. However, simultaneous measurements of various neurotransmitters in CSF obtained from lateral ventricles and the lumbar cistern have disclosed significant differences between the concentrations measured at the two sites (Moir et al. 1970, Jakupcevic et al. 1977, Bertilsson et al. 1982, Nordin et al. 1982, Tyce et al. 1986). These results have been interpreted differently, some advocating that a rostro-caudal gradient is an expression of the central origin of the transmitter substances; others suggesting that the differences in concentrations measured at different sites of the spinal canal depend on the concentrations in the adjacent spinal cord. The purpose of the present study is: 1. To investigate whether there is a relationship between the concentrations of transmitter substances measured and factors influencing CSF dynamics, i.e. the severity of cerebral atrophy indicated by Evans ratio and resistance to outflow of CSF in patients with NPH. 2. To investigate whether lumbar (L-CSF) concentrations of vasoactive intestinal polypeptide (VIP), cholecystokinin (CCK), noradrenaline (NA), dopamine (DA), 5-hydroxyindoleacetic acid (5-HIAA), 3-methoxy-4-hydroxy-phenylglycol (MHPG) and homovanillic acid (HVA) differ from concentrations measured in CSF collected from the lateral ventricles (V-CSF). 3. To investigate whether there is a correlation between concentrations measured in L-CSF and V-CSF.