title: Age-dependence of cerebrospinal parameters.
abstract: OBJECTIVE
  The records of 159 patients were reviewed who routinely underwent a classical volume-pressure testing procedure due to suspected cerebrospinal fluid circulatory disorders.
  
  
  METHODS
  Regression analyses were carried out to explain the cerebrospinal parameters' relationships to age. Least median squares (LMS) algorithms achieved robust estimation of simple linear model parameters. Also, method of weighted regression was used because of unequal variances in the observations.
  
  
  RESULTS
  Cerebrospinal elastance and resistance to outflow revealed significant LMS regressions: y = 0.171x + 7.460 (n = 159, p < 0.0001) and y = 0.096x + 1.871 (n = 97, p < 0.0001), respectively. Similarly, weighting data resulted in models such as y = 0.151x + 6.830 (p < 0.0001) for elastance and y = 0.087x + 1.730 (p < 0.0001) for resistance estimates. The intracranial pressure at rest showed no age-related dependency. Both clear clinical and morphological signs were found in 20% of patients.
  
  
  CONCLUSIONS
  Expecting no time-variant properties we surprisingly found a significant linear relationship in cerebrospinal parameters and age. Thus, parameter magnitudes are not likely dominated by a pathological process only but also determined by temporal system alterations.
authors.affiliation: Medizinische Hochschule Hannover, Neurochirurgische Klinik, Hannover, Germany. koenig.kathrin@mh-hannover.de
authors.forename: K
authors.initials: K
authors.lastname: König
authors.forename: H E
authors.initials: HE
authors.lastname: Heissler
authors.forename: M
authors.initials: M
authors.lastname: Zumkeller
authors.forename: E
authors.initials: E
authors.lastname: Rickels
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D003187:Compliance; D003198:Computer Simulation; D006801:Humans; D006849:Hydrocephalus / Q000134:cerebrospinal fluid / Q000503:physiopathology*; D007427:Intracranial Pressure; D008875:Middle Aged; D008954:Models, Biological; D013223:Statistics as Topic