title: Cerebrospinal fluid markers before and after shunting in patients with secondary and idiopathic normal pressure hydrocephalus.
abstract: BACKGROUND
  The aim of this study was to explore biochemical changes in the cerebrospinal fluid (CSF) induced by shunt surgery and the relationship between these changes and clinical improvement.
  
  
  METHODS
  We measured clinical symptoms and analysed lumbar CSF for protein content, neurodegeneration and neurotransmission markers in patients with secondary (SNPH, n = 17) and idiopathic NPH (INPH, n = 18) before and 3 months after shunt surgery. Patients were divided into groups according to whether or not there was improvement in clinical symptoms after surgery.
  
  
  RESULTS
  Preoperatively, the only pathological findings were elevated neurofilament protein (NFL), significantly more so in the SNPH patients than in the INPH patients, and elevated albumin content. Higher levels of NFL correlated with worse gait, balance, wakefulness and neuropsychological performance. Preoperatively, no differences were seen in any of the CSF biomarkers between patients that improved after surgery and those that did not improve. Postoperatively, a greater improvement in gait and balance performance correlated with a more pronounced reduction in NFL. Levels of albumin, albumin ratio, neuropeptide Y, vasoactive intestinal peptide and ganglioside GD3 increased significantly after shunting in both groups. In addition, Gamma amino butyric acid increased significantly in SNPH and tau in INPH.
  
  
  CONCLUSIONS
  We conclude that a number of biochemical changes occur after shunt surgery, but there are no marked differences between the SNPH and INPH patients. The results indicate that NFL may be a marker that can predict a surgically reversible state in NPH.
authors.affiliation: Institute of Neuroscience and Physiology, The Sahlgrenska Academy at Göteborg University, Sahlgrenska University Hospital, SE 413 45 Göteborg, Sweden. mats.tullberg@neuro.gu.se.
authors.forename: Mats
authors.initials: M
authors.lastname: Tullberg
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.forename: Jan-Eric
authors.initials: JE
authors.lastname: Månsson
authors.forename: Pam
authors.initials: P
authors.lastname: Fredman
authors.forename: Magnus
authors.initials: M
authors.lastname: Tisell
authors.forename: Carsten
authors.initials: C
authors.lastname: Wikkelsö