title: Relative Position of the Third Characteristic Peak of the Intracranial Pressure Pulse Waveform Morphology Differentiates Normal-Pressure Hydrocephalus Shunt Responders and Nonresponders.
abstract: The diversion of cerebrospinal fluid (CSF) remains the principal treatment option for patients with normal-pressure hydrocephalus (NPH). External lumbar drain (ELD) and overnight intracranial pressure (ICP) monitoring are popular prognostic tests for differentiating which patients will benefit from shunting. Using the morphological clustering and analysis of continuous intracranial pulse (MOCAIP) algorithm to extract morphological metrics from the overnight ICP signal, we hypothesize that changes in the third peak of the ICP pulse pressure waveform can be used to differentiate ELD responders and nonresponders.
  
  
  
  Our study involved 66 patients (72.2 ± 9.8 years) undergoing evaluation for possible NPH, which included overnight ICP monitoring and ELD. ELD outcome was based on clinical notes and divided into nonresponders and responders. MOCAIP was used to extract mean ICP, ICP wave amplitude (waveAmp), and a metric derived to study P3 elevation (P3ratio).
  
  
  
  Of the 66 patients, 7 were classified as nonresponders and 25 as significant responders. The mean ICP and waveAmp did not vary significantly (p = 0.19 and p = 0.41) between the outcome groups; however, the P3ratio did show a significant difference (p = 0.04).
  
  
  
  Initial results suggest that the P3ratio might be used as a prognostic indicator for ELD outcome.
authors.affiliation: Neural Systems and Dynamics Laboratory, Department of Neurosurgery, The David Geffen School of Medicine, University of California, Los Angeles, CA, USA.|Biomedical Engineering Graduate Program, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, CA, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Hamilton
authors.affiliation: The David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Fuller
authors.affiliation: Neural Systems and Dynamics Laboratory, Department of Neurosurgery, The David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Baldwin
authors.affiliation: Neural Systems and Dynamics Laboratory, Department of Neurosurgery, The David Geffen School of Medicine, University of California, Los Angeles, CA, USA.|The David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Vespa
authors.affiliation: Neural Systems and Dynamics Laboratory, Department of Neurosurgery, The David Geffen School of Medicine, University of California, Los Angeles, CA, USA. xhu@mednet.ucla.edu.|Biomedical Engineering Graduate Program, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, CA, USA. xhu@mednet.ucla.edu.
authors.forename: Xiao
authors.initials: X
authors.lastname: Hu
authors.affiliation: Neural Systems and Dynamics Laboratory, Department of Neurosurgery, The David Geffen School of Medicine, University of California, Los Angeles, CA, USA.|Biomedical Engineering Graduate Program, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, CA, USA.|The David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA, USA.
authors.forename: Marvin
authors.initials: M
authors.lastname: Bergsneider
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000069461:Bendamustine Hydrochloride; D002557:Cerebrospinal Fluid Shunts; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000503:physiopathology / Q000601:surgery*; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D063177:Pulse Wave Analysis; D012189:Retrospective Studies
chemical_list: D000069461:Bendamustine Hydrochloride
keywords: External lumbar drain; Intracranial pressure; Normal-pressure hydrocephalus; Pulse pressure waveform; Shunt response; Waveform morphology