title: Clinical Validation of a Transcranial Doppler-Based Noninvasive Intracranial Pressure Meter: A Prospective Cross-Sectional Study.
abstract: BACKGROUND
  Noninvasive intracranial pressure (ICP) measurement would represent a major advance for patients with neurological problems. The Vittamed ICP meter is an ultrasound-based device reported to have high agreement with lumbar puncture cerebrospinal fluid (CSF) pressure measurement. However, previous studies included mostly patients with normal levels of ICP. The purpose of our study was to perform an independent clinical validation study of a transcranial Doppler-based noninvasive ICP meter in patients anticipated to have a wide range of ICP.
  
  
  METHODS
  In a prospective cross-sectional design, we simultaneously measured ICP with the Vittamed device and the invasive lumbar CSF pressure. The operator of each procedure was blinded to the result of the other method. Data were analyzed using Bland-Altman plots, Pearson correlation coefficients, and receiver operator characteristic curves.
  
  
  RESULTS
  Twenty-four independent paired measurements of Vittamed and lumbar CSF pressure were obtained; with mean absolute difference between paired measures of 4.5 mmHg (standard deviation 3.1). The 95% limits of agreement were -10.5 to +11.0. The systematic bias (mean of paired differences) was negligible at 0.25 mmHg. The sensitivity, specificity, and area under the curve for ICP >20 mmHg were 0.73, 0.77, and 0.71, respectively.
  
  
  CONCLUSIONS
  The Vittamed ICP meter had fair agreement with lumbar CSF pressure measurement. The wide limits of agreement would preclude using this version of the device as a stand-alone method for ICP determination, but may be useful if combined with other ICP screening methods. Ongoing improvements to the Vittamed hardware and software may lead to improvements in accuracy and clinical utility of this device.
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA; Center for Space Medicine, Baylor College of Medicine, Houston, Texas, USA. Electronic address: bershad@bcm.edu.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Bershad
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Aashish
authors.initials: A
authors.lastname: Anand
authors.affiliation: Department of Biostatistics, University of Texas Health Science at Houston, Houston, Texas, USA.
authors.forename: Stacia M
authors.initials: SM
authors.lastname: DeSantis
authors.affiliation: Department of Biostatistics, University of Texas Health Science at Houston, Houston, Texas, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.affiliation: University of Houston School of Optometry, Houston, Texas, USA.
authors.forename: Rosa A
authors.initials: RA
authors.lastname: Tang
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Eusebia
authors.initials: E
authors.lastname: Calvillo
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Leslie
authors.initials: L
authors.lastname: Malkin-Gosdin
authors.affiliation: Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Rod
authors.initials: R
authors.lastname: Foroozan
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Rahul
authors.initials: R
authors.lastname: Damani
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Nelson
authors.initials: N
authors.lastname: Maldonado
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Pramod
authors.initials: P
authors.lastname: Gupta
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Benedict
authors.initials: B
authors.lastname: Tan
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA; Center for Space Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Chethan P
authors.initials: CP
authors.lastname: Venkatasubba Rao
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA; Center for Space Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Jose I
authors.initials: JI
authors.lastname: Suarez
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas, USA; Center for Space Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Clark
authors.affiliation: Center for Space Medicine, Baylor College of Medicine, Houston, Texas, USA; Department of Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Sutton
authors.affiliation: Center for Space Medicine, Baylor College of Medicine, Houston, Texas, USA; Department of Pharmacology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Dorit B
authors.initials: DB
authors.lastname: Donoviel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D019586:Intracranial Hypertension / Q000175:diagnosis*; D007427:Intracranial Pressure / Q000502:physiology*; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D011446:Prospective Studies; D012372:ROC Curve; D013129:Spinal Puncture; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*; D055815:Young Adult
keywords: Intracranial pressure; Neurocritical care; Noninvasive; Transcranial Doppler ultrasound; Vittamed