title: Clinical assessment of noninvasive intracranial pressure absolute value measurement method.
abstract: OBJECTIVE
  To assess prospectively the accuracy and precision of a method for noninvasive intracranial pressure (ICP) measurement compared with invasive gold standard CSF pressure measurement.
  
  
  METHODS
  Included were 62 neurologic patients (37 idiopathic intracranial hypertension, 20 multiple sclerosis, 1 Guillain-Barré syndrome, 1 polyneuropathy, and 3 hydrocephalus). The average age was 40 ± 12 years. All patients had lumbar puncture indicated as a diagnostic procedure. ICP was measured using a noninvasive ICP measurement method, which is based on a two-depth high-resolution transcranial Doppler insonation of the ophthalmic artery (OA). The OA is being used as a natural pair of scales, in which the intracranial segment of the OA is compressed by ICP and the extracranial segment of the OA is compressed by extracranial pressure (Pe) applied to the orbit. The blood flow parameters in both OA segments are approximately the same in the scales balance case when Pe = ICP. All patients had simultaneous recording of noninvasive ICP values and invasive gold standard CSF pressure values.
  
  
  RESULTS
  Analysis of the 72 simultaneous paired recordings of noninvasive ICP and the gold standard CSF pressure showed good accuracy for the noninvasive method as indicated by the low mean systematic error (0.12 mm Hg; confidence level [CL] 0.98). The method also showed high precision as indicated by the low SD of the paired recordings (2.19 mm Hg; CL 0.98). The method does not need calibration.
  
  
  CONCLUSIONS
  The proposed noninvasive ICP measurement method is precise and accurate compared with gold standard CSF pressure measured via lumbar puncture.
authors.affiliation: Telematics Science Laboratory, Kaunas University of Technology, Kaunas, Lithuania. telematics@ktu.lt
authors.forename: A
authors.initials: A
authors.lastname: Ragauskas
authors.forename: V
authors.initials: V
authors.lastname: Matijosaitis
authors.forename: R
authors.initials: R
authors.lastname: Zakelis
authors.forename: K
authors.initials: K
authors.lastname: Petrikonis
authors.forename: D
authors.initials: D
authors.lastname: Rastenyte
authors.forename: I
authors.initials: I
authors.lastname: Piper
authors.forename: G
authors.initials: G
authors.lastname: Daubaris
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology*; D020275:Guillain-Barre Syndrome / Q000175:diagnosis; D006801:Humans; D006849:Hydrocephalus / Q000175:diagnosis; D019586:Intracranial Hypertension / Q000175:diagnosis*; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods*; D009103:Multiple Sclerosis / Q000175:diagnosis; D009880:Ophthalmic Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011115:Polyneuropathies / Q000175:diagnosis; D013129:Spinal Puncture / Q000379:methods; D017585:Ultrasonography, Doppler, Transcranial; D055815:Young Adult