title: Non-invasive assessment of intracranial pressure.
abstract: Monitoring of intracranial pressure (ICP) is invaluable in the management of neurosurgical and neurological critically ill patients. Invasive measurement of ventricular or parenchymal pressure is considered the gold standard for accurate measurement of ICP but is not always possible due to certain risks. Therefore, the availability of accurate methods to non-invasively estimate ICP has the potential to improve the management of these vulnerable patients. This review provides a comparative description of different methods for non-invasive ICP measurement. Current methods are based on changes associated with increased ICP, both morphological (assessed with magnetic resonance, computed tomography, ultrasound, and fundoscopy) and physiological (assessed with transcranial and ophthalmic Doppler, tympanometry, near-infrared spectroscopy, electroencephalography, visual-evoked potentials, and otoacoustic emissions assessment). At present, none of the non-invasive techniques alone seem suitable as a substitute for invasive monitoring. However, following the present analysis and considerations upon each technique, we propose a possible flowchart based on the combination of non-invasive techniques including those characterizing morphologic changes (e.g., repetitive US measurements of ONSD) and those characterizing physiological changes (e.g., continuous TCD). Such an integrated approach, which still needs to be validated in clinical practice, could aid in deciding whether to place an invasive monitor, or how to titrate therapy when invasive ICP measurement is contraindicated or unavailable.
authors.affiliation: Neurosciences Critical Care Unit, Addenbrooke's Hospital, Cambridge, United Kingdom.|Brain Physics Lab, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Robba
authors.affiliation: Department of Neurosurgery, Galliera Hospital, Genova, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Bacigaluppi
authors.affiliation: Brain Physics Lab, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, United Kingdom.
authors.forename: D
authors.initials: D
authors.lastname: Cardim
authors.affiliation: Brain Physics Lab, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Donnelly
authors.affiliation: Department of Neurosurgery, S. George's Hospital, University of London, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Bertuccio
authors.affiliation: Brain Physics Lab, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Czosnyka
mesh_terms: D000158:Acoustic Impedance Tests; D004569:Electroencephalography; D005074:Evoked Potentials, Visual; D006801:Humans; D019586:Intracranial Hypertension / Q000175:diagnosis*; D007427:Intracranial Pressure / Q000502:physiology; D008991:Monitoring, Physiologic / Q000379:methods*; D017084:Otoacoustic Emissions, Spontaneous; D014057:Tomography, X-Ray Computed; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods
keywords: Cerebral perfusion pressure; cerebral flow; intracranial pressure; neuromonitoring; non-invasive method