An observational study in Intracranial Pressure, sponsored by Odense University Hospital. Recruiting at 1 site in Denmark. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2023-06-02.
Sponsored by Odense University Hospital · Observational
The purpose of this pilot study is to assess whether the intracranial pressure (ICP) can be detected by using a non-invasive retinal fundus scanner, recording the vessels of the eye entering from the optic disc. The artery's diameter (A) is measured and compared to the vein's diameter (V) thereby a ratio A/V can be calculated. This ratio is compared to the values obtained from conventional fiberoptic intraparenchymal, intraventricular ICP monitoring using external ventricular drain (EVD) or lumbar pressure monitoring.
Valid non-invasive techniques for objective measurements of the intracranial pressure do not exist at the given time now and this study could prove to help the development of monitoring patients ICP without surgical intervention.
Intracranial pressure (ICP) is based on the simple principle of Monroe-Kellie Doctrine. Since the volume of the cranial cavity is constant and the brain, CSF and blood can only compensate for a certain change in volume, pressure will increase at a critical increase in volume. An increase in pressure caused by an increase in intracranial volume is distributed throughout the entire brain and spinal canal equally. The normal range of ICP varies with age. Normal values are less than 10-15 mmHg for adults and adolescents, 3-7 mmHg for younger children and 1.5-6 mmHg for newborns even sub-atmospheric ICP has been shown.
The threshold for intracranial hypertension varies in the literature, which is reflected in the clinical use. Generally, ICP above 20 mmHg is defined intracranial hypertension. ICP higher than 20-25 may require treatment, and continuous ICP above 40 mmHg indicates severe, lethal intracranial hypertension.
Some forms of measurements, e.g. 1. Intraparenchymal strain gauge or fiber optics or 2. Intraventricular ICP monitoring via external ventricular drain (EVD). EVD is considered golden standard, but in the daily clinic there is often no or limited difference between 1. and 2. The issue regarding invasive methods are the same as for any surgical procedure, e.g. bleeding and infection. Risk of bleeding is 2-10% for EVD and 2.5% for intraparenchymal monitors. The consequences of such a bleed can be severe and result in disability. EVD has a higher risk of infection (5-20%) compared to intraparenchymal monitors (0-0.1%).
Non-invasive methods such as transcranial doppler ultrasound pulsation index and optic nerve sheath diameter has been used in studies, which seemed promising, but has not yet been validated for routine clinical use. Also, in non-invasive methods there are significant inter observational variation.
Studies of the eye's fundus have shown a correlation between ICP and ratio between artery and vein diameter (A/V ratio, unpublished data) Currently, there are no published work that has considered the correlation between A/V ratio and ICP, however there is a study with a theoretical prediction of such a correlation (Babbs CF 2016. Weldon School of Biomedical Engineering Faculty Working Papers. Paper 1 http://docs.lib.purdue.edu/bmewp/1).
This study investigates the correlation between non-invasive fundus ICP estimation and intracranial pressure monitoring.
In practice, all conscious and able adults admitted to Odense University Hospital for intracranial pressure monitoring/measurements by either an EVD, intraparenchymal ICP monitor or lumbar spinal fluid pressure assessment are enrolled.
165 studies on the registry are indexed under Intracranial Hypertension; 36 are open to participants now.
This study's planned enrollment of 50 is below the median of 60 across 76 observational studies indexed under Intracranial Hypertension.
Browse Intracranial Hypertension studies →Odense University Hospital is the lead sponsor of 479 studies on the registry; 110 are open to participants now.
Counted across the registry records on this site, refreshed daily.
All conscious and able patients of 18 years and older admitted for intracranial pressure monitoring in the department of neurosurgery (Camino, Integra, Switzerland)
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Patients with suspected ventriculo-peritoneal (VP) shunt dysfunction are admitted to the neurosurgical department for intracranial pressure monitoring for 24 hours. The patients are approached within this time frame.
Diagnostic Test: Fundus videos
Patients with suspected NPH (triad of cognitive dysfunction, urine incontinence of urge type, abnormal gait) are admitted to the neurosurgical department for intracranial pressure monitoring for 24 hours. The following day an infusiontest is performed, where data is collected.
Diagnostic Test: Fundus videos
Recordings of fundus videos
Absolute A/V ratio value to conventional intracranial pressure monitors
Comparison of A/V ratio values from the fundus video analysis and conventional intraparenchymal intracranial pressure (ICP), intraventricular ICP monitoring or lumbar pressure monitoring.
Time frame: 2025
Change in A/V ratio value compared to increased intracranial pressure monitor during infusion test.
Assessment of the use of the fundus videos in patients undergoing a lumbar infusion test for 20 minutes for assessment of normal intracranial pressure compared to a conventional intraparenchymal ICP monitor.
Time frame: 2025
Plan to share: Undecided — We wish to share all data of individual intracranial pressure values and A/V ratio.
Started Jun 2017 (actual). Primary completion is estimated for Aug 2025, 98 months after the start.
Of 42 non-industry observational studies under Intracranial Hypertension, half reached primary completion within 31 months of starting (the median), counting those still running; a quarter within 11 and three quarters within 62. This study's planned 98 months is above that.
Counting every sponsor, half of 44 studies reached it within 31 months; a quarter within 11 and three quarters within 62.
How these figures are worked out, and which studies are left out of them.
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