• Written By: Michael Vaphiades, DO

    The authors review the currently available methods of noninvasive intracranial pressure (ICP) assessment and conclude that, although numerous approaches are being used, none of them provides a complete solution.

    They write that there are currently two general approaches for the noninvasive assessment of ICP: 1) qualitative markers that suggest the possibility of increased ICP, and 2) quantitative measures of the patient’s specific ICP or an estimation of the change in ICP after an invasively determined pressure.

    Although a simple test that definitively differentiates normal from high ICP would have substantial clinical utility, quantitative measures would be even more powerful, particularly for long-term monitoring of ICP. 

    However, many studies use a modeling method, such as linear regression, to examine the association between a given measure and the mean ICP. But for a new quantitative marker to be clinically valuable, it must be predictive of the value for a specific individual value rather than the mean.

    In this study, the authors review the numerous qualitative and quantitative approaches to noninvasive evaluation of ICP, classifying them into the categories of neuroradiologic epiphenomena, ophthalmic methods, otic approaches, electrophysiologic methods and fluid dynamics. 

    They conclude that no individual technique clearly represents a complete solution, although combining methods can bring improvement. However, because the diagnostic criteria for many conditions, such as intracranial hypertension, rely not only upon ICP but on the cerebrospinal fluid contents, even if an accurate noninvasive method of assessing ICP was available, one could not yet fully escape the need for invasive ICP measurements, at least for diagnosis.