Background Monitoring of intracranial pressure is a highly valued tool inside neurosurgery practice. There is no consensus about the exact outer zero point for correlation with the brain center while measuring the intracranial pressure using external ventricular drainage system.
Objectives Evaluate the accuracy of using the top of the head serving as the zero-reference point of the intracranial pressure monitoring device and correlate its relation to the foramen of Monro at clinically used positions of the head.
Methods The study included 30 patients who were candidates of invasive intracranial pressure monitoring with external ventricular drain for different pathological reasons. We compared two points as a zero reference point the Glabella and the other one is the tragus as approximation to the foramen of monro in different head positions.
Results Readings while using the tragus were slightly higher than those while using the glabella as regards the intracranial pressure and drained cerebrospinal fluid volumes with no statistically significant difference.
Conclusion Our study revealed that a zero point at the foramen of Monro was found to be insignificantly different from using the glabella as the zero-reference point when the head of the patient was positioned either supine or elevated 45◦.