Intracranial pressure in patients with papilloedema

Area of Science:

• Neurology
• Ophthalmology
• Neurosurgery

Background:

• Papilloedema is a sign of chronically elevated intracranial pressure (ICP), commonly observed in idiopathic intracranial hypertension (IIH).
• The precise ICP level required to cause papilloedema in IIH patients remains unclear.
• Identifying a pathological ICP threshold is crucial for predicting papilloedema development.

Purpose of the Study:

• To compare ICP values between IIH patients with and without papilloedema.
• To determine a predictive ICP threshold for papilloedema in IIH.

Main Methods:

• A single-centre cohort study included IIH patients with 24-hour ICP monitoring and ophthalmology assessments.
• Papilloedema was graded using the Frisén scale.
• Unpaired t-tests and Fisher's exact tests were used to analyze ICP data and predictive values.

Main Results:

• Patients with papilloedema (n=25) had a significantly higher mean median 24-hour ICP (10.4 ± 5.32 mmHg) compared to those without (n=11, 6.31 ± 3.30 mmHg).
• The papilloedema group experienced pressures ≥10 mmHg for ≥30 minutes.
• A 24-hour median ICP of 10 mmHg demonstrated high specificity (91%) and positive predictive value (92%) for detecting papilloedema.

Conclusions:

• An elevated 24-hour ICP of 10 mmHg or more is a strong predictor of papilloedema in IIH.
• This threshold suggests that the pathological ICP level for papilloedema may be lower than previously thought.
• The findings support emerging evidence of lower pathological 24-hour ICP values in IIH.