# Diagnostic accuracy of venous manometry to predict elevated intracranial pressure

## TL;DR

This study shows that measuring venous pressure in the brain's veins can accurately predict high intracranial pressure in patients with venous sinus stenosis.

## Contribution

The study introduces combined thresholds of venous sinus pressure and trans-stenotic gradient as a novel diagnostic method for elevated intracranial pressure.

## Key findings

- Trans-stenotic gradient (TSG) and superior sagittal sinus (SSS) pressure strongly correlate with elevated intracranial pressure.
- Combining TSG ≥6 mmHg and SSS ≥15 mmHg provides high sensitivity and specificity for predicting elevated ICP.
- ROC analysis confirms high diagnostic accuracy when thresholds are combined.

## Abstract

Venous sinus stenting (VSS) is a well-established treatment for idiopathic intracranial hypertension (IIH). Diagnostic workup includes lumbar puncture (LP) for intracranial pressure (ICP) measurement and catheter venography with manometry to assess venous sinus stenosis. We evaluated the diagnostic accuracy of venous manometry in predicting elevated ICP.

We retrospectively reviewed patients with venous sinus stenosis who underwent catheter cerebral venography with venous pressure (mmHg) recording and fluoroscopy-guided LP with cerebrospinal fluid opening pressure (CSF-OP, cmH₂O) measurement during the same session. Elevated ICP was defined as CSF-OP ≥20 cmH₂O. Linear regression assessed relationships between venous pressures, trans-stenotic gradient (TSG), and CSF-OP. Sensitivity, specificity, and receiver operating characteristic (ROC) analyses were performed.

84 female patients (mean age 35.5 years) with ≥50% stenosis of the dominant or codominant lateral venous sinuses were included. TSG demonstrated the strongest correlation with CSF-OP (adjusted R2 = 0.57, p < 0.05), followed by superior sagittal sinus (SSS) pressure (adjusted R2 = 0.53, p < 0.05). ROC analysis showed areas under the curve of 0.87 for TSG, 0.84 for SSS pressure, and 0.94 when combined. Optimal thresholds were SSS pressure ≥15 mmHg (sensitivity 0.88, specificity 0.68) and TSG ≥ 6 mmHg (sensitivity 0.86, specificity 0.80). In patients with TSG ≥ 6 mmHg, an SSS threshold of 15 mmHg yielded sensitivity 0.94 and specificity 0.85.

SSS pressure and TSG strongly predict ICP elevation in venous sinus stenosis, with combined thresholds providing the highest diagnostic accuracy.