Extent of transverse sinus stenosis does not predict visual outcomes in idiopathic intracranial hypertension

Abstract

Background: We aimed to investigate whether the degree of transverse sinus stenosis (TSS) on magnetic resonance venography (MRV) can predict visual outcomes in patients with idiopathic intracranial hypertension (IIH).

Methods: A chart review identified IIH patients followed for at least 6 months. Mean deviation (MD) on visual field (VF) testing at initial and last follow-up visits, best corrected visual acuity (BCVA), patients' age, body mass index, and lumbar puncture opening pressure were recorded. MRV was used to grade TSS on a scale of 0-8 using the grading scheme proposed by Farb et al., whereby a lower score indicates a greater degree of stenosis. Linear regression analysis was used to test for association between above variables and MD on VF, including change in MD over time.

Results: 44 female patients were followed for a median of 26 months. All patients had unilateral or bilateral TSS on MRV. The median TSS score was 3/8. The median BCVA was 0.06 logMAR at baseline. The median VF MD was -3.02 dB at baseline and -1.96 dB at final follow-up. There was no significant association between the degree of TSS and either baseline MD (P-value = 0.34) or the change in MD on VF over the course of follow-up (P-value = 0.54). Baseline BCVA (P = 0.045) and baseline MD (P < 0.001) were the only significant predictors of changes in MD on VF over follow-up.

Conclusions: Baseline BCVA and MD on VF were the only significant predictors of visual outcome in IIH patients. While all patients demonstrated TSS on MRV, the degree of TSS did not correlate with visual prognosis.

Fig. 1. Schematic diagram of transverse and sigmoid sinus stenosis grading system.

A Normal (Score 4 bilaterally, 75–100% of the cross-sectional diameter of the lumen of the distal superior sagittal sinus). B Score 3 on the right side (mildly narrowed, 50–75%). Score 4 on the left. C Score 2 on the right side (moderately narrowed, 25–50%). Score 4 on the left. D Score 1 on the right and 1 on the left side (hypoplasia or severe stenosis, <25%). E Score 0 on the right (complete obstruction/aplasia/discontinuity in the sinus with no appreciable filling), 0 on the left side.

Fig. 2

Distribution of transverse sinus stenosis scores among patients.

Fig. 3. Scatterplot of transverse sinus stenosis scores and total change in visual field mean deviation from baseline to final follow-up.

The combined transverse sinus stenosis (TSS) score (0–8) is plotted on the x-axis, and the change in mean deviation (MD), in decibels (dB), on visual field testing from baseline to final follow-up, is plotted on the y-axis. A regression line is plotted on the graph with corresponding R² and P-values.

Fig. 4. Scatterplot of transverse sinus stenosis scores and change in visual field mean deviation as adjusted by length of follow-up.

The combined transverse sinus stenosis (TSS) score (0–8) is plotted on the x-axis, and the average change in mean deviation (MD) per day, in decibels (dB), on visual field testing from baseline to final follow-up is plotted on the y-axis. There is also a regression line plotted on the graph, with corresponding R² and P-values.

Fig. 5. Boxplot of transverse sinus stenosis scores and change in visual field mean deviation as adjusted by length of follow-up.

The combined transverse sinus stenosis (TSS) score (0–8) is plotted on the x-axis, and the average change in mean deviation (MD) per day, in decibels (dB), on visual field testing from baseline to final follow-up is plotted on the y-axis. The boxplot shows the first, second, and third quartile values, and the values that are outliers are seen as black circles. There is a dotted line that passes through 0.00 for visual reference.