Abstract
Purpose :
Various magnetic resonance imaging (MRI) findings have been identified in patients with idiopathic intracranial hypertension (IIH), including optic disc protrusion, globe flattening, empty sella, vertical optic nerve tortuosity, nerve sheath expansion, slit ventricles, transverse venous sinus stenosis, and tonsillar prolapse. We aimed to innumerate these findings in a Bronx cohort and establish clinico-radiological correlations.
Methods :
A retrospective chart review of 45 consecutive patients with confirmed IIH and 47 controls who had MRIs for other reasons, was conducted. Demographic, clinical and brain MRI/MRV details were analyzed with Pearson correlation, student’s t-test, and Mann Whitney calculations using STATA-14 software. Sensitivity, specificity, positive predictive value (PPV), and likelihood ratios (LR) were calculated, for each MRI sign. Significance was set at p<0.05.
Results :
IIH patients were predominately female (91% vs 68%; p=0.006), younger (28.3 vs 45.2yrs; p<0.001) and obese (BMI=34.8 vs 30.7; p<0.015) compared to controls. Mean (SD) number of MRI findings was 2.8(2.1) in IIH and 1.4(1.7) in the controls; (p<0.001). In the IIH group, mean (SD) lumbar puncture opening pressure (LPOP) was 32.2(11.8) cm H2O. LPOP correlated with the number of MRI/MRV signs (Rho=0.31; p=0.04); BMI had minimal correlation (Rho=0.21; p=0.16). Vertical nerve tortuosity (p=0.003), slit ventricles (p<0.001) and transverse sinus stenosis (p<0.001) occurred more in IIH than controls. Other MRI findings were not significantly different. Optic disc protrusion had low sensitivity, 13.3%; CI 5.9-27.0% but high specificity, 95.7%; CI 84.0-98.9%, PPV, 75.0% and +LR, 3.1 while vertical nerve tortuosity had intermediate sensitivity 52.1%; CI 36.4-65.5% and specificity 78.7%; CI 64.3-88.3% and lower PPV 69.7%, and +LR 2.4. Slit ventricles (sensitivity 53.3%; CI 38.5-67.5%, specificity 93.6%; CI 81.5-97.9%, PPV 88.9%, +LR 8.3), and transverse venous sinus stenosis (sensitivity 40.0%; CI 26.5-55.1%, specificity 93.6%; CI 81.5-97.9%, PPV 85.7%, +LR 6.2) had the highest predictive values.
Conclusions :
The results affirm that IIH occurs in young females with high BMI. Opening pressures positively correlated with the number of MRI signs. Ventricular slits and transverse sinus stenosis were the brain MRI/MRV signs that were most predictive of IIH diagnosis.
This is a 2021 ARVO Annual Meeting abstract.