Table 2:

Breakdown of intrinsic and extrinsic stenosis relative to the total number of sinuses and distribution of additional corollary findings noted in the idiopathic intracranial hypertension and pulsatile tinnitus cohorts^{^a}

Imaging Finding	IIH	PT
Stenosis type
Extrinsic stenosis	58	8
Mixed extrinsic and intrinsic	17	0
Intrinsic stenosis	40	37
Total	115	45
χ² P value ≤ .001^{^b}
Saccular venous aneurysm
Yes	4	11
No	111	34
Total	115	45
χ² P value ≤.001
Sella appearance
Partially empty	49	18
Empty	61	15
Normal	5	11
NA (adenoma)	0	1
Total	115	45
χ² P value ≤ .001
Optic nerve tortuosity
Minimal	46	31
Marked	69	14
Total	115	45
χ² P value = .001

Note:—NA indicates not applicable; IIH, idiopathic intracranial hypertension; PT, pulsatile tinnitus.
↵a χ² cross-tabulation P values were calculated for each variable. Eighty-two percent of pulsatile tinnitus sinuses had intrinsic stenosis, and 65% of idiopathic intracranial hypertension sinuses had extrinsic stenosis (P value < .001). Statistically significant differences were noted when comparing the distribution of optic nerve tortuosity, sella appearance, and saccular aneurysm presence between the 2 groups (P values ≤ .001).
↵b Extrinsic and mixed subgroups summed for χ² calculation.