Cerebrospinal fluid flow dynamics and volume changes are related with sigmoid sinus wall dehiscence-pulsatile tinnitus with idiopathic intracranial hypertension

To evaluate cerebrospinal fluid (CSF) flow dynamics and volume changes of pulsatile tinnitus (PT) patients induced by sigmoid sinus wall dehiscence (SSWD) with intracranial hypertension. Thirty-five SSWD-PT patients coexisted with intracranial hypertension and 35, age-, gender-, and handedness-matched healthy volunteers were prospectively enrolled and performed MRI. Clinical data were collected. CSF flow dynamics were evaluated by phase-contrast magnetic resonance imaging (PC-MRI) and CSF volume was measured using ITK-SNAP software. Compared with controls, the body mass index (BMI) of PT patients increased significantly (P = 0.046). Among CSF flow dynamics, PT patients presented significantly decreased mean flux (MF) (P = 0.017), mean velocity (MV) (P = 0.038), peak velocity (PV) (P = 0.023), and significantly increased regurgitant fraction (RF) (P = 0.010) than controls. There were no significant differences in other CSF flow dynamics parameters between the groups. CSF volume of PT patients was significantly increased than controls (P = 0.024). RF and CSF volume had potential diagnostic value. The AUC, sensitivity, specificity and accuracy of RF and CSF volume were 0.678, 68.6 %, 60.0 %, 61.4 % and 0.656, 68.6 %, 57.1 %, 55.7 %, respectively. The combined diagnostic efficacy of RF and CSF volume was highest, and the AUC, sensitivity, specificity and accuracy were 0.733, 74.3 %, 62.9 %, 67.1 % respectively. SSWD-PT patients present CSF flow dynamics and volume changes, which may be related to the occurrence of PT. In addition to structural abnormalities, the combination of RF and CSF volume can be innovative as a complementary index to identify SSWD as the accurate etiology of PT.