Jugular valve function and petrosal sinuses pressure: a computational model applied to sudden sensorineural hearing loss

Reports of extra-cranial venous outflow disturbances have recently been linked to sudden sensorineural hearing loss (SSNHL). Aims of the present study are: i) to quantify, with mathematical model, the impact of jugular valve function on the pressure of the superior and inferior petrosal sinuses (SPS, IPS) and the main auricolar veins; ii) to verify the feasibility of the application of mathematical model in the clinical setting in terms of consistency respect to the usual measures of SSNHL outcome. Extra-cranial venous outflow and post analysis were respectively blindly assessed by echo colour-Doppler (ECD) and a validated mathematical model for the human circulation. The pilot study was conducted on 1 healthy control and in a group of 4 patients with different outcome of SSNHL. The main finding was the significant increased pressure calculated in the SPS and IPS of patients with ipsilateral jugular obstruction due to not mobile valve leaflets (6.55 mmHg), respect to the other subjects without extracranial complete obstruction (6.01 mmHg), P=0.0006. Moreover, we demonstrated an inverted correlation between the extrapolated pressure values in the SPS/IPS and the mean flow measured in the correspondent internal jugular vein (r= –0.87773; r-squared= 0.7697; P=0.0009). The proposed mathematical model can be applied to venous extra-cranial ECD investigation in order to derive novel clinical information on the drainage of the inner ear. Such clinical information seems to provide coherent parameters potentially capable to drive the prognosis. This innovative approach was proven to be feasible by the present pilot investigation and warrants further studies with an increased sample of patients

Impact of Jugular Vein Valve Function on Cerebral Venous Haemodynamics

We quantify the effect of internal-jugular vein function on intracranial venous haemodynamics, with particular attention paid to venous reflux and intracranial venous hypertension. Haemodynamics in the head and neck is quantified by computing the velocity, flow and pressure fields, and vessel cross-sectional area in all major arteries and veins. For the computations we use a global, closed-loop multi-scale mathematical model for the entire human circulation, recently developed by the first two authors. Validation of the model against in vitro and in vivo Magnetic Resonance Imaging (MRI) measurements have been reported elsewhere. Here, the circulation model is equipped with a sub-model for venous valves. For the study, in addition to a healthy control, we identify two venous-valve related conditions, namely valve incompetence and valve obstruction. A parametric study for subjects in the supine position is carried out for nine cases. It is found that valve function has a visible effect on intracranial venous haemodynamics, including dural sinuses and deep cerebral veins. In particular, valve obstruction causes venous reflux, redirection of flow and intracranial venous hypertension. The clinical implications of the findings are unknown, though they may relate to recent hypotheses linking some neurological conditions to extra-cranial venous anomalies

Jugular valve function and petrosal sinuses pressure: a computational model applied to sudden sensorineural hearing loss

Reports of extra-cranial venous outflow disturbances have recently been linked to sudden sensorineural hearing loss (SSNHL). Aims of the present study are: i) to quantify, with mathematical model, the impact of jugular valve function on the pressure of the superior and inferior petrosal sinuses (SPS, IPS) and the main auricolar veins; ii) to verify the feasibility of the application of mathematical model in the clinical setting in terms of consistency respect to the usual measures of SSNHL outcome. Extra-cranial venous outflow and post analysis were respectively blindly assessed by echo colour-Doppler (ECD) and a validated mathematical model for the human circulation. The pilot study was conducted on 1 healthy control and in a group of 4 patients with different outcome of SSNHL. The main finding was the significant increased pressure calculated in the SPS and IPS of patients with ipsilateral jugular obstruction due to not mobile valve leaflets (6.55 mmHg), respect to the other subjects without extracranial complete obstruction (6.01 mmHg), P=0.0006. Moreover, we demonstrated an inverted correlation between the extrapolated pressure values in the SPS/IPS and the mean flow measured in the correspondent internal jugular vein (r= –0.87773; r-squared= 0.7697; P=0.0009). The proposed mathematical model can be applied to venous extra-cranial ECD investigation in order to derive novel clinical information on the drainage of the inner ear. Such clinical information seems to provide coherent parameters potentially capable to drive the prognosis. This innovative approach was proven to be feasible by the present pilot investigation and warrants further studies with an increased sample of patients