Multiphysics coupling study on the effect of blood flow pulsation in patients with pulsatile tinnitus

Background: Pulsatile tinnitus presents as a unique variation of tinnitus in which a conscious perception of the heartbeat is localized to the ears in either unilateral or bilateral fashion. The sensation is typically caused by an increase in turbulent blood flow in the affected ear, in most cases, due to a structural abnormality of the venous sinuses – the most common of which being stenosis. Herein, we discuss the etiology of pulsatile tinnitus followed by indications for treatment of various pathologies which have been successfully treated with venous sinus stenting and have led to resolution of auditory symptoms. Methods: The authors queried PubMed database using combinations of the keywords “venous sinus stenting,” “endovascular treatment,” and “pulsatile tinnitus” to identify relevant studies published in English after 2001 and before December 1, 2020 and verified selected. Results: Our results corroborate those published in prior reviews reporting a high rate of pulsatile tinnitus resolution with venous sinus stenting. Conclusion: The success of venous sinus stenting is clinically relevant as an effective treatment option for patients suffering from pulsatile tinnitus. Future applications and studies are needed and are currently being developed to further demonstrate the effectiveness of stents in the treatment of pulsatile tinnitus.

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Study on the correlation between hemodynamic status of the transverse sinus-sigmoid sinus and the clinical efficacy of sigmoid sinus wall reconstruction

Interventional Neuroradiology ◽

10.1177/15910199211062025 ◽

2021 ◽

pp. 159101992110620

Author(s):

Zhenfeng Li ◽

Long Jin

Keyword(s):

Blood Flow ◽

Pressure Distribution ◽

Flow Velocity ◽

Clinical Efficacy ◽

Blood Flow Velocity ◽

Transverse Sinus ◽

Sigmoid Sinus ◽

Pulsatile Tinnitus ◽

Sinus Wall ◽

Sinus Stenosis

Background and Purpose For patients with pulsatile tinnitus who have both transverse sinus stenosis and sigmoid sinus wall anomalies, sigmoid sinus wall reconstruction surgery is the first-choice treatment when the trans-stenotic pressure gradient less than 10 mmHg. However, not all patients are cured by surgery. We hypothesized the abnormal hemodynamics caused by transverse sinus stenosis is associated with the clinical efficacy of surgery. Methods Eight pulsatile tinnitus patients treated with surgery were retrospectively reviewed (4 rehabilitated, 4 nonrehabilitated). All patients had radiologically diagnosed transverse sinus stenosis and sigmoid sinus wall anomalies. A numerical simulation of the hemodynamics of the transverse sinus-sigmoid sinus was performed using computational fluid dynamics technology. Changes in the blood flow patterns before and after surgery were observed. The blood flow velocity at the stenosis, vorticity of blood flow in the sigmoid sinus and wall pressure distribution in the sigmoid sinus wall anomalies area were compared. Results The blood flow velocity in the stenosis (preoperative P = 0.04, postoperative P = 0.004) and vorticity in the sigmoid sinus (preoperative P = 0.02, postoperative P = 0.007) pre- and post-surgery were significantly higher in the non-rehabilitation group than in the rehabilitation group. No significant difference was found in the wall pressure distribution in the sigmoid sinus wall anomalies area (preoperative P = 0.12, postoperative P = 0.24). Conclusions There is a clear correlation between the abnormal hemodynamic status caused by transverse sinus stenosis and the clinical efficacy of surgery. The blood flow velocity at the stenosis and vorticity of blood flow in the sigmoid sinus are factors influencing the clinical efficacy of surgery.

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Altered cerebral blood flow in patients with unilateral venous pulsatile tinnitus: an arterial spin labeling study

British Journal of Radiology ◽

10.1259/bjr.20200990 ◽

2021 ◽

pp. 20200990

Author(s):

Xiaoshuai Li ◽

Pengfei Zhao ◽

Xiaoyu Qiu ◽

Han Lv ◽

Heyu Ding ◽

...

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Neuronal Activity ◽

Arterial Spin Labeling ◽

Brain Perfusion ◽

Spin Labeling ◽

Pulsatile Tinnitus ◽

Lingual Gyrus ◽

Healthy Control ◽

The Mean

Objectives: Abnormal neuronal activity and functional connectivity have been reported in patients with venous pulsatile tinnitus (PT). As neuronal activity is closely coupled to regional brain perfusion, the purpose of this study was to investigate the cerebral blood flow (CBF) alterations in patients with unilateral venous PT using arterial spin labeling (ASL). Methods: This study included patients with right-sided PT between January 2018 and July 2019. A healthy control (HC) group matched 1:1 for gender and age was also recruited. All subjects underwent ASL scanning using 3.0T MRI. The correlation between altered CBF and Tinnitus Handicap Inventory (THI) score as well as PT duration was analyzed. Results Twenty-one patients with right-sided PT and 21 HCs were included. The mean PT duration of the patients was 35.9 ± 32.2 months, and the mean THI score was 64.1 ± 20.3. Compared with the HCs, the PT patients exhibited increased CBF in the left inferior parietal gyrus and decreased CBF in the bilateral lingual gyrus (family-wise error corrected, p < 0.05). The increased CBF in the left inferior parietal gyrus showed a positive correlation with the THI score in PT patients (r = 0.501, p = 0.021). Conclusions PT patients exhibit regional CBF alterations. The increased CBF in the left inferior parietal gyrus may reflect the severity of PT. Advances in knowledge: This study not only presents evidence for the potential neuropathology of PT from the perspective of CBF alterations but also offers a new method for investigating the neuropathological mechanism of PT.

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Assessment of blood flow velocities and venous pressures using a dual-sensor guidewire in symptomatic dural sinus stenoses

Journal of Neurosurgery ◽

10.3171/2017.12.jns172364 ◽

2019 ◽

Vol 130 (6) ◽

pp. 1992-1996 ◽

Cited By ~ 2

Author(s):

Stéphanie Lenck ◽

Fabrice Vallée ◽

Vittorio Civelli ◽

Jean-Pierre Saint-Maurice ◽

Patrick Nicholson ◽

...

Keyword(s):

Blood Flow ◽

Intracranial Hypertension ◽

Idiopathic Intracranial Hypertension ◽

Venous Pressure ◽

Venous Blood Flow ◽

Lateral Sinus ◽

Pulsatile Tinnitus ◽

Dual Sensor ◽

Blood Flow Velocities ◽

Flow Velocities

Lateral venous sinus stenoses have been associated with idiopathic intracranial hypertension and venous pulsatile tinnitus. Venous pressure measurement is traditionally performed to assess the indications for stenting in patients with idiopathic intracranial hypertension. However, its reliability has recently been questioned by many authors. The dual-sensor guidewire was first developed for advanced physiological assessment of fractional and coronary flow reserves in coronary artery stenoses. It allows measurement of both venous pressure and blood flow velocities. The authors used this device in 14 consecutively treated patients to explore for symptomatic lateral sinus stenosis. They found that venous blood flow was significantly accelerated inside the stenotic lesion. This acceleration, as well as the pulsatile tinnitus, resolved in all patients following stent placement. According to the authors’ results, this guidewire can be helpful for establishing an indication for stenting in patients with pulsatile tinnitus and idiopathic intracranial hypertension.

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Innervation of endoneurial microvessels in human sural nerve

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100125002 ◽

1992 ◽

Vol 50 (1) ◽

pp. 920-921

Author(s):

John L. Beggs ◽

Peter C. Johnson ◽

Astrid G. Olafsen ◽

C. Jane Watkins

Keyword(s):

Blood Flow ◽

Blood Vessels ◽

Blood Supply ◽

Peripheral Nerves ◽

Sural Nerve ◽

Nerve Fibers ◽

Arterial Supply ◽

Autonomic Nerve ◽

Vasa Nervorum ◽

Endoneurial Blood Flow

The blood supply (vasa nervorum) to peripheral nerves is composed of an interconnected dual circulation. The endoneurium of nerve fascicles is maintained by the intrinsic circulation which is composed of microvessels primarily of capillary caliber. Transperineurial arterioles link the intrinsic circulation with the extrinsic arterial supply located in the epineurium. Blood flow in the vasa nervorum is neurogenically influenced (1,2). Although a recent hypothesis proposes that endoneurial blood flow is controlled by the action of autonomic nerve fibers associated with epineurial arterioles (2), our recent studies (3) show that in addition to epineurial arterioles other segments of the vasa nervorum are also innervated. In this study, we examine blood vessels of the endoneurium for possible innervation.

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Correlation of γ-radioactivity and Scanning Electron Microscopy in measurement of retention of 111Indium-labeled canine endothelial cells on synthetic vascular grafts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156419 ◽

1989 ◽

Vol 47 ◽

pp. 886-887

Author(s):

E.J. Prendiville ◽

S. Laliberté Verdon ◽

K. E. Gould ◽

K. Ramberg ◽

R. J. Connolly ◽

...

Keyword(s):

Blood Flow ◽

Ex Vivo ◽

Vascular Grafts ◽

Retention Data ◽

Vascular Prostheses ◽

Group 4 ◽

Human Fibronectin ◽

Insufficient Time ◽

Group 3 ◽

Group 2

Endothelial cell (EC) seeding is postulated as a mechanism of improving patency in small caliber vascular grafts. However the majority of seeded EC are lost within 24 hours of restoration of blood flow in previous canine studies . We postulate that the cells have insufficient time to fully develop their attachment to the graft surface prior to exposure to hemodynamic stress. We allowed EC to incubate on fibronectin-coated ePTFE grafts for four different time periods after seeding and measured EC retention after perfusion in a canine ex vivo shunt circuit.Autologous canine EC, were enzymatically harvested, grown to confluence, and labeled with 30 μCi 111 Indium-oxine/80 cm 2 flask. Four groups of 5 cm x 4 mm ID ePTFE vascular prostheses were coated with 1.5 μg/cm.2 human fibronectin, and seeded with 1.5 x 105 EC/ cm.2. After seeding grafts in Group 1 were incubated in complete growth medium for 90 minutes, Group 2 were incubated for 24 hours, Group 3 for 72 hours and Group 4 for 6 days. Grafts were then placed in the canine ex vivo circuit, constructed between femoral artery and vein, and subjected to blood flow of 75 ml per minute for 6 hours. Continuous counting of γ-activity was made possible by placing the seeded graft inside the γ-counter detection crystal for the duration of perfusion. EC retention data after 30 minutes, 2 hours and 6 hours of flow are shown in the table.

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