Measurement of Flow in Internal Jugular Vein in the Sitting Position: an Ultrasound Study on Healthy Volunteers

Currently, there are no studies that looked into the IJV flow in sitting position and effect of venous outflow obstruction on the IJV flow. Valsalva maneuver (forced inspiration with closed glottis) and /or compression of internal jugular veins (IJV) are the two commonly used physiological methods that can cause venous outflow obstruction. A custom made neck collar can be used for compression of internal jugular vein and previous investigations have used a similar device in a rat model to demonstrate the protective effects on slosh-mediated brain injury by increasing intracranial blood volume . While the collars have not yet been studied on people for their effectiveness at preventing concussions, many studies have looked at the effect of neck collars on both jugular compression and ICP..

The purpose of this study is to measure the venous blood flow of healthy volunteers by the use of an ultrasound and Doppler velocimetry in sitting position. the investigators will measure the IJV flow on both sides in sitting position at rest and at two conditions of venous outflow obstruction- 1. Neck compression using a custom made collar and 2. During 30 seconds Valsalva maneuver. This study will provide information on the cerebral venous drainage. This information will be very useful in planning and positioning of patients undergoing neurosurgical procedures and to prevent complications from the improper patient position.