Consider adding monitoring assessment for Bow Hunters Syndrome and Eagles Syndrome to your scope of available transcranial doppler testing. Both are vastly under-diagnosed as they require dynamic testing with maneuvers vs a still/resting study.
Bow Hunters Syndrome refers to rotational vertebral artery compression by the vertebrae associated certain neck movements. Eagles syndrome is an elongation of the styloid process or calcification of the styloid ligament and can cause compression of the ICA with certain neck movements. Symptoms include neck pain, vertigo, difficulty swallowing, nausea, and sound sensitivity, and syncope.
Testing with rotational movements while monitoring the MCA and PCA can diagnose these conditions and show that there is inadequate collateral flow present for compensation. Have the patient extend, flex, and rotate the neck and look for hemispheric MVF changes of 50% of greater to baseline. Correlate clinically with radiography if possible. -Shannon York, co-owner of Flow Consultants