Definition

  • Bow Hunter´s syndrome (Rotational vertebral artery occlusion syndrome) is a symptomatic vertebrobasilar insufficiency caused by mechanical compression of the vertebral artery (VA) at the level of the atlanto-axial joint during head rotation within the normal physiologic range

Etiopathogenesis

Content available only for logged-in subscribers (registration will be available soon)

Clinical presentation

  • clinical symptoms are provoked by unilateral head rotation (combined with retroflexion) and disappear after when the head is returned to the neutral position
    • transient vertigo, visual disturbances
    • drop attack or syncope
    • TIA/stroke in the posterior circulation
  • usually present with concomitant contralateral vertebral artery pathology (hypoplasia, stenosis/occlusion), which means that the dominant vertebral artery is compressed

Diagnostic evaluation

Dynamic Doppler ultrasonography

Content available only for logged-in subscribers (registration will be available soon)

Standard and dynamic cervical spine X-ray

  • detects morphologic abnormalities in the spine
  • dynamic images assess for spinal instability
  • functional views should not be performed on trauma patients without the strict instructions of a clinician

Dynamic DSA

  • DSA is performed during symptomatic move
  • it identifies the side and level of the compression (can be anywhere from C6 entrance to C1/2 level)
  • DSA cannot determine the exact cause of the compression

Dynamic CTA

  • able to identify the exact location and cause of the compression
  • higher radiation exposure compared to DSA

Dynamic MRA

  • MR angiography can be a reliable and less invasive diagnostic tool and can be used instead of DSA
  • it is suitable for confirming adequate postoperative decompression and for monitoring recurrence  (Anaizi, 2013)
Bow-hunter syndrom - hypertrophic transverse process with compression of vertebral artery (CTA)
Bow-Hunter syndrom - dynamic DSA demonstrates VA occlusion during head rotation
Bow-Hunter syndrom - dynamic MRA demonstrates VA occlusion during head rotation (Anaizi, 2014)

Management

Content available only for logged-in subscribers (registration will be available soon)
Send this to a friend
Hi,
you may find this topic useful:

Bow Hunter´s syndrome
link: https://www.stroke-manual.com/bow-hunter-syndrome/