The<unk>  or Wallenberg<unk>  is a physical exam for<unk><unk>  insufficiency. Commonly, the VA<unk>  involves cervical spine motion to an end-range position of rotation, extension or a combination of both. At this point, the physician assesses for vertebrobasilar insufficiency (VBI) symptoms. If the patient has VBI symptoms during the<unk> , it is considered a positive result and a contraindication for cervical manipulation. The specifics of VA<unk> ing vary among authors. The<unk>  is positive if the patient complains of dizziness, visual changes, or nystagmus occurs.
Vertebral artery test
Carotid ultrasonography
Cerebral angiography
Acoustic angiography
Sphygmograph
Perfusion scanning
Magnetic resonance neurography
Intravascular fluorescence