The neurology and physical therapy literature has long-identified VBI as an origin of vertigo, nystagmus, diplopia and other focal neurological symptoms. The vertebral arteries are responsible for blood supply to the peripheral and central vestibular mechanisms, pons, cerebellum and visual cortex, thus explaining the associated symptoms when there is a compression, stretching or dissection. This sub-category of patient may sometimes be confusing when referred for vestibular evaluation based on vestibular like symptoms.

Numerous investigators have recommended performing a seated vertebral artery screening prior to performing dynamic positioning tests (Dix-Hallpike) for PC-BPPV. Furthermore, these investigators have also recommended NOT performing any dynamic positioning test that hyper-extends and rotates a patient’s neck.  It is certainly helpful not to confuse non-contributory neurovascular symptoms when testing for PC-BPPV. AIB protocol as published in articles and chapters, is to use only modified Dix-Hallpike testing regardless of vertebral artery screening outcome.

CASE STUDY: 52 year-old male referred for dizziness evaluation.  His primary complaint was a subjective sensation of transient dizziness with head turns to the left. There was no prior history of debilitating attack of vertigo, hearing loss or other medical co-morbidities. He denied any dizziness or vertigo associated with supine or lateral body positions.

Positive VAST- (Watch Video) Observe the persistent left beat nystagmus (LBN) with neck rotation only to the left.  There is no spontaneous or other nystagmus. All vestibular tests, i.e. CDP, VNG, VEMP, etc. were unremarkable.

Radiographic imaging revealed C3-7 degeneration. Patient underwent a stent placement with complete resolution of symptoms.

References:

1. Gans RE, Overview of BPPV: Pathophysiology & Diagnosis, Hearing Review, August 2000
2. Roberts RA and Gans RE, Background, Technique, Interpretation, and Usefulness of Positional/Positioning Testing, In Jacobson GP and Shepard NT (Eds) Balance Function Assessment and Management, Plural Publishing, San Diego, 2008
3. Taylor WB, Vandergriff CL, Opatowsky MJ and Layton KF, Bowhunter’s syndrome diagnosed with provocative digital subtraction cerebral angiography, Proc(Bayl Univ Med Cent) 2012;25 (1) 26-27
4. Choi KD, Shin HY, Kim JS et al. Rotational vertebral artery syndrome: oculographic analysis of nystagmus. Neurology 2005, 65:1156-1157
5. Childs JC et al, Screening for Vertebrobasilar Insufficiency in Patients with Neck Pain: Manual Therapy Decision-Making in the Presence of Uncertainty, Journal of Orthopaedic & Sports Physical Therapy, Volume 35, No.5, May 2000