1. MAC Adult Grand Rounds Vestibular/Balance Center Patient
Mike Hojnacki, AuD
October 21, 2016

2. Spectrum Health Balance Center
Vestibular/Audiology Diagnostics Vestibular Rehabilitation Neurotology oversight Following case adapted from: Hojnacki M, Watkins G. (2015) Positional Vertigo: As Simple as it Gets? Audiology Today 27(5):58-63.

3. 54 Y/O Female Chief Complaint
Positional provoked spells of vertigo for the past two years
Head turns to the RIGHT and UP
Shaving under RIGHT arm
Symptom were limited to provoking positions only, not encounter otherwise; have been present multiple years
Confusion, altered speech, word-finding difficulty, nausea, weakness, imbalance, and intermittent unresponsiveness also reported
She denied LOC, aural symptoms, vomiting, headache, incontinence

4. Medical Work up 2012/13 2012/13 Neurology Eval EEG, MRI head/brain WNL
“Positive RIGHT Hallpike maneuver (reports of subjective vertigo, “nystagmus observed)”, normal Neuro consult
RIGHT Epley performed
Follow up one year later (2013): symptoms unchanged
“Positive RIGHT Hallpike” again reported
Referred to Vestibular Rehab

5. 2013 Vestibular Rehab Eval
Reported symptoms consistent with Neruo notes
Gait and Balance reactions normal (TUG, BERG)
RIGHT and LEFT Hallpike maneuvers NEGATIVE
RIGHT Roll Test – provoked symptoms:
“Patient reported severe dizziness and showed signs of anxiety accompanied by oblique nystagmus lasting 15 seconds. Initial nystagmus appeared more vertical and did not have a clear horizontal or torsional component”
Patient discharged from therapy as eval inconsistent with BPPV, referred back to PCP for further work up

6. 2013/14 Work up
MRA of the neck:
“LEFT vertebral artery is the dominant of two arteries.”
MRI of the spine:
“Minimal uncovertebral degenerative change and posterior endplate osteophytes (bone spurs)” C5-C6
Referred back to treating Neurologist:
Again reported positive RIGHT Hallpike maneuver
Referred for Audiologic/Vestibular Evaluation
Sounds like BPPV???

7. 2014 Vestibular Evaluation
Hearing WNL, excellent speech recognition bilaterally
DHI: 58 = Severe limitations/restriction on daily life
modified clinical test of sensory integration and balance (mCTSIB) WNL
Normal Occularmotor battery
Vertebral Artery screening test NEGATIVE
RIGHT and LEFT Hallpike NEGATIVE
ROLL TEST:

8. Roll Test Robust vertical down-beat nystagmus (DBN).
Head Roll to LEFT, negative
Head Roll RIGHT provoked:
Robust vertical down-beat nystagmus (DBN).
After approximately 15 seconds, DBN fatigued and right-beat horizontal nystagmus developed which then changed to left-beat horizontal nystagmus within the single, sustained head position. VIDEO1; VIDEO2
Immediate onset of concurrent vertigo, dizziness, and nausea. Later reported that she had hallucinated
Nystagmus and subjective symptoms both resolved returning to center
Warm air calorics yield 2% asymmetry

9. Differential Diagnosis:
Atypical/Anterior Canal BPPV
Migrainous vertigo
Vertebrobasilar Insufficiency
Chiari Malformation
ALL CAN PRODUCE DOWNBEATING NYSTAGMUS
NOT PC BPPV (ie positive Hallpike)

10. Differential Diagnosis:
Atypical/Anterior Canal BPPV
Migrainous vertigo
Vertebrobasilar Insufficiency
Chiari Malformation

11. Vertebrobasilar Insufficiency
Bertholon et al (2002) summarized mechanism of VBI:
Lateral head turns induce greater compression in the contralateral vertebral artery. In normal subjects, the ipsilateral vertebral artery compensates for transient reduction of blood flow of the afflicted vertebral artery. However, some individuals have anatomical anomalies where one vertebral artery is “dominant”.
Compression or occlusion to the dominant artery could potentially lead to reduced cerebral blood flow as the malformed side cannot carry the burden of increased blood flow rate/pressure

12. Vertebrobasilar Insufficiency
“…ipsilateral vertebral artery compensates for transient reduction of blood flow of the afflicted vertebral artery…”
Our patient had abnormal RIGHT VA, dominant LEFT VA

13. Vertebrobasilar Insufficiency
“…Compression or occlusion to the dominant artery could potentially lead to reduced cerebral blood flow …”
Our patient had abnormal RIGHT VA, dominant LEFT VA

14. Vertebrobasilar Insufficiency
“…Compression or occlusion to the dominant artery could potentially lead to reduced cerebral blood flow …”
Our patient had abnormal RIGHT VA, dominant LEFT VA

15. Vertebrobasilar Insufficiency
The vertebrobasilar artery system is responsible for oxygenating:
Posterior Fossa
Cerebellum
Brain stem
Vestibular nuclei
Peripheral Labyrinth

16. Vertebrobasilar Insufficiency
The vertebrobasilar artery system is responsible for oxygenating:
Posterior Fossa
Cerebellum
Brain stem
Vestibular nuclei
Peripheral Labyrinth

17. Vertebrobasilar Insufficiency
When blood flow is reduced or ceased the following symptoms can arise: vertigo, visual hallucinations, drop attacks, weakness, visceral sensations, visual field deficits, headaches, hearing loss, tinnitus, dysarthria, and confusion. (Furman and Cass, 2003).

18. The Mechanism
Rightward head turns likely induced compression of dominant LEFT VA given appearance of C5-C6 bone spurs and abnormal RIGHT VA could not carry burden of blood flow

19. The Mechanism Loss of oxygen to: Posterior Fossa Cerebellum
Downbeat nystagmus

20. The Mechanism Loss of oxygen to: Brain stem Vestibular nuclei
Peripheral Labyrinth
Left beat nystagmus
VERTIGO
(aka Alexanders’ Law)

21. The Outcome Referred to U of M vascular surgery
12/16/15 underwent “left distal vertebral artery bypass graft from external carotid artery”
Reported single spell of dizziness with a right head turn since surgery, less severe!!

22. Vertebrobasilar Insufficiency
It was the specific knowledge and understanding of the anatomy and physiology of the peripheral and central vestibular system, as well as the contributing vascular supply, that helped to facilitate proper diagnosis and management for this patient. (Hojnacki and Watkins, 2015)