Learn how the balance system works, what can go wrong in the system, how do we figure things out and what can we do to fix things.

1. Balance Disorders: Dizziness
and Vertigo
Jed A. Kwartler MD, MBA
Dina Leyden PT
Gina Byrnes MSW, LCSW

2. What we will talk about
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How does the balance system work
What can go wrong in the system
How do we figure things out
What can we do to fix things

3. Why do we need a balance system?
• Balance, posture
• Vestibular
• Vision
• Proprioception (ankle, etc)
• Stable sensory platform
• Especially for vision
• Spatial orientation
• Which way is up
• Important in space, underwater,
in the air, and in underground
tunnels

4. Organization of Balance System

5. Anatomy

6. Canal anatomy
• Each canal has a swelling at
its base, called the ampulla
• The crista is a saddle-shaped receptor epithelium
covered with hair cells
• The stereocillia of the cells
are embedded in a gelatinous
membrane (the cupula) that
spans the ampulla and forms
a barrier across it

7. The three semicircular canals lie in 3
orthogonal planes
Cochlea
Anterior
Vertical
Canal
Horizontal
Canal
Posterior
Vertical
Canal
Cochlear N
Vestibular N
VestibuloCochlear N
(Nerve VIII)

8. Canal orientation
The three semicircular canals are
approximately orthogonal to
each other. One is 30 deg
above horizontal, while the
anterior and posterior are
vertical (approximately 45° from
the sagittal plane)
Notice that they are arranged in
pairs:
R Horizontal -- L Horizontal
R Anterior -- L Posterior
R Posterior -- L Anterior

9. The semicircular canals are functionally paired to eye
muscles
• The canals lie in roughly
the same planes as the
extraocular muscles:
Horizontal canals: lateral
and medial recti.
LARP: left vertical recti,
right obliques.
RALP: right vertical recti,
left obliques.
• Each canal excites a pair of
muscles and inhibits a pair
of muscles in its plane. Its
partner excites the muscles
it inhibits, and vice-versa.
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10. Canal function
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When the head rotates, inertia causes
the fluid in the canals to lag behind,
exerting force on the cupula, which in
turn bends the stereocillia
Ipsilateral rotation is excitatory,
contralateral is inhibitory; each canal
pair works as a push-pull system

11. There are 3 major vestibular reflexes
• Vestibulo-ocular reflex – keep the eyes
still in space when the head moves.
• Vestibulo-colic reflex – keeps the head
still in space – or on a level plane when
you walk.
• Vestibular-spinal reflex – adjusts
posture for rapid changes in position.

12. First step – Take a history

13. What are we looking for in the history
• Describing what the sensation feels like
• When and how did it start
• Pattern
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Constant, episodic, getting worse or better
• What makes it worse, makes it better
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Foods, activities, movements, time
• Associated symptoms
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Headache, sensorimotor changes, metabolic
• Other factors
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Sleep, stress, medications, mobility, general condition

14. Physical Examination
• Orthostatic blood pressure
• General head and neck exam
• Otoneurologic exam
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Eye movements
Postural control and coordination
Provocative movements
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“testing for crystals”
Visual fixation/suppression of nystagmus
Dynamic visual acuity with head movement
Dizziness/nystagmus with air pressure or loud sound

15. Testing
• Hearing test
• Tests of balance function
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VNG
Rotary Chair
Posturography
Head thrust
VEMP (cervical or ocular)
• Functional balance assessment by PT

16. Vestibular
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Menieres
Vestibular Neuritis
Benign position vertigo
Idiopathic recurrent vestibulopathy
Neurologic
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Migraine
Concussion
Stroke/Ischemia
Neuropathy
Visual disturbance
Other
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Cardiac – pressure, output, arrythmia, postural
Medications
Metabolic – endocrine
Sleep apnea
Stress/anxiety
Mobility and general conditioning