Introduction to Dizziness and the Vestibular System David R Friedland, MD, PhD

Professor and Vice-Chairman Chief, Division of Otology and Neuro-otologic Skull Base Surgery

Chief, Division of Research Department of Otolaryngology and Communication Sciences

Medical College of Wisconsin, Milwaukee, WI

8:30 am – 9:00 am Introduction to Dizziness and the Vestibular System David Friedland, MD, PhD, Professor & Vice-Chair of Otolaryngology & Communication Sciences, Medical College of Wisconsin, Milwaukee.

9:00 am – 9:30 am Clinical Exam for Dizziness Dennis Moore, MD, Otolaryngologist at Lutheran General Hospital, Park Ridge, IL

9:45 am – 10:30 am Vestibular Tests and Diagnosis Marcello Cherchi, MD, PhD, Assistant Professor of Neurology, Northwestern University, Chicago

10:30 am – 11:00 am Benign Paroxysmal Positional Vertigo (BPPV) Miriam Redleaf, MD, Chief of Otology/ Neurotology/ Skull Base Surgery Services, University of Illinois, Chicago

1:00 pm – 1:30 pm Meniere’s Disease Richard Wiet, MD, Ear Institute of Chicago, Professor of Clinical Otolaryngology & Neurosurgery, Northwestern University Medical School, Chicago

1:30 pm – 2:00 pm Migraine-Associated Vertigo Robert Battista, MD, Ear Insitute of Chicago, Assistant Professor in Clinical Otolaryngology at Northwestern University, Chicago

2:15 pm – 2:45 p Vestibular Physical Therapy Janet Helminski, PhD, PT, Vestibular Therapist, Professor of Physical Therapy, Midwestern University, Downers Grove, IL

2:45 pm – 3:15 pm Intra-Tympanic Therapy Alan Micco, MD, Associate Professor of Otolaryngology and Neurological Surgery, Northwestern Medical Faculty Foundation, Chicago

3:15 pm – 3:45 pm Future Therapies- gene/stem cells/implants Hinrich Staecker, MD, PhD, Professor of Otolaryngology – Head & Neck Surgery, University of Kansas, Kansas City, MO

Goals and Objective • Understand the complexity of the vestibular

system and that dizziness can come from a number of different sources

• Recognize features of dizziness that come from ear-related disorders

• Recognize the association of dizziness with migraine

• Learn about new treatments and potential therapies

Balance System

www.resourcesonbalance.com

Descriptions of Dizziness • Vertigo

– Sensation of inappropriate movement – Spinning

• Disequilibrium / Imbalance – Unsteadiness; listing to one side – Drunk feeling

• Lightheadedness / Giddiness – Woozy, disorientation, feeling “off” – Faint

Descriptions of Dizziness

• Acute • Chronic • Wax and wane • Episodic

– Seconds – Minutes – Hours – Days

• Spontaneous • Provoked

– Position change – Visual stimuli – Foods – Stress – Sound / pressure

The Vestibular System

Anatomy

The Vestibular System Inner Ear

The Vestibular System Fluid Filled Compartments

Hearing Balance

Semicircular Canals Angular Acceleration

Otolith Organs Linear Acceleration

Ross et al, Histology, 1995

The Vestibular System Passing Information to the Brain

www.resourcesonbalance.com

The Vestibular System

Functions

Vestibular System Sense of Movement

• Linear acceleration • up/down; front/back; left/right (i.e., elevator,

airport conveyor)

• Angular acceleration: • Pitch: head shake “yes” • Yaw: head shake “no” • Roll: head shake “na-na-nah-nah-nah-nah”

• Sends this information to the brain, eyes, neck, spine, extremities, etc.

Central Integration

• Both ears send signals to the brain

• The brain compares both sides and determines plane, speed and degree of movement

• The brain tells the eyes how to adjust

Balance = Balance

Put in slide with brain in the middle of a see-saw. The inner ears are on either side

baseline

high

low

Activity

Sensing Motion: Comparing signals

Slide showing turning head to one side with the see saw going up on the activated side and down on the other

omparing

Vestibular Ocular Reflex VOR

• Most important vestibular reflex • Maintains eye position during motion • Extremely fast responses • Disturbances are demonstrated by eye

examination • Eye movements that are inappropriate

cause sensations of dizziness

Loss of VOR on Left Side

Zee and Minor, 2002

Vestibular Physiology

Laws to Live By

Ewald’s First Law

Stimulation of a semicircular canal generates eye movements in the plane of that canal

L. Minor, 2001

Eye Movements Evoked by Stimulation of Individual Semicircular Canals

Nystagmus • Opposite the direction evoked by canal

excitation • Corrective mechanism

– Rapidly bring eyes back to where they belong

• Named for the fast direction of motion – Left / right; up / down – Rotary: clockwise / counterclockwise

Nystagmus Directions

Nystagmus

nystagmus

Dizziness – Ear Disease • Ear diseases

– can cause • Inappropriate signals from the

semicircular canals – which causes

• Inappropriate eye movements – which causes

• A sensation of dizziness

Dizziness – Non Ear Disease • Other diseases

– do not cause • Inappropriate signals from a

semicircular canal – so they do not cause

• Inappropriate eye movements – but there can be

• A sensation of dizziness

Ear vs. Non-Ear

• Clinical examination • Vestibular Testing • Ear Diseases

– BPPV – Meniere’s Disease

• Non Ear Disease – Migraine

8:30 am – 9:00 am Introduction to Dizziness and the Vestibular System David Friedland, MD, PhD, Professor & Vice-Chair of Otolaryngology & Communication Sciences, Medical College of Wisconsin, Milwaukee.

9:00 am – 9:30 am Clinical Exam for Dizziness Dennis Moore, MD, Otolaryngologist at Lutheran General Hospital, Park Ridge, IL

9:45 am – 10:30 am Vestibular Tests and Diagnosis Marcello Cherchi, MD, PhD, Assistant Professor of Neurology, Northwestern University, Chicago

10:30 am – 11:00 am Benign Paroxysmal Positional Vertigo (BPPV) Miriam Redleaf, MD, Chief of Otology/ Neurotology/ Skull Base Surgery Services, University of Illinois, Chicago

1:00 pm – 1:30 pm Meniere’s Disease Richard Wiet, MD, Ear Institute of Chicago, Professor of Clinical Otolaryngology & Neurosurgery, Northwestern University Medical School, Chicago

1:30 pm – 2:00 pm Migraine-Associated Vertigo Robert Battista, MD, Ear Insitute of Chicago, Assistant Professor in Clinical Otolaryngology at Northwestern University, Chicago

2:15 pm – 2:45 p Vestibular Physical Therapy Janet Helminski, PhD, PT, Vestibular Therapist, Professor of Physical Therapy, Midwestern University, Downers Grove, IL

2:45 pm – 3:15 pm Intra-Tympanic Therapy Alan Micco, MD, Associate Professor of Otolaryngology and Neurological Surgery, Northwestern Medical Faculty Foundation, Chicago

3:15 pm – 3:45 pm Future Therapies- gene/stem cells/implants Hinrich Staecker, MD, PhD, Professor of Otolaryngology – Head & Neck Surgery, University of Kansas, Kansas City, MO