Benign Paroxysmal Positioning Vertigo (BPPV) Tracy Murphy, Au.D.

Role of the Audiologist in the diagnosis and treatment of the dizzy patient

Perspective Many disciplines address some functional aspects of balance Otolaryngology Audiology Neurology Cardiology Physical / occupational therapy Ophthalmology Psychology/Psychiatry

No single discipline can claim exclusive control over the domain of dizziness

Broad perspective – multidisciplinary approach Understand cause and effect relationships as they pertain to dizziness and balance Be more than a technician – 3 sources of knowledge Patient experience Survey signs and symptoms Knowledge of the discipline

Diagnostic Acumen All three knowledge sources are critical in order to come up with the correct diagnosis Test data must be placed into the context of each specific case to determine its significance

Audiologists have so much to offer…

BPPV

Introduction BPPV is a common cause of dizziness BPPV is the most common cause of dizziness in the elderly Approximately 50% of people over the age of 65 will experience BPPV Characterized by short episodes of dizziness associated with changes in head position

Anatomy Overview

Anatomy Overview Semicircular Canals The vestibular labyrinth consists of three fluid-filled semicircular canals oriented at 90° to each other, representing all three planes of space Herdman & Tusa, 2004

Anatomy Overview Ampulla – dilated end of each canal that houses a mound of hair cells called the cristae ampullaris The hair cells of the crista ampullaris project into the cupula, a gelatinous structure that seals the semicircular canal and is displaced with angular acceleration of the head

Anatomy Overview Jacobson, et. al., 1997 Angular head movements cause movement of the endolymph within the semicircular canals, placing pressure on the cupula Hair cells embedded in the cupula send excitatory or inhibitory signals depending on the direction of the fluid displacement

Ampullopetal vs. ampullofugal displacement Anatomy Overview Ampullopetal vs. ampullofugal displacement

Anatomy Overview Utricle and Saccule Linear accelerometers oriented vertically (saccule) and horizontally (utricle) in the vestibule of the labyrinth Hair cells are embedded in the maculae and covered with the otolithic membrane

Central Vestibular System Information from the hair cells in the semicircular canals is sent to the vestibular nuclei Second order neurons transmit signals through the medial longitudinal fasciculus to the third, fourth, and sixth oculomotor nuclei

Central Vestibular System Third order neurons innervate the extraocular muscles The muscles are responsible for making eye movements equal to and opposite head movement Basis for the vestibuloocular reflex (VOR) Herdman & Tusa, 2004

Mechanisms underlying BPPV Dislodged otoconia from the utricle settle in a semicircular canal causing overexcitability with angular head movements How do the otoconia become dislodged?

Causes of BPPV Primary or idiopathic BPPV Head trauma Vestibular neuritis Viral labyrinthitis History of inner ear pathology History of otologic surgery Migraines

Mechanisms underlying BPPV Canalithiasis vs. Cupulolithiasis

Mechanisms underlying BPPV Herdman & Tusa, 2004 Canalithiasis Delayed onset Short duration Symptoms coincide with nystagmus

Mechanisms underlying BPPV Cupulolithiasis Typically not delayed onset Long duration Symptoms may stop Herdman & Tusa, 2004

Posterior Canal BPPV Characterized by brief attacks of rotary nystagmus caused by head movements Rolling over in bed Looking up/down Bending forward Sitting up Lying down Turning quickly

Posterior Canal BPPV Most common variant Position relative to vestibule Canalithiasis more predominant Diagnosed using the Dix-Hallpike Maneuver Best seen with Frenzel lenses or Videonystagmography

Posterior Canal BPPV Typically, the nystagmus beats toward the undermost (affected) ear As seen by the investigator Abnormal Dix-Hallpike maneuver to the right will result in nystagmus with a counter-clockwise fast phase Abnormal Dix-Hallpike maneuver to the left will result in nystagmus with a clockwise fast phase

Posterior Canal BPPV Diagnostic criteria Latency Duration Linear-rotary nystagmus Reversal Fatigability

Anterior Canal BPPV Least common variant – 1-2% Diagnosed using Dix-Hallpike Maneuver Characterized by downbeat rotary nystagmus Can be provoked from the opposite ear to the side of the Dix-Hallpike maneuver Can be provoked from the Dix-Hallpike maneuver from either side or head-hanging back position Due to orientation of anterior limb of the anterior canal (near saggital plane) Will typically beat toward the affected ear

Horizontal Canal BPPV Approximately 3-12% of individuals with paroxysmal positioning vertigo Diagnosed by positional test or Roll test

Horizontal Canal BPPV Characterized by short latency horizontal nystagmus that is provoked by bilateral head turns Prolonged duration and poor fatigability Nystagmus can be seen in both lateral right and lateral left positions Geotropic nystagmus - “bad” ear typically has the strongest response Ageotropic nystagmus – “bad” ear typically has the weaker response (inhibitory response)

Horizontal Canal BPPV Nystagmus can be geotropic or ageotropic Geotropic – canalithiasis Otoconia move freely in the canal to the lowest position (toward the ampulla) causing an excitatory response with the affected ear down

Horizontal Canal BPPV Ageotropic – cupulolithiasis Otoconia are adherent to the cupula causing gravity sensitivity and an inhibitory response with the affected ear down Nystagmus will beat toward the uppermost ear

Right Horizontal SCC Herdman & Tusa, 2004

Mixed Canal BPPV BPPV can affect more than one semicircular canal resulting in varying patterns of nystagmus Posterior and horizontal canals most common Simultaneous posterior and horizontal canal BPPV

CASE STUDIES

HB 41 year old female Three month hx of dizziness when tilting head to the right Dizziness lasts approximately 5 seconds occurs with turning head to right, tilting head, getting up quickly Pt. has 2 bulging discs in neck

HB Physical exam Audiologic evaluation Prior MRI

HB – Head-Hanging Right

HB – HHR repeat

HB – Post Treatment

MP 51 year old female Fell off bicycle – loss of consciousness Helmet cracked – fractured L temporal bone, shoulder, and ribs L inner ear structures appeared normal Small intracerebral bleed

MP Complains of mild vertigo when leaning backward or lying down Dizziness passes quickly Muffled hearing on left side Pt. had blood in left ear canal, middle ear, and mastoid Treated with prednisone

MP L middle ear clear, but hearing still muffled 1 month later L middle ear clear, but hearing still muffled Persistent vertigo – lasts for seconds Audiogram showed improvement in L hearing VNG ordered

MP – Head-Hanging Right

MP – Head Hanging Left

MP – HHR repeat

MP – Post Treatment

MP – Post Treatment Two days later – c/o different form of dizziness Patient denied any side-lying Dizziness ranges from 5 to 8 on scale of 1 to 10 Four days post treatment

SM 56 year-old male Complains of intermittent dizziness Left Dix-Hallpike Maneuver Downward and leftward torsional nystagmus after 5 seconds Right Dix-Hallpike Maneuver Upward and rightward torsional nystagmus with severe vertigo When returned upright nystagmus changed to downbeat torsional

SM Involvement of right posterior and left anterior semicircular canals? Central lesion?

Summary BPPV is easy to diagnose and treat Take an active role in the diagnosis and treatment of dizziness Know your limitations Multidisciplinary approach

References Goebel J. (Ed.) (2001) Practical Management of the Dizzy Patient. Philadelphia: Lippincott Williams & Wilkins. Hain, T. (2007) Anterior Canal BPPV. http://www.dizziness-and-balance.com/disorders/bppv/anteriorbppv.htm Herdman SJ, Tusa RJ. (2004) Diagnosis and Treatment of Benign Paroxysmal Positional Vertigo, Schaumburg: GN Otometrics. Jacobson G, Newman C, Kartush J. (Ed.) (1997) Handbook of Balance Function Testing. San Diego: Singular Publishing Group, Inc. Parnes L, Agrawal S, Atlas, J. (2003) Diagnosis and management of benign paroxysmal positional vertigo (BPPV). CMAJ, 169 (7), 681-693. http://www.cmaj.ca/cgi/content/full/169/7/681#F716