May 23, 2026 PDF Available

Topic Overview

DISORDERS OF VESTIBULAR SYSTEM

INTRODUCTION

Definition

Vestibular disorders are conditions affecting the peripheral or central balance system, producing symptoms such as:

Vertigo
Imbalance
Motion intolerance
Oscillopsia
Gait instability

These disorders may involve:

Labyrinth
Vestibular nerve
Brainstem vestibular pathways
Cerebellum
Vestibular cortex

Anatomy Relevant to Vestibular Disorders

Peripheral Vestibular System

Includes:

Semicircular canals
Utricle
Saccule
Vestibular nerve

Functions

Structure	Function
Semicircular canals	Angular acceleration
Utricle	Horizontal linear acceleration
Saccule	Vertical acceleration

Central Vestibular System

Includes:

Vestibular nuclei
Cerebellum
Medial longitudinal fasciculus
Vestibular cortex

Functions

Coordination of balance
Eye movement control
Postural stability

Physiology Relevant to Vertigo

Mechanism of Vertigo

Vertigo occurs due to imbalance of vestibular tone between both labyrinths.

Examples

Vestibulo-Ocular Reflex

Maintains stable vision during head movement.

Vestibulospinal Reflex

Maintains posture and equilibrium.

DEFINITIONS

Vertigo

False sensation of movement of self or surroundings.

Dizziness

Non-specific feeling of disturbed spatial orientation.

Disequilibrium

Sense of imbalance without illusion of movement.

Presyncope

Feeling of impending faintness.

Commonly cardiovascular in origin.

Oscillopsia

Illusion that surroundings are moving or bouncing.

Usually seen in:

Bilateral vestibular loss

APPROACH TO A PATIENT WITH VERTIGO

History Taking

Duration

Duration	Common Causes
Seconds	BPPV
Minutes	TIA
Hours	Ménière disease
Days	Vestibular neuritis

Triggering Factors

Position change
Head movement
Loud sound
Stress
Motion

Hearing Symptoms

Suggest peripheral inner-ear disease:

Hearing loss
Tinnitus
Ear fullness

Neurological Symptoms

Suggest central pathology:

Diplopia
Dysarthria
Limb weakness
Ataxia
Sensory symptoms

Positional Symptoms

Seen in:

BPPV
Central positional vertigo

Clinical Examination

Nystagmus

Observe:

Direction
Fatigability
Suppression by fixation

Cerebellar Signs

Dysmetria
Intention tremor
Ataxia
Dysdiadochokinesia

Gait Abnormalities

Gait	Suggests
Veering gait	Vestibular lesion
Broad-based gait	Cerebellar lesion

Vestibular Bedside Tests

Romberg test
HIT
Dix-Hallpike test
Fukuda stepping test
Test of skew

CLASSIFICATION OF VESTIBULAR DISORDERS

Peripheral Vestibular Disorders

Benign Paroxysmal Positional Vertigo (BPPV)

Most common cause of peripheral vertigo.

Ménière Disease

Endolymphatic hydrops causing episodic vertigo with hearing symptoms.

Vestibular Neuritis

Acute unilateral vestibular inflammation without hearing loss.

Labyrinthitis

Inflammation involving vestibular apparatus with hearing loss.

Perilymph Fistula

Abnormal communication between inner and middle ear.

Vestibular Schwannoma

Benign tumor of vestibular nerve.

Ototoxicity

Vestibular damage caused by drugs.

Bilateral Vestibulopathy

Bilateral vestibular hypofunction causing oscillopsia and imbalance.

Central Vestibular Disorders

Cerebellar Stroke

May mimic vestibular neuritis.

Brainstem Stroke

Produces central vertigo with neurological deficits.

Multiple Sclerosis

Demyelinating lesions involving vestibular pathways.

Vestibular Migraine

Common episodic vertigo disorder associated with migraine.

Posterior Fossa Tumors

May compress vestibular pathways.

Syndromic Classification

Acute Vestibular Syndrome (AVS)

Acute prolonged vertigo lasting days with:

Nausea
Vomiting
Nystagmus
Gait instability

Causes

Vestibular neuritis
Cerebellar stroke

Episodic Vestibular Syndrome

Recurrent attacks separated by symptom-free intervals.

Causes

BPPV
Ménière disease
Vestibular migraine

Chronic Vestibular Syndrome

Persistent dizziness and imbalance.

Causes

Bilateral vestibulopathy
Cerebellar degeneration
PPPD

BENIGN PAROXYSMAL POSITIONAL VERTIGO (BPPV)

Definition

Disorder caused by displaced otoconia within semicircular canals producing brief positional vertigo.

Etiology

Idiopathic

Most common.

Secondary Causes

Head trauma
Vestibular neuritis
Ménière disease
Post-surgical
Prolonged bed rest

Pathophysiology

Canalithiasis

Free-floating otoconia within semicircular canal.

Most common mechanism.

Cupulolithiasis

Otoconia attached to cupula causing prolonged symptoms.

Types of BPPV

Type	Most Common Canal
Posterior canal BPPV	Most common
Horizontal canal BPPV	Second most common
Anterior canal BPPV	Rare

Posterior Canal BPPV

Most common due to gravity-dependent position of canal.

Horizontal Canal BPPV

Produces horizontal positional nystagmus.

Anterior Canal BPPV

Rare; may produce downbeat torsional nystagmus.

Secondary BPPV

Occurs secondary to:

Trauma
Inner-ear disease
Surgery

Post-Traumatic BPPV

Often:

Bilateral
Recurrent
Resistant to treatment

Central Positional Vertigo

Causes

Cerebellar lesions
Brainstem lesions
Multiple sclerosis

Features Suggesting Central Cause

Feature	Central
Latency	Absent
Fatigability	Absent
Neurological signs	Present

Clinical Features

Symptoms

Brief positional vertigo
Triggered by turning in bed
Looking upward
Bending forward

Duration

Usually less than 1 minute.

Hearing

Usually normal.

Diagnosis

Dix-Hallpike Test

Diagnostic for posterior canal BPPV.

Positive Findings

Torsional upbeat nystagmus
Latency
Fatigability

Roll Test

Used for horizontal canal BPPV.

Differential Diagnosis

Disease	Distinguishing Feature
Ménière disease	Hearing loss/tinnitus
Vestibular migraine	Migraine history
Central positional vertigo	Neurological signs

Treatment

Epley Maneuver

Principle

Canalith repositioning maneuver moving otoconia back into utricle.

Used For

Posterior canal BPPV.

Semont Maneuver

Liberatory maneuver mainly for cupulolithiasis.

Brandt-Daroff Exercises

Home habituation exercises.

Barbecue Maneuver

Used for horizontal canal BPPV.

Complications

Falls
Anxiety
Recurrence

Recurrence

Common after successful treatment.

Recurrence Predictors

Advanced age
Trauma
Ménière disease
Migraine
Osteoporosis

MÉNIÈRE DISEASE

Definition

Disorder characterized by episodic vertigo, fluctuating SNHL, tinnitus, and aural fullness due to endolymphatic hydrops.

Etiopathogenesis

Endolymphatic Hydrops

Excess endolymph accumulation causing distension of membranous labyrinth.

Pathogenesis

Possible mechanisms:

Impaired endolymph absorption
Autoimmune factors
Viral infection
Genetic predisposition

AAO-HNS Diagnostic Criteria

Definite Ménière Disease

≥2 spontaneous vertigo episodes lasting 20 min–12 hr
Audiometrically documented SNHL
Fluctuating aural symptoms
No better alternative diagnosis

Clinical Features

Episodic Vertigo

Severe spinning sensation lasting minutes to hours.

Fluctuating SNHL

Initially low-frequency sensorineural hearing loss.

Tinnitus

Usually roaring tinnitus.

Aural Fullness

Feeling of pressure in affected ear.

Tumarkin Otolithic Crisis

Definition

Sudden falls without loss of consciousness due to otolithic dysfunction.

Drop Attacks

Sudden collapse episodes due to vestibular dysfunction.

Types

Cochlear Ménière Disease

Predominantly hearing symptoms.

Vestibular Ménière Disease

Predominantly vestibular symptoms.

Bilateral Ménière Disease

Both ears affected.

Staging

Stage	Hearing Status
Early	Fluctuating low-frequency SNHL
Intermediate	Progressive hearing loss
Late	Permanent severe SNHL

Investigations

Audiometry

Shows:

Fluctuating SNHL
Low-frequency loss initially

Electrocochleography

Shows elevated SP/AP ratio.

VEMP

May show abnormal otolith function.

Treatment

Medical Treatment

Salt Restriction

Low sodium diet reduces endolymphatic pressure.

Diuretics

Examples:

Hydrochlorothiazide
Acetazolamide

Betahistine

Improves labyrinthine microcirculation.

Vestibular Suppressants

Used during acute attacks:

Prochlorperazine
Diazepam
Meclizine

Intratympanic Therapy

Steroids

Reduce inflammation and preserve hearing.

Gentamicin

Chemical labyrinthectomy causing vestibular ablation.

Risk

Hearing loss.

Surgical Treatment

Endolymphatic Sac Surgery

Decompression/shunt procedure.

Vestibular Nerve Section

Preserves hearing while abolishing vertigo.

Labyrinthectomy

Complete destruction of labyrinth.

Indication

Non-serviceable hearing.

VESTIBULAR NEURITIS

Definition

Acute unilateral vestibular dysfunction due to inflammation of vestibular nerve without hearing loss.

Etiology

Viral Causes

Most common etiology.

Common viruses:

HSV
Influenza
EBV
CMV

HSV Association

HSV type 1 reactivation suspected in vestibular ganglion.

Types

Superior Vestibular Neuritis

Most common.

Involves:

Horizontal canal
Superior canal
Utricle

Inferior Vestibular Neuritis

Less common.

Involves:

Posterior canal
Saccule

Pathophysiology

Inflammation causes:

Sudden unilateral vestibular hypofunction
Vestibular asymmetry
Spontaneous nystagmus

Clinical Features

Symptoms

Acute severe vertigo
Nausea
Vomiting
Imbalance

Duration

Days to weeks.

Hearing

Usually normal.

Examination Findings

Finding	Result
Spontaneous nystagmus	Away from lesion
HIT	Positive
Caloric test	Canal paresis

Diagnosis

Clinical Diagnosis

Based on:

Acute vestibular syndrome
No hearing loss
Positive HIT

HINTS Examination

Component	Vestibular Neuritis
HIT	Abnormal
Nystagmus	Unidirectional
Skew	Negative

Treatment

Steroids

Improve vestibular recovery if given early.

Example:

Prednisolone

Vestibular Rehabilitation

Promotes central compensation.

Symptomatic Treatment

Antiemetics
Vestibular suppressants

Used only short term.

Chronic Uncompensated Vestibulopathy

Definition

Persistent imbalance after vestibular neuritis due to poor central compensation.

Causes

Sedentary lifestyle
Prolonged vestibular suppressant use
Anxiety
Bilateral vestibular loss

Treatment

Intensive vestibular rehabilitation
Avoid long-term vestibular suppressants

LABYRINTHITIS

Definition

Labyrinthitis is inflammation of the membranous labyrinth involving:

Cochlea
Vestibular apparatus

It produces:

Vertigo
Hearing loss
Nystagmus

Unlike vestibular neuritis, hearing is affected.

Types of Labyrinthitis

Serous Labyrinthitis

Definition

Toxic inflammatory reaction of labyrinth without bacterial invasion.

Mechanism

Bacterial toxins diffuse into inner ear from adjacent infection.

Features

Mild vertigo
Mild SNHL
Potentially reversible

Suppurative Labyrinthitis

Definition

Bacterial invasion of labyrinth causing destructive inflammation.

Features

Severe vertigo
Severe SNHL
Often irreversible

Tympanogenic Labyrinthitis

Definition

Spread of infection from middle ear/mastoid to labyrinth.

Common Cause

Cholesteatoma
Chronic otitis media

Meningogenic Labyrinthitis

Definition

Spread of infection from meningitis to labyrinth.

Common in Children

Especially:

Pneumococcal meningitis

Hematogenous Labyrinthitis

Definition

Spread of infection through bloodstream.

Causes

Septicemia
Viral infections

Etiology

Otitis Media

Most common cause.

Routes of Spread

Oval window
Round window
Bony erosion

Meningitis

Can spread through:

Cochlear aqueduct
Internal auditory canal

Other Causes

Trauma
Viral infection
Cholesteatoma
Syphilis
Tuberculosis

Clinical Features

Vertigo

Usually severe.

Hearing Loss

Sensorineural
Often profound in suppurative labyrinthitis

Nausea and Vomiting

Marked in acute stage.

Nystagmus

Early Stage

Irritative nystagmus toward affected side.

Late Stage

Paretic nystagmus away from affected side.

Tinnitus

Common.

Fever and Ear Discharge

May occur with associated middle-ear infection.

Investigations

Audiometry

Shows SNHL.

Caloric Testing

Reduced or absent vestibular response.

CT Temporal Bone

Detects:

Cholesteatoma
Bony erosion
Labyrinthine fistula

MRI

Useful for:

Labyrinth enhancement
Intracranial complications

Laboratory Tests

CBC
ESR
Blood culture
CSF analysis if meningitis suspected

Complications

Deafness

May become permanent.

Intracranial Spread

Includes:

Meningitis
Brain abscess
Lateral sinus thrombosis

Other Complications

Labyrinthine ossification
Chronic imbalance
Facial nerve palsy

Treatment

Medical Treatment

Antibiotics

Broad-spectrum IV antibiotics.

Examples:

Ceftriaxone
Vancomycin

Vestibular Suppressants

Used short term only.

Antiemetics

Control nausea and vomiting.

Surgical Treatment

Mastoid Surgery

Indicated if:

Cholesteatoma
Mastoiditis
Persistent infection

Drainage Procedures

For intracranial complications.

Labyrinthectomy

Rarely required in uncontrolled suppurative disease.

ACUTE LABYRINTHINE FAILURE

Definition

Sudden loss of vestibular function due to acute labyrinthine damage.

Etiology

Viral Labyrinthitis

Most common.

Vascular Insult

Labyrinthine artery ischemia.

Trauma

Temporal bone fracture
Surgical trauma

Ototoxicity

Especially aminoglycosides.

Clinical Features

Sudden Severe Vertigo

Acute onset.

Nausea and Vomiting

Usually severe.

Imbalance

Marked gait instability.

Nystagmus

Typically away from lesion.

Hearing Loss

May or may not occur depending on cochlear involvement.

Management

Acute Symptomatic Treatment

Vestibular suppressants
Antiemetics
Hydration

Steroids

May improve recovery in inflammatory causes.

Vestibular Rehabilitation

Promotes compensation.

Treat Underlying Cause

Antibiotics
Vascular management
Stop ototoxic drugs

VESTIBULAR MIGRAINE

Definition

Episodic vestibular symptoms associated with migraine mechanisms.

One of the most common causes of recurrent spontaneous vertigo.

International Headache Society Criteria

Diagnostic Criteria

At least 5 episodes of vestibular symptoms
Duration 5 min–72 hr
Current or previous migraine history
Migraine features during at least 50% of episodes

Migraine Features

Headache
Photophobia
Phonophobia
Visual aura

Clinical Features

Episodic Vertigo

Can be:

Spontaneous
Positional
Motion induced

Associated Migraine Symptoms

Headache
Photophobia
Aura
Motion sickness

Hearing

Usually normal or mildly fluctuating.

Vestibular Findings

Often normal between attacks.

Migraine Equivalents

Includes:

Motion sickness
Benign paroxysmal vertigo of childhood
Cyclic vomiting

Pediatric Vestibular Migraine

Common Pediatric Cause of Vertigo

Features

Episodic imbalance
Motion sensitivity
Migraine family history

Differential Diagnosis

Disease	Differentiating Feature
Ménière disease	Hearing loss/tinnitus
BPPV	Brief positional attacks
TIA	Vascular risk factors

Treatment

Lifestyle Modification

Sleep regulation
Trigger avoidance
Stress reduction

Acute Treatment

NSAIDs
Triptans
Antiemetics

Prophylactic Treatment

Drugs

Propranolol
Flunarizine
Amitriptyline
Topiramate

Vestibular Rehabilitation

Helpful in chronic imbalance.

PERILYMPH FISTULA

Definition

Abnormal communication between perilymphatic space and middle ear causing leakage of perilymph.

Etiology

Trauma

Head injury
Temporal bone fracture

Surgery

Especially:

Stapes surgery
Cochlear implantation

Barotrauma

Diving
Flying
Explosive pressure change

Hennebert Sign

Pressure-induced vertigo or nystagmus.

Third Window Lesions

Abnormal bony opening causing altered labyrinthine fluid dynamics.

Examples:

Superior canal dehiscence

Clinical Features

Sudden Vertigo

Often worsened by:

Straining
Sneezing
Loud sound

Hearing Loss

Usually SNHL.

Tinnitus

Common.

Aural Fullness

May occur.

Fistula Test

Positive Test

Pressure changes induce:

Vertigo
Nystagmus

Diagnosis

Clinical Suspicion

Important because no single definitive test exists.

Audiometry

May show SNHL.

VEMP

May suggest third-window physiology.

CT Temporal Bone

May identify:

Dehiscence
Fracture

Exploratory Tympanotomy

Sometimes diagnostic and therapeutic.

Treatment

Conservative Treatment

Bed rest
Avoid straining
Stool softeners

Surgical Repair

Patch or grafting of oval/round window.

SUPERIOR SEMICIRCULAR CANAL DEHISCENCE (SSCD)

Definition

Absence/thinning of bone over superior semicircular canal producing third-window phenomenon.

Pathophysiology

Third Window Effect

Abnormal opening alters transmission of sound and pressure waves within labyrinth.

Clinical Features

Tullio Phenomenon

Sound-induced vertigo/nystagmus.

Autophony

Abnormally loud perception of:

Own voice
Eye movements
Footsteps

Other Symptoms

Pressure-induced vertigo
Conductive hyperacusis
Oscillopsia

Investigations

VEMP

Typically shows:

Low threshold
High amplitude response

HRCT Temporal Bone

Best imaging test.

Findings

Bony defect over superior canal

Treatment

Conservative

Avoid triggers if symptoms mild.

Surgical

Canal plugging
Resurfacing surgery

VESTIBULAR SCHWANNOMA

Definition

Benign tumor arising from Schwann cells of vestibular nerve.

Most commonly from:

Inferior vestibular nerve

Also called:

Acoustic neuroma

Etiology

Sporadic

Most common.

Neurofibromatosis Type 2

Often bilateral.

Pathology

Histology

Antoni A areas
Antoni B areas
Verocay bodies

Growth Pattern

Slow-growing CPA tumor.

Clinical Features

Hearing Loss

Most common symptom.

Type

Unilateral progressive SNHL

Tinnitus

Usually unilateral.

Imbalance

More common than true vertigo.

Large Tumors May Cause

Cerebellar signs
Trigeminal symptoms
Raised ICP
Facial nerve weakness

Investigations

MRI with Gadolinium

Gold Standard Investigation

Findings

Enhancing CPA/internal auditory canal mass.

MRI Internal Auditory Canal

Detects small intracanalicular tumors.

Audiometry

Asymmetric SNHL.

ABR (Auditory Brainstem Response)

May show delayed wave latency.

Vestibular Testing

Often shows unilateral vestibular weakness.

Treatment

Observation

Indications

Small tumors
Elderly patients
Minimal symptoms

Radiosurgery

Examples

Gamma knife
Cyberknife

Indications

Small/moderate tumors
Poor surgical candidates

Microsurgery

Approaches

Approach	Hearing Preservation
Retrosigmoid	Possible
Middle cranial fossa	Good for small tumors
Translabyrinthine	Hearing sacrificed

Complications of Surgery

Facial nerve palsy
CSF leak
Hearing loss
Meningitis

BILATERAL VESTIBULOPATHY

Definition

Bilateral vestibulopathy is bilateral reduction or loss of vestibular function causing:

Imbalance
Oscillopsia
Gait instability

It results from failure of vestibulo-ocular and vestibulospinal reflexes on both sides.

Etiology

Ototoxicity

Most common cause.

Important Drugs

Gentamicin
Streptomycin
Cisplatin

Autoimmune Disease

Examples:

Cogan syndrome
Autoimmune inner-ear disease

Other Causes

Bilateral Ménière Disease

Can produce progressive vestibular loss.

Meningitis

Especially with labyrinthitis.

Bilateral Vestibular Neuritis

Rare.

Neurodegenerative Disorders

Examples:

CANVAS syndrome
Cerebellar degeneration

Idiopathic

Cause not identified in many patients.

Clinical Features

Oscillopsia

Definition

Illusion that surroundings move or bounce during head movement.

Mechanism

Failure of vestibulo-ocular reflex.

Typical Complaint

“Objects jump while walking.”

Imbalance

Features

Unsteady gait
Worse in darkness
Difficulty walking on uneven ground

Visual Dependence

Patients rely heavily on vision for balance.

Falls

Especially:

Elderly patients
Low-light conditions

Vertigo

Usually absent or mild because vestibular loss is symmetrical.

Examination Findings

Finding	Result
HIT	Bilaterally positive
Dynamic visual acuity	Reduced
Romberg	Worse with eyes closed
Gait	Broad based

Diagnosis

Clinical Suspicion

Important in patients with:

Oscillopsia
Bilateral imbalance
Ototoxic drug history

Caloric Testing

Shows:

Bilateral reduced or absent responses

Video Head Impulse Test (vHIT)

Shows:

Bilateral reduced VOR gain
Corrective saccades

Dynamic Visual Acuity Test

Reduced visual acuity during head movement.

Rotational Chair Testing

Useful for:

Quantifying bilateral vestibular loss

VEMP

May show reduced otolith responses.

Treatment

Vestibular Rehabilitation

Mainstay of Treatment

Improves:

Balance
Gait
Visual stabilization

Gaze Stabilization Exercises

Improve adaptation and substitution.

Examples:

VOR x1 exercises
VOR x2 exercises

Fall Prevention

Walking aids
Home safety modification
Night lighting

Treat Underlying Cause

Stop ototoxic drugs
Treat autoimmune disease

Prognosis

Recovery depends on:

Degree of vestibular loss
Central compensation
Rehabilitation compliance

OTOTOXIC VESTIBULAR DISORDERS

Definition

Vestibular dysfunction caused by toxic injury to vestibular sensory epithelium or vestibular nerve due to drugs or chemicals.

Vestibulotoxic vs Cochleotoxic Drugs

Feature	Vestibulotoxic Drugs	Cochleotoxic Drugs
Main damage	Vestibular apparatus	Cochlea
Main symptom	Imbalance/oscillopsia	Hearing loss/tinnitus
Example	Gentamicin	Amikacin
Vertigo	Usually absent	Usually absent

Ototoxic Drugs

Aminoglycosides

Important Drugs

Drug	Main Toxicity
Gentamicin	Vestibulotoxic
Streptomycin	Vestibulotoxic
Amikacin	Cochleotoxic
Neomycin	Cochleotoxic

Cisplatin

Features

Mainly cochleotoxic
Can also affect vestibular system

Loop Diuretics

Drugs

Furosemide
Ethacrynic acid

Features

Usually reversible toxicity.

Other Vestibulotoxic Drugs

Vancomycin
Salicylates
Antimalarials
Alcohol

Gentamicin Vestibulotoxicity

Features

Most important cause of bilateral vestibular loss.

Mechanism

Damages:

Type I hair cells
Crista ampullaris
Vestibular dark cells

Clinical Features

Oscillopsia
Gait imbalance
Worse in darkness
No severe vertigo usually

Risk Factors

Renal failure
Prolonged therapy
High cumulative dose
Elderly age
Concurrent ototoxic drugs

Monitoring Protocols

Clinical Monitoring

Assess:

Imbalance
Oscillopsia
Gait difficulty

Audiovestibular Monitoring

Pure tone audiometry
vHIT
Caloric testing
Dynamic visual acuity
VEMP

Drug Level Monitoring

Monitor:

Peak levels
Trough levels

Especially important in:

Renal disease
ICU patients

Pathophysiology

Hair Cell Damage

Reactive oxygen species cause:

Hair cell apoptosis
Loss of stereocilia

Vestibular Structures Affected

Crista ampullaris
Maculae
Vestibular nerve endings

Permanent Damage

Hair-cell regeneration in humans is poor.

Clinical Features

Imbalance

Most common complaint.

Oscillopsia

Occurs during walking/head movement.

Difficulty Walking in Dark

Due to dependence on visual cues.

Falls

Common in elderly.

Vertigo

Often absent because damage is bilateral and symmetrical.

Hearing Loss

May coexist depending on drug.

Examination Findings

Test	Finding
HIT	Bilaterally positive
Caloric test	Bilateral weakness
vHIT	Reduced gain
Dynamic visual acuity	Reduced

Prevention

Avoid Unnecessary Ototoxic Drugs

Use only when essential.

Dose Adjustment

Especially in:

Renal impairment
Elderly patients

Therapeutic Drug Monitoring

Maintains safe serum levels.

Avoid Combination Therapy

Avoid multiple ototoxic agents together when possible.

Early Detection

Regular vestibular and audiological assessment.

Treatment

Stop Offending Drug

Most important step.

Vestibular Rehabilitation

Main Treatment

Improves:

Adaptation
Substitution
Balance

Gaze Stabilization Exercises

Improve visual fixation during head movement.

Fall Prevention

Walking aids
Physiotherapy
Environmental modification

Prognosis

Vestibular hair-cell loss is often irreversible.

Early detection improves functional outcome.

HIGH-YIELD EXAM POINTS

Gentamicin is more vestibulotoxic than cochleotoxic.
Bilateral vestibular loss classically causes oscillopsia.
Severe vertigo is usually absent in bilateral vestibular failure.
Oscillopsia worsens during walking due to impaired VOR.
vHIT is highly useful in bilateral vestibulopathy.
Vestibular rehabilitation is the cornerstone of treatment.

CENTRAL VESTIBULAR DISORDERS

Definition

Central vestibular disorders are disorders involving:

Brainstem vestibular nuclei
Cerebellum
Central vestibular pathways
Vestibular cortex

They produce vertigo, imbalance, and ocular motor abnormalities due to CNS pathology.

Cerebellar Stroke

Definition

Infarction or hemorrhage involving cerebellum affecting vestibular pathways.

Important Arteries

Posterior inferior cerebellar artery (PICA)
Anterior inferior cerebellar artery (AICA)
Superior cerebellar artery (SCA)

Clinical Features

Vertigo

Often acute and severe.

Ataxia

Usually marked.

Nystagmus

Direction-changing
Vertical
Pure torsional

Other Features

Dysarthria
Limb incoordination
Severe gait instability
Headache
Vomiting

AICA Stroke

Important Features

Vertigo
Hearing loss
Facial weakness
Ataxia

Can mimic vestibular neuritis.

Brainstem Stroke

Definition

Stroke involving vestibular nuclei or brainstem pathways.

Clinical Features

Vertigo

Usually associated with neurological deficits.

Neurological Signs

Diplopia
Dysarthria
Dysphagia
Hemiparesis
Facial numbness

Nystagmus

Often:

Vertical
Direction-changing
Non-fatigable

Vertebrobasilar Insufficiency

Definition

Transient ischemia involving posterior circulation.

Risk Factors

Hypertension
Diabetes
Smoking
Atherosclerosis

Clinical Features

Recurrent vertigo
Diplopia
Dysarthria
Drop attacks
Visual disturbance

Multiple Sclerosis

Definition

Demyelinating CNS disease affecting vestibular pathways.

Clinical Features

Vertigo
Oscillopsia
Diplopia
Internuclear ophthalmoplegia

Eye Movement Abnormalities

Pendular nystagmus
Gaze-evoked nystagmus

MRI Findings

Demyelinating plaques in:

Brainstem
Cerebellum
Periventricular region

Chiari Malformation

Definition

Downward displacement of cerebellar tonsils through foramen magnum.

Clinical Features

Occipital headache
Vertigo
Downbeat nystagmus
Ataxia

Cerebellopontine Angle (CPA) Tumors

Common Tumors

Vestibular schwannoma
Meningioma
Epidermoid cyst

Clinical Features

Progressive imbalance
Hearing loss
Facial numbness
Cerebellar signs

Degenerative Cerebellar Disorders

Examples

Spinocerebellar ataxia
Multiple system atrophy
CANVAS syndrome

Clinical Features

Progressive imbalance
Ataxia
Gaze abnormalities
Dysarthria

Clinical Features of Central Vestibular Disorders

Feature	Central Vertigo
Vertigo	Often mild
Imbalance	Severe
Neurological deficits	Common
Nystagmus	Vertical/direction-changing
Hearing symptoms	Less common

Red Flag Signs

Features Suggesting Central Cause

Vertical nystagmus
Direction-changing nystagmus
Severe gait ataxia
Normal HIT in acute vestibular syndrome
Diplopia
Dysarthria
Limb weakness
Sensory deficits
Persistent vomiting
New headache

Investigations

MRI Brain

Gold Standard

Especially diffusion-weighted MRI for stroke.

MR Angiography

Evaluates posterior circulation.

CT Scan

Useful in hemorrhage.

Vestibular Testing

VNG
vHIT
Caloric testing

Audiometry

Helpful if AICA stroke suspected.

Laboratory Tests

Blood sugar
Lipid profile
Autoimmune markers
CSF examination if needed

Management

Treat Underlying Cause

Disease	Treatment
Stroke	Stroke protocol
MS	Steroids/immunotherapy
Tumor	Surgery/radiosurgery

Symptomatic Treatment

Antiemetics
Vestibular suppressants (short term only)

Vestibular Rehabilitation

Improves central compensation.

Risk Factor Control

Hypertension
Diabetes
Smoking cessation

MOTION SICKNESS

Definition

Motion sickness is a syndrome caused by sensory mismatch between visual, vestibular, and proprioceptive inputs during motion.

Also called:

Travel sickness
Sea sickness
Air sickness

Pathophysiology

Sensory Conflict Theory

Mismatch occurs between:

Visual input
Vestibular input
Proprioceptive input

Example:

Vestibular system senses movement
Eyes perceive stationary environment

Vestibular Pathways Involved

Connections to:

Vomiting center
Autonomic nervous system

Clinical Features

Nausea

Most common symptom.

Vomiting

May be severe.

Other Symptoms

Pallor
Sweating
Drowsiness
Dizziness
Salivation
Headache

Treatment

General Measures

Look at horizon
Avoid reading during travel
Adequate ventilation
Head stabilization

Antihistamines

Drugs

Dimenhydrinate
Meclizine
Promethazine

Mechanism

Suppress vestibular pathways.

Anticholinergics

Drug

Scopolamine (hyoscine)

Route

Transdermal patch
Oral

Side Effects

Dry mouth
Blurred vision
Drowsiness

MAL DE DÉBARQUEMENT SYNDROME (MdDS)

Definition

Persistent sensation of rocking, swaying, or bobbing after exposure to passive motion.

Commonly occurs after:

Sea travel
Cruise journey
Flight

Clinical Features

Sensation of Motion

Rocking
Swaying
Bobbing

Improvement During Passive Motion

Symptoms paradoxically improve while traveling again.

Associated Symptoms

Fatigue
Anxiety
Brain fog
Imbalance

Pathophysiology

Proposed Mechanism

Failure of readaptation of vestibular velocity-storage mechanism after prolonged motion exposure.

Central Vestibular Dysfunction

Likely involves:

Vestibulocerebellum
Spatial orientation networks

Treatment

Vestibular Rehabilitation

May help adaptation.

Medications

Sometimes helpful:

Benzodiazepines
SSRIs
SNRIs

Stress Reduction

Important supportive measure.

Prognosis

May persist for months or years.

PERSISTENT POSTURAL PERCEPTUAL DIZZINESS (PPPD)

Definition

Chronic functional vestibular disorder characterized by:

Persistent dizziness
Non-spinning vertigo
Postural instability

lasting >3 months.

Usually worsened by:

Upright posture
Motion
Complex visual environments

Pathophysiology

Functional Vestibular Disorder

Involves maladaptation of:

Balance control
Visual dependence
Anxiety pathways

Triggering Events

Often follows:

Vestibular neuritis
BPPV
Panic disorder
Migraine
Concussion

Clinical Features

Persistent Dizziness

Present most days.

Motion Sensitivity

Worsened by:

Walking
Crowds
Moving objects

Visual Dependence

Symptoms worsen in:

Supermarkets
Traffic
Complex visual scenes

Anxiety

Frequently associated.

Examination

Usually normal or minimally abnormal.

Diagnosis

Clinical Diagnosis

Based on:

Symptoms >3 months
Functional impairment
Absence of structural explanation

Diagnostic Criteria

Symptoms aggravated by:

Upright posture
Motion
Visual stimuli

Exclusion of Other Causes

Important to exclude:

Stroke
Vestibular schwannoma
Neurodegenerative disease

Treatment

Patient Education

Very important.

Vestibular Rehabilitation

Reduces visual dependence.

Cognitive Behavioral Therapy (CBT)

Helpful in anxiety-associated PPPD.

SSRIs / SNRIs

Drugs

Sertraline
Escitalopram
Venlafaxine

Useful in chronic symptoms.

Prognosis

Improves gradually with:

Rehabilitation
Psychological support
Treatment adherence

HIGH-YIELD EXAM POINTS

Vertical nystagmus is central until proven otherwise.
Normal HIT in acute vestibular syndrome strongly suggests stroke.
AICA stroke may mimic vestibular neuritis because hearing loss may occur.
Motion sickness occurs due to sensory mismatch.
MdDS classically improves during passive motion.
PPPD is a chronic functional vestibular disorder.
Persistent visual-motion sensitivity is typical of PPPD.

PSYCHOGENIC / FUNCTIONAL DIZZINESS

Definition

Psychogenic or functional dizziness refers to dizziness without primary structural vestibular pathology, usually associated with:

Anxiety
Psychological stress
Functional neurological mechanisms

Symptoms are genuine but arise from abnormal sensory processing and maladaptive balance behavior.

Anxiety-Related Dizziness

Mechanism

Anxiety increases:

Visual dependence
Postural vigilance
Autonomic activation

This produces subjective dizziness and imbalance.

Clinical Features

Symptoms

Lightheadedness
Floating sensation
Subjective imbalance
Motion sensitivity

Associated Features

Palpitations
Sweating
Hyperventilation
Panic attacks

Triggers

Crowded places
Stressful situations
Motion-rich environments

Examination

Usually normal.

Somatoform Dizziness

Definition

Chronic dizziness occurring as part of somatization disorder.

Features

Multiple vague symptoms
Excessive health concern
Inconsistent examination findings

Common Symptoms

Head heaviness
Internal spinning
Subjective swaying

Functional Dizziness Disorders

Includes

PPPD
Functional gait disorders
Anxiety-associated dizziness

Clinical Features

Disproportionate Symptoms

Symptoms severe despite minimal objective findings.

Visual Dependence

Symptoms worsen in:

Crowds
Supermarkets
Busy visual environments

Fluctuating Severity

Symptoms vary with stress and attention.

Diagnosis

Clinical Diagnosis

Based on:

Typical history
Normal investigations
Exclusion of structural disease

Treatment

Patient Education

Important to explain:

Symptoms are real
Condition is treatable

Cognitive Behavioral Therapy (CBT)

Improves maladaptive behaviors and anxiety.

Vestibular Rehabilitation

Reduces visual dependence and improves confidence.

SSRIs / SNRIs

Useful when anxiety/depression coexist.

Examples:

Sertraline
Escitalopram
Venlafaxine

VESTIBULAR REHABILITATION

Definition

Exercise-based therapy promoting:

Vestibular compensation
Adaptation
Balance improvement

Mainstay treatment for chronic vestibular dysfunction.

Principles of Vestibular Rehabilitation

Goals

Improve gaze stability
Improve balance
Reduce dizziness
Improve functional mobility

Mechanisms

Adaptation
Habituation
Substitution

Adaptation Theory

Definition

Central nervous system recalibrates vestibulo-ocular reflex after vestibular injury.

Principle

Repeated retinal slip stimulates VOR adaptation.

Exercises

Examples:

VOR x1 exercises
VOR x2 exercises

Substitution Exercises

Principle

Use alternative sensory inputs to compensate for vestibular loss.

Mechanisms

Increased visual dependence
Increased proprioceptive reliance

Examples

Eye-head coordination exercises
Balance training using visual cues

Habituation Exercises

Principle

Repeated exposure to provocative movement reduces dizziness response.

Mechanism

Central desensitization occurs over time.

Indications

Motion sensitivity
Chronic dizziness
PPPD

Cawthorne-Cooksey Exercises

Definition

Classic vestibular rehabilitation exercises promoting compensation.

Components

Eye Exercises

Looking up/down
Side-to-side eye movement

Head Exercises

Head turning
Head bending

Sitting Exercises

Shoulder shrugging
Trunk turning

Standing Exercises

Sit-to-stand
Turning while standing

Walking Exercises

Tandem walking
Walking with head movement

Advantages

Improves compensation
Reduces imbalance
Improves confidence

Brandt-Daroff Exercises

Indication

Mainly for BPPV.

Principle

Repeated positional movement causes habituation and particle repositioning.

Procedure

Sit upright
Quickly lie to one side
Hold position
Return upright
Repeat opposite side

Balance Retraining

Definition

Exercises improving postural stability and gait.

Methods

Static balance training
Dynamic balance exercises
Gait exercises
Foam surface training

Indications

Bilateral vestibulopathy
Elderly imbalance
Chronic vestibular disorders

COMPLICATIONS OF VESTIBULAR DISORDERS

Falls

Causes

Imbalance
Gait instability
Oscillopsia

High-Risk Groups

Elderly
Bilateral vestibular loss
Cerebellar disorders

Anxiety Disorders

Mechanism

Chronic dizziness increases:

Fear
Hypervigilance
Panic symptoms

Depression

Causes

Functional limitation
Chronic symptoms
Social withdrawal

Chronic Imbalance

Features

Persistent gait instability
Fear of walking
Motion intolerance

Functional Disability

Includes

Reduced mobility
Occupational disability
Reduced quality of life

IMPORTANT TABLES

CORE TABLES

Peripheral vs Central Vertigo

Feature	Peripheral	Central
Vertigo	Severe	Mild/moderate
Nystagmus	Horizontal-rotatory	Vertical/direction-changing
Hearing loss	Common	Rare
Neurological deficits	Absent	Present
Gait instability	Mild	Severe

Peripheral vs Central Nystagmus

Feature	Peripheral	Central
Direction	Unidirectional	Direction-changing
Fatigability	Present	Absent
Visual suppression	Present	Absent
Type	Horizontal-torsional	Vertical/pure torsional

BPPV vs Ménière Disease vs Vestibular Neuritis

Feature	BPPV	Ménière Disease	Vestibular Neuritis
Duration	Seconds	Hours	Days
Hearing loss	Absent	Present	Absent
Trigger	Position	Spontaneous	Acute onset
Vertigo severity	Brief severe	Episodic severe	Severe prolonged

Vestibular Neuritis vs Labyrinthitis

Feature	Vestibular Neuritis	Labyrinthitis
Hearing loss	Absent	Present
Cochlear involvement	No	Yes
Cause	Vestibular nerve inflammation	Labyrinth inflammation

Vestibular Migraine vs Ménière Disease

Feature	Vestibular Migraine	Ménière Disease
Migraine history	Common	Rare
Hearing loss	Usually absent	Present
Tinnitus	Less common	Common
Duration	Variable	20 min–12 hr

Canalithiasis vs Cupulolithiasis

Feature	Canalithiasis	Cupulolithiasis
Particle location	Free-floating	Attached to cupula
Duration of vertigo	Brief	Longer
Fatigability	Present	Less marked

Serous vs Suppurative Labyrinthitis

Feature	Serous	Suppurative
Infection	Toxin-mediated	Bacterial invasion
Hearing loss	Mild/reversible	Severe/permanent
Prognosis	Better	Poor

Vestibular Schwannoma vs Ménière Disease

Feature	Vestibular Schwannoma	Ménière Disease
Hearing loss	Progressive unilateral	Fluctuating
Vertigo	Mild imbalance	Episodic severe
MRI	Positive tumor	Normal

Causes of Recurrent Vertigo

BPPV
Ménière disease
Vestibular migraine
Vertebrobasilar insufficiency
Panic disorder

Causes of Bilateral Vestibular Loss

Aminoglycosides
Bilateral Ménière disease
Autoimmune disease
Meningitis
Neurodegenerative disease

Peripheral vs Central Positional Vertigo

Feature	Peripheral	Central
Latency	Present	Absent
Fatigability	Present	Absent
Neurological signs	Absent	Present

Vestibular Neuritis vs Stroke

Feature	Vestibular Neuritis	Stroke
HIT	Abnormal	Normal
Nystagmus	Unidirectional	Direction-changing
Skew deviation	Absent	Present

Vestibulotoxic vs Cochleotoxic Drugs

Vestibulotoxic	Cochleotoxic
Gentamicin	Amikacin
Streptomycin	Neomycin
Oscillopsia	Hearing loss

DRUG TABLES

Vestibular Suppressants

Drug	Class
Meclizine	Antihistamine
Diazepam	Benzodiazepine
Prochlorperazine	Antiemetic

Antiemetics in Vertigo

Drug	Mechanism
Ondansetron	5-HT3 antagonist
Metoclopramide	Dopamine antagonist
Prochlorperazine	Dopamine antagonist

Drugs Causing Ototoxicity

Drug	Main Toxicity
Gentamicin	Vestibular
Amikacin	Cochlear
Cisplatin	Cochlear
Furosemide	Reversible cochlear

Intratympanic Drugs Comparison

Drug	Purpose
Steroid	Hearing preservation
Gentamicin	Vestibular ablation

HIGH-YIELD EXAM TABLES

Duration of Vertigo in Common Diseases

Duration	Disease
Seconds	BPPV
Minutes-hours	Ménière disease
Days	Vestibular neuritis

Nystagmus Patterns in Vestibular Disorders

Pattern	Disease
Torsional upbeat	Posterior canal BPPV
Horizontal	Vestibular neuritis
Vertical	Central lesion

HINTS Findings in Stroke vs Vestibular Neuritis

Finding	Stroke	Vestibular Neuritis
HIT	Normal	Abnormal
Nystagmus	Direction-changing	Unidirectional
Skew	Positive	Negative

Central Red Flag Signs

Vertical nystagmus
Severe ataxia
Diplopia
Dysarthria
Limb weakness
Sensory loss

Causes of Positional Vertigo

BPPV
Central positional vertigo
Vestibular migraine

Causes of Oscillopsia

Bilateral vestibulopathy
CANVAS syndrome
Oscillating nystagmus

Ménière Disease Staging

Stage	Hearing
Early	Fluctuating low-frequency SNHL
Intermediate	Progressive SNHL
Late	Permanent severe SNHL

Causes of Drop Attacks

Tumarkin crisis
Vertebrobasilar insufficiency
Atonic seizures

Central Causes Mimicking BPPV

Cerebellar stroke
Multiple sclerosis
Chiari malformation
Posterior fossa tumor

IMPORTANT FLOWCHARTS

Disorders of Vestibular System

Approach to Vertigo

Patient with vertigo
        ↓
Confirm true vertigo
        ↓
Assess duration + trigger
        ↓
Seconds + positional trigger → BPPV
Minutes to hours + hearing symptoms → Ménière disease
Days + no hearing loss → Vestibular neuritis
Days + hearing loss → Labyrinthitis / AICA stroke
        ↓
Look for central red flags
        ↓
Red flags present → MRI brain + neurology referral
Red flags absent → Vestibular testing + ENT management

Approach to Acute Vestibular Syndrome

Acute continuous vertigo lasting days
+ nausea/vomiting
+ spontaneous nystagmus
+ gait instability
        ↓
Perform HINTS examination
        ↓
Head impulse abnormal
+ unidirectional nystagmus
+ no skew deviation
        ↓
Peripheral AVS likely
→ Vestibular neuritis

Head impulse normal
OR direction-changing nystagmus
OR skew deviation present
        ↓
Central AVS likely
→ Cerebellar / brainstem stroke
        ↓
MRI brain with DWI

Diagnostic Algorithm of BPPV

Brief positional vertigo
        ↓
Dix-Hallpike test
        ↓
Positive torsional upbeat nystagmus
        ↓
Posterior canal BPPV
        ↓
Epley maneuver

If Dix-Hallpike negative
        ↓
Supine roll test
        ↓
Horizontal nystagmus
        ↓
Horizontal canal BPPV
        ↓
Barbecue roll maneuver

Management Algorithm of Ménière Disease

Ménière disease
        ↓
Lifestyle modification
- Low salt diet
- Avoid caffeine/alcohol
- Stress control
        ↓
Medical treatment
- Betahistine
- Diuretics
- Vestibular suppressants during attack
        ↓
Persistent vertigo
        ↓
Intratympanic therapy
- Steroid
- Gentamicin
        ↓
Refractory disabling vertigo
        ↓
Surgery
- Endolymphatic sac surgery
- Vestibular nerve section
- Labyrinthectomy if non-serviceable hearing

Approach to Recurrent Vertigo

Recurrent vertigo
        ↓
Assess duration of each attack
        ↓
Seconds → BPPV
Minutes → TIA / vestibular migraine
Hours → Ménière disease / vestibular migraine
Variable duration → vestibular migraine
        ↓
Check hearing symptoms
        ↓
Hearing loss + tinnitus + aural fullness
        ↓
Ménière disease

Migraine history + photophobia/phonophobia/aura
        ↓
Vestibular migraine

Neurological symptoms
        ↓
Central cause / TIA

Approach to Central Vertigo

Vertigo with suspected central cause
        ↓
Look for red flags
- Vertical nystagmus
- Direction-changing nystagmus
- Severe ataxia
- Diplopia
- Dysarthria
- Limb weakness
- Normal HIT in AVS
        ↓
Red flags present
        ↓
MRI brain with DWI
+ MR angiography if vascular suspicion
        ↓
Identify cause
        ↓
Stroke → Stroke protocol
MS → Neurology + steroids/immunotherapy
Tumor → Neurosurgery / radiosurgery
Degenerative disease → Rehabilitation

Evaluation of Unilateral Vestibular Weakness

Suspected unilateral vestibular weakness
        ↓
Clinical examination
- HIT
- Spontaneous nystagmus
- Fukuda test
        ↓
Objective testing
        ↓
Caloric test
        ↓
Canal paresis present
        ↓
Unilateral peripheral vestibular lesion
        ↓
Common causes
- Vestibular neuritis
- Labyrinthitis
- Ménière disease
- Vestibular schwannoma
        ↓
Audiometry + MRI internal auditory canal if needed

Treatment Algorithm of Vestibular Neuritis

Acute severe vertigo
+ no hearing loss
+ positive HIT
        ↓
Vestibular neuritis likely
        ↓
Acute phase
- Antiemetics
- Short-term vestibular suppressants
- Hydration
        ↓
Early steroid therapy if appropriate
        ↓
Avoid prolonged vestibular suppressants
        ↓
Start vestibular rehabilitation
        ↓
Persistent imbalance
        ↓
Intensive vestibular rehabilitation

Vestibular Rehabilitation Algorithm

Chronic dizziness / imbalance
        ↓
Identify deficit
        ↓
Gaze instability → Adaptation exercises
Motion sensitivity → Habituation exercises
Balance impairment → Balance retraining
Bilateral vestibular loss → Substitution exercises
        ↓
Exercise program
- VOR x1 / VOR x2
- Cawthorne-Cooksey exercises
- Gait training
- Foam surface balance
        ↓
Monitor improvement
        ↓
DHI / Berg Balance Scale / Timed Up and Go

Management of Acute Vertigo

Acute vertigo
        ↓
Check danger signs
- Stroke symptoms
- Severe headache
- New neurological deficit
- New hearing loss
- Inability to walk
        ↓
Danger signs present
        ↓
Emergency imaging + neurology evaluation

No danger signs
        ↓
Assess type
        ↓
Positional brief vertigo → BPPV → Repositioning maneuver
Continuous vertigo without hearing loss → Vestibular neuritis
Vertigo with hearing loss → Labyrinthitis / Ménière / AICA stroke
        ↓
Symptomatic treatment
+ cause-specific treatment

Evaluation of Vertigo with Hearing Loss

Vertigo + hearing loss
        ↓
Type of hearing loss
        ↓
Fluctuating low-frequency SNHL
+ tinnitus
+ aural fullness
        ↓
Ménière disease

Acute vertigo + acute hearing loss
        ↓
Labyrinthitis / AICA stroke / sudden SNHL

Progressive unilateral SNHL
+ imbalance
        ↓
Vestibular schwannoma
        ↓
Audiometry
        ↓
MRI internal auditory canal with gadolinium

Approach to Episodic Vertigo

Episodic vertigo
        ↓
Trigger present?
        ↓
Position-triggered → BPPV
Sound/pressure-triggered → Superior canal dehiscence / perilymph fistula
No clear trigger → Ménière / vestibular migraine / TIA
        ↓
Associated symptoms
        ↓
Hearing symptoms → Ménière disease
Migraine features → Vestibular migraine
Neurological symptoms → TIA / central cause

Diagnostic Pathway for Vestibular Migraine

Recurrent vestibular symptoms
        ↓
Duration 5 minutes to 72 hours
        ↓
History of migraine?
        ↓
Yes
        ↓
Migraine features during ≥50% attacks
- Headache
- Photophobia
- Phonophobia
- Visual aura
        ↓
Exclude other causes
- Ménière disease
- BPPV
- TIA
        ↓
Vestibular migraine likely

Approach to Chronic Dizziness

Chronic dizziness >3 months
        ↓
Character of symptom
        ↓
Oscillopsia + imbalance
        ↓
Bilateral vestibulopathy

Persistent non-spinning dizziness
+ worse upright
+ worse with motion
+ worse in complex visual environment
        ↓
PPPD

Progressive ataxia
+ cerebellar signs
        ↓
Degenerative cerebellar disorder

Progressive unilateral hearing loss
        ↓
Vestibular schwannoma
        ↓
Vestibular testing + audiometry + MRI as indicated