Lecture 5: Vertigo and Tinnitus COPY Flashcards
What is vertigo?
Cardinal symptom of vestibular disease. It is a sensation of movement without any movement.
* Physiologic: sustained head rotation
* Pathologic: vestibular dysfunction
What is fainting due to usually?
Brain hypoperfusion
What is disequilibrium/imbalance?
Feeling off-balance, often due to either a CNS lesion or vestibular dysfunction.
Often the first sign of MS.
Clinical
Name whether each symptom is vertigo, lightheadedness, or disequilibrium.
* I felt like I was about to pass out.
* The room was spinning around me.
* I felt very unsteady when walking.
* My head felt like it was twirling around like a top.
* I thought I might just tip over at any moment.
* Everything started to go black; I had to lay down.
- Lightheadedness
- Vertigo
- Disequilibrium
- Vertigo
- Disequilibrium
- Lightheadedness
What is peripheral vertigo characterized by?
- Sudden onset
- Associated unilateral tinnitus
- N/V
- Possible horizontal nystagmus
What is central vertigo characterized by?
- Gradual onset
- No hearing symptoms
- If tinnitus, usually bilateral
- Vertical or any direction nystagmus.
What are the common etiologies for peripheral vertigo?
- Vestibular neuritis
- Labyrinthitis
- Meniere’s
- BPPV
- Barotrauma
- Perilymphatic fistulas
- Semicircular canal dehiscence
- Ethanol intoxication
What are the common etiologies for central/mixed vertigo?
- Seizure
- MS
- Wernicke’s
- Chiari malformation
- Cerebellar ataxia syndromes
- Migraine
- Ischemia, infarct, hemorrhage, infection, or mass of brainstem/cerebellum.
What should we ask regarding dizziness in patient history?
- Unilateral or bilateral
- Acute or chronic
- Progressive?
What etiologies could produce dizziness lasting months?
- Acoustic neuroma
- Ototoxicity
- MS
- Neurodegeneration
How long does a migraine generally produce dizziness?
Seconds to days.
If a patient’s dizziness is triggered by movement, what are the two more likely etiologies?
- BPPV
- Orthostasis
If a patient presents with unilateral tinnitus, what is the more likely vertigo type?
Peripheral
If a patient presents with aural fullness, what is the most likely etiology?
Meniere’s
What is pursuit movement? Saccade movement?
- Pursuit eye movement is constant eye movement to track an object.
- Saccade eye movement is a sudden eye movement, shifting from looking at one thing to another.
- Abnormal suggests cerebellar pathologies.
Pursuit = H testing for EOM.
What is a head impulse test?
- Patient stares straight ahead.
- Patient’s head is rotated quickly one direction and back to the other; their focus should remain in front still.
Assesses for vestibulo-ocular reflex.
Positive test indicates peripheral vertigo.
What is a Dix-Hallpike maneuver?
- Patient sits on a table, with legs stretched out in front of them.
- Patient turns head to one side (45d) and lies down quickly with head NOT resting on table, 30 deg off the edge of the table.
- If a patient suddenly gets vertigo AND NYSTAGMUS, they most likely have BPPV (Benign paroxysmal positional vertigo)
What are some specific diagnostic tests we can order to help determine vertigo etiology?
- Audiometry
- Caloric testing
- CT/MRI
- Electronystagmography (ENG) or Videonystagmography (VNG)
- Vestibular evoked myogenic potentials (VEMPS)
Explain the process of caloric testing.
- cold/warm water irrigated into ear.
- Normal should induce nystagmus.
- Abnormal = NO nystagmus.
- Warm water mimics IPSILATERAL.
- Cold water mimics CONTRALATERAL
What indicates an abnormal caloric test? What could give a false reading?
Abnormal = no nygstagmus = vestibular system, nerve, or brain damage.
False positives can occur due to alcohol, antihistamines, or sedatives in the past 24hr.
What are the CIs to caloric testing?
- Ear: OE, Middle ear effusion, TM perforation.
- Medical: Epilepsy, psychosis, HTN, severe cardiac disease
- Meds: 2nd generation antihistamines, anxiolytics, antidepressants in past 48hrs.
AKA discharge in ear or prone to seizures.
What is the mnemonic to remember the water temp for caloric testing?
COWS.
Cold opposite, Warm same.
Warm water causes nystagmus towards the same ear.
Cold water causes nygstagmus towards opposite ear.
When do we want to order a MRI for suspected vertigo?
When we suspect central etiology or an acoustic neuroma.
What is an ENG test?
Electrodes placed on patient, with tracing of eye movements.
What is a VNG test?
ENG with video imaging of the eyes as well.
When is an ENG/VNG test usually performed?
Alongside caloric testing or chair tilt/movement testing.
What is VEMP testing?
- Electrodes placed on head/face.
- Repetitive sound stimulus to one ear and measurement of muscle reaction to it.
Assess otolith function.
What are the two VEMPs measured? What muscle do they correspond to?
- Cervical VEMP: saccule. Loud sound delivered to a single ear should trigger ipsilateral SCM.
- Ocular VEMP: utricle. Records EOM potentials during head vibration.
What is the usual etiology of BPPV?
Canalithiasis: calcium deposits in the semicircular canal, usually due to free-floating otoconia in the posterior semicircular canal.
What are the risk factors for BPPV?
- Age > 50
- Female (esp in menopause)
- Whiplash/trauma
- Chronic OM
How does BPPV usually present?
- Acute, recurrent BRIEF vertigo lasting < 1min.
- Usually occurs a few seconds after head position changes.
What are the 3 types of BPPV that can be detected via a Dix-Hallpike maneuver?
- Posterior Canal: Upward, torsional nystagmus
- Superior/Anterior Canal: Vertical Nystagmus
- Lateral/Horizontal Canal: Horizontal Nystagmus beating side to side