Vertigo

Question 1

What is vertigo?

Answer 1

• type of dizziness with a central/peripheral cause
• sensation of motion without actual motion/exaggerated sense of motion
• sense of spinning, swaying/tilting
• not a disease, can be a symptom of vestibular disorder
• some perceive self motion (subjective), other perceive motion of environment (objective)

Question 2

What are the signs and symptoms for vertigo?

Answer 2

1. Nausea
2. Vomiting (can be severe & cause e imbalance & dehydration)
3. Postural and gait instability
4. Pallor & swearing (ANS stimulated)
5. Tinnitus (peripheral cause)
6. Deafness
7. Headache. ^
8. Photophobia v migrainous vertigo
9. Nystagmus (horizontal, vertical and rotary)

Question 3

What are the assessments to be done for vertigo?

Answer 3

1. Hx taking
   
   • not continuous/permanent
   • may be single/recurrent episode that lasts for seconds/hrs/days
2. Aggravating and provoking factors
   I. Head movement
   II. Coughing
   III. Sneezing
   IV. Loud noises
   V. Head trauma (concussion/contusion)
   VI. Hyperextension of neck
   VII. Viral infection
3. Past med hx
   I. Migraine attacks
   II. Stroke risk factors: DM, HTN, Smoking, vascular disease (sometimes may suggest TIA & initial symptoms may have vertigo)
   III. Fam hx of motion sickness/vestibular neuronitis
   IV. Meds associated with vestibular (aminoglycosides - ototoxic, can induce vertigo) & cerebellar toxicity (phenytoin - know to cause cerebellar/central type vertigo)
4. PE
   
   • confirm vestibular dysfunction and distinguish central from peripheral causes
   • some types of nystagmus + suggest origin from vestibular system
   • look for gait and balance abnormalities (Romberg test to differentiate between cerebellar and vestibular vertigo)
   • neurological examination; look out for:
     A) CN abnormalities (esp CN VIII/vestibular nerve)
     B) sensory and motor changes
     C) abnormal reflexes
   • hearing test (Rinne and Weber)
     > TRO deafness/sensory neuro deafness which can cause vertigo
   • caloric test (*seldom done; can be replaced with other tests)
     > differentiate abnormalities in vestibular system, cerebellum/brainstem
     > pour hot and cold water into ear alternatively to test for nystagmus
5. Diagnostic tests
   I. MRI for suspected central cause (*CT scan is less sensitive)
   II. Electronystagmography (ENG)
   > use electrodes to record eye movement
   III. Videonystagmography (VNG)
   > use video to record eye movement
   V. Audiometry
   > detect hearing loss

Question 4

What are the characteristics of peripheral nystagmus?

Answer 4

1. Unilateral, fast, nvr reverses direction
2. Horizontal with rotary/torsional component
3. Suppressed upon eye fixation
4. Absent neurological signs
5. Unilateral instability, walking preserved
6. Present deafness/tinnitus (possible)

Question 5

What are the characteristics of central nystagmus?

Answer 5

1. Multidirectional, slow, reverses direction
2. Can move horizontal, vertical and rotary/torsional
3. Not suppressed upon eye fixation
4. Present neurological signs
5. Severe instability, falls when walking
6. Absent deafness/tinnitus

Question 6

What is the pathophysiology behind vertigo?

Answer 6

CNS receives signals from R & L ladybrinth & compare signals with one another
- head still = tonic discharges in both ladybrinth = balanced
- movement/motion = both R & L ladybrinth alternate between excited and inhibited
- acute unilateral peripheral vestibular disorder = interpreted by CNS as motion/vertigo even though no movement was made due to L & R differences

Vestibular ladybrinth relays info into vestibular portion of CN VIII to brainstem vestibular nuclei and from there to cerebellum, ocular motor nuclei and spinal cord (define posture of patient)
- vestibulocular connections = coordinate movement of eye during head motion (connection between ladybrinth and eye = nystagmus)
- vestibulospinal pathways = maintain upright posture (severe disturbances = fall/gait disturbances)
- cerebellar connection = modulate acitvies by vestibulocular and vestibulospinal connections (*cerebellar cause = nystagmus and gait disturbances)

Semicircular canals = sense angular motion
Otolith organs = detect linear motion

Vertigo occurs when there’s abnormality in semicircular canal/CNS structure that process signals from semicircular canals

Question 7

What are the peripheral causes of vertigo?

Answer 7

1. Benign paroxysmal postional vertigo
   
   • spinning sensation when tilting head upwards/look up/turning in bed (very brief, in seconds)
   • due to accumulation of Ca debris within posterior semicircular canal (canalithasis)
     > head position change = upset fluid and Ca particle balance = stimulate nerve cells within canal = inaccurate sensory signal transmission = think head is spinning
2. Vestibular neuritis
   
   • viral/post viral inflammatory disorder affecting vestibular portion of CN VIII
   • severe, rapid onset of vertigo
3. Ménière’s disease
   
   • excess endolymph fluid pressure = episodic inner ear dysfunction
   • signs and symptoms
     A) severe vertigo (spontaneous, episodic vertigo lasting from mins to hours)
     B) sensorineuronal hearing loss
     C) tinnitus
     D) ear fullness
     E) nausea
     F) vomiting
     G) disabling imbalance
   • can go into remission with/without tx (& can recur)
4. Herpes zoster
   
   • activation of latent herpes zoster infection of gerniculate ganglion (happen a few wks/mths)
   • SS:
     A) hearing loss
     B) ipsilateral facial paralysis
     C) ear pain
     D) vesicles in auditory canal auricle
     E) acute unilateral dermatological rash & neuritis with vesicular lesions
5. Ladybrinthitis
   
   • inflammation of inner ear
   • causes:
     A) infection
     B) drug toxicity - aminoglycoside
     C) trauma
     D) tumor
   • cause severe vertigo and sensorineural hearing loss when head moves (due to relation to ladybrinth)