Vertigo

Question 1

What is vertigo?

Answer 1

Sensation that the environment around you is moving/spinning. Can be severe such that patients find it difficult to balance.

Question 2

What is conductive hearing loss?

Answer 2

When the ear is not capable of transmitting vibration of sound waves onto the cochlear, this type of hearing loss therefore concerns the OUTER and MIDDLE EAR.

Question 3

What is sensorineural hearing loss?

Answer 3

When the ear is not capable of hearing as a result of problems associated with the INNER EAR – sensory apparatus (cochlea) or the vestibulocochlear nerve.

Question 4

What is hearing loss as a result of damage to the vestibulocochlear nerve specifically called?

Answer 4

Retrocochlear hearing loss.

Question 5

What is Meniere’s disease?

Answer 5

AKA endolymphatic hydrops. Recurrent episodes of auditory and vestibular disease characterised by tinnitus, paroxysmal (sudden attack) vertigo, unilateral fluctuating hearing loss and sensation of fullness in the affected ear.

Question 6

What is the aetiology of Meniere’s disease? (x5)

Answer 6

• Mostly unknown
• Allergic responses esp. to food
• Syphilis
• Lyme disease
• Hypothyroidism
• Stenosis of internal auditory canal

Question 7

What are the risk factors of Meniere’s disease? (x3)

Answer 7

Viral or autoimmune disease. Family history.

Question 8

What is the pathophysiology of Meniere’s disease?

Answer 8

• Disturbed homeostasis of endolymph (fluid within the inner ear), meaning over-production or impaired absorption.
• In acute attacks, this results in cochlear distension and rupture of Reissner’s membrane (a membrane which separates the vestibular and cochlear duct and creates a compartment in the cochlear filled with endolymph).
• This causes potassium-rich endolymph release into the sensory and neural elements of the inner ear leading to symptoms.

Question 9

What is the epidemiology of Meniere’s disease: Age?

Answer 9

Peak age of onset is 40s.

Question 10

What are the signs and symptoms of Meniere’s disease? (x4 +3)

Answer 10

• Unilateral tinnitus, paroxysmal (sudden attack) vertigo (associated with N&V), unilateral fluctuating low-frequency hearing loss and sensation of fullness in the affected ear. • Late stages may be associated with sudden loss of balance without loss of consciousness.
• Positive Romberg’s test: swaying or falling when asked to stand with feet together and eyes closed
• Fukuda’s stepping test: turning towards affected side when asked to march in place with eyes closed

Question 11

What are the investigations for Meniere’s disease?

Answer 11

• No definitive test
• Audiometry: unilateral sensorineural hearing loss; air and bone conduction are equal (indicating pathology in cochlear or auditory nerve). Hearing loss affects lower frequencies first
• Electronystagmography, vestibular evoked myogenic potential, MRI of internal acoustic meatus: to rule out other causes

Question 12

What is BPPV?

Answer 12

Peripheral vestibular disorder that manifests as sudden vertigo lasting seconds to minutes on changing head position

Question 13

What is the aetiology of BPPV? (x2 (x7))

Answer 13

• PRIMARY: idiopathic; 50-70% of cases
• SECONDARY: head trauma, labyrinthitis, vestibular neuronitis, Meniere’s disease, migraines, ischaemic processes and iatrogenic causes (surgery).

Question 14

What are the components of the vestibular system and what are their roles?

Answer 14

Semi-circular canals and otoliths. Semi-circular canals sense angular (rotary) motion of the head and are involved in enabling visual fixation on a target when the head is moving (vestibulo-ocular reflex); Otoliths sense linear movement of head and the strength and direction of gravity (utricle and saccule – part of the labyrinth).

Question 15

! What is the pathophysiology of BPPV? Two forms?

Answer 15

• Migration of free-floating endolymph particles (thought to be displaced otoconia (bio-crystals involved in sensing movement) from the utricular otolithic membrane) into the posterior (more commonly), horizontal (less commonly), or anterior (rarely) semi-circular canals renders them sensitive to gravity.
• Posterior most common as its positioned in an orientation the traps particles, whereas anterior and horizontal are easier for particles to escape
• Can occur in two forms: canalithiasis (free-floating endolymph particle called canalith) and cupuloithiasis (canalith adheres to cupular resulting in chronic BPPV resistant to management by repositioning manoeuvres)
• This manifests as misperception of movement (vertigo) and nystagmus of the eye in the plane of the affected canal.

Question 16

What is the epidemiology of BPPV: Common? Age? Gender?

Answer 16

One of the most common causes of vertigo. Peak age of incidence is 60. Females twice as likely to be affected.

Question 17

What are the signs and symptoms of BPPV? (x3)

Answer 17

• Mostly unilateral
• Paroxysmal, brief episodes of vertigo provoked by looking up and down, getting up, turning head, and rolling over in bed to one side. Less than 30 seconds.
• Associated symptoms: N&V, imbalance, presyncope
• Nystagmus
• No additional neurological/ontological symptoms

Question 18

What is nystagmus?

Answer 18

Slow phase of eye movement in one direction, followed by fast phase corrective response in the opposite direction.

Question 19

What are the investigations for BPPV? (x2)

Answer 19

• Dix-Hallpike manoeuvre (see photo): diagnoses posterior canal BPPV. Patient seated and head turned 45 degrees towards the ear being tested. Patient quickly lowered to supine position with head extended over edge of bed and held in the same 45 degree angle. Positive test means patient experiences vertigo and nystagmus can be observed. Reverse nystagmus present also on returning patient to seated position
• Supine lateral head turns: diagnoses lateral (horizontal) canal BPPV. Head extended over edge of bed and head rotated to one side, left for a minute, and rotated to the opposite side. Positive test when patient experiences vertigo with nystagmus.