PBL 5

Question 1

What is tinnitus?

Answer 1

A sensation of sound when there is no auditory stimulus

can occur without hearing loss and results from heightened awareness of neural activity in the auditory pathways

Question 2

What is vertigo?

Answer 2

A sensation of whirling and loss of balance that is due to inner ear dysfunction

either a sensation of movement without movement or an exaggerated sense of motion

Question 3

What symptoms accompany vertigo?

Answer 3

• nausea
• vomiting
• palor
• sweating
• nystagmus

Question 4

What is nystagmus?

Answer 4

rapid involuntary movements of the eye

Question 5

What causes vertigo?

Answer 5

vestibular dysfunction

either a peripheral vestibular cause or a central cause

Question 6

What are the symptoms of tinnitus?

Answer 6

Patient describes a hissing or a ringing in their ears

Question 7

What diseases can be associated with tinnitus?

Answer 7

• vascular malformation (e.g. aneurysm)

- vascular tumour

Question 8

What causes tinnitus?

Answer 8

awareness of neural activity in the auditory pathways that our brains are made aware of.

Question 9

What is Meniere’s disease?

Answer 9

excessive accumulation of endolymph in the membranous labyrinth causing a distortion of hearing

Question 10

What are the clinical features of meniere’s disease?

Answer 10

• tinnitus
• fluctuating sensoneural hearing loss
• vertigo
• sensation of ear fullness

Question 11

Describe the symptom of tinnitus in meniere’s disease

Answer 11

typically a low buzzing or blowing sound that is frewquently louder before the attack of vertigo

attacks not precipitated by positional changes and may be months or weeks apart

Question 12

Descibe the symptom of fluctuating sensorineural hearing loss in meniere’s disease

Answer 12

in early stages, hearing loss fluctuates with return to normal after the rupture heals

remissions and exacerbations typical

Question 13

Describe the symptom of vertigo in meniere’s disease

Answer 13

episodes may be preceeded by sensation of pressure in the ear, increased hearing loss or increased tinnitis

usually sudden onset with maximum intensity reached in a few minutes

Usually lasts for an hour or more

Question 14

What is a schwannoma of the vestibulocochlear nerve?

Answer 14

An acoustic neuroma

= a benign slow-growing tumour of the schwann cells surrounding the vestibulocochlear nerve (CNVIII) and facial nerve (CN VII)

tumour usually arises from the vestibular branch

Question 15

What are the clinical features of an acoustic neuroma?

Answer 15

• unilateral sensorineural hearing loss (most common)
• vertigo
• facial numbness
• tinnitus

larger tumours may cause headaches, coordination difficulties, obstructive hydrocephalus

Question 16

What treatments can be given in Meniere’s disease to provide symptomatic relief?

Answer 16

During acute attacks:

• antiemetics
• anticholinergics

Between acute attacks:

• eating a low-sodium diet
• using diueretics
• smoking cessation
• stress management
• caffeine elimination

Question 17

What surgical interventions can be given to patients with meniere’s disease?

Answer 17

Shunts can be placed to drain excessive endolymph

removal of portions of the vestibulococchlear nerve and destruction of the membranous labyrinth are options

Question 18

What treatment can be given for an acoustic neuroma?

Answer 18

• chemotherapy/radiotherapy

- surgery -using sub-occipital retrosigmoid approach

Question 19

What is the sub-occipital retrosigmoid approach

Answer 19

Part of the occipital bone behind the ear is removed to gain access to the tumout

retrosigmoid = requires the surgeon to go under the sigmoid sinus in the brain to reach the internal acoustic meatus

Question 20

Describe the course of the vestibulocochlear nerve

Answer 20

CN VIII leaves the CNS at the level of the pons and travels via the internal acoustic meatus and splits into two branches

Question 21

What are the branches of the vestibulocochlear nerve and what are their functions?

Answer 21

vestibular branch
> balance (sensory)

cochlear branch
> hearing (sensory)

Question 22

Describe the course of the facial nerve

Answer 22

CN VII originates from the pons anf exits the skull via the internal acoustic meatus

reaches the posterior wall of the middle ear then passes inferiorly to exit the skull at the stylomastoid foramen

Then enters the parotid gland, giving rise to the terminal branches

Question 23

What are the branches of the facial nerve and what are their function?

Answer 23

• Temporal
• Zygomatic
• Buccal
• Marginal mandibular
• Cervical

> motor control of the facial muscles
sensation of taste to the anterior 2/3 of the tongue
parasympathetic division supplying various glands

Question 24

Which glands does the facial nerve supply?

Answer 24

• submandibular
• sublingual
• nasal
• palatine
• lacrimal
• pharyngeal

Question 25

Why does surgery on the vestibulocochlear nerve pose a risk to the facial nerve?

Answer 25

Both travel along the internal acoustic meatus, which is often the location of the tumour.

The size of the tumour can affect the surrounding structures

Question 26

What is facial palsy?

Answer 26

The loss of muscle control on one side of the face, which may be temporary or permanent

Question 27

What is a tarsorrhaphy?

Answer 27

The orbicularis oculi muscle will be affected which will make it difficult for patients to close their eyes resulting in drying of the eye and cornea

This procedure partially sews the eyelids together to narrow the eyelid opening