Hearing Loss and Tinnitus

Question 1

Define tinnitus

Answer 1

Perception of sound in the absence of an environmental acoustic stimulus

Question 2

How should tinnitus be characterised?

Answer 2

Objective vs subjective
Unilateral vs bilateral
Symmetrical vs asymmetrical
Pulsatile vs non-pulsatile (important to determine if in time with patient’s pulse or not; objective and pulsatile indicates organic cause??)

Question 3

What are the 5 things that an ear can do? What is the clinical relevance of these?

Answer 3

Otorrhoea
Otalgia
Hearing
Tinnitus
Vertigo
If a patient has one of these symptoms, ask about all the others

Question 4

What characteristic of tinnitus is typically not clinically useful?

Answer 4

Pitch or specific description

Question 5

Objective tinnitus

Answer 5

We can hear the noise (have a listen)

Question 6

Subjective tinnitus

Answer 6

Only patient can hear it

Question 7

What causes tinnitus?

Answer 7

All causes of hearing loss can cause tinnitus

Question 8

Stapedius myoclonus

Answer 8

Pulsatile tinnitus not in time with pulse (happens every time muscle twitches)

Question 9

5 broad categories of causes of pulsatile tinnitus

Answer 9

Hypervascularity
Arterial causes
Venous causes
Arteriovenous causes
Other

Question 10

2 causes of hypervascularity producing pulsatile tinnitus

Answer 10

Physiological (e.g. pregnancy, exercise, children)

Pathological (e.g. thyrotoxicosis, cardiac shunts and abnormal circulatory dynamics)

Question 11

4 arterial causes of pulsatile tinnitus

Answer 11

Arteriosclerosis
Aneurysms
Dissection
Aberrant vessels (including in cancer)

Question 12

2 venous causes of pulsatile tinnitus

Answer 12

Benign intracranial hypertension

Dehiscent jugular bulb

Question 13

How should pulsatile tinnitus be investigated, in order of priority?

Answer 13

Audiogram
Imaging (CT of temporal bone)
MRI/MRA for acoustic neuromas, benign intracranial hypertension
ENT surgeon will commonly do both, CT is most strongly indicated
Doppler of carotid arteries

Question 14

Arteriovenous cause of pulsatile tinnitus

Answer 14

AVMs

Question 15

Other causes of pulsatile tinnitus

Answer 15

Myoclonus (of stapedus, tensor tympani, tensor veli palatani)

Question 16

What are the 4 types of hearing loss and what are the sites affected for each type?

Answer 16

Sensorineural (inner ear)
Mixed
Conductive (middle/outer ear)
Central (auditory cortex)

Question 17

2 causes of conductive hearing loss involving the external auditory canal (EAC)

Answer 17

Material in canal lumen

Narrowed lumen

Question 18

4 causes of conductive hearing loss involving the tympanic membrane (TM)

Answer 18

Retraction
Infection
Perforation
Scar

Question 19

5 causes of sensorineural hearing loss

Answer 19

Ageing (presbycusis)
Noise-induced HL
Trauma
Neoplasm
Infection