Session 7

Question 1

commonality of ear conditions and parts of the ear

Answer 1

An organ of hearing and balance (equilibrium)
• Conditions affecting the ear are common – Present in adults and children – Present to primary and secondary care
• Three parts: external, middle and inner ear – Different pathologies can involve these three different areas or specific structures within them

Question 2

Signs and symptoms of ear disease

Answer 2

Otalgia (ear pain)
Discharge
Hearing loss (conductive vs sensorineural)
Tinnitus
Vertigo
Facial nerve palsy

Question 3

Describe the parts of the ear and what each part contains

Answer 3

External - pinna, external auditory meatus, skin lined
Middle - air filled, ossicles, lined with respiratory epithelium, PT connects it to NP
Inner - cochlea, smicircular canals, fluid filled

Question 4

General sensation of the ear and referred pain

Answer 4

Many Nerves Carry General Sensation from Ear Implications for Referred Pain
• Branches of
• Cervical spinal nerves (C2/C3)
• Vagus
• Trigeminal (auriculotemporal n.)
• Glossopharyngeal (tympanic n.) the medial surface of the tympanic membrane and middle ear cavity is supplied by the glossopharyngeal nerve (CNIX)

• …and a small contribution from CN VII

Special sensory (“hearing and balance”) carried in CN VIII

Question 5

Otalgia with a normal ear examination should lead you to suspect what?

Answer 5

• Otalgia can be non-otological or otological in origin • There are many non-ontological causes for otalgia • TMJ dysfunction (CN Vc) • Diseases of oropharynx (CN IX) • Disease of larynx and pharynx including cancers

Question 6

The External Ear:

Answer 6

pinna, external auditory meatus and lateral surface of tympanic membrane
Collects, transmits and focuses sound waves onto the tympanic membrane
Composed of Cartilage, skin and fatty tissue

Question 7

Pinna (Auricle) and Abnormalities

Answer 7

Congenital
Inflammatory
Infective
Traumatic
Facial Palsy…and a painful, red ear with vesicles…? 
Perichondritis
Pinna Haematoma

Question 8

Pinna Haematoma

Answer 8

Accumulation of blood between cartilage and its overlying perichondrium
• Secondary to blunt injury to the pinna • Common in contact sports
• Subperichondrial haematoma deprives cartilage of blood supply + pressure necrosis of tissue
• Drainage & revent re-accumulation/re-apposition of two layers
• Untreatedfibrosis, new asymmetrical cartilage development  ‘cauliflower deformity’

Question 9

External acoustic meatus

Answer 9

Skin-lined cul-de-sac ~2.5 cm in length
• Lined with keratinising, stratified squamous epithelium continuous onto lateral surface of tympanic membrane
• Cartilaginous (outer 1/3) and bony (inner 2/3)
• Sigmoid shape
• Hair, sebaceous and ceruminous glands line cartilage part: barrier to foreign objects… • Ceruminous glands produce ear wax
• Bony part lacks these glands and hairs
Self-cleaning function…
• Desquamation and skin migration laterally off tympanic membrane out of canal • Epithelial migration

Question 10

Common Conditions Involving External Acoustic Meatus

Answer 10

Wax/ Foreign bodies
Otits externa
malignant otitis externa - *rare: serious ++, potentially life threatening; immunocompromised inc. diabetics at risk

Question 11

Tympanic Membrane: common abnormalities

Answer 11

Bulging secondary to bacterial acute otitis media

Retracted and evidence of fluid within middle ear cavity (otitis media with effusion)

Question 12

Cholesteatoma

Answer 12

Rare..but should not be missed
• Retraction of pars flaccida (TM) forms a sac/pocket • Trapping stratified squamous epithelium and keratin • Proliferates forming cholesteatoma
• Usually secondary to chronic Eustachian Tube (ET) dysfunction • -ve pressures pull the ‘pocket’ into the middle ear
• Painless, often smelly otorrhea (ear discharge) +/- hearing loss
• Not malignant but slowly grows and expands – Potentially more serious consequences due to enzymatic bony destruction e.g. erode ossicles, mastoid/petrous bone, cochlea

Question 13

The Middle Ear:

Answer 13

Air Filled Cavity Between Tympanic Membrane and Inner Ear Containing Ossicles
• Ossicles connected via synovial joints
• Amplify and relay vibrations from the TM to the oval window of the cochlea (inner ear) • Transmitting vibration to waves in a fluidmedium
• Ossicle movement ‘tampered’ by 2 muscles tensor tympani and stapedius • Contract if excessive vibration due to loud noise (protective; acoustic reflex)
• Malleus • Incus • Stapes

Question 14

Otosclerosis

Answer 14

One of most common causes of Acquired Hearing Loss in Young Adults
• Both genetic and environmental causes
• Exact cause unknown (?viral ?hereditary triggers?)
• Ossicles fused at articulations due to abnormal bone growth particular between base plate of stapes and oval window • Sound vibrations cannot be transmitted effectively to cochlea
• Present with gradual unilateral or bilateral conductive hearing loss

Question 15

Pressure control in the middle ear

Answer 15

Pharyngotympanic Tube equilibrates pressure of middle ear with atmospheric pressure
Mucous membrane of middle ear continuously reabsorbs air in middle ear causing negative pressure Pharyngotympanic tube (Eustachian Tube) allows equilibration of pressure within middle ear cavity with that of the atmosphere. It also allows for ventilation of and drainage of mucus from the middle ear

Question 16

otitis media with effusion

Answer 16

(“glue ear”)
• Not an actual infection.. but can predispose to
• Due to Eustachian tube dysfunction
• Fluid and negative pressure in middle ear • Decreases mobility of TM and ossicles  affecting hearing
• Most resolve spontaneously in 2-3 months..
• May persist and/or impede speech & language development/school performance Require grommets (tympanostomy tube) Act to maintain equilibration of pressures

Question 17

acute otitis media

Answer 17

• Acute middle ear infection – More common in infants/ children than in adults
• Signs and symptoms include – Otalgia (infants may pull or tug at the ear) – Other non-specific symptoms e.g. temperature – Red +/- bulging TM and loss of normal landmarks
• Mostly viral aetiology
• Occasionally bacterial… causes – Streptococcus pneumoniae – Haemophilus influenzae

Question 18

Why are infants more likely to get middle ear infections?

Answer 18

Pharyngotympanic tube is shorter and more horizontal in infants
In infants therefore: • Easier passage for infection from the nasopharynx to the middle ear • Tube can block more easily, compromising ventilation and drainage of middle ear, increasing risk of middle ear infection and “glue ear”

Question 19

Complications of Acute Otitis Media

Answer 19

• Tympanic membrane perforation
• Facial nerve involvement (rare) – Close relationship to middle ear cavity (via facial canal) – Two intrapetrous branches run through middle ear cavity (chorda tympani, n to stapedius)
• Rarer but potentially life-threatening complications include – Mastoiditis – Intracranial complications • Meningitis • Sigmoid sinus thrombosis • Brain abscess

Question 20

Mastoiditis

Answer 20

Middle ear cavity communicates via mastoid antrum with mastoid air cells. Provides a potential route for middle ear infections to spread into the mastoid bone (mastoid air cells)

Question 21

Important Anatomical Relations of the Ear

Answer 21

slide 25 lec 1

Question 22

The Inner Ear:

Answer 22

Vestibular apparatus and cochlea: fluid filled tubes
• Inner ear contains structures involved in hearing and position-sense/balance
• Cochlea converts fluid movement (generated by footplate of stapes) into action potentials (in CN VIII) perceived as sound
• Vestibular apparatus converts fluid movement (generated by position and rotation of head) into action potentials (in CN VIII) perceived as position sense and balance
• Disease of the inner ear can present with one of or combination of.. – Hearing loss (sensorineural) – Tinnitus – Disturbances balance and vertigo

Question 23

Cochlea

Answer 23

Fluid-filled tube with specialized hair cells that generate action potentials when moved
The cochlea is the organ of hearing. It is fluid filled tube.
Movements at the oval window set up movements of the fluid in the cochlear duct.
Waves of fluid cause movement of special sensory cells (stereocilia) which generate action potentials in CN VIII
Slide 27

Question 24

How do we hear?

Answer 24

Auricle and external auditory canal focuses and funnels sound waves towards tympanic membrane which vibrates
Vibration of the ossicles (stapes at the oval window) sets up vibrations/movement in cochlear fluid
Sensed by stereocilia (nerve cells) in the cochlear duct (part called the spiral organ of Corti)
Movement of the stereocilia in organ of Corti trigger action potentials in cochlear part of CN VIII
Primary auditory cortex (make sense of the input)

Question 25

Vestibular apparatus

Answer 25

Fluid-filled tubes with specialized hair cells that generate action potentials when moved Vestibular apparatus includes the semicircular ducts, the saccule and utricle: these are a fluid-filled tubes sacs containing stereocilia Fluid movements due to moving position or rotation of head, bends stereocilia which generate action potentials via CN VIIIbrain Perceive and maintain our sense of balance

Question 26

Various Conditions Can Affect Inner Ear

Answer 26

May Involve Cochlea and/or Vestibular Apparatus Symptoms and signs will depend on inner ear structures involved • Presbycusis – Sensorineural hearing loss associated with old age – Bilateral and gradual • Benign Paroxysmal Positional Vertigo – Vertigo only – Short-lived episodes (seconds); triggered by movement of head e.g. turning over in bed, bending down – Dix-Hallpike and Epley manoeuvres * Meniere’s Disease – Vertigo, hearing loss and tinnitus (typically unilateral) – May also describe ‘aural fullness’, and nausea and vomiting – Symptoms longer-lasting (30 mins, sometimes up to 24 hrs) – Recovery in between; recurrent episodes – Hearing may deteriorate over time (as well as dipping during ‘episodes’) * Acute Labrynthitis vs Acute Vestibular Neuronitis – History of upper respiratory tract infection – AL= involvement of all inner ear structures, associated with hearing loss/tinnitus, vomiting and vertigo – AVN=usually no hearing disturbance or tinnitus • Sudden onset of vomiting and severe vertigo (lasting days)

Question 27

A Patient Presents with Hearing Loss…

Answer 27

* History • Examination – Inspection and palpation of external ear – Otoscopy * Gross hearing assessment (whispering a word or number and patient repeating back while masking the ear not being tested) * Tuning forks tests (512 Hz) • Weber’s and Rinne’s test * Referral for more formal audiometry testing (pure tone audiometry)

Question 28

Conductive vs sensorineural hearing loss

Answer 28

Conductive hearing loss Pathology involving the external or middle ear e.g. • Wax • Acute Otitis media • Otitis Media with effusion • Otosclerosis Sensorineural hearing loss Pathology involving the inner ear structures or CN VIII e.g. • Presbycusis (most common type in >55 year olds) • Noise-related hearing loss • Meniere’s Disease • Ototoxic medications • Acoustic neuroma

Question 29

Functions of the nose and nasal cavity

Answer 29

Sense of smell Provides a route for inspired air Filters inspired air- trapping particles in nasal hair or mucous Moistens (humidifies) and warms inspired air Resonating chamber for speech

Question 30

External nose

Answer 30

Composed of cartilage and bone Prominence of nasal bones make them susceptible to fracture in facial injuries Vestibule is lined with skin containing sebaceous/ sweat glands and hair- filters inspired air Inspired air enters via vestibule (of external nose)

Question 31

Boundaries of the nasal cavities

Answer 31

Floor - hard palate (roof of the oral cavity) Medial wall is the nasal septum Posteriorly communicates with nasopharynx

Question 32

Describe the lateral wall of the nasal cavity

Answer 32

Lateral wall is Irregular Due to Presence of Bony Projections Bony projections (conchae) • Superior • Middle • Inferior superior and middle conchae are part of the ethmoid bone Meatuses • Superior • Middle • Inferior • Slows airflow by causing turbulence of airflow • Increases surface area over which air passes

Question 33

Paranasal Air Sinuses and Orbit

Answer 33

Paranasal Air Sinuses and Orbit Communicate with Nasal Cavity Through Openings in Lateral Wall • Openings under the meatuses allow for drainage of • Paranasal air sinuses into nasal cavity • Nasolacrimal duct into nasal cavity

Question 34

Nasal Septum

Answer 34

Nasal Septum (medial wall) Consists of a Bony and Cartilaginous Part • Cartilage of nasal septum receives blood supply from overlying perichondrium • Injury to nose can buckle septum and shears blood vessels • Blood accumulates sub-perichondrium, depriving underlying cartilage of its blood supply • Septal Haematoma slide 9 lec 2

Question 35

Saddle-nose Deformity

Answer 35

• Untreated septal haematoma leads to avascular necrosis of cartilaginous septum – Saddling of nasal dorsum (‘saddle-nose’ deformity) • Can also develop infection in the collecting haematoma – Septal abscess formation further increases likelihood of avascular necrosis of septum Always examine for septal haematomas in patients presenting with nasal injury

Question 36

While picking her nose one morning, the Queen accidently catches her nail on the nasal mucosa. The pain is intense, causing her to wince. Which cranial nerve carries general sensation from the nasal cavity?

Answer 36

panopto

Question 37

Nerve Innervation to Nose and Nasal Cavity

Answer 37

slide 12 lec 2

Question 38

Lining of the nasal cavity

Answer 38

Whole Nasal Cavity Lined with Mucous Membrane and is Highly Vascular • Olfactory mucous membrane housing olfactory receptor neurones – Olfaction (smell): CN I • Respiratory mucous membrane – Pseudostratified columnar ciliated epithelium rich in goblet cells – Filters (mucous/cilia) – Humidifies (watery secretions) – Warms (rich blood supply)

Question 39

Nasal Polyps

Answer 39

Nasal Polyps: Fleshy, Benign Swellings of Nasal Mucosa • Usually bilateral: common (>40 years) • Pale or yellow in appearance/fleshy and reddened • Symptoms include – Blocked nose and watery rhinorrhoea – Post-nasal drip – Decreased smell and reduced taste – Unilateral polyp +/- blood-tinged secretion may suggest tumour

Question 40

Rhinitis

Answer 40

Rhinitis: an inflammation of the nasal mucosal lining • Many causes, all lead to similar symptoms – Nasal congestion – Rhinorrhoea (“runny” nose) – Sneezing – Nasal irritation – Postnasal drip • Common causes – Simple acute infective rhinitis (viral- the common cold!) – Allergic rhinitis

Question 41

One beautiful summer’s day a 6 year old child is brought to the GP with a 1 week history of a runny nose. His mum notes that this discharge is only coming from his right nostril. Over the last few days the discharge has become ‘smelly’ and blood stained. He has been otherwise well. What is the likely diagnosis?

Answer 41

panopto

Question 42

Rich Blood Supply to Nasal Mucosa allows for what?

Answer 42

Rich Blood Supply to Nasal Mucosa Allow for warming and humidification of inspired air • Mucosa and blood vessels easily injured – Nose bleed (epistaxis) • Arterial supply to nasal cavity arises from branches of ophthalmic artery and maxillary artery – Arterial anastomoses in anterior septum (Kiesselbach’s plexus) • Most common source of bleeding in epistaxis • Easily treatable with simple first aid measure (“pinching nose”) • Venous drainage from nasal cavity into pterygoid venous plexus (also drainage to cavernous sinus and facial vein)

Question 43

Keisselbach’s Plexus

Answer 43

Bleeding from the sphenopalatine artery (branch of maxillary a) is source for small minority of nosebleeds Potentially more serious and more difficult to treat (not easily reachable to tamponade

Question 44

Paranasal Sinuses

Answer 44

• Air filled spaces that are extensions of nasal cavity – Rudimentary or absent at birth • Lined with respiratory muscosa (thus are also ciliated and secrete mucous) • Named according to bone in which they are found • Help humidify and warm inspired air – Reduce weight of the skull • All drain into the nasal cavity via small channels called ostia into a meatus – Most into middle meatus • Infections in nasal cavity can involve sinuses (sinusitis) – Maxillary sinus most commonly affected Important anatomical relations of the paranasal sinuses include the nasal cavity, orbit and anterior cranial fossa Roots of upper teeth can sometimes project in maxillary sinus General Sensory innervation is from branches of CN V • Frontal, ethmoidal and sphenoid  Va • Maxillary  Vb slide 20 lec 2

Question 45

Acute Sinusitis

Answer 45

Symptomatic Inflammation of Mucosal Lining of Nasal Cavity and Paranasal Air sinuses • Often secondary to viral infection of nasal cavity – Symptoms typically peak early but resolve gradually (last <10 days) • Clinical diagnosis (i.e. based on history and examination) – Recent URTI – Blocked nose and rhinorrhoea +/- green/ yellow discharge – Pyrexia – Headache/ facial pain (in area of affected sinus) • Worse on leaning forward • Self-limiting: treatment is symptomatic (e.g. analgesics, antipyretics, steam inhalation) Pathophysiology: • Primary infection (e.g. rhinitis) leads to reduced ciliary function, oedema of nasal mucosa and sinus ostia and increased nasal secretions • Drainage from sinus is impeded • Maxillary sinus is the most commonly affected • Stagnant secretions within the sinus become ideal breading ground for bacteria-secondary infection • Commonest bacteria include Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis Acute bacterial sinusitis more likely if • Symptoms particularly severe at onset • Symptoms >10 days without improvement (but <4 weeks) • Symptoms that worsen after an initial improvement (suggesting secondary bacterial infection)