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• EENT refers to Ear Conditions

Anatomy of the Ear

• Includes the outer, middle, and inner ear.
• Key structures: auricle, helix, tragus, lobule, semicircular canals, vestibule, vestibular apparatus, temporal bone, tympanic membrane, external auditory canal, vestibulocochlear nerve, auditory ossicles, cochlea, oval window, round window, and eustachian tube.

External Ear Structures

• Auricle/Pinna
• External Auditory Canal

Auricle

• Also known as the pinna.
• It is attached to the side of the head by skin.
• It is made mostly of cartilage.
• Earlobe: primarily fat and subcutaneous tissue.
• It collects sound waves and directs vibrations into the external auditory canal.

Anatomy of the Auricle:

• Helix
• Superior crus
• Inferior crus
• Concha
• Antihelix
• Antitragus
• Lobule
• Darwin's tubercle
• Scapha
• Triangular fossa
• Helical crus
• Cymba concha
• Incisura
• External auditory meatus
• Intertragal notch

External Auditory Canal

• Length: 2 to 3 cm long.
• Lateral Third: Elastic cartilaginous and dense fibrous framework, with attached skin.
• Medial Two-Thirds: Bone lined, featuring thin skin.
• It ends at the tympanic membrane.
• It contains hair, sebaceous glands, and ceruminous glands which produce cerumen.
• Is self-cleaning by moving old skin cells and cerumen to the outer part of ear
• Anterior to the tempomandibular joint.

Middle Ear

• An air filled cavity
• It is connected to the nasopharynx by the Eustachian tube.
• Is continuous with air filled cells in the adjacent mastoid portion of the temporal bone.
• Structures include: tympanic membrane, eustachian tube, and ossicles.

Eustachian Tube

• About 35mm long, and 1mm wide.
• It connects the middle ear to the nasopharynx.
• It drains secretions from the middle ear.
• It equalizes pressure in the middle ear with atmospheric pressure.
• It is usually closed but opens by action of the tensor veli palatini muscle
• The tensor veli palatini opens during a valsalva maneuver, yawn, or swallow

Tympanic Membrane

• Also Known as the eardrum.
• It is about 1cm in diameter and very thin.
• Described as pearly grey and translucent.
• Has three layers: outer layer (continuous with ear canal skin), middle layer (fibrous), and inner layer (mucosal, continuous with the middle ear cavity lining).
• Pars tensa: 80% is covered by all three layers
• Pars flaccida: 20% which lacks the middle layer
• Conducts sound vibrations from external canal to ossicles
• Sound pressure is magnified 22x because of transmission from larger to smaller area.

Anatomy of the Tympanic Membrane

• Pars flaccida
• Anterior fold
• Posterior fold
• Short process of malleus
• Manubrium of malleus
• Umbo
• Pars tensa
• Cone of light
• Annulus
• Incus

Ossicles

• Three smallest bones in the body.
• Held in place by joints, muscles, and ligaments
• Assist in transmission of sound
• Includes: malleus, incus, and stapes.

Inner Ear

• It is housed within the temporal bone.
• Consists of structures for hearing by the cochlea, and balance by semicircular canals.
• Facial nerve (VII) and vestibulocochlear nerve (VIII) are located here.
• Parts: bony labyrinth and membranous labyrinth.

Membranous Labyrinth

• Housed inside the bony labyrinth.
• Bathed in endolymph.
• Composed of the utricle and saccule for linear movement, cochlear duct, semicircular canals for rotational movement, and the organ of corti for hearing.

Functions of the Ears

• Hearing
  • bone conduction (BC) vs air conduction (AC) : AC > BC
• Balance and Equilibrium

Hearing Process

• Air Conduction
  • Sound waves travel through the external auditory canal.
  • The tympanic membrane vibrates, causing the ossicles to vibrate to the oval window.
  • Lag occurs between the oval and round window with healthy TM, but no lag and hearing loss if TM is perforated. Oval window moves, lag time, round window.
  • The hair cells of the organ of Corti convert energy into electrical signals.
  • Cranial nerve VIII is stimulated to send signals to central nervous system to interpret the sound.
• Bone Conduction
  • Sound waves bypass the external and middle ear, traveling directly to the inner ear through bone.
  • Next to stapes rock and fluid waves
  • Movement of basilar membrane which stimulates hair cells in organ of corti in cochlea.
  • Electrical current formed stimulates cochlear area.
  • Hair cells get stimulated, and impulses sent to auditory cortex in the brain.

Assessment of the Ear

• Inspection of External Ear
  • Inspection and Direct palpation
  • Assess auricle and surrounding tissues for deformities, lesions, discharge
  • Assess for Size/symmetry, angle of attachment to the head
• Otoscopic Examination
• Inspect tympanic membrane and external auditory canal
• Evaluation of Gross Auditory Acuity
  • Whisper Test: occlude one ear at a time while examiner whispers towards clear ear on either side to test general hearing
    • Examiner covers untested ear with palm and whispers into tested ear for 1-2 ft away.
    • Patient with NORMAL acuity can correctly repeat whispered word
  • Weber and Rinne Test - use tuning fork to test for conductive vs sensorineural hearing loss
    • Sound heard equally in both ears and AC is heard longer than BC = Normal Hearing
    • Sound heard best in affected ear and Sound heard as long or longer in affected ear (hearing loss) = Conductive Hearing Loss
    • Sound is heard best in normal hearing ear and Air conduction is audible longer than bone conduction in affected ear = Sensorineural Hearing Loss

Diagnostic Evaluation

• Audiometry
  • Detects degree and type of hearing loss.
  • Single most important diagnostic instrument.
  • Two main types: Pure tone audiometry and Speech audiometry.
  • Evaluates three characteristics: Frequency, Pitch, and Intensity.
    • 0-15dB is normal hearing, greater than 90dB is profound hearing loss

Diagnostic Evaluation:

• Typanogram/impedance audiometry
  • Measures middle ear muscle reflex to sound stimulation.
  • Measures compliance of tympanic membrane by changing air pressure in sealed ear canal.
  • Compliance is impaired with middle ear disease
• Middle Ear Endoscopy
• Use of endoscopes
• Minimally inclusive
• Evaluate suspected perilymphatic fistula and new onset hearing loss/anatomy of round window and tympanic cavity

Auditory Disturbances:

• Otitis Externa
• Malignant Otitis Externa
• Otitis Media: acute, chronic, or serous
• Cholesteatoma
• Otosclerosis

Otitis Externa

• Inflammation of external auditory canal.
• Causes: water in ear canal (swimmer's ear), trauma and systemic conditions (vitamin deficiency and endocrine problems)
• Mainly due to bacteria and fungal infections Common Bacteria: S. Aureus and Pseudomonas species Fungal: Aspergillus
• Could also be to Psoriasis, Eczema, Seborrheic dermatitis, Allergic reactions (hair spray, dye, lotions)
• Symptoms: pain, aural tenderness, fever and hearing loss.
• Sign: Erythema, edema, yellow or green discharge or fungal like black spores

Otitis Externa: Medical Management

• Goal: Pain relief, reduce swelling, and infection eradication
• Include: Analgesics, Antimicrobial or Antifungal medications, Corticosteroids
• Instruct patient: avoid cleaning ear and keep ear dry to prevent swimmer's ear.

Otitis Externa Prevention

• Protect the external canal when swimming/showering/washing hair by using ear plugs or cotton and drying with hairdryer on low.
• Place alcohol drops to dry out ear canal
• Prevent trauma to the external canal such as scratching
• Avoid any water sport for 7-10 days to allow the external canal to completely heal.

Malignant Otitis External

• More serious, rare, external ear infection.
• Also known as temporal bone osteomyelitis
• Progressive, debilitating, occasionally fatal infection of auditory canal
• Risk populations: patients with immune system deficiencies (AIDS/HIV)
• Causative agent: Pseudomonas aeruginosa
• Treatment: IV antibiotics, wound care and combination antipseudomonal and aminoglycoside.

Acute Otitis Media

• Acute infection of the middle ear that occurs for less or less than 6 weeks.
• Most commonly seen in children
• Risk Factors: younger aged children, having chronic URTI, infections, medical conditions such as Down Syndrome or a cleft palate.
• Risk Factors: exposure to Second hand smoke.
• Pathogens: bacterial and viral
• A purulent exudate is mostly related to conductive hearing loss Symptoms: otalgia(ear pain) may be unilateral, drainage from ear, fever and hearing loss.
• Medical Management: Broad-spectrum antibiotics antibiotic otic preparation for drainage infection

Acute Otitis Media: Surgical Intervention

• Myringotomy/Tympanotomy: painless, less than 15 minutes, outpatient
• Performed if pain persists to allows for drainage and analyzed.
• Healing time is between 24- 74 hours

Serous Otitis Media

• Middle ear effusion.

• Presence of fluid WITHOUT evidence of active infection

• From negative pressure in middle ear caused by Eustachian tube obstruction

• Seen in patients post-radiation therapy or barotrauma or eustachian tube dysfunction.

• Clinical Manifestations: hearing loss, feelings of fullness and congestion, crackling noises as eustachian tube opens.

• Otoscopy, dull tympanic membrane with air bubbles.

• Audiogram causes conductive hearing loss

• Medical intervention not needed unless INFECTION occurs May consider: hearing loss is significant myringotomy, decrease edema with corticosteriods. Valsalva maneuver cautiously, may perforate tympanic membrane or worsen pain

Chronic Otitis Media

• Recurrent AOM that causes irreversible tissue pathology.
• Includes damage to tympanic membrane and mastoid.
• Rare in developed countries
• Clinical Manifestations: may be minimal, varying degrees of hearing loss, persistent or intermittent foul-smelling otorrhea, otoscope shows perforation or can see cholesteatoma
• Symptoms: NO PAIN unless acute mastoiditis or may have mastoiditis leading to cholesteatoma
• Cholesteatoma: A cyst-like lesion of external layer of tympanic membrane into middle ear, sac that forms with dead skin/materials
• Medical Management: local treatment suctioning under otoscopic guidance, antibiotic drops or powders
• IN ACUTE infection, systemic antibiotics are only give

Chronic Otitis Media: Surgical Interventions

• Tympanoplasty
• Ossiculoplasty
• Mastoidectomy

Surgical Interventions: Tympanoplasty

• Most common surgical procedure or COM
• Purpose: surgical reconstruction of tympanic membrane & reestablish middle ear function and prevent reoccurrence
• Done through trans canal approach

Types of tympanoplasty

• TM or malleus
• Incuse or remnant of malleus
• Stapes superstructure
• Stapes footplate
• Fenestra of hormone

Surgical Interventions: Occiculoplasty

• The ossicles get surgical reconstruction.
• Prostheses can be used like Teflon, and stainless steel.
• The larger amount of damage, leads the lower rate of success to restore normal hearing

Surgical Interventions: Mastoidectomy

• Objective: remove cholesteatoma, to fix diseased structures
• Ossicle can be reconstructed
• A two stage operation may be operated due to extensive disease -1st stage: eliminate infection -2nd stage: To remove cyst and reconstruct bones
• To check to see in air sells got removed
• Facial nerve can be damaged

Otosclerosis

• Risk factors: Women and Familial condition
• Causes:
  • Involves stages
  • Formation abnormal,spony bone, and a stapes vibration cant occur which prevents sound transmission May include one to both ears, may or may not have chronic tinnitus. Ostoscope is not damaged but rinne test is BC < AC (bone condition is more in effect than auditiory canal ) May involve one to both ears

Clinical manifestation Otoscleros

 - Progressive conducted
 - Test confirms mixed hearing loss

Medical: May use sodium fluoride after surgery

Otosclerosis medical managment

• stapedectomy.
• majority of patients experience solution by conducting in new hearing loss balance destruction is rare after surgical

Homework Topics: to learn more about ears

• Trace the following ear disorders like impcated cerumen, foreign bodies Signs and symptoms, medical and surgical managment
• Meniere's Diease/versis benigon parostysamal: medical and surgical Risk factors and medical complications.