BMS 200: HEENT Overview Quiz

HEENT 2 - Overview

• Topics covered include ear and vestibular apparatus pathologies, general mouth and sinus anatomy, and the neurology of olfactory and gustatory pathways.
• This is a BMS 200 course.

Ear Pathologies

• Conductive vs. sensorineural hearing loss: Distinguishing between types of hearing loss.
• Otitis externa & otomycosis: Ear canal infections.
• Otitis media: Inflammation of the middle ear.
  • Acute otitis media (AOM): Rapid onset of symptoms.
  • Otitis media with effusion (OME): Fluid buildup in the middle ear.
  • Chronic otitis media: Long-term inflammation.
• Cholesteatoma: A non-cancerous cyst with keratin debris.
• Tympanic membrane perforations: A hole in the eardrum.

Hearing Loss - Generalities

• Incidence of hearing loss: About 15% of people between 20 and 69 years old experience some degree of high-frequency hearing loss, often due to noise.
• Outer hair cell vulnerability: Outer hair cells are more susceptible to noise damage than inner hair cells.
• Presbycusis: Age-related hearing loss caused by a combination of neuronal and hair cell loss.
• Ototoxic substances: Antibiotics and other drugs can damage the inner ear.

Hearing Loss - Generalities (Conductive and Sensorineural)

• Conductive hearing loss: Impaired sound transmission in the outer or middle ear. Impacted by trauma, infection, plugging of the ear canal, otosclerosis, or cholesteatoma. This affects all frequencies.
• Sensorineural hearing loss: Loss of higher frequencies more than lower ones. This is often caused by presbycusis, ototoxic agents, or noise. Also involves endolymph problems, labyrinth or CN 8 infections/tumors.

Tuning Fork Investigation of Hearing

• Weber test: Tuning fork placed on the head to assess bone conduction hearing. If sound is louder in one ear, it might suggest conduction hearing loss in that ear. Sound is heard equally in both ears if normal.
• Rinne test: Tuning fork placed on mastoid then near ear to assess both air and bone conduction. Air conducted sound is heard after bone conduction stops if normal.

Audiometry

• Frequency range: Human hearing range from 20 to 20,000 Hz, though best between 1000-4000 Hz for speech (500-2000Hz).
• Audiometry assessment: Measures hearing at specific frequencies to characterize hearing loss better than tuning forks.
• Different forms of audiometry: Includes speech audiometry.

Otitis Externa

• Causative agent: Bacterial (90%) - mainly staphylococcal, Pseudomonas aeruginosa, or E. coli.
• Risk factors: Humidity, cerumen loss (trauma/Q-tip use), heat, increased pH, ear canal obstruction, and exposure to water (especially colonized).
• Clinical features: Otalgia (pain in ear), movement of pinna can elicit pain, otorrhea (ear discharge) - can be purulent, itching of external canal, edema/occlusion of ear canal, conductive hearing loss.
• Treatment: Topical antibiotics.

Otitis Externa - Variations

• Furunculosis: Staphylococcal infection in outer 1/3 ear canal. Often painful.
• Chronic otitis externa: Repetitive trauma cause, more itchy, chronic drainage.
• Malignant/necrotizing otitis externa: Progressive, serious, often damaging temporal bone/cranial nerves.
• Otomycosis: Fungal infection (usually 80% Aspergillus, remaining common species Candida).

Otitis Media

• Acute otitis media (AOM): Rapid onset of symptoms (fever, otalgia), typically lasting less than 6 months, recurrent is ≥ 3 episodes within 6 months with complete resolution in between episodes or ≥ 4 in 12 months.
• Causes: Auditory tube dysfunction, blocked tube due to adenoid swelling/URTI. Bacteria often from upper airway/oral flora.
• Symptoms: Rapid onset and severity of otalgia, fever, and sometimes conductive hearing loss. Possible otorrhoea (possible).
• Clinical features: Bulging, redness in tympanic membrane, often opaque, loss of bony landmarks, limited mobility (especially with effusion behind membrane) on pneumatoscopy.
• OME (Serous Otitis Media): Unresolved AOM, persistent effusion in affected ear. 3 months of persistent effusion.
• Clinical features: Conductive hearing loss, fullness in ear (possible tinnitus or low-grade fever).
• Otoscopic features: Translucent/gray TM, possibly fluid behind TM visible as air/fluid levels or bubbles. Loss of light reflex/reduced mobility.

Tympanic Membrane Perforations

• Causes: Middle ear infections, trauma (barotrauma or physical injury).
• Clinical features: Sudden onset of pain, hearing loss, might be bloody otorrhoea, dizziness, or tinnitus.
• Healing: Often self-heals spontaneously.
• Importance of location: Posterio-superior damage to TM more likely to damage ossicles, needing urgent referral.

Chronic Otitis Media

• Causes: Recurrent or chronic ear infections, Eustachian tube dysfunction (approximately 70% of patients observed after middle ear surgery).
• Types: Suppurative or serous, described by chronic drainage through perforated TM, Benign - no active infection "dry". Inflammatory effect, both middle ear and affected mastoid.
• Clinical features: Otorrhoea. Possible conductive hearing loss, tinnitus and fullness in ear.

Cholesteatomas

• Definition: Non-neoplastic cysts lined with keratinizing epithelium. Filled with debris.
• Location: Mostly in the posterior-superior region (attic) of the middle ear.
• Size: Typically 1-4 cm.
• Types: Congenital (rare). Primary acquired, Secondary acquired.
• Complications: Conductive hearing loss (most minor), bony erosion, temporal bone infections, meningitis, intracranial involvement, deep neck infections, possible rupture resulting in life-threatening problems.

Dizziness

• Classification: Vertiginous (vertigo-environment moving) or Non-vertiginous (organic or functional).
• Vertiginous/vertigo: Caused by issues with inner ear or brainstem-cerebellar disorders (peripheral/central).
• Non-vertiginous: Usually organic disorders involving vision compromise or low blood pressure, or functional disorders related to mood.

Benign Paroxysmal Positional Vertigo (BPPV)

• Description: Short-lasting episodes of vertigo triggered by head position changes (especially when getting out of bed, turning head), typically not involving spontaneous nystagmus.
• Presentation: Quick onset, usually <1 minute, of rotatory nystagmus (movement of eyeball), often accompanied by nausea or vomiting.
• Cause: Free-floating otoliths in semicircular canals causing sensory disruption.
• Diagnosis: Dix-Hallpike test, showing nystagmus when turning head in specific positions.

Meniere's Disease

• Symptoms: Episodic attacks of tinnitus, hearing loss, and vertigo lasting minutes to hours.
• Mechanism: Endolymphatic over-accumulation in the membranous labyrinth may result in distorting inner ear.
• Triggers: High salt intake, caffeine, stress, nicotine, alcohol
• Diagnostics: Two spontaneous episodes of rotational vertigo lasting > 20 minutes. Associated to sensorineural hearing loss.

Vestibular Neuronitis

• Description: Sudden onset of disabling vertigo, often accompanied by nausea/vomiting, and imbalance. Hearing loss is usually absent.
• Presentation: Acute phase: severe vertigo, nausea, vomiting, and imbalance lasting 1-5 days, nystagmus. Convalescent phase: imbalance, motion sickness lasting days to weeks, gradual vestibular adaptation for weeks-months.

Labyrinthitis

• Description: Acute infection of the inner ear resulting in vertigo and hearing loss. Infection can be viral (serous) or purulent/bacterial (often a complication of acute or chronic otitis media).
• Presentation: Sudden onset of vertigo, nausea/vomiting, tinnitus, hearing loss (unilateral). May be associated with fever/pain(uncommon), bacterial may involve meningitis.
• Causes: Bacterial (S. pneumoniae, H. influenzae, M. catarrhalis, etc.), viral (rubella, CMV, measles, mumps, varicella zoster), and possible autoimmune cause; meningitis could be complication.

Acoustic Neuroma

• Description: Intracranial tumor that develops from Schwann cells in vestibular and/or cochlear nerve. Often observed in the cerebellopontine angle with ~ 80% of tumors in the area being related to acoustic.
• Presentation: Imparting hearing, sometimes facial nerve symptoms via tumor expansion. May have elevated intracranial pressure if tumor progresses enough.
• Diagnosis: MRI imaging of the relevant area of the brain.
• Treatment: Surgical removal/radiation.

Test your knowledge on the anatomy and pathologies of the ear, mouth, and sinus as covered in the BMS 200 course. This quiz focuses on various types of hearing loss, infections, and the neurological pathways related to taste and smell. Dive into the details of otitis and other key topics.