Tympanic Membrane Perforation

Tympanic Membrane Perforation

Tympanic Membrane Perforation

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TM Perforation: Anatomy & Intro - The Drum Breach

  • Definition: A defect or hole in the tympanic membrane (TM), separating the external auditory canal from the middle ear.
  • Anatomy of TM:
    • Layers (3): Outer squamous epithelium, middle fibrous (radial & circular fibers), inner mucosal. 📌 Mnemonic: Elephants Find Mice (Epithelial, Fibrous, Mucosal).
    • Parts: Pars Tensa (inferior, larger, taut, 3 layers, main vibratory part); Pars Flaccida (Shrapnell's membrane; superior, smaller, lax, 2 layers - lacks fibrous layer).
  • Significance: Impairs sound conduction (hearing loss) & protection. Anatomy of the Tympanic Membrane with Key Landmarks

⭐ The absence of the middle fibrous layer in Pars Flaccida makes it more susceptible to retraction and the development of attic cholesteatoma.

TM Perforation: Etiology & Types - Why Drums Burst

  • Etiology:
    • Traumatic:
      • Direct: Q-tip injury, foreign body, iatrogenic (e.g., syringing).
      • Indirect: Barotrauma (slap, blast, diving), temporal bone fracture.
    • Infective:
      • Acute Suppurative Otitis Media (ASOM): Pus bursts through TM.
      • Chronic Suppurative Otitis Media (CSOM): Persistent perforation.
  • Types (Site):
    • Central (Tubotympanic): Pars tensa; TM remnant all around. Generally safer.
    • Marginal (Atticoantral): Involves annulus; cholesteatoma risk ↑.
    • Attic (Atticoantral): Pars flaccida; cholesteatoma risk ↑.

      ⭐ Marginal & Attic perforations are considered unsafe/dangerous due to high cholesteatoma risk.

  • Types (Size): Small (<25%), medium (25-50%), large (>50%), subtotal.

Tympanic membrane perforations: central, marginal, and atticoka

TM Perforation: Clinical Features - Hole Telltales

  • Symptoms:
    • Hearing loss: Conductive, severity varies with size/location.
    • Otorrhea: If infected; mucoid, purulent, or blood-tinged.
    • Tinnitus: Whistling, especially with small perforations.
    • Otalgia: Usually brief, with acute injury or infection.
  • Signs (Otoscopy):
    • Visible perforation: Central, marginal, or attic.
    • Loss of landmarks: Cone of light, handle of malleus may be visible through hole.
    • Middle ear mucosa: May be visible, normal or inflamed.

⭐ Rinne test negative (bone conduction > air conduction) in affected ear; Weber test lateralizes to affected ear (conductive hearing loss).

TM Perforation: Diagnosis - Spotting the Split

  • Otoscopy:
    • Direct visualization of perforation (site, size, shape).
    • Margins: Acute (sharp edges), Chronic (rounded, epithelialized).
    • Middle ear mucosa may be visible. Perforated Tympanic Membrane: Otoscopic View vs. Diagrams
  • Tuning Fork Tests (512 Hz):
    • Rinne: Negative (BC > AC) in affected ear.
    • Weber: Lateralizes to affected ear.
  • Audiometry:
    • Pure Tone Audiometry (PTA): Conductive Hearing Loss (CHL); degree varies with size/site.
    • Tympanometry: Type B curve (large ear canal volume).

⭐ In PTA, an air-bone gap > 15-20 dB is significant for CHL in TM perforation contexts.

TM Perforation: Management & Complications - Mending & Mayhem

Myringoplasty: Tympanic Membrane Perforation Repair

Management Strategy:

  • Conservative:
    • Keep ear dry (water precautions).
    • Antibiotic ear drops if signs of infection (e.g., ciprofloxacin).
    • Observation for spontaneous healing (common in traumatic perforations).
  • Surgical (Myringoplasty):
    • Indications: Perforation persisting > 3-6 months, recurrent otorrhea, significant hearing loss.
    • Techniques: Underlay, Overlay (temporalis fascia commonest graft).

Potential Complications:

  • Hearing Loss (Conductive/Mixed).
  • Chronic Suppurative Otitis Media (CSOM) - persistent discharge.
  • Cholesteatoma formation (especially marginal perforations).
  • Tympanosclerosis.
  • Recurrent infections.

⭐ Most traumatic TM perforations, especially small to moderate central ones, heal spontaneously within 6-8 weeks to 3 months. Water precautions are crucial during this period.

High‑Yield Points - ⚡ Biggest Takeaways

  • Most common causes: Trauma (e.g., slap, Q-tip injury) and Acute Suppurative Otitis Media (ASOM).
  • Most common site: Pars tensa, especially the anteroinferior quadrant.
  • Key symptoms: Conductive hearing loss (CHL), tinnitus; otorrhea if infected.
  • "Safe" vs. "Unsafe": Central perforations are generally safe; marginal and attic perforations are unsafe due to cholesteatoma risk.
  • Healing: Small, dry traumatic perforations often heal spontaneously within weeks.
  • Management: Keep ear dry; myringoplasty for persistent or symptomatic perforations.
  • Blast injury: Often causes multiple perforations or subtotal/total loss of the tympanic membrane.

Practice Questions: Tympanic Membrane Perforation

Test your understanding with these related questions

A 65-year-old patient presents with gradual progressive hearing loss over several years. Rinne test shows bone conduction > air conduction bilaterally. Weber test lateralizes to the worse ear. Tympanic membranes are intact and normal. Which is the most likely diagnosis?

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Flashcards: Tympanic Membrane Perforation

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The surgery done to widen the cartilaginous part of the external auditory canal is _____.

TAP TO REVEAL ANSWER

The surgery done to widen the cartilaginous part of the external auditory canal is _____.

meatoplasty

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