Mastoidectomy — MCQs
Nerve most commonly damaged in radical mastoidectomy is -
All of the following techniques are used to control bleeding from bone during mastoid surgery except:
All of the following are of adult size at birth except?
What is the treatment of choice for atticoantral type of chronic suppurative otitis media?
In a child aged 3-12 years with an ear problem, which one of these situations merits urgent referral to hospital?
All are true about Mastoid antrum except
A 72-year-old man presents to his primary care physician with progressively worsening hearing loss. He states that his trouble with hearing began approximately 7-8 years ago. He is able to hear when someone is speaking to him; however, he has difficulty with understanding what is being said, especially when there is background noise. In addition to his current symptoms, he reports a steady ringing in both ears, and at times experiences dizziness. Medical history is significant for three prior episodes of acute otitis media. Family history is notable for his father being diagnosed with cholesteatoma. His temperature is 98.6°F (37°C), blood pressure is 138/88 mmHg, pulse is 74/min, and respirations are 13/min. On physical exam, when a tuning fork is placed in the middle of the patient's forehead, sound is appreciated equally on both ears. When a tuning fork is placed by the external auditory canal and subsequently on the mastoid process, air conduction is greater than bone conduction. Which of the following is most likely the cause of this patient's symptoms?
A patient with cholesteatoma has lateral semicircular canal fistula. The most specific sign is:
What is the diagnosis shown in the following image?
The cough response elicited while cleaning the external ear canal is mediated by stimulation of which nerve?
Mastoidectomy Indian Medical PG Practice Questions and MCQs
Question 1: Nerve most commonly damaged in radical mastoidectomy is -
- A. Cochlear
- B. Facial (Correct Answer)
- C. Vestibular
- D. All of the options
Explanation: ***Facial*** - The **facial nerve (cranial nerve VII)** runs through the temporal bone in close proximity to the operative field during a radical mastoidectomy. - Due to its anatomical course through the middle ear and mastoid, it is the most vulnerable nerve to iatrogenic injury during this procedure, leading to **facial paralysis**. *Cochlear* - The **cochlear nerve** is responsible for hearing and is located deeper within the inner ear (cochlea). - While damage to the inner ear structures can cause hearing loss, direct injury to the cochlear nerve itself is less common during a mastoidectomy compared to the facial nerve. *Vestibular* - The **vestibular nerve** is responsible for balance and is part of the vestibulocochlear nerve (cranial nerve VIII), located in the inner ear. - Damage to the vestibular nerve or associated structures can cause **vertigo and imbalance**, but direct injury to the nerve during mastoidectomy is less common than facial nerve injury. *All of the options* - While damage to the cochlear and vestibular nerves (leading to hearing loss or balance issues) can occur with extensive or complicated mastoid surgery affecting the inner ear, the **facial nerve** is by far the most frequently implicated and specifically vulnerable nerve during a radical mastoidectomy due to its anatomical course. - Therefore, it is incorrect to state that all these nerves are equally or most commonly damaged.
Question 2: All of the following techniques are used to control bleeding from bone during mastoid surgery except:
- A. Cutting drill over the bleeding area (Correct Answer)
- B. Diamond drill over the bleeding area
- C. Bipolar cautery over the bleeding area
- D. Bone wax
Explanation: ***Cutting drill over the bleeding area*** - A **cutting drill** is designed to remove bone rapidly and would *exacerbate bleeding* from bone by causing further trauma to blood vessels, not control it. - Its sharp flutes create a cutting action that is unsuitable for managing hemorrhage, unlike instruments designed for coagulation or surface abrasion. *Diamond drill over the bleeding area* - A **diamond drill** is effective for controlling superficial bone bleeding because its abrasive action polishes and **occludes small vascular channels**, creating less trauma than a cutting drill. - The friction generated by the diamond burr can also contribute to **thermal coagulation** of small vessels. *Bipolar cautery over the bleeding area* - **Bipolar cautery** uses electrical current to **coagulate bleeding vessels** directly in the bone, effectively sealing them. - It is a common and effective method for controlling bone bleeding, especially for larger vascular channels exposed during drilling. *Bone wax* - **Bone wax** (e.g., paraffin wax or beeswax) is a sterile mixture used to mechanically **occlude bleeding capillaries and small vessels** within the cut edges of bone. - It acts as a **physical barrier** to bleeding, providing immediate hemostasis when pressed onto the bleeding bone surface.
Question 3: All of the following are of adult size at birth except?
- A. Tympanic cavity
- B. Mastoid (Correct Answer)
- C. Tympanic membrane
- D. Ossicle
Explanation: ***Mastoid*** - The **mastoid air cells** and the entire mastoid bone are not fully developed at birth and continue to **pneumatize and grow** throughout childhood. - This ongoing development is why infants and young children are more susceptible to complications like **mastoiditis** that spread from middle ear infections, as the bone is still permeable and developing. *Tympanic cavity* - The **tympanic cavity** (middle ear space) reaches its adult size relatively early in fetal development, meaning it is largely adult-sized at birth. - This allows for the immediate function of sound transmission, even in newborns. *Tympanic membrane* - The **tympanic membrane (eardrum)** is also essentially adult-sized at birth, although its position and angle may change during development. - Its full size and structure are crucial for efficient sound reception from delivery. *Ossicle* - The **ossicles (malleus, incus, stapes)**, the smallest bones in the body, are fully formed and adult-sized at birth. - Their completed development is necessary for the immediate and effective transmission of sound vibrations to the inner ear.
Question 4: What is the treatment of choice for atticoantral type of chronic suppurative otitis media?
- A. Tympanoplasty
- B. Modified radical mastoidectomy (Correct Answer)
- C. Antibiotics
- D. None of the options
Explanation: ***Modified radical mastoidectomy*** - This procedure is the treatment of choice for **atticoantral type of chronic suppurative otitis media (CSOM)** due to the presence of **cholesteatoma**, which requires complete surgical removal. - It involves removing the posterior and superior canal wall, exenterating the mastoid air cells, and exteriorizing the **aditus and antrum** into the external auditory canal to create a common cavity. - Unlike radical mastoidectomy, it **attempts to preserve the tympanic membrane and ossicular chain when disease extent permits**, thereby maintaining the middle ear transformer mechanism and optimizing hearing outcomes. *Antibiotics* - While antibiotics may be used to manage acute exacerbations or infections, they cannot eradicate the inherent **cholesteatoma** found in atticoantral CSOM. - They primarily target bacteria and have no effect on the **pathological skin growth** that characterizes cholesteatoma. *Tympanoplasty* - **Tympanoplasty** is a reconstructive procedure primarily used for repairing a **perforated tympanic membrane** or ossicular chain defects, typically in the tubotympanic type of CSOM. - It does not address the fundamental problem of **cholesteatoma** and its destructive potential in atticoantral disease. *None of the options* - This is incorrect because **modified radical mastoidectomy** is a well-established and effective treatment for atticoantral CSOM. - Omitting treatment would lead to progressive destruction of middle ear structures and potentially life-threatening complications.
Question 5: In a child aged 3-12 years with an ear problem, which one of these situations merits urgent referral to hospital?
- A. Pus seen draining from the ear, and discharge reported for more than or equal to 14 days
- B. Pus seen draining from the ear, and discharge reported for less than 14 days
- C. Tender swelling behind the ear (Correct Answer)
- D. Pus seen draining from both ears, irrespective of duration
Explanation: ***Tender swelling behind the ear*** - A **tender swelling behind the ear**, particularly in a child with an ear problem, is a classic sign of **mastoiditis**, which is a serious complication requiring urgent medical attention due to the risk of intracranial spread. - **Mastoiditis** often presents with fever, pain, and a prominent, pushed-out auricle. *Pus seen draining from the ear, and discharge reported for more than or equal to 14 days* - This suggests **chronic suppurative otitis media (CSOM)**, which typically requires a referral to ENT for assessment and management but is not usually an *urgent* referral unless there are signs of complications. - While concerning, the chronicity itself doesn't immediately indicate an acute emergency in the absence of other symptoms like fever or severe pain. *Pus seen draining from the ear, and discharge reported for less than 14 days* - This indicates acute otitis media (AOM) with perforation, which is very common in children. - It usually resolves with antibiotics and local care, and while a follow-up is important, it doesn't typically require urgent hospital referral. *Pus seen draining from both ears, irrespective of duration* - Bilateral ear discharge suggests bilateral acute or chronic otitis media, but does not inherently imply an acute emergency that requires urgent hospital referral. - The key factor for urgency would be signs of complications, such as mastoiditis or intracranial involvement, rather than the bilaterality of discharge alone.
Question 6: All are true about Mastoid antrum except
- A. Surface marking done by McEwen's Triangle
- B. It does not communicate with middle ear (Correct Answer)
- C. Thickness of bone of lateral wall is about 1.5 cm
- D. Air cells are present in the upper part
Explanation: ***It does not communicate with middle ear*** - The **mastoid antrum** is a crucial air-filled cavity located in the mastoid process of the **temporal bone**. - It **communicates directly with the middle ear** cavity through an opening called the **aditus ad antrum**, making this statement false. *Surface marking done by McEwen's Triangle* - **McEwen's Triangle** (also known as the **suprameatal triangle**) is a widely recognized surgical landmark used to locate the **mastoid antrum**. - Its boundaries are formed by the **supramastoid crest**, the **posterior margin of the external auditory meatus**, and a line tangential to the superior margin of the external auditory meatus. *Thickness of bone of lateral wall is about 1.5 cm* - The thickness of the **lateral wall** of the **mastoid antrum** varies among individuals but averages around **1.5 cm** in adults. - This anatomical measure is clinically important during mastoidectomy procedures to avoid intracranial complications. *Air cells are present in the upper part* - The **mastoid antrum** itself is a relatively large, singular air-filled cavity. - However, it **communicates with numerous mastoid air cells**, which are indeed found throughout the mastoid process, with a significant number often present in the **upper part** and surrounding regions.
Question 7: A 72-year-old man presents to his primary care physician with progressively worsening hearing loss. He states that his trouble with hearing began approximately 7-8 years ago. He is able to hear when someone is speaking to him; however, he has difficulty with understanding what is being said, especially when there is background noise. In addition to his current symptoms, he reports a steady ringing in both ears, and at times experiences dizziness. Medical history is significant for three prior episodes of acute otitis media. Family history is notable for his father being diagnosed with cholesteatoma. His temperature is 98.6°F (37°C), blood pressure is 138/88 mmHg, pulse is 74/min, and respirations are 13/min. On physical exam, when a tuning fork is placed in the middle of the patient's forehead, sound is appreciated equally on both ears. When a tuning fork is placed by the external auditory canal and subsequently on the mastoid process, air conduction is greater than bone conduction. Which of the following is most likely the cause of this patient's symptoms?
- A. Stapedial abnormal bone growth
- B. Endolymphatic hydrops
- C. Cochlear hair cell degeneration (Correct Answer)
- D. Accumulation of desquamated keratin debris
Explanation: ***Cochlear hair cell degeneration*** - The patient's **progressive, bilateral hearing loss** over several years, difficulty understanding speech in noise, and **tinnitus** are classic symptoms of **presbycusis**, which results from age-related **degeneration of cochlear hair cells**. - The **normal Weber test** (no lateralization) and **Rinne test** (air conduction > bone conduction) indicate a **sensorineural hearing loss**, consistent with cochlear pathology rather than conductive issues. *Stapedial abnormal bone growth* - This condition (**otosclerosis**) causes **conductive hearing loss** due to fixation of the stapes, which would present with an **abnormal Rinne test** (bone conduction > air conduction) in the affected ear. - While it can cause progressive hearing loss and tinnitus, the normal Rinne test contradicts this diagnosis. *Endolymphatic hydrops* - This is the underlying pathology of **Ménière's disease**, which typically presents with episodic vertigo, fluctuating sensorineural hearing loss, tinnitus, and aural fullness. - The patient's dizziness is non-episodic, and the absence of fluctuating hearing loss and aural fullness makes Ménière's less likely. *Accumulation of desquamated keratin debris* - This describes a **cholesteatoma**, which typically causes **conductive hearing loss** and often presents with otorrhea, earache, and possibly vestibular symptoms. - The normal Rinne test (indicating sensorineural loss) and lack of otorrhea or earache make cholesteatoma unlikely, despite a family history.
Question 8: A patient with cholesteatoma has lateral semicircular canal fistula. The most specific sign is:
- A. Head thrust test
- B. Fistula test (Correct Answer)
- C. Hennebert's sign
- D. Dix-Hallpike test
Explanation: ***Fistula test*** - The **fistula test** (Positive pressure test or Hennebert's test) directly assesses for a communication between the middle ear and the labyrinth by applying positive or negative pressure to the external auditory canal. - A positive result, indicated by **nystagmus** or **vertigo** induced by pressure changes, is the **most specific sign** for a **labyrinthine fistula** in the context of **cholesteatoma**. - The lateral semicircular canal is the most commonly affected site in cholesteatoma-related fistulae. *Hennebert's sign* - **Hennebert's sign** refers to **nystagmus** or **vertigo** induced by pressure changes in the external auditory canal **in the absence of an actual fistula**. - It represents a **false positive fistula test** and is classically associated with **congenital syphilis**, **Meniere's disease**, or other conditions causing increased labyrinthine membrane mobility. - In this case with a **confirmed fistula**, the positive pressure test would be called a **positive fistula test**, not Hennebert's sign. *Head thrust test* - The **head thrust test** evaluates the function of the **vestibulo-ocular reflex (VOR)** and is used to detect **peripheral vestibular hypofunction**. - While cholesteatoma can affect vestibular function, this test is **not specific** for identifying a **labyrinthine fistula**. *Dix-Hallpike test* - The **Dix-Hallpike test** is used to diagnose **Benign Paroxysmal Positional Vertigo (BPPV)** by identifying nystagmus and vertigo triggered by specific head positions. - This test detects **otoconia displacement** in the semicircular canals and is **not relevant** for identifying a **labyrinthine fistula**.
Question 9: What is the diagnosis shown in the following image?
- A. Hyperinsulinism
- B. Conductive hearing defect
- C. Perichondritis (Correct Answer)
- D. Mucopolysaccharidosis
Explanation: ***Perichondritis*** - The image exhibits signs of **inflammation and swelling** of the external ear, consistent with **perichondritis**, an infection of the tissue surrounding the ear cartilage. - This condition can lead to **redness**, **pain**, and fluid collection (abscess formation) that distorts the ear's normal architecture. - Typically spares the **lobule** (which lacks cartilage) and presents as an **acute inflammatory condition**. *Hyperinsulinism* - **Hyperinsulinism** is a metabolic disorder characterized by excessive insulin secretion and has no relationship to external ear pathology. - This is not an appropriate option for an acute inflammatory ear condition shown in clinical images. *Conductive hearing defect* - A **conductive hearing defect** is a functional diagnosis, not a structural/pathological diagnosis visible on examination. - It refers to problems in sound transmission through the **external or middle ear**, but is not itself visible as inflammation or swelling. - The image shows an **acute inflammatory condition**, not a hearing disorder. *Mucopolysaccharidosis* - **Mucopolysaccharidoses** are lysosomal storage disorders that can cause progressive dysmorphic facial features, including ear structure changes. - However, these present with **chronic, diffuse structural changes** rather than acute inflammation and swelling. - The acute inflammatory presentation in the image is inconsistent with this genetic storage disorder.
Question 10: The cough response elicited while cleaning the external ear canal is mediated by stimulation of which nerve?
- A. The V cranial nerve
- B. Innervation of the external ear canal by C1 and C2
- C. The X cranial nerve (Correct Answer)
- D. Branches of the VII cranial nerve
Explanation: This phenomenon is known as **Arnold’s Reflex** (or the Ear-Cough Reflex). It occurs due to the stimulation of the **Auricular branch of the Vagus Nerve (Arnold’s Nerve)**, which provides sensory innervation to the posterior and inferior walls of the external auditory canal (EAC). ### Why the Correct Answer is Right: When the EAC is stimulated (e.g., during syringing or cleaning with a cotton bud), sensory impulses are carried via the Vagus nerve (CN X) to the nucleus tractus solitarius in the brainstem. This triggers the efferent limb of the cough reflex, leading to an involuntary cough. This is a classic example of a referred reflex where stimulation of a peripheral nerve causes a response in a visceral organ system. ### Why Other Options are Incorrect: * **Option A (V cranial nerve):** The Auriculotemporal branch of the Mandibular nerve (V3) supplies the anterior and superior walls of the EAC. While it carries sensation, it does not mediate the cough reflex. * **Option B (C1 and C2):** The Greater Auricular nerve (C2, C3) supplies the skin over the mastoid and the lateral/lower part of the auricle, not the deep canal associated with this reflex. * **Option C (VII cranial nerve):** The Facial nerve provides minor sensory innervation to the concha and retroauricular area (often involved in Ramsay Hunt Syndrome), but it is not responsible for the cough reflex. ### High-Yield Clinical Pearls for NEET-PG: * **Arnold’s Nerve:** A branch of the Vagus (CN X). * **Vagal Reflexes in ENT:** Stimulation of the EAC can occasionally cause **bradycardia or fainting** (Vaso-vagal syncope) due to the same nerve. * **Hitchelberger’s Sign:** Reduced sensation in the area supplied by the facial nerve in the EAC, seen in Acoustic Neuroma. * **Nerve Supply of EAC (Summary):** 1. Anterior/Superior: V3 (Auriculotemporal). 2. Posterior/Inferior: X (Arnold’s). 3. Concha/Posterior wall: VII (Facial).
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