Otology — MCQs
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What is true about the Eustachian tube?
A child presents with glue ear, following otitis media two weeks prior. What is the treatment of choice for glue ear?
The fistula test stimulates which of the following structures?
All of the following diseases have a consistent symptom of tinnitus, except?
What is the distance of the promontory from the tympanic membrane?
Radical mastoidectomy is indicated in:
Which of the following statements about ototoxicity is FALSE?
A 70-year-old male with long-standing type 2 diabetes mellitus presents with a complaint of left ear pain and purulent drainage. Examination reveals a tender pinna of the left ear, with a swollen and edematous external auditory canal. The patient is afebrile and has a normal white blood cell count. What is the most likely organism to grow from the ear drainage?
Which of the following best describes glue ear?
A girl presented with chronic ear discharge, pain on ocular movements, and vertigo, and underwent mastoidectomy. Postoperatively, there was no relief and continuous purulent ear discharge persisted. The patient also had sensorineural hearing loss. What is the most probable diagnosis?
Otology Indian Medical PG Practice Questions and MCQs
Question 21: What is true about the Eustachian tube?
- A. Its length is 36 mm in adults and 1.6 mm to 3 mm in children.
- B. It has a higher elastin content in adults. (Correct Answer)
- C. The ventilatory function of the ear is better developed in infants.
- D. It is more horizontal in adults.
Explanation: The Eustachian tube (ET) is a dynamic osteocartilaginous canal connecting the middle ear to the nasopharynx. Understanding its developmental anatomy is crucial for NEET-PG. ### **Explanation of the Correct Option** **Option B is correct.** The cartilage of the Eustachian tube in adults contains a significantly **higher density of elastin** compared to infants. This increased elastin content provides the necessary structural rigidity and elastic recoil required for the tube to remain closed at rest and open effectively during swallowing or yawning. In infants, the lack of elastin contributes to "floppiness" of the tube, leading to functional obstruction or easy reflux. ### **Analysis of Incorrect Options** * **Option A:** While the adult length is indeed **36 mm** (24 mm cartilaginous, 12 mm bony), the length in infants is approximately **18 mm**, not 1.6–3 mm. * **Option C:** The ventilatory function is **poorer** in infants. Due to the shorter, wider, and more horizontal orientation, along with an immature *tensor veli palatini* muscle, infants are highly predisposed to Otitis Media with Effusion (OME). * **Option D:** The ET is **more horizontal** in infants (at an angle of ~10° to the horizontal). In adults, it becomes more **angulated/vertical** (~45°) as the facial skeleton grows. ### **High-Yield Clinical Pearls for NEET-PG** * **Muscles:** The **Tensor Veli Palatini** is the primary dilator (opener) of the ET. The Salpingopharyngeus also assists. * **Anatomy:** The narrowest part of the ET is the **isthmus**, located at the junction of the bony and cartilaginous portions. * **Ostmann’s Fat Pad:** Located in the lateral wall, it helps keep the tube closed; its loss (e.g., rapid weight loss) leads to a **Patulous Eustachian Tube**. * **Infection:** The horizontal and shorter ET in children is the primary reason why Upper Respiratory Tract Infections (URTI) frequently lead to Acute Otitis Media (AOM).
Question 22: A child presents with glue ear, following otitis media two weeks prior. What is the treatment of choice for glue ear?
- A. Myringotomy with cold knife
- B. Myringotomy with diode laser
- C. Myringotomy with ventilation tube insertion (Correct Answer)
- D. Conservative treatment with analgesics and antibiotics
Explanation: **Explanation:** **Glue Ear (Otitis Media with Effusion - OME)** is characterized by the accumulation of non-purulent, sterile fluid in the middle ear cleft, leading to conductive hearing loss. **1. Why Option C is Correct:** The definitive surgical treatment for persistent or symptomatic glue ear is **Myringotomy with Ventilation Tube (Grommet) insertion**. The grommet serves two primary functions: it bypasses the dysfunctional Eustachian tube to provide continuous ventilation to the middle ear and allows for the drainage/aspiration of the thick "glue-like" secretions. This restores middle ear pressure and improves hearing immediately. **2. Why Other Options are Wrong:** * **Option A & B:** Myringotomy alone (whether by cold knife or laser) provides only temporary relief. Without a ventilation tube, the incision typically heals within 48–72 hours, leading to the re-accumulation of fluid if the underlying Eustachian tube dysfunction persists. * **Option D:** While conservative management (watchful waiting) is often the *initial* step for 3 months, the question asks for the "treatment of choice" for the established condition. Antibiotics are generally ineffective because the fluid in OME is typically sterile and not an active infection. **Clinical Pearls for NEET-PG:** * **Most common cause of hearing loss in children:** Otitis Media with Effusion. * **Tympanogram Finding:** Characteristically shows a **Type B (Flat) curve**. * **Most common site for Myringotomy:** Antero-inferior quadrant (to avoid injury to the ossicles and chorda tympani). * **Indication for Adenoidectomy:** Often performed alongside grommet insertion if the child has adenoid hypertrophy causing Eustachian tube obstruction.
Question 23: The fistula test stimulates which of the following structures?
- A. Lateral semicircular canal (Correct Answer)
- B. Posterior semicircular canal
- C. Round window
- D. Anterior semicircular canal
Explanation: **Explanation:** The **fistula test** is a clinical procedure used to identify an abnormal communication (fistula) between the inner and middle ear. **Why the Lateral Semicircular Canal is Correct:** The test involves applying positive and negative pressure to the external auditory canal using a Siegle’s speculum. In the presence of a bony erosion (most commonly caused by **cholesteatoma**), this pressure is transmitted to the endolymph of the inner ear. The **Lateral Semicircular Canal (LSCC)** is the most common site for a fistula because of its anatomical proximity to the aditus and antrum, where cholesteatomas typically expand. The pressure change induces endolymph movement, stimulating the crista ampullaris and resulting in vertigo and nystagmus (Hennebert’s sign). **Why Other Options are Incorrect:** * **Posterior and Anterior Semicircular Canals:** While these are part of the vestibular system, they are located deeper within the petrous temporal bone and are rarely involved in chronic suppurative otitis media (CSOM) compared to the LSCC. * **Round Window:** Pressure changes at the round window are physiological (part of normal sound conduction). A "fistula" here usually refers to a perilymph fistula (often post-traumatic), but the classic "fistula test" in ENT exams specifically refers to LSCC erosion by cholesteatoma. **High-Yield Clinical Pearls for NEET-PG:** * **Hennebert’s Sign:** A "false positive" fistula test (nystagmus without a bony fistula). Seen in **Meniere’s disease** (fibrosis between stapes footplate and saccule) and **Congenital Syphilis**. * **False Negative Test:** May occur if the fistula is plugged by cholesteatoma/granulations or if the labyrinth is "dead" (non-functional). * **Management:** A positive fistula test is a surgical indication, usually requiring a Modified Radical Mastoidectomy.
Question 24: All of the following diseases have a consistent symptom of tinnitus, except?
- A. Meniere's disease
- B. Chronic suppurative otitis media (CSOM)
- C. Otosclerosis
- D. Mastoiditis (Correct Answer)
Explanation: **Explanation:** The correct answer is **Mastoiditis**. **1. Why Mastoiditis is the correct answer:** Mastoiditis is an acute inflammatory process of the mastoid air cells, typically occurring as a complication of Acute Otitis Media (AOM). Its hallmark clinical features are **exudative ear discharge, post-auricular pain, tenderness, and swelling (mastoid flare)**. While a patient may experience a dull sense of hearing loss, **tinnitus is not a consistent or defining symptom** of this acute bacterial infection. The clinical focus is on systemic signs of infection and local abscess formation rather than auditory phantom sounds. **2. Analysis of incorrect options:** * **Meniere’s Disease:** Characterized by the classic triad of episodic vertigo, sensorineural hearing loss, and **low-pitched roaring tinnitus**. Tinnitus is a core diagnostic criterion. * **Otosclerosis:** This condition involves abnormal bone remodeling in the middle ear. It consistently presents with progressive conductive hearing loss and **tinnitus** (often described as a hissing or rushing sound) in about 75% of cases. * **CSOM:** Chronic inflammation of the middle ear and mastoid often presents with persistent ear discharge and hearing loss. **Tinnitus** is a very common secondary symptom due to the chronic irritation of the ossicular chain or inner ear (labyrinthitis). **High-Yield Clinical Pearls for NEET-PG:** * **Pulsatile Tinnitus:** Highly suggestive of vascular tumors like **Glomus Jugulare**. * **Clicking Tinnitus:** Often associated with **Palatal Myoclonus**. * **Schwartze Sign:** A flamingo-pink flush on the promontory seen in active Otosclerosis. * **Bezold’s Abscess:** A complication of mastoiditis where pus tracks down into the sternocleidomastoid muscle.
Question 25: What is the distance of the promontory from the tympanic membrane?
- A. 2 mm (Correct Answer)
- B. 5 mm
- C. 6 mm
- D. 7 mm
Explanation: **Explanation:** The middle ear cavity (tympanic cavity) is shaped like a biconcave disc, being narrowest at its center due to the inward bulging of the tympanic membrane (the umbo) and the outward bulging of the medial wall (the promontory). 1. **Why 2 mm is correct:** The distance between the tympanic membrane and the medial wall (promontory) varies across the cavity. At the **center (mesotympanum)**, the distance is at its minimum, measuring approximately **2 mm**. This is a high-yield anatomical fact often tested to emphasize the narrowness of the middle ear space. 2. **Why the other options are wrong:** * **6 mm:** This is the distance at the **roof (epitympanum)** of the middle ear. * **4 mm:** (Though not an option, it is a common distractor) This is the distance at the **floor (hypotympanum)**. * **5 mm and 7 mm:** These values do not correspond to the standard anatomical dimensions of the middle ear width. **Clinical Pearls & High-Yield Facts for NEET-PG:** * **The Promontory:** It is a rounded projection on the medial wall formed by the **basal turn of the cochlea**. * **Jacobson’s Nerve:** The tympanic branch of the Glossopharyngeal nerve (CN IX) lies in a groove on the surface of the promontory. * **Dimensions of Middle Ear:** Remember the "6-2-4" rule for the width of the tympanic cavity: 6 mm at the top, 2 mm at the center, and 4 mm at the bottom. * **Vertical and Anteroposterior diameters:** Both are approximately 15 mm. * **Clinical Significance:** The narrow 2 mm gap explains why even small middle ear effusions or masses (like a glomus tumor) can easily come into contact with the tympanic membrane.
Question 26: Radical mastoidectomy is indicated in:
- A. Cholesteatoma without complication
- B. Coalescent mastoiditis (Correct Answer)
- C. Chronic suppurative otitis media with brain abscess
- D. Perforation in Pars flaccida
Explanation: **Explanation:** **1. Why Coalescent Mastoiditis is the Correct Answer:** Coalescent mastoiditis is a complication of acute otitis media where the bony septa between mastoid air cells are destroyed, leading to a single pus-filled cavity (empyema). The primary surgical goal is to drain the pus and remove the diseased bone. While **Cortical Mastoiditis (Schwartze operation)** is the standard initial procedure for coalescent mastoiditis, in the context of this specific question and available options, a mastoidectomy (specifically to address the coalescence) is the definitive management. It is important to note that "Radical Mastoidectomy" in older textbooks was sometimes used as a broad term for mastoid clearance in acute complications, though modern practice favors cortical mastoidectomy for this condition. **2. Analysis of Incorrect Options:** * **A & D (Cholesteatoma / Pars Flaccida Perforation):** These represent "unsafe" CSOM. The standard treatment is **Modified Radical Mastoidectomy (MRM)**. A Radical Mastoidectomy is avoided here because it involves the removal of the tympanic membrane and ossicles, leading to significant permanent hearing loss. MRM preserves hearing by maintaining the middle ear assembly. * **C (CSOM with Brain Abscess):** This is a life-threatening complication. The priority is neurosurgical drainage of the abscess followed by a **Modified Radical Mastoidectomy** to clear the source of infection while attempting to preserve function. **3. High-Yield Clinical Pearls for NEET-PG:** * **Cortical Mastoiditis:** Indicated for Coalescent Mastoiditis and Masked Mastoiditis. * **Modified Radical Mastoidectomy (MRM):** The most common surgery for Cholesteatoma. It preserves the middle ear remnants. * **Radical Mastoidectomy:** Rarely performed today; indicated only when the Eustachian tube needs permanent closure or in rare cases of malignancy (e.g., SCC of the middle ear). * **Bondy’s Procedure:** A type of MRM used specifically for attic cholesteatomas with an intact ossicular chain and pars tensa.
Question 27: Which of the following statements about ototoxicity is FALSE?
- A. Causes bilateral hearing loss
- B. Low frequency hearing loss occurs initially (Correct Answer)
- C. Aminoglycosides cause permanent hearing loss
- D. Can be prevented by withdrawing the drug
Explanation: Ototoxicity typically presents as **bilateral, symmetrical, sensorineural hearing loss (SNHL)**. The hallmark of ototoxic damage is that it affects the **basal turn of the cochlea** first, which is responsible for processing **high-frequency sounds**. ### Explanation of Options: * **Option B (Correct Answer):** This is false because ototoxicity characteristically begins at high frequencies (8,000–20,000 Hz). Patients often do not notice early damage until it progresses to the lower frequencies involved in speech. * **Option A:** Ototoxicity is a systemic effect; therefore, it almost always causes bilateral and symmetrical hearing loss. * **Option C:** Aminoglycosides (e.g., Gentamicin, Amikacin) cause the death of outer hair cells in the Organ of Corti. Since these cells do not regenerate, the resulting hearing loss is permanent. * **Option D:** Prevention is the primary management strategy. Monitoring drug levels (TDM) and withdrawing or substituting the offending agent at the first sign of toxicity (tinnitus or high-frequency loss on serial audiometry) can prevent further progression. ### High-Yield Clinical Pearls for NEET-PG: * **Aminoglycoside Specificity:** Gentamicin and Streptomycin are more **vestibulotoxic** (causing vertigo/disequilibrium), while Amikacin, Neomycin, and Kanamycin are more **cochleotoxic** (causing hearing loss). * **Loop Diuretics:** (e.g., Furosemide) cause reversible hearing loss by affecting the *stria vascularis*. * **Salicylates:** Cause reversible SNHL and are classically associated with high-pitched tinnitus. * **Cisplatin:** A common chemotherapeutic agent that causes significant, permanent high-frequency SNHL. * **Monitoring:** High-frequency audiometry is the most sensitive tool for early detection.
Question 28: A 70-year-old male with long-standing type 2 diabetes mellitus presents with a complaint of left ear pain and purulent drainage. Examination reveals a tender pinna of the left ear, with a swollen and edematous external auditory canal. The patient is afebrile and has a normal white blood cell count. What is the most likely organism to grow from the ear drainage?
- A. P. aeruginosa (Correct Answer)
- B. Staphylococcus aureus
- C. Candida albicans
- D. Haemophilus influenzae
Explanation: **Explanation:** The clinical presentation describes a classic case of **Malignant Otitis Externa (MOE)**, also known as Necrotizing Otitis Externa. This is a life-threatening, invasive infection of the external auditory canal that typically affects elderly patients with uncontrolled diabetes mellitus or immunocompromised states. **1. Why P. aeruginosa is correct:** *Pseudomonas aeruginosa* is the causative pathogen in more than **95% of cases** of Malignant Otitis Externa. It is an opportunistic gram-negative aerobe that thrives in moist environments. In diabetic patients, the microangiopathy and alkaline pH of the earwax facilitate the deep tissue invasion of this organism into the bony canal and skull base. **2. Why the other options are incorrect:** * **Staphylococcus aureus:** While a common cause of localized furunculosis (otitis externa), it is rarely the primary driver of the invasive necrotizing process seen in diabetic patients. * **Candida albicans:** Fungal infections (Otomycosis) typically present with intense itching and "wet newspaper" debris but do not cause the deep, excruciating pain or cranial nerve involvement characteristic of MOE. * **Haemophilus influenzae:** This is a common pathogen in **Otitis Media** (middle ear infection), particularly in children, rather than infections of the external ear canal. **Clinical Pearls for NEET-PG:** * **Pathognomonic Sign:** Presence of **granulation tissue** at the junction of the cartilaginous and bony part of the external auditory canal (isthmus). * **Key Symptom:** Severe, deep-seated ear pain (otalgia) that is out of proportion to clinical findings and worsens at night. * **Diagnosis:** **Technetium-99m** scan is the most sensitive for initial diagnosis (detects osteoblastic activity); **Gallium-67** scan is used to monitor treatment response. * **Complication:** Facial nerve (CN VII) palsy is the most common cranial nerve involvement as the infection spreads to the stylomastoid foramen.
Question 29: Which of the following best describes glue ear?
- A. It is typically painful.
- B. It is typically painless. (Correct Answer)
- C. Radical mastoidectomy is the primary treatment.
- D. Sodium fluoride is a useful treatment.
Explanation: **Explanation:** **Glue ear**, medically known as **Otitis Media with Effusion (OME)**, is characterized by the accumulation of non-purulent, mucoid, or serous fluid in the middle ear cleft without signs of acute infection. 1. **Why Option B is correct:** Unlike Acute Otitis Media (AOM), glue ear is **typically painless**. The primary symptom is **conductive hearing loss** (the most common cause of hearing loss in children). Because there is no active bacterial suppuration or pressure from pus, patients do not experience otalgia or fever. 2. **Why the other options are incorrect:** * **Option A:** Pain is a hallmark of Acute Otitis Media or Otitis Externa, not OME. * **Option C:** Radical mastoidectomy is an aggressive surgery for cholesteatoma. The primary surgical treatment for glue ear is **Myringotomy with Grommet (ventilation tube) insertion**, often combined with an adenoidectomy if indicated. * **Option D:** Sodium fluoride is used to stabilize active bony resorption in **Otosclerosis** (Schwartze sign), not for middle ear effusions. **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Often associated with **Eustachian tube dysfunction** or adenoid hypertrophy. * **Diagnosis:** The gold standard for diagnosis is **Tympanometry**, which typically shows a **Type B (flat) curve**. * **Otoscopy:** Findings include a dull, retracted tympanic membrane with restricted mobility (assessed via pneumatic otoscopy). An "amber-colored" drum or air-fluid bubbles may be seen. * **Management:** Initial management is usually observation (watchful waiting for 3 months) as many cases resolve spontaneously. If persistent, Myringotomy is performed in the **antero-inferior quadrant**.
Question 30: A girl presented with chronic ear discharge, pain on ocular movements, and vertigo, and underwent mastoidectomy. Postoperatively, there was no relief and continuous purulent ear discharge persisted. The patient also had sensorineural hearing loss. What is the most probable diagnosis?
- A. Suppurative labyrinthitis
- B. Apical petrositis (Correct Answer)
- C. Serous labyrinthitis
- D. Lateral sinus thrombophlebitis
Explanation: ### Explanation The clinical presentation described is a classic manifestation of **Apical Petrositis** (Gradenigo’s Syndrome). **Why Apical Petrositis is the Correct Answer:** Apical petrositis occurs when infection spreads from the middle ear/mastoid into the petrous apex of the temporal bone. The hallmark is **Gradenigo’s Triad**: 1. **Persistent Ear Discharge:** Otorrhea that continues despite a cortical or radical mastoidectomy (as the focus of infection is deeper in the petrous apex). 2. **Retro-orbital Pain:** Due to irritation of the **Trigeminal nerve (V)** in Meckel’s cave. In this question, "pain on ocular movements" points toward trigeminal/abducens irritation. 3. **Diplopia/Abducens Palsy:** Due to involvement of the **VIth Cranial Nerve** as it passes through Dorello’s canal. The presence of **vertigo and sensorineural hearing loss (SNHL)** indicates that the infection has involved the inner ear structures (labyrinthine involvement), which is a common associated finding in advanced petrositis. **Why the Other Options are Incorrect:** * **Suppurative Labyrinthitis:** While it causes severe vertigo and SNHL, it does not typically cause retro-orbital pain or persistent discharge after mastoidectomy unless petrositis is also present. * **Serous Labyrinthitis:** This is an inflammatory (non-purulent) reaction. While it causes vertigo and SNHL, the hearing loss is often reversible, and it lacks the deep-seated pain and persistent post-op discharge characteristic of petrositis. * **Lateral Sinus Thrombophlebitis:** Presents with "picket-fence" fever, headache, and signs of raised intracranial pressure (Griesinger's sign), but not typically with ocular movement pain or isolated SNHL/vertigo. **High-Yield Clinical Pearls for NEET-PG:** * **Gradenigo’s Triad:** Otorrhea + Abducens palsy + Trigeminal neuralgia (Retro-orbital pain). * **Dorello’s Canal:** The anatomical site where the VIth nerve is compressed in petrositis. * **Investigation of Choice:** **MRI with Gadolinium** is superior for visualizing the petrous apex, though CT shows bone destruction. * **Management:** Intensive IV antibiotics; if failing, surgical drainage via various "Petrosectomy" approaches.
Practice by Chapter
Tympanic Membrane Perforation
Practice Questions
Cholesteatoma
Practice Questions
Tympanoplasty Techniques
Practice Questions
Ossicular Chain Reconstruction
Practice Questions
Mastoidectomy
Practice Questions
Stapedectomy
Practice Questions
Implantable Hearing Devices
Practice Questions
Congenital Aural Atresia
Practice Questions
Otologic Trauma
Practice Questions
Glomus Tumors
Practice Questions
Facial Nerve Decompression
Practice Questions
Rehabilitative Audiology
Practice Questions
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