A 45-year-old man is brought to the emergency department after being found down in the middle of the street. Bystanders reported to the police that they had seen the man as he exited a local bar, where he was subsequently assaulted. He sustained severe facial trauma, including multiple lacerations and facial bone fractures. The man is taken to the operating room by the ENT team, who attempted to reconstruct his facial bones with multiple plates and screws. Several days later, he complains of the inability to open his mouth wide or to completely chew his food, both of which he seemed able to do prior to the surgery. Where does the affected nerve exit the skull?
Q22
A 72-year-old woman presents to the emergency department for vision loss. She was reading a magazine this afternoon when she started having trouble seeing out of her left eye. Her vision in that eye got progressively darker, eventually becoming completely black over the course of a few minutes. It then returned to normal after about 10 minutes; she reports she can see normally now. She had no pain and no other symptoms then or now. Past medical history is notable for hypertension and hyperlipidemia. A high-pitched sound is heard when the diaphragm of the stethoscope is placed on her left neck, but her physical exam is otherwise unremarkable; vision is currently 20/30 bilaterally. The etiology of her symptoms most likely localizes to which of the following anatomic locations?
Q23
A 12-year-old boy is brought in by his mother with a 2-day history of fever and generalized weakness. She says that her son was involved in a school fight with some other kids 4 days ago and sustained minor injuries to the face. He was otherwise well, until this morning, when he complained of pain in his right eye. Physical examination reveals periorbital erythema and edema of the right eye, along with ophthalmoplegia and proptosis. Which of the following findings will most likely be present in this patient on the affected side as a sequela of his current condition?
Q24
A 30-year-old man comes to the physician because of recurrent episodes of right-sided jaw pain over the past 3 months. The patient describes the pain as dull. He says it worsens throughout the day and with chewing, and that it can also be felt in his right ear. He also reports hearing a cracking sound while eating. Over the past 2 months, he has had several episodes of severe headache that improves slightly with ibuprofen intake. Vital signs are within normal limits. Physical examination shows limited jaw opening. Palpation of the face shows facial muscle spasms. Which of the following is the most likely underlying cause of this patient's symptoms?
Q25
An otherwise healthy 45-year-old man comes to the physician because of a painful ulcer on his tongue for 3 days. Examination shows a shallow, tender 5-mm wide ulcer on the lateral aspect of the tongue, adjacent to his left first molar. There is no induration surrounding the ulcer or cervical lymphadenopathy. A lesion of the cranial nerve responsible for the transmission of pain from this ulcer would most likely result in which of the following?
Q26
A 27-year-old man presents to a physician for evaluation of 3 months of increased vertigo. He says that occasionally he will experience several seconds of intense vertigo that makes him lose his balance. He came in for evaluation because this symptom is affecting his ability to drive to work. He has also been occasionally experiencing tinnitus. Physical exam reveals rotatory nystagmus that is delayed in onset and stops with visual fixation. The nerve that is most likely causing these symptoms exits the skull at which of the following locations?
Q27
A 28-year-old man comes to the physician because of a persistent tingling sensation in the right side of his face. The sensation began after he underwent an extraction of an impacted molar 2 weeks ago. Examination shows decreased sensation of the skin over the right side of the mandible, chin, and the anterior portion of the tongue. Taste sensation is preserved. The affected nerve exits the skull through which of the following openings?
Q28
A 55-year-old woman comes to the physician because of a 2-week history of painful swelling on the right side of her face. The pain worsens when she eats. Examination of the face shows a right-sided, firm swelling that is tender to palpation. Oral examination shows no abnormalities. Ultrasonography shows a stone located in a duct that runs anterior to the masseter muscle and passes through the buccinator muscle. Sialoendoscopy is performed to remove the stone. At which of the following sites is the endoscope most likely to be inserted during the procedure?
Q29
A 37-year-old machinist presents to his primary care physician with eye problems. The patient states that he has had a mass in his eye that has persisted for the past month. The patient has a past medical history of blepharitis treated with eye cleansing and squamous cell carcinoma of the skin treated with Mohs surgery. His temperature is 99.5°F (37.5°C), blood pressure is 157/102 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for a firm and rubbery nodule palpable inside the patient's left eyelid. Physical exam does not elicit any pain. Which of the following is the most likely diagnosis?
Q30
A 69-year-old man comes to the physician with a 2-year history of progressive hearing loss. His hearing is worse in crowded rooms, and he has noticed that he has more difficulty understanding women than men. He has no history of serious illness and does not take any medications. A Rinne test shows air conduction is greater than bone conduction bilaterally. This condition is most likely associated with damage closest to which of the following structures?
Head & Neck US Medical PG Practice Questions and MCQs
Question 21: A 45-year-old man is brought to the emergency department after being found down in the middle of the street. Bystanders reported to the police that they had seen the man as he exited a local bar, where he was subsequently assaulted. He sustained severe facial trauma, including multiple lacerations and facial bone fractures. The man is taken to the operating room by the ENT team, who attempted to reconstruct his facial bones with multiple plates and screws. Several days later, he complains of the inability to open his mouth wide or to completely chew his food, both of which he seemed able to do prior to the surgery. Where does the affected nerve exit the skull?
A. Foramen rotundum
B. Foramen ovale (Correct Answer)
C. Jugular foramen
D. Superior orbital fissure
E. Inferior orbital fissure
Explanation: ***Foramen ovale***
- The symptoms of inability to open the mouth wide and difficulty chewing are indicative of damage to the **motor branches of the trigeminal nerve (mandibular nerve)**, which innervates the muscles of mastication.
- The **mandibular nerve (V3)** exits the skull through the **foramen ovale**.
*Foramen rotundum*
- The **foramen rotundum** transmits the **maxillary nerve (V2)**, which is primarily sensory to the midface.
- Damage to this nerve would cause sensory deficits in the cheek, upper lip, and teeth, but not issues with mastication.
*Jugular foramen*
- The **jugular foramen** transmits the **glossopharyngeal (IX)**, **vagus (X)**, and **accessory (XI)** cranial nerves.
- Damage here would lead to problems with swallowing, speech, gag reflex, or shoulder movement, not specifically jaw movement or chewing.
*Superior orbital fissure*
- The **superior orbital fissure** transmits the **oculomotor (III)**, **trochlear (IV)**, **ophthalmic (V1)**, and **abducens (VI)** cranial nerves.
- Damage here would primarily affect eye movements or sensation around the eye and forehead.
*Inferior orbital fissure*
- The **inferior orbital fissure** transmits the **infraorbital nerve** (a branch of V2), **zygomatic nerve**, and other vessels.
- Damage here would result in sensory deficits in the infraorbital region and potentially affect lacrimal gland function, but not mastication.
Question 22: A 72-year-old woman presents to the emergency department for vision loss. She was reading a magazine this afternoon when she started having trouble seeing out of her left eye. Her vision in that eye got progressively darker, eventually becoming completely black over the course of a few minutes. It then returned to normal after about 10 minutes; she reports she can see normally now. She had no pain and no other symptoms then or now. Past medical history is notable for hypertension and hyperlipidemia. A high-pitched sound is heard when the diaphragm of the stethoscope is placed on her left neck, but her physical exam is otherwise unremarkable; vision is currently 20/30 bilaterally. The etiology of her symptoms most likely localizes to which of the following anatomic locations?
A. Left atrium
B. Subclavian artery
C. Temporal artery
D. Carotid artery (Correct Answer)
E. Vertebral artery
Explanation: ***Carotid artery***
- The sudden, temporary vision loss (amaurosis fugax) in one eye, described as a "curtain coming down," is a classic symptom of an **embolus originating from the ipsilateral carotid artery**.
- The **bruit** heard in the left neck further points to significant **carotid artery stenosis**, which can be a source of these emboli to the **ophthalmic artery**.
*Left atrium*
- An embolus from the left atrium (e.g., in atrial fibrillation) would typically cause symptoms of a **cerebral stroke** or vision loss in **both eyes** if it affects a major supplying vessel before the intracranial branches, or could affect the carotid artery system, but the neck bruit directly implicates the carotid.
- While a source of emboli, the direct finding of a neck bruit makes the carotid the more immediate and specific localization.
*Subclavian artery*
- **Subclavian artery** stenosis can cause **subclavian steal syndrome**, leading to vertebrobasilar insufficiency and symptoms like **dizziness** or **syncope**, but generally does not cause unilateral amaurosis fugax.
- Its territory primarily supplies the arm and posterior circulation, not the anterior cerebral circulation or ophthalmic artery directly as suggested by amaurosis fugax.
*Temporal artery*
- **Temporal arteritis** (Giant Cell Arteritis) can cause sudden vision loss, often irreversible, and is usually associated with **headaches**, **jaw claudication**, and a very high **ESR**, none of which are reported here.
- While it affects the ophthalmic artery, the absence of pain and the transient nature of the vision loss (amaurosis fugax) make it less likely than an embolic event.
*Vertebral artery*
- The **vertebral arteries** supply the **posterior circulation** of the brain, leading to symptoms such as **diplopia**, **vertigo**, **ataxia**, or **hemiparesis**, but not isolated unilateral amaurosis fugax.
- Problems in this artery typically manifest as **vertebrobasilar insufficiency**, which affects both eyes or causes other brainstem symptoms, not transient unilateral blindness.
Question 23: A 12-year-old boy is brought in by his mother with a 2-day history of fever and generalized weakness. She says that her son was involved in a school fight with some other kids 4 days ago and sustained minor injuries to the face. He was otherwise well, until this morning, when he complained of pain in his right eye. Physical examination reveals periorbital erythema and edema of the right eye, along with ophthalmoplegia and proptosis. Which of the following findings will most likely be present in this patient on the affected side as a sequela of his current condition?
A. Anesthesia along the CN V3 distribution
B. Intact sympathetic innervation to the pupil, but not parasympathetic innervation
C. Monocular diplopia
D. Absent blink reflex
E. Decreased vision with optic disc swelling (Correct Answer)
Explanation: ***Decreased vision with optic disc swelling***
- The patient's presentation with **periorbital erythema**, **edema**, **ophthalmoplegia**, and **proptosis** suggests **orbital cellulitis** or a related orbital infection, potentially progressing to **cavernous sinus thrombosis**.
- This condition can lead to compression of the **optic nerve**, resulting in **decreased vision** and **optic disc swelling** due to impaired venous outflow and elevated intraorbital pressure.
*Anesthesia along the CN V3 distribution*
- **Anesthesia along the CN V3 (mandibular nerve) distribution** is unlikely as orbital infections and cavernous sinus thrombosis primarily affect structures superior and medial to the orbit, involving CN V1 (ophthalmic) and CN V2 (maxillary) divisions if facial sensation is implicated.
- CN V3 involvement would typically arise from pathology within or inferior to the cavernous sinus, which is not the primary site of injury in this presentation.
*Intact sympathetic innervation to the pupil, but not parasympathetic innervation*
- This statement describes a specific pattern of autonomic dysfunction affecting the pupil, such as in **Horner's syndrome (sympathetic denervation)** or **oculomotor nerve palsy (parasympathetic denervation)**.
- While the oculomotor nerve (CN III) is often affected in orbital cellulitis or cavernous sinus thrombosis, causing ophthalmoplegia, the question describes a combination of symptoms that more directly point to **optic nerve compression** rather than isolated pupillary changes.
*Monocular diplopia*
- **Monocular diplopia** typically results from optical abnormalities within one eye, such as **cataracts**, **astigmatism**, or **corneal irregularities**, where light is split before reaching the retina.
- The patient's symptoms of ophthalmoplegia and proptosis suggest involvement of **extraocular muscles** and nerves, which would more commonly cause **binocular diplopia** (double vision that resolves when one eye is closed) due to misalignment of the eyes.
*Absent blink reflex*
- The **blink reflex** involves the **trigeminal nerve (afferent limb)** and the **facial nerve (efferent limb)**. While the trigeminal nerve's ophthalmic division (CN V1) might be affected by orbital pathology or cavernous sinus thrombosis, leading to decreased sensation, a complete absence of the blink reflex is a severe sign.
- The more direct and common sequela of the described proptosis and ophthalmoplegia affecting visual function and optic nerve health is **decreased vision with optic disc swelling**.
Question 24: A 30-year-old man comes to the physician because of recurrent episodes of right-sided jaw pain over the past 3 months. The patient describes the pain as dull. He says it worsens throughout the day and with chewing, and that it can also be felt in his right ear. He also reports hearing a cracking sound while eating. Over the past 2 months, he has had several episodes of severe headache that improves slightly with ibuprofen intake. Vital signs are within normal limits. Physical examination shows limited jaw opening. Palpation of the face shows facial muscle spasms. Which of the following is the most likely underlying cause of this patient's symptoms?
A. Chronic inflammation of the sinuses
B. Dental abscess
C. Dysfunction of the temporomandibular joint (Correct Answer)
D. Trigeminal nerve compression
E. Infection of the mandible
Explanation: ***Dysfunction of the temporomandibular joint***
- The patient's symptoms of **right-sided jaw pain** that worsens with chewing, radiating to the ear, a **cracking sound during eating**, and **limited jaw opening** are classic indicators of **temporomandibular joint (TMJ) dysfunction**.
- **Facial muscle spasms** and associated **headaches** are also common manifestations of TMJ disorders, which can be triggered by stress or bruxism.
*Chronic inflammation of the sinuses*
- Sinusitis typically presents with **facial pain and pressure**, usually around the eyes and forehead, and can be accompanied by **nasal discharge**, congestion, and fever.
- While headaches can occur, the prominent jaw symptoms, cracking sounds, and aggravation with chewing are not characteristic of chronic sinusitis.
*Dental abscess*
- A dental abscess would cause **localized, severe throbbing pain** in a tooth, which might radiate but would not typically present with the described widespread jaw symptoms, cracking, or limited range of motion.
- It would also likely involve **swelling, tenderness to percussion**, and possibly pus discharge.
*Trigeminal nerve compression*
- **Trigeminal neuralgia** presents with **sudden, severe, brief, shock-like pain** in the distribution of one or more branches of the trigeminal nerve, often triggered by light touch, chewing, or speaking.
- The patient's symptoms of dull, worsening pain with activity and cracking sounds are inconsistent with the paroxysmal nature of trigeminal neuralgia.
*Infection of the mandible*
- An infection of the mandible (osteomyelitis) would present with **severe pain, swelling, erythema**, and potentially fever and systemic signs of infection.
- The chronicity, association with chewing, and cracking sounds are not typical of mandibular osteomyelitis in its presentation.
Question 25: An otherwise healthy 45-year-old man comes to the physician because of a painful ulcer on his tongue for 3 days. Examination shows a shallow, tender 5-mm wide ulcer on the lateral aspect of the tongue, adjacent to his left first molar. There is no induration surrounding the ulcer or cervical lymphadenopathy. A lesion of the cranial nerve responsible for the transmission of pain from this ulcer would most likely result in which of the following?
A. Loss of taste from the supraglottic region
B. Lateral deviation of the tongue
C. Inability to wrinkle the forehead
D. Decreased sensation in the upper lip
E. Loss of sensation in the anterior two-thirds of the tongue (Correct Answer)
Explanation: ***Loss of sensation in the anterior two-thirds of the tongue***
- The sensation of pain from the **anterior two-thirds of the tongue** is transmitted by the **lingual nerve**, which is a branch of the mandibular division (V3) of the **trigeminal nerve**. A lesion affecting this nerve would therefore cause loss of sensation in this region.
- The ulcer is located on the **lateral aspect of the tongue**, placing it within the distribution of the lingual nerve.
*Loss of taste from the supraglottic region*
- **Taste sensation** from the **supraglottic region** and epiglottis is primarily mediated by the **superior laryngeal nerve** (a branch of the vagus nerve, CN X), not the nerve responsible for pain sensation from the anterior tongue.
- A lesion of the lingual nerve would affect taste sensation from the **anterior two-thirds of the tongue** (carried by the chorda tympani, a branch of CN VII, which joins the lingual nerve), but not the supraglottic region.
*Lateral deviation of the tongue*
- **Lateral deviation of the tongue** (towards the side of the lesion) occurs due to damage to the **hypoglossal nerve (CN XII)**, which innervates the intrinsic and extrinsic muscles of the tongue.
- This is a motor deficit, whereas the question describes a sensory issue related to pain transmission from an ulcer on the tongue.
*Inability to wrinkle the forehead*
- The **inability to wrinkle the forehead** (along with other facial expressions) results from damage to the **facial nerve (CN VII)**, specifically its temporal branch.
- This is a motor deficit affecting the muscles of facial expression, unrelated to pain sensation from the tongue.
*Decreased sensation in the upper lip*
- **Sensation in the upper lip** is supplied by the **infraorbital nerve**, a branch of the maxillary division (V2) of the **trigeminal nerve**.
- A lesion affecting the nerve responsible for pain from the anterior two-thirds of the tongue (lingual nerve, V3) would not directly impact sensation in the upper lip.
Question 26: A 27-year-old man presents to a physician for evaluation of 3 months of increased vertigo. He says that occasionally he will experience several seconds of intense vertigo that makes him lose his balance. He came in for evaluation because this symptom is affecting his ability to drive to work. He has also been occasionally experiencing tinnitus. Physical exam reveals rotatory nystagmus that is delayed in onset and stops with visual fixation. The nerve that is most likely causing these symptoms exits the skull at which of the following locations?
A. Internal auditory meatus (Correct Answer)
B. Cribriform plate
C. Foramen ovale
D. Jugular foramen
E. Foramen rotundum
Explanation: ***Internal auditory meatus***
- The symptoms described, particularly **vertigo** and **tinnitus**, are indicative of an issue with the **vestibulocochlear nerve (CN VIII)**.
- The **vestibulocochlear nerve** exits the skull through the **internal auditory meatus**, which is also the pathway for the **facial nerve (CN VII)**.
*Cribriform plate*
- The **cribriform plate** is associated with the passage of the **olfactory nerves (CN I)**, which are responsible for the sense of smell.
- Damage to this area would typically cause **anosmia**, not vertigo or tinnitus.
*Foramen ovale*
- The **foramen ovale** is the exit point for the **mandibular nerve (V3)**, a branch of the trigeminal nerve.
- Dysfunction here would lead to problems with **mastication** or altered sensation in the lower face, not vertigo.
*Jugular foramen*
- The **jugular foramen** transmits several cranial nerves: the **glossopharyngeal (CN IX)**, **vagus (CN X)**, and **accessory (CN XI)** nerves.
- Issues in this region would manifest as difficulties with **swallowing**, **speech**, or **shoulder/neck movement**, not balance or hearing.
*Foramen rotundum*
- The **foramen rotundum** transmits the **maxillary nerve (V2)**, another branch of the trigeminal nerve.
- Damage to this nerve would primarily affect **sensation in the middle third of the face**, not balance or hearing.
Question 27: A 28-year-old man comes to the physician because of a persistent tingling sensation in the right side of his face. The sensation began after he underwent an extraction of an impacted molar 2 weeks ago. Examination shows decreased sensation of the skin over the right side of the mandible, chin, and the anterior portion of the tongue. Taste sensation is preserved. The affected nerve exits the skull through which of the following openings?
A. Foramen rotundum
B. Hypoglossal canal
C. Foramen magnum
D. Foramen ovale (Correct Answer)
E. Stylomastoid foramen
Explanation: ***Foramen ovale***
- This patient presents with **paresthesia** in the distribution of branches of the **mandibular nerve (V3)** following molar extraction. The affected areas (mandible, chin, and anterior tongue sensation) indicate injury to the **inferior alveolar nerve** (lower teeth, chin, lower lip) and/or **lingual nerve** (general sensation to anterior 2/3 of tongue).
- Both the **inferior alveolar nerve** and **lingual nerve** are branches of the **mandibular nerve (V3)**, which exits the skull through the **foramen ovale**. These nerves run in close proximity during molar extraction and are commonly injured together.
- Taste sensation is preserved because the **chorda tympani** (taste fibers from CN VII) travels with the lingual nerve but does not exit through foramen ovale.
*Foramen rotundum*
- The **foramen rotundum** transmits the **maxillary nerve (V2)**, which innervates the midface, upper teeth, and palate.
- Injury to this nerve would cause sensory deficits in the upper lip and cheek, not the mandible or chin.
*Hypoglossal canal*
- The **hypoglossal canal** transmits the **hypoglossal nerve (CN XII)**, which is a motor nerve to the intrinsic and extrinsic muscles of the tongue.
- Damage to this nerve would result in **tongue weakness** or **atrophy**, not sensory changes to the face or tongue.
*Foramen magnum*
- The **foramen magnum** is the largest opening in the skull, transmitting the **spinal cord**, vertebral arteries, and accessory nerve (CN XI).
- Damage here would likely involve severe neurological deficits, not isolated sensory loss to the lower face.
*Stylomastoid foramen*
- The **stylomastoid foramen** transmits the **facial nerve (CN VII)**, which is primarily responsible for facial expression and taste sensation to the anterior two-thirds of the tongue via the chorda tympani.
- While CN VII provides taste to the tongue, it does not provide general sensory innervation to the skin of the mandible or chin, and taste is preserved in this patient.
Question 28: A 55-year-old woman comes to the physician because of a 2-week history of painful swelling on the right side of her face. The pain worsens when she eats. Examination of the face shows a right-sided, firm swelling that is tender to palpation. Oral examination shows no abnormalities. Ultrasonography shows a stone located in a duct that runs anterior to the masseter muscle and passes through the buccinator muscle. Sialoendoscopy is performed to remove the stone. At which of the following sites is the endoscope most likely to be inserted during the procedure?
A. Lateral to the lingual frenulum
B. Into the floor of the mouth
C. Lateral to the superior labial frenulum
D. Into the mandibular foramen
E. Opposite the second upper molar tooth (Correct Answer)
Explanation: ***Opposite the second upper molar tooth***
- The description of the duct running anterior to the **masseter muscle** and through the **buccinator muscle** is characteristic of the **parotid duct (Stensen's duct)**.
- The parotid duct opens into the oral cavity on the buccal mucosa **opposite the second upper molar tooth**, which is the most likely entry point for sialoendoscopy to remove a stone from this duct.
*Lateral to the lingual frenulum*
- This location is where the **submandibular duct (Wharton's duct)** opens into the oral cavity.
- While stones can occur in the submandibular duct, the patient's symptoms and the duct's anatomical description do not match this location.
*Into the floor of the mouth*
- The floor of the mouth is the general area where the submandibular and sublingual ducts open.
- However, the specific anatomical description of the duct in relation to the masseter and buccinator muscles points away from the submandibular/sublingual glands.
*Lateral to the superior labial frenulum*
- This area is associated with the openings of minor salivary glands in the upper lip.
- These glands are typically too small to be the source of such a prominent swelling or a large stone requiring sialoendoscopy.
*Into the mandibular foramen*
- The **mandibular foramen** is an opening on the medial surface of the mandibular ramus.
- It is an anatomical landmark for the **inferior alveolar nerve and vessels** and has no direct involvement in salivary gland duct openings.
Question 29: A 37-year-old machinist presents to his primary care physician with eye problems. The patient states that he has had a mass in his eye that has persisted for the past month. The patient has a past medical history of blepharitis treated with eye cleansing and squamous cell carcinoma of the skin treated with Mohs surgery. His temperature is 99.5°F (37.5°C), blood pressure is 157/102 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for a firm and rubbery nodule palpable inside the patient's left eyelid. Physical exam does not elicit any pain. Which of the following is the most likely diagnosis?
A. Meibomian gland carcinoma
B. Chalazion (Correct Answer)
C. Hordeolum
D. Ingrown eyelash follicle
E. Foreign body
Explanation: ***Chalazion***
- This patient's presentation of a **firm, rubbery, painless nodule** inside the eyelid, persistent for a month, is characteristic of a **chalazion**. It often develops after a hordeolum or **blepharitis** due to obstruction of a Meibomian gland.
- Chalazia are typically **non-tender** as they represent a chronic, sterile inflammation rather than an acute infection.
*Meibomian gland carcinoma*
- While a Meibomian gland carcinoma can present as a nodule, it often shows suggestive signs like **loss of eyelashes (madarosis)**, ulceration, or recurrent chalazion in an elderly patient. This patient's presentation does not describe these features.
- Carcinomas tend to be more **invasive** and may present with less defined borders or rapid growth, which are not mentioned here.
*Hordeolum*
- A **hordeolum (stye)** is an acute, painful, localized infection of an eyelash follicle (**external hordeolum**) or Meibomian gland (**internal hordeolum**).
- It would typically cause **pain, redness, and tenderness** which are absent in this patient's description.
*Ingrown eyelash follicle*
- An ingrown eyelash (trichiasis) primarily causes **irritation, foreign body sensation**, and possibly corneal abrasion from the misdirected lash rubbing against the eye.
- It does not typically present as a firm, rubbery, painless nodule *inside* the eyelid, but rather as an eyelash growing inwards.
*Foreign body*
- A foreign body in the eye would typically cause acute onset of **pain, irritation, tearing**, and potentially redness.
- The persistent, painless, firm nodule described is less consistent with a foreign body, which would usually be more symptomatic or eventually expelled.
Question 30: A 69-year-old man comes to the physician with a 2-year history of progressive hearing loss. His hearing is worse in crowded rooms, and he has noticed that he has more difficulty understanding women than men. He has no history of serious illness and does not take any medications. A Rinne test shows air conduction is greater than bone conduction bilaterally. This condition is most likely associated with damage closest to which of the following structures?
A. Tympanic membrane
B. Round window
C. Base of the stapes
D. External acoustic meatus
E. Basal turn of the cochlea (Correct Answer)
Explanation: ***Basal turn of the cochlea***
- The patient's presentation of progressive hearing loss, difficulty hearing in crowded rooms (**presbycusis**), and trouble understanding women's voices (higher frequencies) is characteristic of **sensorineural hearing loss**.
- The **basal turn of the cochlea** is responsible for detecting high-frequency sounds, making it the most likely site of damage in presbycusis.
*Tympanic membrane*
- Damage to the **tympanic membrane** would typically result in a **conductive hearing loss**, characterized by bone conduction being greater than air conduction (abnormal Rinne test).
- The patient's Rinne test shows air conduction greater than bone conduction, indicating a sensorineural or normal hearing pattern.
*Round window*
- The **round window** plays a role in relieving pressure in the cochlea, allowing fluid movement and sound transmission.
- While damage here can affect hearing, it's not the primary site of progressive, age-related high-frequency sensorineural loss.
*Base of the stapes*
- Issues at the **base of the stapes**, particularly **otosclerosis**, cause **conductive hearing loss** due to the ossification of the oval window, hindering sound transmission.
- This would present with an abnormal Rinne test (BC > AC), which is not observed in this patient.
*External acoustic meatus*
- Obstruction or damage to the **external acoustic meatus** (e.g., earwax impaction, otitis externa) would cause a **conductive hearing loss**.
- The Rinne test would show bone conduction greater than air conduction, which is inconsistent with the patient's findings.