Head and Neck Surgery — MCQs

Head and Neck Surgery Indian Medical PG Practice Questions and MCQs

Question 421: Site for placing an electrode in auditory brain stem implant is?

A. Round window
B. Sinus tympani
C. Lateral ventricle
D. Recess of fourth ventricle (Correct Answer)

Explanation: ***Recess of fourth ventricle*** - The auditory brainstem implant (ABI) electrode arrays are typically placed on the surface of the **cochlear nucleus**, which lies in the **lateral recess of the fourth ventricle and cerebellopontine angle**. - This placement allows direct stimulation of the central auditory pathways, bypassing a damaged or absent auditory nerve. *Round window* - The round window is the site for electrode placement in a **cochlear implant**, not an auditory brainstem implant. - A cochlear implant stimulates the **auditory nerve terminals** within the cochlea. *Sinus tympani* - The sinus tympani is an **anatomical space** within the middle ear. - It is not a site for implant electrode placement for either cochlear or brainstem implants. *Lateral ventricle* - The lateral ventricles are spaces within the brain that contain **cerebrospinal fluid** and are not directly involved in the auditory pathway for implant stimulation. - Implants for hearing are generally directed towards the auditory neural structures.

Question 422: Not a landmark of facial nerve identification in parotid surgery:

A. Peripheral branches
B. Post belly of digastric
C. Inferior belly of omohyoid (Correct Answer)
D. Tragal pointer

Explanation: ***Inferior belly of omohyoid*** - The **inferior belly of the omohyoid muscle** is located in the anterior triangle of the neck and is not a surgical landmark for the facial nerve during parotidectomy. - Its anatomical position is too far inferior and anterior to the parotid gland and facial nerve trunk to be useful for facial nerve identification. *Peripheral branches* - While careful dissection of **peripheral branches** is crucial for preserving facial nerve function, they are typically identified *after* locating the main trunk, not as primary landmarks for initially finding the nerve. - Direct identification of peripheral branches first is challenging and carries a higher risk of injury without prior identification of the main trunk or its primary divisions. *Post belly of digastric* - The **posterior belly of the digastric muscle** serves as a vital deep landmark for locating the facial nerve trunk. - The facial nerve typically passes superior to and deep to the posterior belly of the digastric muscle, providing a reliable point of reference for approaching the nerve. *Tragal pointer* - The **tragal pointer**, referring to the anterior surface of the cartilaginous tragus, is a superficial landmark used to approximate the location of the facial nerve trunk. - The facial nerve's main trunk typically emerges from the stylomastoid foramen, which is positioned anterior and inferior to the tragus, making it a useful starting point for surgical dissection.

Question 423: Post parotidectomy, patient feels numb while shaving. Which nerve was involved?

A. Auriculotemporal
B. Facial
C. Greater auricular (Correct Answer)
D. Mandibular

Explanation: ***Greater auricular*** - The **greater auricular nerve** provides **sensory innervation** to the skin over the parotid gland, mastoid process, and auricle. - Due to its superficial course over the **sternocleidomastoid muscle** and proximity to the parotid gland, it is frequently damaged during parotidectomy, leading to numbness in its distribution. - This numbness is typically felt in the **lower ear, angle of mandible, and cheek region** — areas commonly shaved. *Auriculotemporal* - The **auriculotemporal nerve** provides **sensory innervation** to the temple, part of the auricle, and carries secretomotor fibers to the parotid gland. - While it runs through the parotid gland, direct damage to its sensory function would lead to numbness in the **temporal region**, not typically the area affected during shaving after parotidectomy. *Facial* - The **facial nerve (cranial nerve VII)** is a **motor nerve** responsible for facial expressions. - Injury to the facial nerve during parotidectomy would result in **facial paralysis** or weakness, not numbness. *Mandibular* - The **mandibular nerve** is a branch of the **trigeminal nerve (cranial nerve V)** and primarily provides motor innervation to the muscles of mastication and sensory innervation to the lower face and chin. - Damage to this nerve during parotidectomy is unlikely to cause numbness in the typical area of shaving on the cheek/ear region.

Question 424: A 40-year-old patient presents with lower cranial nerve (CN IX, X, XI) palsies, otitis media, and headache. CT scan reveals a mass in the jugular foramen. What is the most likely diagnosis?

A. Glomus jugulare (Correct Answer)
B. Metastasis
C. Schwannoma
D. Meningioma

Explanation: ***Glomus jugulare*** - A **glomus jugulare tumor** (paraganglioma) - It arises in the **jugular bulb** and typically presents with a pulsatile mass, **cranial nerve palsies (IX, X, XI)**, and sometimes symptoms related to middle ear involvement like **otitis media** or conductive hearing loss, along with headache due to mass effect. *Metastasis* - While metastases can cause cranial nerve palsies and present as masses, they are generally not isolated to the **jugular foramen** with the specific constellation of symptoms including **otitis media** unless primary tumor is in the ear and also the history is acute and rapidly progressive - The presentation is more suggestive of a **primary lesion** arising from the structures within or immediately adjacent to the jugular foramen rather than a metastatic deposit. *Schwannoma* - **Schwannomas** (e.g., of CN IX, X, or XI) can occur in the jugular foramen and cause similar cranial nerve palsies. - However, they are less commonly associated with features like **otitis media** or a pulsatile character, which are more specific to a glomus tumor. They are also slower growing *Meningioma* - **Meningiomas** can involve the skull base, including the jugular foramen, leading to cranial neuropathies and headache. - They typically originate from the **dura mater** and generally do not cause otitis media as a direct symptom unless there's extensive local invasion into the middle ear, which is less characteristic than in glomus tumors.

Question 425: A patient presents with facial nerve palsy and vertigo after mastoid surgery. The most likely site of injury is:

A. Vertical segment (Correct Answer)
B. Geniculate ganglion
C. Tympanic segment
D. Labyrinthine segment

Explanation: ***Vertical segment (Mastoid segment)*** - The **vertical (mastoid) segment** of the facial nerve descends through the mastoid bone from the second genu to the stylomastoid foramen. - This segment is **most vulnerable during mastoidectomy** due to its course through the surgical field, particularly in patients with dehiscent facial nerve canals or anatomical variations. - Injury manifests as **facial nerve palsy** (complete or partial facial weakness). - **Vertigo** occurs when surgical trauma extends to adjacent structures like the **semicircular canals** (especially the lateral/horizontal canal which lies close to the mastoid antrum) or causes thermal injury to the vestibular apparatus. - This combined presentation of facial palsy + vertigo points specifically to the vertical segment injury during mastoid surgery. *Labyrinthine segment* - The **labyrinthine segment** is the shortest and narrowest segment, running from the internal auditory canal to the geniculate ganglion. - It lies **deep within the petrous temporal bone**, far from the typical mastoid surgical field. - Injury here is rare during mastoidectomy unless there is extensive petrous bone drilling or complications. - Would cause facial palsy and potentially hearing loss, but is not the typical site of injury during mastoid surgery. *Geniculate ganglion* - The **geniculate ganglion** is located at the first genu where the facial nerve transitions from labyrinthine to tympanic segment. - It lies **medial and superior** to the middle ear cavity, protected by bone. - Injury would cause facial palsy, loss of taste (anterior 2/3 tongue via chorda tympani), hyperacusis (stapedius dysfunction), and decreased lacrimation. - **Less commonly injured** during routine mastoidectomy; vertigo is not a primary feature unless there is extension to the vestibular apparatus. *Tympanic segment* - The **tympanic (horizontal) segment** runs along the medial wall of the middle ear above the oval window. - While it can be exposed during mastoidectomy with extended approaches, it is **less frequently injured** than the vertical segment in standard mastoid surgery. - Injury causes facial palsy but **vertigo is less characteristic** unless the procedure directly involves the oval window or horizontal semicircular canal.

Question 426: Best treatment for traumatic facial nerve injury with no improvement after 3 months?

A. Conservative management
B. Steroids
C. Facial nerve decompression (Correct Answer)
D. Facial sling

Explanation: ***Facial nerve decompression*** - After **3 months without improvement** in traumatic facial nerve injury, electrodiagnostic studies (EMG/NCS) should guide management. - If nerve continuity is maintained but there is **compression from edema, hematoma, or bony fragments**, surgical **decompression** is indicated to relieve pressure and facilitate **nerve regeneration** (which occurs at ~1 mm/day). - This is the appropriate intervention for **severe axonotmesis** where the nerve remains anatomically continuous but functionally impaired due to compression. - Decompression is particularly indicated in **temporal bone fractures** with facial nerve involvement showing no recovery by 3 months. *Conservative management* - Appropriate for **neuropraxia** (temporary conduction block) where spontaneous recovery typically occurs within **6-12 weeks**. - After 3 months of no improvement, continued observation alone would be inappropriate and delay definitive surgical intervention. - The lack of improvement by 3 months suggests **axonotmesis** or **neurotmesis** requiring active surgical management. *Steroids* - Corticosteroids are beneficial in the **acute phase** (first 1-2 weeks) for reducing **edema** and inflammation, particularly in Bell's palsy or acute traumatic injury. - After 3 months, steroids provide **no therapeutic benefit** as the injury pattern is now chronic and likely involves structural nerve damage requiring surgical intervention. - The window for anti-inflammatory therapy has long passed. *Facial sling* - A **static facial sling** is a reconstructive procedure for **permanent, non-recoverable** facial paralysis to improve facial symmetry at rest. - This is considered only after **12-24 months** when all potential for nerve recovery has been exhausted. - It does not address nerve injury or promote regeneration, and would be premature at 3 months when surgical nerve decompression or grafting might still restore function.

Question 427: Lower lip paralysis after a parotidectomy is most likely due to injury to which structure?

A. Buccal branch of the facial nerve
B. Cervical branch of the facial nerve
C. Temporal branch of the facial nerve
D. Marginal mandibular branch of the facial nerve (Correct Answer)

Explanation: ***Marginal mandibular branch of the facial nerve*** - The **marginal mandibular branch** innervates the muscles of the lower lip and chin, including the **depressor anguli oris**, **depressor labii inferioris**, and **mentalis**. - Injury to this nerve during a **parotidectomy**, where it can be inadvertently cut or damaged due to its superficial course over the mandible, results in ipsilateral **lower lip paralysis** and an asymmetric smile. *Buccal branch of the facial nerve* - The **buccal branch** primarily innervates the muscles around the mouth, such as the buccinator and orbicularis oris, affecting **upper lip movement** and cheek function. - Damage to this branch would typically affect functions like chewing and smiling, but not specifically the lower lip. *Cervical branch of the facial nerve* - The **cervical branch** innervates the **platysma muscle**, which is involved in neck skin tension and depressing the mandible. - Injury to this branch would cause weakness or paralysis of the platysma, not lower lip paralysis. *Temporal branch of the facial nerve* - The **temporal branch** innervates the muscles of the forehead and around the eye, including the **frontalis** and **orbicularis oculi**. - Damage to this branch would result in the inability to wrinkle the forehead and close the eye, but not lower lip paralysis.

Question 428: A 55-year-old male patient presents to the clinic with left lower lip weakness following a recent parotid gland surgery. Considering the surgical history and current symptoms, what is the most likely site of the lesion causing this patient's condition?

A. Main trunk of facial nerve
B. Temporal branch of facial nerve
C. Parotid duct
D. Marginal mandibular branch of the facial nerve (Correct Answer)

Explanation: ***Marginal mandibular branch of the facial nerve*** - This branch supplies the muscles around the lower lip, including the **depressor anguli oris** and **depressor labii inferioris**, which are responsible for lower lip movement. - Damage to this specific branch during **parotid gland surgery** is a common cause of isolated **lower lip weakness**, as it runs superficial to the submandibular gland and is vulnerable during dissections in this area. *Main trunk of facial nerve* - Injury to the main trunk would result in **widespread paralysis** of all facial muscles on the affected side, not just isolated lower lip weakness. - The main trunk emerges from the stylomastoid foramen and then enters the parotid gland before branching, so damage here would affect all subsequent branches. *Temporal branch of facial nerve* - This branch innervates muscles responsible for eyebrow movement and forehead wrinkling (e.g., **frontalis muscle**). - Damage to the temporal branch would cause inability to raise the eyebrow and smooth out the forehead, not lower lip weakness. *Parotid duct* - The parotid duct (Stensen's duct) is responsible for transporting saliva from the parotid gland to the oral cavity. - Injury to the parotid duct would lead to complications like **salivary fistula** or **sialocele**, but it does not carry motor innervation to facial muscles and would not cause weakness.

Question 429: Which of the following steps in thyroid surgery is least likely to result in hoarseness of voice?

A. Ligation of superior thyroid artery
B. Removal of the tubercle of Zuckerkandl
C. Division of strap muscles (Correct Answer)
D. Dissection of Beahrs triangle

Explanation: ***Division of strap muscles*** - Dividing the **strap muscles** (sternohyoid, sternothyroid, omohyoid) provides surgical access to the thyroid gland but does not directly involve structures critical for vocal cord function. - While it may cause temporary **neck discomfort** or altered neck contour, it is least likely to lead to hoarseness. *Ligation of superior thyroid artery* - Ligation of the **superior thyroid artery** occurs in close proximity to the **external laryngeal nerve**, a branch of the superior laryngeal nerve. - Damage to the external laryngeal nerve can cause subtle voice changes due to **cricothyroid muscle paralysis**, impacting pitch. *Removal of the tubercle of Zuckerkandl* - The **tubercle of Zuckerkandl** is a posterior extension of the thyroid gland, often lying close to the **recurrent laryngeal nerve**. - Its removal requires careful dissection in an area where the recurrent laryngeal nerve is vulnerable to **traction or direct injury**, which can cause hoarseness. *Dissection of Beahrs triangle* - **Beahrs triangle** is an anatomical landmark formed by the common carotid artery, inferior border of the thyroid lobe, and the recurrent laryngeal nerve. - Dissection within this triangle carries a high risk of **recurrent laryngeal nerve injury**, leading to vocal cord paralysis and significant hoarseness.

Question 430: During a neck dissection, a surgeon inadvertently cuts a nerve that results in a deviation of the tongue. Which nerve is likely severed?

A. Vagus nerve; loss of soft palate elevation
B. Accessory nerve; shoulder droop
C. Glossopharyngeal nerve; loss of taste sensation
D. Hypoglossal nerve; weakness in tongue movement (Correct Answer)

Explanation: ***Hypoglossal nerve; weakness in tongue movement*** - Damage to the **hypoglossal nerve (CN XII)** results in paralysis of the **intrinsic and extrinsic muscles of the tongue** on the ipsilateral side. - Unopposed action of the contralateral tongue muscles causes the tongue to deviate **towards the side of the lesion** when protruded. *Vagus nerve; loss of soft palate elevation* - The **vagus nerve (CN X)** innervates most muscles of the **soft palate, pharynx, and larynx**. - Injury to the vagus nerve causes issues like hoarseness, dysphagia, and a **uvula deviation away from the lesioned side**, due to paralysis of the ipsilateral palatoglossal and palatopharyngeal muscles. *Accessory nerve; shoulder droop* - The **accessory nerve (CN XI)** primarily innervates the **sternocleidomastoid** and **trapezius muscles**. - Damage to this nerve would lead to **weakness in head rotation, shrugging the shoulders**, and elevating the arm above 90 degrees. *Glossopharyngeal nerve; loss of taste sensation* - The **glossopharyngeal nerve (CN IX)** provides sensory innervation to the posterior third of the tongue for taste and general sensation, and motor innervation to the **stylopharyngeus muscle**. - A lesion would primarily result in **loss of taste and sensation on the posterior tongue**, and potentially difficulty swallowing, but not tongue deviation.

Practice by Chapter

Salivary Gland Diseases

Practice Questions

Thyroid Gland Disorders

Practice Questions

Parathyroid Gland Disorders

Practice Questions

Neck Masses Evaluation

Practice Questions

Oral Cavity Lesions

Practice Questions

Laryngeal Disorders

Practice Questions

Head and Neck Cancer

Practice Questions

Reconstructive Techniques in Head and Neck Surgery

Practice Questions

Surgical Management of Sleep Apnea

Practice Questions

Airway Management in Head and Neck Surgery

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Surgical Approaches to the Neck

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Neck Dissection Techniques

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