Head and Neck Surgery Practice Questions

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

Recess of fourth ventricle. ***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.

Q: Not a landmark of facial nerve identification in parotid surgery:

Inferior belly of omohyoid. ***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.

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

Greater auricular. ***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.

Q: 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?

Glomus jugulare. ***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.

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

Marginal mandibular branch of the facial nerve. ***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.

Q: 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?

Marginal mandibular branch of the facial nerve. ***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.

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

Division of strap muscles. ***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.

Q: During thyroidectomy, which nerve, if damaged, can cause a hoarse voice?

Recurrent laryngeal; loops under aorta/subclavian. ***Recurrent laryngeal; loops under aorta/subclavian*** - The **recurrent laryngeal nerve (RLN)** innervates most of the intrinsic muscles of the larynx, including the **posterior crico-arytenoid muscle**, which is responsible for abducting the vocal cords. - Damage to the RLN during thyroidectomy can lead to **vocal cord paralysis**, resulting in a hoarse voice, stridor, or aspiration. *Superior laryngeal; with superior thyroid artery* - The **superior laryngeal nerve (SLN)** branches into external and internal laryngeal nerves. The **external laryngeal nerve** runs with the **superior thyroid artery** and innervates the **cricothyroid muscle**, which is responsible for tensioning the vocal cords. - Damage to the SLN can cause subtle changes in voice pitch and reduced vocal range but typically does not cause hoarseness or vocal cord paralysis, which is more characteristic of RLN injury. *Glossopharyngeal; along posterior thyroid* - The **glossopharyngeal nerve (CN IX)** provides sensory innervation to the posterior third of the tongue, tonsils, pharynx, and middle ear, and motor innervation to the stylopharyngeus muscle. - It is not directly related to vocal cord function or hoarseness as a result of thyroid surgery. *Hypoglossal; inferior to thyroid* - The **hypoglossal nerve (CN XII)** innervates all extrinsic and intrinsic muscles of the tongue, controlling tongue movement. - Damage to the hypoglossal nerve would affect speech articulation and swallowing but not directly cause hoarseness or vocal cord paralysis.

Question 1

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

Accepted Answer

Recess of fourth ventricle

Answer

Round window

Answer

Sinus tympani

Answer

Lateral ventricle

Question 2

Not a landmark of facial nerve identification in parotid surgery:

Accepted Answer

Inferior belly of omohyoid

Answer

Peripheral branches

Answer

Post belly of digastric

Answer

Tragal pointer

Question 3

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

Accepted Answer

Greater auricular

Answer

Auriculotemporal

Answer

Facial

Answer

Mandibular

Question 4

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?

Accepted Answer

Glomus jugulare

Answer

Metastasis

Answer

Schwannoma

Answer

Meningioma

Question 5

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

Accepted Answer

Vertical segment

Answer

Geniculate ganglion

Answer

Tympanic segment

Answer

Labyrinthine segment

Question 6

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

Accepted Answer

Facial nerve decompression

Answer

Conservative management

Answer

Steroids

Answer

Facial sling

Question 7

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

Accepted Answer

Marginal mandibular branch of the facial nerve

Answer

Buccal branch of the facial nerve

Answer

Cervical branch of the facial nerve

Answer

Temporal branch of the facial nerve

Question 8

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?

Accepted Answer

Marginal mandibular branch of the facial nerve

Answer

Main trunk of facial nerve

Answer

Temporal branch of facial nerve

Answer

Parotid duct

Question 9

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

Accepted Answer

Division of strap muscles

Answer

Ligation of superior thyroid artery

Answer

Removal of the tubercle of Zuckerkandl

Answer

Dissection of Beahrs triangle

Question 10

During thyroidectomy, which nerve, if damaged, can cause a hoarse voice?

Accepted Answer

Recurrent laryngeal; loops under aorta/subclavian

Answer

Superior laryngeal; with superior thyroid artery

Answer

Glossopharyngeal; along posterior thyroid

Answer

Hypoglossal; inferior to thyroid

Head and Neck Surgery — MCQs

Head and Neck Surgery — MCQs

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