Complications of Skull Base Surgery — MCQs

10 questions

Cranial nerve 8 palsy is associated with all of the following symptoms except:

A lady comes to OPD after fall from scooty. Her vitals are stable. She is having continuous, clear watery discharge from nose after 2 days. This is most likely a feature of?

Which clinical sign can detect facial nerve palsy occurring due to the lesion at the outlet of stylomastoid foramen -

Frontal sinuses drain into:

Which of the following is not a complication of maxillary sinus lavage and insufflation?

CSF Otorrhea is due to trauma of:

Which of the following is most specific for CSF in rhinorrhea?

Least common complication of a fall from height is -

The complication which will not occur after PCNL surgery:

Q10Easy

What is the most common space-occupying lesion in the cerebellopontine angle?

Complications of Skull Base Surgery Indian Medical PG Practice Questions and MCQs

Question 1: Cranial nerve 8 palsy is associated with all of the following symptoms except:

A. Gag reflex (Correct Answer)
B. Hearing loss
C. Tinnitus
D. Vertigo

Explanation: ***Gag reflex*** - The **gag reflex** is primarily mediated by the **glossopharyngeal (CN IX)** and **vagus (CN X)** nerves. - CN VIII, the vestibulocochlear nerve, is solely responsible for hearing and balance, and thus has no role in the gag reflex. *Vertigo* - **Vertigo** is a common symptom of CN VIII palsy, specifically involving the **vestibular branch** of the nerve. - Damage to this branch can disrupt the sense of balance and spatial orientation. *Hearing loss* - **Hearing loss** is a hallmark symptom of CN VIII palsy, affecting the **cochlear branch** of the nerve. - This can manifest as conductive, sensorineural, or mixed hearing loss, depending on the specific pathology. *Tinnitus* - **Tinnitus**, the perception of sound when no external sound is present, is frequently associated with CN VIII palsy. - It often accompanies hearing loss and is a common complaint in conditions affecting the auditory system.

Question 2: A lady comes to OPD after fall from scooty. Her vitals are stable. She is having continuous, clear watery discharge from nose after 2 days. This is most likely a feature of?

A. CSF rhinorrhoea (Correct Answer)
B. Acute respiratory infection
C. Rhinitis
D. Middle cranial fossa fracture

Explanation: ***CSF rhinorrhoea*** - **Clear watery discharge** appearing **two days after head trauma** (fall from scooty) is highly suggestive of **cerebrospinal fluid (CSF) rhinorrhoea**. - This occurs due to a breach in the **skull base**, allowing CSF to leak from the subarachnoid space into the nasal cavity. *Acute respiratory infection* - An acute respiratory infection typically presents with symptoms like **fever, cough**, and **nasal discharge** that is often thicker and discolored, not clear and watery. - The onset of discharge two days after trauma without other signs of infection also makes this less likely. *Rhinitis* - Rhinitis involves inflammation of the nasal mucosa, leading to watery discharge, sneezing, and congestion. - However, the traumatic etiology and the specific timing of the discharge make **CSF leak** a more pertinent diagnosis than simple rhinitis. *Middle cranial fossa fracture* - While a **middle cranial fossa fracture** can cause CSF leakage, the discharge from the nose (rhinorrhoea) typically originates from an **anterior cranial fossa fracture**. - A middle cranial fossa fracture is more commonly associated with **otorrhoea** (CSF leakage from the ear) if the temporal bone is involved.

Question 3: Which clinical sign can detect facial nerve palsy occurring due to the lesion at the outlet of stylomastoid foramen -

A. Deviation of tongue towards opposite side
B. Loss of sensation over right cheek
C. Loss of taste sensation in anterior 2/3 of tongue
D. Deviation of angle of mouth towards opposite side (Correct Answer)

Explanation: ***Deviation of angle of mouth towards opposite side*** - A lesion of the facial nerve at the **stylomastoid foramen** specifically affects the motor innervation to the **muscles of facial expression**. [1] - This leads to **paralysis of facial expression muscles** on the ipsilateral side, causing the mouth to **deviate towards the unaffected side** due to unopposed muscle action. [1] *Deviation of tongue towards opposite side* - **Tongue deviation** is primarily indicative of a lesion in the **hypoglossal nerve (CN XII)**, which controls the intrinsic and extrinsic muscles of the tongue. - The facial nerve is not involved in **tongue movement**. *Loss of sensation over right cheek* - **Sensory innervation** to the face, including the cheek, is provided by the **trigeminal nerve (CN V)**, not the facial nerve. - The facial nerve is primarily a **motor nerve** for facial expression, although it carries some sensory fibers for taste and a small area of the ear. *Loss of taste sensation in anterior 2/3 of tongue* - **Taste sensation** from the **anterior two-thirds of the tongue** is carried by the **chorda tympani nerve**, which is a branch of the facial nerve. - However, the **chorda tympani branches off proximal to the stylomastoid foramen**, meaning a lesion at the foramen itself would not affect taste.

Question 4: Frontal sinuses drain into:

A. Superior meatus
B. Middle meatus (Correct Answer)
C. Ethmoid recess
D. Inferior meatus

Explanation: ***Middle meatus*** - The **frontal sinuses** drain via the **frontonasal duct** into the anterior part of the **middle meatus** through the **semilunar hiatus**. - This drainage pathway is crucial for mucus clearance and ventilation of the frontal sinuses. *Superior meatus* - The **superior meatus** primarily receives drainage from the **posterior ethmoid air cells**. - It handles drainage from different sinus structures located more superiorly and posteriorly. *Inferior meatus* - The **inferior meatus** is the sole drainage site for the **nasolacrimal duct**, which carries tears from the eye into the nasal cavity. - It does not receive drainage from any of the paranasal sinuses. *Ethmoid recess* - The **sphenoethmoidal recess** (often referred to as ethmoid recess) is the drainage site for the **sphenoid sinus** and the **posterior ethmoid air cells**. - The frontal sinus does not drain into this specific region.

Question 5: Which of the following is not a complication of maxillary sinus lavage and insufflation?

A. Orbital injury
B. Epistaxis
C. Facial nerve injury (Correct Answer)
D. Air embolism

Explanation: ***Facial nerve injury*** - The **facial nerve (CN VII)** passes through the parotid gland and temporal bone, far from the maxillary sinus. - There is no anatomical proximity or procedural mechanism during maxillary sinus lavage and insufflation that would put the facial nerve at risk of injury. *Air embolism* - **Insufflation of air** into the maxillary sinus, especially under pressure, can lead to air entering the bloodstream if a blood vessel is inadvertently punctured. - This can result in a serious and potentially fatal **air embolism**, particularly if the air reaches the cerebral circulation. *Orbital injury* - The **medial wall of the maxillary sinus** is in close proximity to the orbit, separated by thin bone. - During lavage, excessive force or incorrect angulation of instruments can perforate this thin bone, leading to **orbital complications** such as periorbital hematoma or injury to orbital contents. *Epistaxis* - During the procedure, the **mucosa of the nasal cavity** or the sinus itself can be traumatized by the instruments used for lavage. - This local trauma to the rich blood supply of these areas can easily cause **nasal bleeding (epistaxis)**.

Question 6: CSF Otorrhea is due to trauma of:

A. Tympanic membrane
B. Cribriform plate
C. Parietal bone
D. Petrous temporal bone (Correct Answer)

Explanation: ***Petrous temporal bone*** - **CSF otorrhea** (leakage of cerebrospinal fluid from the ear) most commonly results from a fracture of the **petrous portion of the temporal bone**. - This bone forms part of the skull base and houses structures of the inner and middle ear, a fracture here can create a direct communication between the **subarachnoid space** and the external ear canal. *Tympanic membrane* - A rupture of the **tympanic membrane** alone would lead to **otorrhea** (ear discharge), but it would primarily involve blood or middle ear fluid, not CSF. - While a ruptured tympanic membrane is necessary for CSF to exit the ear canal, the source of the CSF leak itself is proximal to the middle ear. *Cribriform plate* - A fracture of the **cribriform plate** typically results in **CSF rhinorrhea** (CSF leakage from the nose), as it is located structurally above the nasal cavity. - It is not directly involved in CSF leakage from the ear. *Parietal bone* - Fractures of the **parietal bone** are typically associated with epidural or subdural hematomas or brain injury, depending on the extent of the trauma. - They are not a usual cause of CSF leakage from the ear since this bone does not contain CSF pathways that directly communicate with the ear.

Question 7: Which of the following is most specific for CSF in rhinorrhea?

A. Albumin
B. Macroglobulin
C. Beta-2 transferrin (Correct Answer)
D. Beta-2 microglobulin

Explanation: ***b-2 transferrin*** - **Beta-2 transferrin** is a desialylated form of transferrin found almost exclusively in **cerebrospinal fluid (CSF)**, perilymph, and aqueous humor. - Its presence in nasal discharge is highly **specific** for the diagnosis of CSF rhinorrhea, as it is not typically found in serum or other bodily secretions. *Albumin* - **Albumin** is abundant in both serum and CSF, so its presence in nasal discharge is not specific for CSF and could indicate the presence of blood or inflammatory exudates. - Measuring albumin levels alone would not reliably differentiate CSF rhinorrhea from other types of nasal discharge. *Macroglobulin* - **Alpha-2 macroglobulin** is a large plasma protein primarily found in **blood**, not typically in significant concentrations in CSF. - Its presence would be more indicative of serum contamination rather than CSF leakage. *b-2 microglobulin* - **Beta-2 microglobulin** is a protein found on the surface of most nucleated cells and is present in various body fluids including **serum** and **CSF**, though usually in higher concentrations in conditions associated with inflammation or malignancy. - While present in CSF, it is not specific enough to reliably distinguish CSF rhinorrhea from other types of nasal discharge, especially if blood is also present.

Question 8: Least common complication of a fall from height is -

A. Fracture fibula (Correct Answer)
B. Fracture base of skull
C. Fracture 12th thoracic vertebra
D. Fracture calcaneum

Explanation: ***Fracture fibula*** - A fibula fracture is the **least common** with a fall from height because the force is typically axial, impacting the lower limbs. - The fibula is a **non-weight-bearing bone**, making it less susceptible to direct axial compression trauma from a fall. *Fracture base of skull* - **Basilar skull fractures** can occur from significant head trauma in a fall, especially when the head strikes a surface. - While not as common as extremity fractures, they are a serious and known complication of falls from height. *Fracture 12th thoracic vertebra* - **Vertebral compression fractures**, particularly in the thoracolumbar region (like T12), are common due to axial loading upon landing on the buttocks or feet. - This is a frequent injury in falls from height due to the **compressive forces** transmitted through the spine. *Fracture calcaneum* - **Heel bone fractures** (calcaneum) are very common in falls from height, as direct impact often occurs on the feet. - The calcaneus bears the initial and substantial impact, making it highly vulnerable to **crush injuries** in such falls.

Question 9: The complication which will not occur after PCNL surgery:

A. Organ injury
B. Urethral stricture (Correct Answer)
C. Bleeding
D. Sepsis

Explanation: ***Urethral stricture*** - **Urethral stricture** is a complication typically associated with transurethral procedures involving instrumentation through the urethra, such as a **Transurethral Resection of the Prostate (TURP)** or repeated urethral catheterisation. - **PCNL (Percutaneous Nephrolithotomy)** involves direct access to the kidney through the skin in the flank, bypassing the urethra entirely, therefore, making urethral stricture not a direct complication of this procedure. *Organ injury* - **Organ injury**, particularly to adjacent organs like the **colon**, **pleura**, or **spleen/liver**, can occur during PCNL if the access tract is misdirected or during instrumentation. - This is a well-recognised but infrequent complication requiring careful pre-operative planning and imaging guidance. *Bleeding* - **Bleeding** is a common complication of PCNL due to the invasive nature of the procedure, involving puncture of the kidney and fragmentation of stones. - It can range from minor self-limiting bleeding to significant haemorrhage requiring transfusion or further intervention such as **angiography** and **embolization**. *Sepsis* - **Sepsis** is a serious potential complication, particularly if the patient has pre-existing urinary tract infection or if bacteria are dislodged during stone fragmentation. - **Infection** can disseminate into the bloodstream, leading to severe systemic inflammatory response syndrome and septic shock.

Question 10: What is the most common space-occupying lesion in the cerebellopontine angle?

A. Meningioma
B. Glioma
C. Neurofibroma
D. Acoustic neuroma (Correct Answer)

Explanation: **Explanation:** The **Cerebellopontine Angle (CPA)** is a potential space in the posterior cranial fossa. The correct answer is **Acoustic Neuroma** (also known as Vestibular Schwannoma), which accounts for approximately **80–85%** of all CPA tumors. 1. **Acoustic Neuroma (Correct):** These are benign, slow-growing tumors arising from the Schwann cells of the vestibular nerve (most commonly the inferior vestibular nerve). They typically present with unilateral sensorineural hearing loss, tinnitus, and dysequilibrium. 2. **Meningioma (Incorrect):** This is the **second most common** CPA lesion, accounting for about 10–15% of cases. Unlike acoustic neuromas, they often do not widen the internal auditory canal (IAC) and may show calcification or a "dural tail" on MRI. 3. **Epidermoid Cyst (Incorrect):** These are the third most common CPA lesions (approx. 5%). They are congenital and characterized by a "pearly" appearance and restricted diffusion on MRI. 4. **Neurofibroma (Incorrect):** While associated with Neurofibromatosis Type 1, the tumors in the CPA (specifically in NF-2) are actually **Schwannomas**, not neurofibromas. 5. **Glioma (Incorrect):** These are primary brain parenchyma tumors (e.g., brainstem gliomas) and are rarely primary occupants of the CPA space. **NEET-PG High-Yield Pearls:** * **Gold Standard Investigation:** Contrast-enhanced MRI (Gadolinium) is the investigation of choice. * **Bilateral Acoustic Neuromas:** Pathognomonic for **Neurofibromatosis Type 2 (NF-2)**. * **Audiometry Finding:** Characterized by "Retrocochlear" pathology (Poor speech discrimination score out of proportion to pure tone loss and absence of recruitment). * **Order of Frequency in CPA:** Acoustic Neuroma > Meningioma > Epidermoid > Facial Nerve Schwannoma.

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