Temporal Bone Fractures — MCQs

10 questions

All are intracranial complications of otitis media except which of the following?

CSF otorrhea is a feature of:

A 43-year-old man presents to the emergency department after falling down a flight of stairs and landing on his head. He did not lose consciousness. He complains of severe headache, marked decreased acuity in hearing in the left ear, and a "runny nose" since the fall. On physical examination, he is found to have a left-sided Battle's sign (an ecchymosis in the area of the left mastoid process) and hemotympanum. He has a constant dripping of a clear, watery fluid through his nose. Findings on his neurologic examination, other than the hearing loss, are completely normal. X-ray studies will reveal which of the following?

A patient presents with vertigo, tinnitus, and head tilt. He underwent myringoplasty for the safe type of chronic suppurative otitis media (CSOM) 6 months back. What is your diagnosis?

What type of fracture of petrous temporal bone has the highest chance of facial nerve paralysis?

CSF otorrhoea is caused by

Which vessel is most likely damaged in an extradural (epidural) hemorrhage?

A 25-year-old male presents with a head injury following a motorcycle accident, and a CT scan shows a fracture of the skull. Which bone is most commonly fractured in such injuries?

Which of the following statements regarding traumatic facial nerve palsy is false?

Q10

A fracture of the middle cranial fossa may result in an injury of the

Temporal Bone Fractures Indian Medical PG Practice Questions and MCQs

Question 1: All are intracranial complications of otitis media except which of the following?

A. Brain abscess
B. Hydrocephalus
C. Lateral sinus thrombophlebitis
D. Facial nerve palsy (Correct Answer)

Explanation: ***Facial nerve palsy*** - This is an **extracranial complication** of otitis media affecting the **facial nerve within the temporal bone**, not an intracranial structure. - The facial nerve (CN VII) runs through the **fallopian canal** in the temporal bone and can be affected by inflammation from adjacent mastoid or middle ear infection. - Classified as a **temporal bone complication** rather than an intracranial complication. *Lateral sinus thrombophlebitis* - This is a true **intracranial complication** involving thrombosis of the **sigmoid and lateral venous sinuses** within the cranial cavity. - Results from direct extension of infection through the **mastoid tegmen** or via septic thrombophlebitis. - Presents with features of sepsis, headache, and papilledema. *Brain abscess* - A severe **intracranial complication** representing focal suppurative infection within the **brain parenchyma** (commonly temporal lobe or cerebellum). - Occurs through direct extension via bony erosion, retrograde thrombophlebitis, or hematogenous spread. - Requires urgent neurosurgical intervention. *Hydrocephalus* - An **intracranial complication** that can occur secondary to **otogenic meningitis** or **lateral sinus thrombosis**. - Results from impaired CSF absorption or obstruction of CSF pathways. - More common in pediatric otitis media with CNS complications.

Question 2: CSF otorrhea is a feature of:

A. Anterior cranial fossa fracture.
B. Middle cranial fossa fracture. (Correct Answer)
C. All of the options.
D. Posterior cranial fossa fracture.

Explanation: ***Middle cranial fossa fracture*** - Fractures of the **middle cranial fossa** frequently involve the **temporal bone**, which encases the middle and inner ear. - Damage to the temporal bone can lead to a direct communication between the **subarachnoid space** and the external auditory canal, resulting in **CSF leakage** from the ear (otorrhea). *Anterior cranial fossa fracture* - Fractures in the **anterior cranial fossa** are more commonly associated with **CSF rhinorrhea**, where CSF leaks from the nose due to damage to the cribriform plate or frontal sinus. - While possible, CSF otorrhea is a less typical presentation for isolated anterior fossa fractures compared to middle fossa involvement. *All of the options* - This option is incorrect because CSF otorrhea is primarily associated with middle cranial fossa fractures due to the anatomical structures involved in that region. - While other cranial fossa fractures can cause CSF leaks, otorrhea specifically points to temporal bone involvement, making it less characteristic of *all* regions. *Posterior cranial fossa fracture* - Fractures of the **posterior cranial fossa** are rare but can involve structures like the **foramen magnum** or occipital bone. - These fractures are more likely to cause symptoms related to brainstem compression or lower cranial nerve deficits, with CSF otorrhea being an unusual presentation.

Question 3: A 43-year-old man presents to the emergency department after falling down a flight of stairs and landing on his head. He did not lose consciousness. He complains of severe headache, marked decreased acuity in hearing in the left ear, and a "runny nose" since the fall. On physical examination, he is found to have a left-sided Battle's sign (an ecchymosis in the area of the left mastoid process) and hemotympanum. He has a constant dripping of a clear, watery fluid through his nose. Findings on his neurologic examination, other than the hearing loss, are completely normal. X-ray studies will reveal which of the following?

A. A temporal bone fracture with CSF rhinorrhea (Correct Answer)
B. Occipital bone fracture
C. A skull-base fracture with a mucocele
D. A fracture of the cribriform plate with a CSF leak into the paranasal sinuses

Explanation: ***A temporal bone fracture with CSF rhinorrhea*** - The combination of **Battle's sign**, **hemotympanum**, unilateral hearing loss, and clear nasal discharge after head trauma strongly indicates a **temporal bone fracture**. - **CSF rhinorrhea** refers to cerebrospinal fluid leaking from the nose due to a skull base fracture involving the temporal bone, typically affecting the petrous part. - The CSF can reach the nasal cavity via the **eustachian tube** or through fracture lines extending to the middle ear and mastoid air cells. *Occipital bone fracture* - While occipital fractures are possible with head trauma, they do not directly explain the specific findings of **hemotympanum** or unilateral hearing loss. - An occipital fracture would typically cause symptoms related to damage to the **brainstem** or **cerebellum**, depending on the extent. *A skull-base fracture with a mucocele* - A **mucocele** is a cyst filled with mucus, usually resulting from obstruction of a sinus ostium, and is not an acute traumatic finding. - While a skull-base fracture is present, the presence of a mucocele does not fit the acute injury presentation. *A fracture of the cribriform plate with a CSF leak into the paranasal sinuses* - A **cribriform plate fracture** would result in CSF rhinorrhea, but it typically causes CSF to leak directly from the anterior cranial fossa into the nasal cavity. - It would not explain the **hemotympanum**, Battle's sign, or unilateral hearing loss, which are characteristic of **temporal bone injury**.

Question 4: A patient presents with vertigo, tinnitus, and head tilt. He underwent myringoplasty for the safe type of chronic suppurative otitis media (CSOM) 6 months back. What is your diagnosis?

A. Paget disease
B. Labyrinthitis
C. Vestibular schwannoma
D. Perilymphatic fistula (Correct Answer)

Explanation: ***Perilymphatic fistula*** - The combination of **vertigo**, **tinnitus**, and **head tilt** occurring after a **myringoplasty**, even for a safe type of CSOM, suggests a perilymphatic fistula. - Myringoplasty can occasionally involve trauma to the **oval or round window**, leading to a direct communication between the inner ear (perilymph) and the middle ear, causing these symptoms. *Paget disease* - This is a **bone remodeling disorder** that primarily affects the skull, pelvis, and long bones, leading to bone pain and deformities. - While it can cause hearing loss (due to otosclerosis) and a sense of imbalance, it does not typically present with the acute onset of **vertigo** and **tinnitus** following ear surgery. *Labyrinthitis* - **Labyrinthitis** is an inflammation of the inner ear, typically caused by a viral infection, leading to sudden, severe **vertigo**, **nausea**, and often **hearing loss** or **tinnitus**. - While the symptoms of vertigo and tinnitus are present, the history of recent myringoplasty makes a **structural compromise** like a perilymphatic fistula a more specific diagnosis than generalized inflammation. *Vestibular schwannoma* - Also known as an acoustic neuroma, this is a **benign tumor** on the eighth cranial nerve, causing **gradual unilateral hearing loss**, **tinnitus**, and **imbalance**, but rarely sudden, intense vertigo unless very large. - The presentation with a history of myringoplasty and acute symptoms makes a **spontaneous structural defect** more likely than a slowly growing tumor.

Question 5: What type of fracture of petrous temporal bone has the highest chance of facial nerve paralysis?

A. All have equal incidence
B. Transverse (Correct Answer)
C. Oblique
D. Longitudinal

Explanation: ***Transverse*** - **Transverse fractures** of the petrous temporal bone run perpendicular to the long axis of the petrous bone and are typically caused by direct blows to the occiput or high-energy trauma. - These fractures have the **highest incidence (30-50%)** of facial nerve paralysis due to direct involvement of the facial nerve within the petrous canal, often resulting in complete and immediate paralysis from transection or severe crush injury. *All have equal incidence* - This is incorrect because the incidence of facial nerve paralysis varies significantly depending on the **type and direction of the fracture** pattern. - Different fracture orientations impact the facial nerve's intricate intratemporal course in distinct ways, resulting in markedly different injury rates. *Oblique* - **Oblique fractures** are less common and their impact on the facial nerve is variable, generally considered intermediate between longitudinal and transverse fractures. - The specific angulation and degree of facial canal involvement determine the risk, but the incidence is typically lower than transverse fractures. *Longitudinal* - **Longitudinal fractures** run parallel to the long axis of the petrous bone, typically resulting from lateral temporal impacts. - These fractures have a **much lower incidence (10-20%)** of facial nerve paralysis, usually incomplete and often due to edema or hematoma rather than direct nerve transection, as they tend to spare the facial nerve's intratemporal course.

Question 6: CSF otorrhoea is caused by

A. Fracture of petrous temporal bone (Correct Answer)
B. Fracture of cribriform plate
C. Fracture of tympanic membrane
D. Fracture of parietal bone

Explanation: ***Fracture of petrous temporal bone*** - A fracture in the **petrous portion of the temporal bone** can disrupt the integrity of the dura mater and the bony structures separating the middle ear from the subarachnoid space. - This allows **cerebrospinal fluid (CSF)** to leak into the middle ear and then out through the external ear canal, resulting in **CSF otorrhoea**. *Fracture of cribriform plate* - A fracture of the **cribriform plate** typically leads to **CSF rhinorrhea**, as it allows CSF to leak into the nasal cavity. - This structure is located in the anterior cranial fossa and is not directly involved in fluid drainage from the ear. *Fracture of tympanic membrane* - A **ruptured tympanic membrane** (eardrum) on its own would primarily cause **otorrhea** (discharge from the ear) but would involve blood or fluid from the middle ear, not directly CSF. - While it can be a pathway for CSF to escape if there's an underlying connection to the subarachnoid space (like a petrous bone fracture), it's not the primary cause of CSF leakage from the cranial vault itself. *Fracture of parietal bone* - A fracture of the **parietal bone** is a skull fracture that typically affects the calvarium. - It would not directly cause **CSF otorrhoea** unless it was a very extensive fracture extending to the temporal bone and middle ear structures, which is not the primary association.

Question 7: Which vessel is most likely damaged in an extradural (epidural) hemorrhage?

A. Basilar artery
B. Vertebral artery
C. Middle meningeal artery (Correct Answer)
D. Anterior cerebral artery

Explanation: Middle meningeal artery - An extradural (epidural) hemorrhage often results from head trauma, especially to the temporal region, which can cause a fracture across the course of the middle meningeal artery [1]. - This artery runs in a groove on the inner surface of the temporal bone, making it vulnerable to laceration during trauma [1]. Basilar artery - The basilar artery is located at the base of the brainstem and is a common site for strokes, but not typically involved in an extradural hemorrhage. - Damage to the basilar artery usually leads to subarachnoid hemorrhage or ischemic stroke, not an epidural hematoma. Vertebral artery - The vertebral arteries ascend through the cervical vertebrae and join to form the basilar artery, supplying the posterior circulation of the brain. - Damage to these arteries is typically associated with neck trauma or dissection, leading to subarachnoid hemorrhage or ischemia, not an epidural hemorrhage. Anterior cerebral artery - The anterior cerebral artery supplies the frontal lobes and medial aspects of the cerebral hemispheres. - While it can be involved in subarachnoid or intracranial hemorrhages from aneurysm rupture or trauma, it is not the typical source of an epidural hematoma.

Question 8: A 25-year-old male presents with a head injury following a motorcycle accident, and a CT scan shows a fracture of the skull. Which bone is most commonly fractured in such injuries?

A. Parietal bone (Correct Answer)
B. Occipital bone
C. Temporal bone
D. Frontal bone

Explanation: ***Parietal bone*** - The **parietal bones** are the **most commonly fractured skull bones** in head trauma, accounting for approximately **30-40% of all skull fractures**. - This high frequency is due to their **large surface area**, **convex shape**, and **direct exposure** to impact forces during falls and accidents. - The parietal bones form a significant portion of the lateral and superior skull vault, making them vulnerable to direct blows. - Parietal fractures can be associated with **epidural or subdural hematomas**, especially when involving the **middle meningeal artery** groove. *Temporal bone* - While **clinically significant** due to proximity to vital structures (middle ear, inner ear, facial nerve), temporal bone fractures account for only about **20% of skull fractures**. - They typically result from **lateral impact** to the thinner squamous portion or base of the skull. - Complications include **hearing loss**, **facial nerve palsy**, and **CSF otorrhea**. *Occipital bone* - **Occipital bone fractures** are less common, typically occurring with **posterior impacts** to the back of the head. - They may be associated with injuries to **posterior fossa structures**, **cerebellar contusions**, and **venous sinus injuries**. *Frontal bone* - The **frontal bone** is relatively **thick** and forms the forehead, providing good protection against fractures. - Fractures require significant **direct frontal impact** and may involve the **frontal sinuses**, leading to complications like **CSF rhinorrhea** or **frontal sinus infection**.

Question 9: Which of the following statements regarding traumatic facial nerve palsy is false?

A. Posttraumatic facial nerve palsy may be complete at the time of presentation
B. Decompression of the canal can be useful treatment
C. Usually occurs with longitudinal petrous temporal bone fracture (Correct Answer)
D. Usually occurs with transverse petrous temporal bone fracture

Explanation: ***Usually occurs with longitudinal petrous temporal bone fracture*** ✓ FALSE - This is the correct answer - **Longitudinal temporal bone fractures** account for the majority (70-80%) of temporal bone fractures but are **less likely to cause severe facial nerve palsy** (10-20% incidence) compared to transverse fractures. - When facial nerve injury does occur with a longitudinal fracture, it typically involves the **tympanic segment** and can be caused by **edema or contusion**, often presenting with delayed or incomplete palsy rather than direct transection. *Usually occurs with transverse petrous temporal bone fracture* - **Transverse temporal bone fractures** are less common (20-30%) but are associated with a **higher incidence and severity of immediate facial nerve paralysis** (30-50% incidence) due to direct nerve transection or severe compression. - These fractures typically cross the **internal auditory canal** and otic capsule, often damaging the labyrinth and facial nerve directly. *Posttraumatic facial nerve palsy may be complete at the time of presentation* - **Complete facial nerve paralysis** can occur immediately after trauma, particularly with **transverse temporal bone fractures**, indicating severe injury such as nerve transection. - Early assessment of the degree of paralysis using the House-Brackmann grading system is crucial for determining prognosis and guiding management strategies. *Decompression of the canal can be useful treatment* - **Surgical decompression of the facial nerve canal** may be considered for patients with **immediate complete paralysis** or **progressive paralysis** following trauma, especially if imaging shows nerve entrapment or significant edema. - The decision for surgery is usually guided by **electrophysiological studies** (electroneuronography showing >90% degeneration) and high-resolution CT imaging to assess the extent of nerve damage and fracture pattern.

Question 10: A fracture of the middle cranial fossa may result in an injury of the

A. Sixth cranial nerve (Correct Answer)
B. Tenth cranial nerve
C. Eighth cranial nerve
D. Eleventh cranial nerve

Explanation: ***Sixth cranial nerve*** - The **abducens nerve (CN VI)** passes through the **Dorello's canal (or petroclival ligament)**, located in the vicinity of the middle cranial fossa. - Fractures in this region can lead to **stretching or compression** of the abducens nerve, resulting in **lateral rectus palsy** and *diplopia*. *Tenth cranial nerve* - The **vagus nerve (CN X)** exits the skull via the **jugular foramen**, located in the **posterior cranial fossa**. - Injury to this nerve is less likely with a fracture specifically confined to the middle cranial fossa. *Eighth cranial nerve* - The **vestibulocochlear nerve (CN VIII)** courses through the **internal auditory meatus** in the **petrous part of the temporal bone**, which is part of the posterior cranial fossa. - While acoustic trauma or petrous bone fractures can affect it, it's not a primary concern with general middle cranial fossa fractures. *Eleventh cranial nerve* - The **spinal accessory nerve (CN XI)** exits the skull through the **jugular foramen**, similar to the vagus nerve, placing it in the **posterior cranial fossa**. - Damage to this nerve would primarily cause weakness in the **sternocleidomastoid** and **trapezius muscles**, and is not typically associated with isolated middle cranial fossa fractures.

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