fascial nerve

Question 1

What are the etiologies of facial nerve injury?

Answer 1

Answer: Lesions of the pyramidal tract above the facial nucleus (supranuclear) result in upper motor neuron facial nerve paralysis. Lesions anywhere from the nucleus of the nerve to its termination lead to lower motor neuron facial nerve paralysis (peripheral).

Question 2

What are the causes of upper motor neuron facial nerve paralysis?

Answer 2

Answer: Upper motor neuron facial nerve paralysis can be caused by embolism, apoplexy (hemorrhage), thrombosis, inflammation (encephalitis), tumors, trauma, or brain abscess.

Question 3

What are the intracranial causes of facial nerve paralysis?

Answer 3

Answer: In the pons, affection of the facial nerve nucleus can occur, leading to facial paralysis accompanied by 6th nerve paralysis and pontine manifestations. This can be caused by congenital aplasia of the facial nucleus, pontine hemorrhage, pontine tumors, or basal meningitis. At the cerebellopontine angle, facial nerve paralysis is usually associated with 8th nerve (vestibulocochlear) affection, caused by tumors (e.g., acoustic neuroma, meningioma), arachnoid cyst, or congenital cholesteatoma.

Question 4

What are the causes of lower motor neuron facial paralysis?

Answer 4

Answer: Lower motor neuron facial paralysis can be caused by traumatic factors such as temporal bone fractures or ear surgeries, inflammatory factors like acute suppurative otitis media or malignant otitis externa, and tumors such as glomus jugulare, acoustic neuroma, neuroma of the facial nerve, or squamous cell carcinoma.

Question 5

How can the level of facial nerve lesion be determined?

Answer 5

Answer: Topognostic tests can be used to detect the level of the lesion in the facial nerve.

Question 6

What are the diagnostic tests used to identify the cause of facial nerve paralysis?

Answer 6

Answer: Diagnostic tests include CT of the brain and petrous bone to show tumors or trauma, MRI of the petrous bone to show tumors (especially acoustic neuroma and facial neuroma), and audiometric tests (pure tone audiometry, audiometry, ABR). Electrodiagnostic studies can also be performed to assess the condition of the facial nerve and facial muscles.

Question 7

What are the general lines of treatment for facial paralysis?

Answer 7

Answer: General lines of treatment include taking care of the eye to prevent complications, providing physiotherapy for the paralyzed muscles after the acute stage, and treating the underlying cause of facial paralysis.

Question 8

What is Bell’s palsy, and what are its clinical features?

Answer 8

Answer: Bell’s palsy is an idiopathic sudden lower motor neuron facial nerve paralysis. It presents as sudden unilateral facial paralysis, either partial or complete, and may be accompanied by retroauricular pain. Other investigations and diagnostic tests may be performed to exclude other causes of facial paralysis.

Question 9

What is the prognosis of Bell’s palsy, and how is it treated?

Answer 9

Answer: Satisfactory recovery occurs in most cases of Bell’s palsy. The treatment approach includes general measures such as care of the eye and care of paralyzed muscles, as well as medical treatment with full-dose steroids. Surgical treatment (decompression of the nerve) may be indicated if electrodiagnostic studies show significant degeneration within two weeks.

Question 10

What are the etiologies and clinical features of traumatic facial paralysis?

Answer 10

Answer: Traumatic facial paralysis can be caused by temporal bone fractures or surgical trauma. Transverse temporal bone fractures commonly result in immediate and complete facial paralysis, while longitudinal fractures may lead to delayed and partial paralysis. Clinical features may vary depending on the type of fracture.

Question 11

How is facial paralysis due to suppurative otitis media diagnosed and treated?

Answer 11

Answer: Facial paralysis due to suppurative otitis media can be diagnosed through clinical evaluation, including otoscopic examination, and confirmed by investigations such as culture and sensitivity of discharge, audiometry, and CT scan of the petrous bone. Treatment involves urgent myringotomy and systemic antibiotics for acute cases, while mastoidectomy to deal with cholesteatoma and exploration of the nerve are performed for chronic cases.

Question 12

What is the likely diagnosis and treatment for a 3-year-old child with a history of fever and ear pain followed by facial nerve paralysis?

Answer 12

Answer: Diagnosis: Facial nerve paralysis due to acute suppurative otitis media.
Treatment: Urgent myringotomy, systemic antibiotics, and steroids.

Question 13

In a newborn who was delivered with the use of forceps, which area should be examined for assessment of facial nerve function, and what is the most likely diagnosis?

Answer 13

Answer: The area to be examined is the stylomastoid foramina. The most likely diagnosis in this case would be facial nerve paralysis due to birth injury.

Question 14

What is the likely diagnosis and treatment for a 35-year-old man with ear pain and sudden facial asymmetry?

Answer 14

Answer: Diagnosis: Bell’s palsyTreatment: General care of the eye, physiotherapy for paralyzed muscles, and medical treatment with full-dose steroids.

Question 15

Q1: Where does the facial nucleus lie in the brain?

Answer 15

A1: The facial nucleus lies in the pons near the 6th cranial nerve nucleus.

Question 16

Q2: What is the path of the facial nerve from the pons to the porus acousticus?

Answer 16

A2: The fibers of the facial nerve loop around the 6th nerve in the pons, then the facial nerve emerges from the pons, crosses the cerebellopontine angle, and courses 12mm to the porus acousticus.

Question 17

Q3: What is the meatal portion of the facial nerve?

Answer 17

A3: The meatal portion of the facial nerve is the segment after it crosses the cerebellopontine angle and enters the internal auditory canal.

Question 18

Q4: What structures accompany the facial nerve in the internal auditory canal?

Answer 18

A4: The facial nerve enters the internal auditory canal accompanied by the 8th nerve (vestibulocochlear nerve) and labyrinthine vessels.

Question 19

Q5: What is the length of the Fallopian canal, and what are its segments?

Answer 19

A5: The Fallopian canal, through which the facial nerve passes, is 30-33 mm in length. It is divided into three segments: labyrinthine segment, tympanic (horizontal) segment, and mastoid (vertical) segment.

Question 20

Q6: Where does the geniculate ganglion lie, and what fibers travel with it?

Answer 20

A6: The geniculate ganglion lies in the Fallopian canal. It houses the cell bodies of the taste fibers, which travel with the chorda tympani nerve.

Question 21

Q7: What are the three segments of the Fallopian canal, and what are their characteristics?

Answer 21

A7: The three segments of the Fallopian canal are the labyrinthine segment (above the inner ear, reaching the geniculate ganglion), the tympanic (horizontal) segment (from the geniculate ganglion to the pyramidal turn), and the mastoid (vertical) segment (passing vertically downwards at the posterior wall of the middle ear cavity).

Question 22

Q8: What branches arise from the geniculate ganglion?

Answer 22

A8: From the geniculate ganglion, the facial nerve gives rise to one branch, the greater superficial petrosal nerve, which carries secretomotor preganglionic parasympathetic fibers to lacrimal, nasal, and palatine glands.

Question 23

Q9: What are the branches of the facial nerve in the vertical segment of the Fallopian canal?

Answer 23

A9: In the vertical segment of the Fallopian canal, there are two branches: the nerve to stapedius (motor to stapedius muscle) and the chorda tympani nerve (carries taste sensation from the anterior 2/3 of the tongue and secretomotor parasympathetic fibers to the submandibular and sublingual salivary glands).

Question 24

Q10: How is the facial nucleus controlled from high centers?

Answer 24

A10: The facial nucleus is controlled from high centers by extrapyramidal fibers (responsible for involuntary motor impulses of the face) and pyramidal fibers from the motor cortex area 4. The upper part of the facial nerve nucleus is under the control of both sides of the cerebral cortex, while the lower part is under the control of the opposite cerebral cortex.