Central Nerve disorder - Cranial nerves disorder

Question 1

What is Trigeminal neuralgia?

Answer 1

Syndrome featuring painful paroxysms in one or more distribution of the Trigeminal nerve

• Uncommon – 4/10,000
• Women > men – 1.7: 1
• Peak age 50 to 69years
• More commonly affect the R side of face

Question 2

What is the pathophysiology of Trigeminal Neuralgia?

Answer 2

• idiopathic disorder
• Compression of the trigeminal nerve root caused by a tortuous blood vessel in the posterior fossa. This is true in 80 to 90% of the cases – NOT ALL.

Question 3

What are the clinical features of Trigeminal Neuralgia?

Answer 3

• unilateral facial pain
• lancination paroxysms of pain in the lips, teeth, shaving, washing or touch the affected area
• Most commonly affect the maxillary and Mandibular division of TG nerve
• Rarely affect the ophthalmic division.
• Lasted only a few seconds to several minutes
• Rarely occurs while sleeping

Question 4

What are the diagnostic strategies for trigeminal neuralgia?

Answer 4

• History - unilateral facial pain associated with non painful triggers
• Careful physical examination - no neurological deficit
• NB – 2 to 4% of trigeminal neuralgia also have MS

Question 5

What arer the differential diagnosis for the Trigemina neuralgia?

Answer 5

• Odontogenic infection
• Sinus disease
• Otitis media
• Acute glaucoma
• TMJ disease
• Herpes Zoster
• MS
• Acoustic Neuroma

Question 6

What are the management principle for Trigeminal neuralgia?

Answer 6

• High rate of spontaneous remission

Medical management
- Carbamazepine 100mg bd then increase to TDS ( NB level)

Surgical management – peripheral and central approach // Open procedure

1) Peripheral – medication injection or cryotherapy ( recurrent is common)
2) Central procedure - percutaneous approach (radiofrequency ablation/ thermal ablation/balloon micro compression/ Glycerol injection.
3) Open procedure – 80 to 95% successful but higher complication rate of deafness, facial anesthesia, CSF leak , meningitis and death

Question 7

What is Acoustic Neuroma?

Answer 7

• also referred to as Schwanoma – arise for the Schwann cells covering the vestibular branch of the 8th CN as it passes through the internal auditory canal
• Compression of the Cochlear (Acoustic ) branch resulted in :
  o Hearing loss
  o Tinnitus ( Continuous )
  o Dysequilibrium ( not true vertigo)
• Further growth in size causes compression of the cerebellopontine angle
  o Compression of facial nerves
  o Compression of trigeminal; nerves
• Larger tumor may compress the Brain stem, 4th ventricle resulting in raise ICP

Question 8

What is the feature / perspective of Acoustic Neuroma?

Answer 8

• Important cause of sensorineural hearing loss
• Rare 1/100,000 incidence with female :male ratio 1.5 : 1
• Patient with unilateral tinnitus or hearing loss should be evaluated to rule out acoustic Neuroma
• 5% can be bilateral /associated with type II neurofibromatosis
• Although benign it can cause damage through direct compression on CNS 8 + structure at the cerebellopontine angle

Question 9

What are the clinical features of Acoustic Neuroma?

Answer 9

• Asymmetric sensorineural hearing loss
• 15% have normal audiogram – may have tinnitus with imbalances, headache, fullness in the ear, otalgia, facial nerve weakness.
• Extremely slow growing and symptoms are gradual in nature ( one study – 4years from onset to discovery)

Question 10

What are the diagnostic Strategies for Acoustic Neuroma?

Answer 10

• History + physical exam suggestive of AN as above
• Audiogram
• If normal – Gadolinium – enhanced MRI ( extremely sensitive – led to earlier diagnosis
• Smaller the tumor the more option for management and better prognosis

Question 11

What are the differential diagnosis for Acoustic Neuroma?

Answer 11

• Asymetrical – Meniere’s disease (Tinnitus is intermittent)/ true vertigo
• AN account for 80% of all cerebellopontine angle tumors
• Meningioma is the next most common

Question 12

What are the Management for Acoutic Neuroma?

Answer 12

• Surgically removed
• Stereotatic radiation
• Complication include damage to TG nerve, Facial nerve, Acoustic nerve and to the cerebellum are all possible

Question 13

What is Bell Palsy?

Answer 13

This the paralysis of Cranial nerve VII - Facial nerve
Aet - Herpes virus infection
- HIV
- Lyme disease

Question 14

What are the clinical features of Bells Palsy

Answer 14

History
• Onset: whether abrupt followed by worsening over the following day (Bell’s palsy).
• Pain preceding or accompanying the weakness (Bell’s palsy).
• The face itself feels stiff and pulled to one side.
• Ipsilateral restriction of eye closure. Eyes roll back as patient tried to close his eyes.
• Difficulty with eating.
• Disturbance of taste (due to chorda tympani fibres).- anterior 2/3
• Hyperacusis (involvement of stapedius muscle in the inner ear)

Examination
• Weakness of muscles of one half of the face - patient is unable to screw her eyes tightly shut or move the angle of the mouth on the affected side.
• Loss of facial expression.
• Widened palpebral fissure

Question 15

What are the differential diagnosis for Bells Palsy?

Answer 15

· Ramsay-Hunt syndrome
· Acoustic neuroma
· Pontine CVA or tumour
· Guillian-Barre disease
· Multiple sclerosis

Question 16

What is Ramsay hunt syndrome ?

Answer 16

• Acute facial paralysis that occurs in association with herpetic blisters of the skin of the ear canal, auricle, or both is referred to as the Ramsay Hunt syndrome, or herpes zoster oticus.
• also is known as geniculate neuralgia or nervus intermedius neuralgia.
• Ramsay Hunt syndrome was described first in 1907 by J. Ramsay Hunt in patients who had otalgia associated with cutaneous and mucosal rashes, which he ascribed to infection of the geniculate ganglion by human herpesvirus 3 (ie, varicella-zoster virus).

Question 17

What is the pathophysiology of Ramsay Hunt syndrome?

Answer 17

Primary pathophysiology of Ramsay Hunt syndrome is located in the geniculate ganglion of the seventh cranial nerve (CN VII).

• Associated with VZV ( varicella zoster virus)
• NB - VZV can also be cultured from a proportion of Bells palsy patient but no rash.

Question 18

What are the clinical features for Ramsay Hunt syndrome - history

Answer 18

1) Deep earache
- radiates outward into the pinna of the ear
- associated with a more constant, diffuse, and dull background pain

2) always develops after a herpetic infection - rash or blisters in the distribution of the nervus intermedius.
- herpetic blisters of the skin of the ear canal, auricle, or both

3) Associated with the following:
- Vertigo and
- ipsilateral hearing loss
- Tinnitus
- Facial paresis

Question 19

Clinical features RHS - Examination

Answer 19

Physical:
1) peripheral facial nerve paresis with
2) associated rash or herpetic blisters in the - distribution of the nervus intermedius -
may include the following:
Anterior two thirds of the tongue
Soft palate
External auditory canal
Pinna
3) associated ipsilateral hearing loss and balance problems.
A thorough physical examination must be performed, including
- neuro-otologic and
- audiometric assessment

Question 20

What are the differential diagnosis for Ramsay Hunt syndrome

Answer 20

DIFFERENTIALS
Atypical Facial Pain 
Bell Palsy 
Postherpetic Neuralgia 
Temporomandibular Joint Syndrome 
Trigeminal Neuralgia 

Other Problems to be Considered: 
Adenocystic carcinoma
Carcinoma of the nasopharynx
External otitis
Otitis media
Referred pain
Dental infection or abscess
Labyrinthitis
Vertigo