Cranial Neuralgias

Question 1

What is neuralgia?

Answer 1

• Intense stabbing pain
• Pain usually brief but may be severe
• Pain extends along course of the affected nerve
• Usually caused by irritation of or damage to nerve

Question 2

What nerves can be included in cranial neuralgias?

Answer 2

• Trigeminal CN V
• Glossopharyngeal CN IX
• Vagus CN X
• Nervus intermedia (part of facial nerve CN VII)
• Occipital

Question 3

What is the Incidence of Trigeminal neuralgia?

Answer 3

• F:M 6:3
• Usually elderly pt (60s or above )
• 4 in 100 000 people per year

Question 4

What is Trigeminal neuralgia?

Answer 4

• A sudden usually unilateral severe brief stabbing recurrent episode of pain in the distribution of one or more branches of the trigeminal nerve

Question 5

What are the classifications of TN?

Answer 5

• Idiopathic
• Classic
• Secondary

Question 6

What is the clinical presentation of TN?

Answer 6

• Stabbing, paroxysmal, reminiscent of electric shock or burning limited to area innervated by one or more branches of trigeminal nerves
• Each episode of pain followed by refractory period lasting few seconds to several mins
• Mask like face
• No obvious precipitating pathology

Question 7

Give some triggers for TN

Answer 7

• Slight touch to face
• Toothbrushing
• Activation if masticatory muscles and facial during speech or feeding
• Even slight wind breeze or cold

Question 8

What is the pathophysiology of Classic TN?

Answer 8

• Neurovascular compression mostly the superior cerebelalr artery of the trigeminal nerve roots into the pons
• Compression results in demyelination of nerve fibres leading to ectopic firing
• Compression leads to nerve root atrophy or displacement

Question 9

What causes secondary TN?

Answer 9

• Ass with underlying disease such as MS , Space occupying lesion, connective tissue disease, arteriovenous malformation

Question 10

State the order of what branches are affected in TN with most affected at the start

Answer 10

Only one either max or mand > both max and mand > opthalmic

Question 11

Give some TN red flags

Answer 11

• Younger pt >40yrs
• Sensory deficit in facial region like hearing loss (acoustic neruoma)
• Other cranial nerve lesions

Test cranial nerve
MRI

Question 12

What is the first line drug therapy for TN?

Answer 12

• Carbamazepine
• Oxcarbazepine
• Lamotrigine (slow onset of action)

Question 13

What is the second line drug therapy for TN?

Answer 13

• Gabapentin
• Pregablin
• Phenytoin
• Baclofen

Question 14

What are the side effects of carbamazepine?

Answer 14

• Thrombocytopenia
• Neutropenia
• Pancytopenia
• Electrolyte imbalances
• Paraesthesia
• Vestibular problems
• Liver toxicity
• Skin reactions

Question 15

What are the surgery indications for pts with TN?

Answer 15

• When approaching max tolerable medical management
• Younger pt with sig drug use (as will have many years of drug use)

Question 16

What are the surgical options for TN?

Answer 16

• Microvascular decompression (MVD)
• Destructive central procedures like balloon compression
• Stereotactic radiosurgery using a gamma knife to kill trigeminal nerve cells
• Destructive peripheral neurectomies

Question 17

What are some complications after surgery of TN?

Answer 17

Sensory loss of
- Corneal reflex
- General sensation
- Hearing loss

Motor deficits

Reversible or irreversible

Question 18

What are some causes of painful trigeminal neuropathy? (Not TN)

Answer 18

• Herpes Zoster Virus (post herpetic neuralgia
• Trauma (can present <6months of traumatic event
• Idiopathic

Question 19

What are the characteristics of painful trigeminal neuropathy?

Answer 19

• Pain localised to distribution of trigeminal nerve
• Burning or squeezing or pins and needles
• Continuous or near continuous pain
• Accompanied with clinically evident cutaneous allodynia (pain from stimulus not usually painful)

Question 20

Name some trigeminal autonomic cephalalgias

Answer 20

• Cluster headache
• Paroxysmal hemicrania
• SUNCT

Question 21

Describe a cluster headache attack

Answer 21

• Pain mainly orbital and temporal region
• Unilateral
• Rapid onset and can last 15mins to 3 hrs
• Rapid cessation of pian
• Excruciatingly severe (suicide headache)
• Prominent ipsilateral autonomic symptoms
• Migraine symptoms

Question 22

Describe the bout of cluster headaches

Answer 22

• Attacks cluster into bouts typ 1-3 months with remission lasting 1 month
• 1 every other day to 8 per day
• Alcohol triggers attack in bout but not in remission
• Attacks occur at same time each day
• Bouts occur same time each year

Question 23

Describe paroxysmal hemicrania

Answer 23

• Pain from orbital and temporal region
• Attacks are unilateral
• Rapid onset
• Duration 2-30mins
• Rapid cessation of pain
• 2-40 attacks per day (no circadian rhythm ass)
• Excruciatingly severe
• Prominent ipsilateral autonomic symptoms
• 10% attacks started by bending or rotating head

Question 24

What is the drug therapy for cluster headache?

Answer 24

Abortive attack:
- Subcutaneous sumatriptan 6mg or nasal zolmatriptan 5mg
- 100% oxygen 7-12 L/min via non-rebreathing mask

Abortive bout
- Occipital depomedrone / lidocaine injection
- tapering course oral prednisolone

Preventative
- Lithium
- Verapamil
- Methysergide

Question 25

What is the drug therapy of paroxysmal hemicrania?

Answer 25

• No abortive txt
• Prophylaxis with indomethacin
• COX-II inhibitors , Topiramate