Episodic Neuropathic Pain (A)

Question 1

Define: Neuropathic Pain

Answer 1

• Pain initiated or caused by primary lesion or dysfunction in the nervous system
• Abnormal Structure or function in peripheral or central nervous system

Question 2

Neuropathic Pain: Etiologies

Answer 2

• Infection
• inflammation
• Metabolic Abnormalities
• Chemotherapy
• Radiation
• Surgery
• Neurotoxin
• Nerve compression
• Tumor infiltration
• Trauma

Question 3

Characteristics of Neuropathic Pain

Answer 3

• Pain w/no nociception
• Intense pain
  
  • not proportional to stimulus
• bright, stimulating, burning
• Not responsive to NSAIDs & Los dose opioids

Question 4

Central Pain: Mechanisms

Answer 4

• Trigeminothalamic (spinothalamic) pathway damage
• Sensitization of CNS neurons

Question 5

Central Pain: Causes

Answer 5

• Abscess
• Cerebrovascular lesions
  
  • infarcts
  • hemorrhage
• Traumatic brain/spinal injury
• Tumors
• Multiple Sclerosis (MS)
• Parkinson’s

Question 6

Peripheral Pain

Answer 6

• most common site for neurogenic pain
• Nerve Injury
  
  • compression
  • inflammation
  • transection

Question 7

Episodic Neruopathic Pain

Answer 7

• Sudden burst of electric-like, shooting, or cutting pain
  
  • unilateral

Question 8

Trigeminal Neuralgia (TN): General

Answer 8

• CN5
• Intense stabbing, electrical shock like Face Pain
  
  • Episodes
    
    • several seconds (5-10)
  • Paroxysmal
  • Multiple attacks
• Unilateral
• Duration: several weeks, months or years then goes into remission
  
  • increases in frequency, duration, and severity of attacks until symptoms become continuous (no remission)
• Refractory interval
  
  • time between attacks where nerves do not fire

Question 9

Trigeminal Neuralgia: Trigger Zones

Answer 9

• Extraoral:
  
  • cutaneous corner of lip
  • cheek
  • ala of nose
  • lateral brow
• Intraoral:
  
  • gingiva

Question 10

Trigeminal Neuralgia: Classification

Answer 10

• Syptomatic TN:
  
  • Clear Cause
• Essential/Idiopathic
  
  • unclear cause

Question 11

Trigeminal Neuralgia: Treatment

Answer 11

• Pharmaceuticals:
  
  • Carbamazepine
  • Oxcarbazepine
  • Baclofen
  • Lamotrigine
  • Gabapentin
• Surgical Intervention (If pharm doesn’t work)
  
  • Microvascular Decompression
  • Percutaneous Procedures
  • Gamma Knife

Question 12

Percutaneous Treatment

Answer 12

• Balloon Compression (BC)
• Glycerol rhizotomy (GR)
• Radiofrequency thermocoagulation (RF)

Question 13

Microvascular Decompression

Answer 13

• Trigeminal Nerve cushioned from artery

Question 14

Gamma Knife

Answer 14

• Least invasive
• Advantage:
  
  • brain is not exposed→reduce risk factors
• Unknown MOA
  
  • Burst of gamma rays on trigeminal root entry zone
• 70% pain relief

Question 15

Pretrigeminal Neuralgia

Answer 15

• Dull continuous aching pain
  
  • area of tooth/alveolar bone
• persists for days to years before typical TN symptoms

Question 16

What are the different types of Episodic Neuropathic Pain?

Answer 16

• Trigeminal Neuralgia
• Glossopharyngeal Neuralgia
• Occipital Neuralgia
• Nervus Intermedius Neuralgia
• Superior Laryngeal Neuralgia