Description

• Trigeminal neuralgia (TN) is a painful disorder of the sensory nucleus of the 5th cranial (trigeminal) nerve that commonly produces episodic, paroxysmal, severe, lancinating facial pain lasting seconds to minutes
• Often precipitated by stimulation of well-defined, ipsilateral trigger zones: usually perioral, perinasal, and occasionally intraoral (e.g., by talking, washing your face, shaving, or exposure to cold air)
• Subtypes:
  • Classical: secondary to neurovascular compression
  • Idiopathic: when the criterion for TN is met, but neither classic nor secondary TN can be diagnosed based on MRI and electrophysiological testing.
  • Secondary: diagnosed based on fulfillment of criteria for TN but attributed to a separate causative comorbid condition. The three subtypes of secondary TN are TN attributed to multiple sclerosis (MS), space-occupying lesions (such as cerebellopontine angle tumors, meningioma, neuroma, etc.), or attributed to other causes
• System(s) affected: nervous
• Synonym(s): tic douloureux; Fothergill neuralgia; trifacial neuralgia; prosopalgia

Epidemiology

Incidence

• 4 to 29/100,000 per year
• Incidence increases with age, mean onset of 55 years
• Female-to-male ratio 3:2

Prevalence


Pregnancy Considerations
Teratogenicity of medication therapy limits their use during 1st and 2nd trimesters

Etiology and Pathophysiology

• Compression of the trigeminal nerve root by an anomalous artery or vein
• Compression by tumors such as meningioma, acoustic neuroma, or arteriovenous malformation
• Demyelination from compression, or other secondary cause such as MS, leads to an ectopic impulse generation with erratic responses such as hyperexcitability of damaged nerves and transmission of action potentials along adjacent, undamaged, and unstimulated sensory fibers.
• Dysregulation of voltage gated sodium channels

Risk Factors

MS associated with a 20-fold increased risk of developing TN

Commonly Associated Conditions

• Sjögren syndrome; rheumatoid arthritis
• Acute polyneuropathy
• MS
• Charcot-Marie-Tooth neuropathy