Description

• A painful disorder of the sensory nucleus of the 5th cranial (trigeminal) nerve (CN V) that 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: no abnormalities seen on neuroimaging
  • Secondary: cerebellopontine angle tumors (e.g., meningioma); tumors of CN V (e.g., neuroma, vascular malformations), trauma, demyelinating disease (e.g., multiple sclerosis [MS])
• 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

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 of the nerve into the pons accounts for up to 90%.
• Compression by tumors such as meningioma, acoustic neuroma, or arteriovenous malformation
• Demyelination around the compression site causes 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.

Genetics
Unknown

Risk Factors

Unknown

Commonly Associated Conditions

• Sjögren syndrome; rheumatoid arthritis
• Acute polyneuropathy
• MS
• Hemifacial spasm
• Charcot-Marie-Tooth neuropathy
• Arterial hypertension