Trigeminal neuralgia

From WikEM
Jump to: navigation, search

Background

Clinical Features

  • Paroxysms of severe unilateral pain in trigeminal nerve distribution lasting only seconds
  • Normal neuro exam
  • No pain between paroxysms
  • Variant with headache
  • More common in Middle aged women

Differential Diagnosis

Headache

Common

Killers

Maimers

Others

Aseptic Meningitis

Facial paralysis

Evaluation

  • Sensory loss, bilateral involvement, and younger age (<40) are associated with a higher risk of secondary TN, but their absence does not rule out secondary TN
  • Consider CT/MRI in these patients to rule out structural etiology
  • <5% of patients have V1 distribution, examine carefully for zoster in these patients

Management

Phenytoin

  • 250mg IV to abort an acute attack
  • Relief lasts from four hours to three days
  • Fosphenytoin seems to work similarly

Carbamazepine

  • First-line agent with 75% success rate initially
  • Proposed Mechanism: Decreases the response of neurons to peripheral stimulation
  • Started at 100mg one to two times per day
  • Increase by 100-200mg every 3 days
  • Usual maintenance dose is 400-800mg (rare >1500mg)
  • Pain relief occurs within several hours to days (94% within 48 hours)
  • Target serum concentration is 24-43 ╬╝mol/L
    • If unsuccessful, phenytoin 200-400mg/day is used in combination

Other agents

Surgery

  • Posterior fossa microvascular decompressive surgery
    • Approximately 50% of patients will require surgery
  • Successful in 70% of patients

Disposition

  • Typically outpatient

See Also

References

  • J Pain Symptom Manage 2001; 21(6):506-510.