Treatment of Trigeminal Neuralgia
Start carbamazepine 200 mg twice daily as first-line treatment, titrating up to 400-800 mg daily for maintenance, as it is FDA-approved specifically for trigeminal neuralgia and remains the gold standard with 70% of patients achieving partial or complete pain relief. 1, 2
First-Line Pharmacological Management
Carbamazepine is the drug of choice, starting at 100 mg twice daily (200 mg/day total), increasing by up to 200 mg/day at weekly intervals until pain freedom is achieved, not exceeding 1200 mg daily. 1
Oxcarbazepine is equally effective as carbamazepine but has a superior side effect profile, making it the preferred first-line option when carbamazepine causes intolerable adverse effects (which occurs in approximately 27% of patients). 2, 3
Expect pain relief within 24 hours in up to one-third of eventual responders, with over 40% achieving complete relief within one week and maximal benefit typically within one month. 2
Monitor for common side effects including drowsiness, headache, dizziness, dry mouth, constipation, and sedation. 3
Second-Line and Adjunctive Medications
When first-line agents fail or cause intolerable side effects:
Lamotrigine, baclofen, gabapentin, or pregabalin can be used as monotherapy or add-on treatment. 2, 3
Gabapentin combined with ropivacaine has shown efficacy in randomized controlled trials. 2
In elderly patients, start gabapentin at 100-200 mg/day (not the standard dose) and titrate gradually to 900-3600 mg/day in 2-3 divided doses. 2
Pregabalin should be initiated at 25-50 mg/day in elderly patients, increasing to 150-600 mg/day in two divided doses. 2
Baclofen starts at 5 mg three times daily, though elderly patients rarely tolerate above 30-40 mg/day and it carries significant risks of sedation, confusion, and falls. 2
Surgical Intervention Timing and Options
Refer for early neurosurgical consultation when initiating treatment to establish a comprehensive plan, and proceed to surgery when pain intensity increases despite medication optimization or side effects become intolerable. 2
Microvascular Decompression (MVD)
MVD is the technique of choice for patients with minimal comorbidities and evidence of neurovascular compression on MRI, as it is the only non-ablative procedure. 2, 4
Provides a 70% chance of being pain-free at 10 years. 2
Carries a 2-4% risk of hearing loss and 0.4% mortality risk. 2
Patients may expect 100% pain relief, off all medications, for over five years after successful MVD. 2
Ablative Procedures
For elderly patients, those with major comorbidities, or when MVD is not desired:
Radiofrequency thermocoagulation of the Gasserian ganglion is recommended for elderly or high-risk patients. 4, 5
Glycerol rhizotomy, balloon compression, and Gamma Knife radiosurgery are alternative ablative options that result in varying degrees of sensory loss. 2, 3
Stereotactic radiosurgery delivers 70 Gy to a 4 mm target, providing pain relief within three months, with three-quarters achieving complete relief initially but only half maintaining this at three years. 2
The most frequent complication of radiosurgery is sensory disturbance, including anaesthesia dolorosa. 2
Critical Diagnostic Considerations
Before finalizing treatment:
Obtain MRI with contrast including high-resolution trigeminal sequences to distinguish classical TN (with neurovascular compression), secondary TN (from MS or tumors), and idiopathic TN. 6, 7
Classical TN presents with paroxysmal attacks lasting seconds to minutes with mandatory refractory periods between attacks—not continuous pain. 6
Type 2 TN has prolonged continuous pain between sharp attacks and may originate from more central mechanisms, responding less predictably to treatment. 2, 6
If continuous pain is present, urgently rule out secondary causes including MS, tumors, or structural lesions. 6
Common Pitfalls to Avoid
Do not confuse TN with trigeminal autonomic cephalgias (SUNCT/SUNA), which present with autonomic features like tearing, red eye, and rhinorrhea, up to 200 attacks daily with no refractory period. 6
In patients over 50 with temporal region pain, always rule out giant cell arteritis which requires urgent systemic steroids. 2
Approximately 15% of patients fail to obtain at least 50% pain relief with carbamazepine; do not delay surgical referral in these cases. 2
In elderly patients, start with lower doses and titrate more slowly, monitoring carefully for sedation, confusion, and fall risk. 2
Attempt dose reduction every 3 months to find the minimum effective level or potentially discontinue treatment during remission periods. 1