What are the diagnosis and treatment options for trigeminal neuralgia (Trigeminal Neuralgia)?

From the Guidelines

Trigeminal neuralgia should be treated with carbamazepine as the first-line medication, starting at 200 mg at night and gradually increasing by 200 mg every 7 days to a final dose of 400–1200 mg, divided in 2–3 doses per day, as it has been shown to provide significant pain relief in 70% of patients 1.

Diagnosis

Trigeminal neuralgia is diagnosed through clinical evaluation of the patient's symptoms, particularly the characteristic brief, severe, shock-like facial pain triggered by light touch along the distribution of the trigeminal nerve. Diagnosis typically involves a thorough neurological examination and may include MRI imaging to rule out structural causes like tumors or multiple sclerosis.

Treatment

Treatment begins with first-line medications such as carbamazepine, which stabilizes neural membranes by blocking sodium channels, reducing abnormal nerve firing.

• The dose of carbamazepine can be tapered to a minimal effective dose once response has been achieved and patients maintain pain relief 1.
• If first-line treatments fail, second-line options include baclofen, gabapentin, or pregabalin.
• For refractory cases, surgical interventions may be considered, including microvascular decompression to separate blood vessels from the trigeminal nerve, or ablative procedures like radiofrequency thermocoagulation, glycerol rhizotomy, or gamma knife radiosurgery 1.

Management

Patients should be monitored for medication side effects, particularly hyponatremia with carbamazepine, and should understand that finding the right treatment may require trial and error.

• Pain diaries can help track trigger factors and treatment effectiveness.
• Patients should avoid triggers when possible and maintain good oral hygiene, as dental infections can exacerbate symptoms.
• International guidelines and Cochrane reviews suggest that carbamazepine remains the primary drug of choice, but oxcarbazepine is equally effective with fewer side effects 1.

From the FDA Drug Label

Trigeminal Neuralgia Carbamazepine tablets are indicated in the treatment of the pain associated with true trigeminal neuralgia. Beneficial results have also been reported in glossopharyngeal neuralgia. Initial:On the first day, 100 mg twice a day for tablets for a total daily dose of 200 mg This daily dose may be increased by up to 200 mg/day using increments of 100 mg every 12 hours for tablets, only as needed to achieve freedom from pain. Do not exceed 1200 mg daily. Maintenance:Control of pain can be maintained in most patients with 400 to 800 mg daily. However, some patients may be maintained on as little as 200 mg daily, while others may require as much as 1200 mg daily At least once every 3 months throughout the treatment period, attempts should be made to reduce the dose to the minimum effective level or even to discontinue the drug

The diagnosis of Trigeminal Neuralgia is not directly addressed in the provided drug labels. However, the treatment of Trigeminal Neuralgia with carbamazepine is described.

• The initial dose of carbamazepine for Trigeminal Neuralgia is 100 mg twice a day.
• The dose may be increased by up to 200 mg/day in increments of 100 mg every 12 hours as needed to achieve freedom from pain, not to exceed 1200 mg daily.
• The maintenance dose is typically between 400 to 800 mg daily, but may range from 200 mg daily to 1200 mg daily. 2 2

From the Research

Diagnosis of Trigeminal Neuralgia

• Trigeminal neuralgia is characterized by sudden, severe, brief, and stabbing recurrent episodes of facial pain in one or more branches of the trigeminal nerve 3, 4, 5, 6.
• The diagnosis of trigeminal neuralgia can be subclassified into classical TN, secondary TN, and idiopathic TN, based on the presence of trigeminal neurovascular conflict or an underlying neurological disorder 3, 4, 6.
• MR imaging, including high-resolution trigeminal sequences, should be performed as part of the diagnostic work-up to identify any neurovascular conflict or other underlying conditions 3.

Treatment of Trigeminal Neuralgia

• The first-line treatment for trigeminal neuralgia is medical, with carbamazepine and oxcarbazepine being the drugs of choice 3, 4, 5, 7.
• Other drugs that can be used as add-on therapy or as alternatives include lamotrigine, gabapentin, pregabalin, botulinum toxin type A, and baclofen 3, 4, 7.
• Surgery should be considered if the pain is poorly controlled or the medical treatments are poorly tolerated, with trigeminal microvascular decompression being the first-line surgery in patients with trigeminal neurovascular conflict 3, 7.
• Other surgical options include neuroablative surgical treatments, such as radiofrequency thermal rhizotomy, glycerol rhizotomy, balloon compression, partial sensory trigeminal rhizotomy, and peripheral neurectomy 6, 7.
• Stereotactic radiosurgery is also being evaluated as a treatment option for trigeminal neuralgia, particularly for elderly frail patients 7.