What is the diagnosis and treatment for Trigeminal Neuralgia?

From the Guidelines

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

Treatment Overview

Trigeminal neuralgia is a chronic pain condition characterized by severe, shock-like facial pain, and its treatment should prioritize medications that can effectively manage this pain while minimizing side effects.

• The condition is often caused by compression of the trigeminal nerve by blood vessels, leading to demyelination and abnormal nerve firing.
• Treatment options include anticonvulsant medications, with carbamazepine being the most effective, as well as alternative medications like oxcarbazepine, gabapentin, and pregabalin.
• For patients who do not respond to medication, surgical options such as microvascular decompression, gamma knife radiosurgery, or percutaneous rhizotomy may be considered.

Medication Management

• Carbamazepine is the primary drug of choice for trigeminal neuralgia, with a recommended starting dose of 200mg at night, gradually increasing to a final dose of 400-1200mg, divided into 2-3 doses per day 1.
• Alternative medications include oxcarbazepine, gabapentin, and pregabalin, which may be used in patients who do not respond to carbamazepine or experience intolerable side effects.
• The dose of these medications should be adjusted based on the patient's response and side effects, with regular follow-ups to monitor medication effectiveness and side effects.

Surgical Options

• Microvascular decompression is a surgical option that addresses blood vessel compression of the nerve, with a 70% chance of being pain-free at 10 years 1.
• Other surgical options, such as gamma knife radiosurgery or percutaneous rhizotomy, may also be considered for patients who do not respond to medication.
• These procedures can damage the nerve and reduce pain signals, but may also result in varying degrees of sensory loss.

From the FDA Drug Label

Trigeminal Neuralgia(see INDICATIONS AND USAGE) 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

• Initial dose: 100 mg twice a day (200 mg/day)
• Dose titration: Increase by up to 200 mg/day in increments of 100 mg every 12 hours as needed to achieve freedom from pain
• Maximum daily dose: 1200 mg daily
• Maintenance dose: 400 to 800 mg daily, with some patients requiring as little as 200 mg daily or as much as 1200 mg daily 2

From the Research

Definition and Characteristics of Trigeminal Neuralgia

• Trigeminal neuralgia (TN) is a highly disabling disorder characterized by very severe, brief, and electric shock-like recurrent episodes of facial pain 3.
• It is classified into idiopathic, classic, and secondary forms, with classic trigeminal neuralgia associated with neurovascular compression in the trigeminal root entry zone 4.
• The condition can cause sudden, brief, and excruciating facial pain attacks in one or more branches of the trigeminal nerve, leading to a severe reduction in the quality of life of affected patients 4.

Diagnostic Criteria and Work-up

• New diagnostic criteria subclassify TN based on the presence of trigeminal neurovascular conflict or an underlying neurological disorder, allowing for better characterization of patients and decision-making regarding medical and surgical treatments 3.
• MR imaging, including high-resolution trigeminal sequences, should be performed as part of the diagnostic work-up to rule out multiple sclerosis, tumor processes, or other underlying conditions 3, 5.

Medical Treatment Options

• Carbamazepine and oxcarbazepine are the drugs of first choice for treating trigeminal neuralgia, with their mechanism of action involving modulation of voltage-gated sodium channels 3, 4.
• Other drugs that may be useful for pain control in trigeminal neuralgia include gabapentin, pregabalin, lamotrigine, phenytoin, baclofen, and botulinum toxin type A, which can be coadministered with carbamazepine or oxcarbazepine for a synergistic approach 3, 4.
• New pharmacological alternatives, such as eslicarbazepine and vixotrigine, are being explored, although there is a paucity of robust clinical evidence to support their use in trigeminal neuralgia 6, 4.

Surgical Treatment Options

• Surgery should be considered if the pain is poorly controlled or medical treatments are poorly tolerated, with trigeminal microvascular decompression being the first-line surgery in patients with trigeminal neurovascular conflict 3.
• Other surgical options include neuroablative surgical treatments, such as percutaneous balloon microcompression, percutaneous glycerol rhizolysis, and percutaneous radiofrequency (RF), which can be offered if MR imaging does not show any neurovascular contact or if patients are considered too frail for microvascular decompression 3, 5.
• Stereotactic radiation therapy (gamma knife) may also be used as a treatment option, particularly for elderly or frail patients 7, 5.