What is the diagnosis and treatment for Trigeminal Neuralgia?

From the Guidelines

Trigeminal neuralgia should be treated with carbamazepine (CBZ) as the first-line agent for pain control, given its proven efficacy in achieving partial or complete pain relief in 70% of patients, as demonstrated in a systematic review of four placebo-controlled studies 1. The condition is characterized by severe, shock-like facial pain, typically occurring in brief episodes along one side of the face, following the distribution of the trigeminal nerve branches. Key features of trigeminal neuralgia include:

• Sudden, unilateral, severe, brief stabbing recurrent episodes of pain in the distribution of one or more branches of the trigeminal nerve
• Profound effect on quality of life
• Rare cases may be symptomatic of other conditions, such as tumors or multiple sclerosis
• Clinical features are outlined in Table 2 of the British Journal of Anaesthesia study 1 The most common cause of trigeminal neuralgia is neurovascular compression of the trigeminal nerve in or around the root entry zone. Treatment options for trigeminal neuralgia include:
• Anticonvulsant medications, such as carbamazepine, oxcarbazepine, gabapentin, or pregabalin
• Surgical interventions, including microvascular decompression, gamma knife radiosurgery, or percutaneous treatments, for patients who do not respond to medication
• Alternative medications, such as lamotrigine and baclofen, may also be considered, as suggested by international guidelines and Cochrane reviews 1 It is essential to note that patients should avoid triggers when possible and take medications consistently to prevent pain episodes. In cases where side effects become intolerable or pain control becomes sub-optimal, surgical interventions should be considered, with microvascular decompression being a viable option, offering a 70% chance of being pain-free at 10 years, as reported in the British Journal of Anaesthesia study 1

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 Carbamazepine tablets are indicated in the treatment of the pain associated with true trigeminal neuralgia. The initial dose of carbamazepine for Trigeminal Neuralgia is 100 mg twice a day, with a total daily dose of 200 mg. The dose can be increased by up to 200 mg/day in increments of 100 mg every 12 hours as needed to achieve freedom from pain, not exceeding 1200 mg daily. The maintenance dose to control pain is typically between 400 to 800 mg daily, but can range from 200 mg daily to 1200 mg daily 2. Carbamazepine is indicated for the treatment of pain associated with true trigeminal neuralgia 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 one of the most debilitating presentations of orofacial pain, with a significant impact on the quality of life of affected patients 4, 5.

Diagnosis and Diagnostic Criteria

• 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 3.

Medical Treatment

• Carbamazepine and oxcarbazepine are the drugs of first choice for treating TN 3, 6, 5.
• Other drugs that can be used alone or as add-on therapy include lamotrigine, gabapentin, pregabalin, botulinum toxin type A, and baclofen 3, 5.
• The antiepileptic drugs carbamazepine and oxcarbazepine work by modulating voltage-gated sodium channels, leading to a decrease in neuronal activity 5.

Surgical Treatment

• Surgery should be considered if the pain is poorly controlled or medical treatments are poorly tolerated 3.
• Trigeminal microvascular decompression is the first-line surgery in patients with trigeminal neurovascular conflict 3, 4, 6.
• Neuroablative surgical treatments can be offered if MR imaging does not show any neurovascular contact or where patients are considered too frail for microvascular decompression or do not wish to take the risk 3.
• Other surgical options include percutaneous methodologies such as glycerol or radiofrequency ablation, radiosurgery, and peripheral neurectomies 4, 6, 7.

Comparison of Medical and Surgical Treatment

• A long-term cohort study comparing medical (oxcarbazepine) and surgical management of intractable TN found that surgery was associated with better outcomes and longer pain-free periods 7.
• The study suggested that patients may benefit from having surgery earlier rather than later in the disease process to improve quality of life, freedom from medication, and the need for regular follow-up 7.