Introduction

Have you ever had an electric shock-like discomfort that was abrupt and intense on one side of your face? What if you experienced that pain whenever you chewed, spoke, or even smiled? For many who have trigeminal neuralgia, this is their everyday situation. Trigeminal neuralgia (TN) is frequently referred to as one of the most painful conditions in medicine, making even the most straightforward actions dreadful.

But what is causing this severe facial pain, precisely? How can it be controlled and why does it happen suddenly? So let's review several approaches to treating TN pain,  from medications to advanced surgical procedures.

Overview

Trigeminal neuralgia is a chronic pain disorder that affects the areas innervated by the fifth cranial nerve. The trigeminal nerve innervates the lower jaw, face, and forehead. Recurrent, brief episodes of electric shock-like symptoms depict it.  

The most common type of trigeminal neuralgia is unilateral, but it can affect one or more trigeminal nerve divisions. Trigeminal neuralgia is also known as Fothergill disease, tic douloureux, trifacial neuralgia, or suicide disease.¹

Prevalence     

An estimated 150,000 individuals are affected by trigeminal neuralgia (TN) each year. Although the condition can affect anyone, those over 50 are most likely to be affected. It occurs twice as often in women than in men.¹

What is trigeminal neuralgia?

Anatomy of the trigeminal nerve

The trigeminal nerve is one of the cranial nerves that connects various parts of the face to the brain and brain stem. The branches of the trigeminal nerve are the ophthalmic, maxillary and mandibular nerve branches. These branches transmit and receive sensations from all over the face. The sensory functions include sensations such as pressure, temperature and pain. The motor function includes chewing and not facial expressions.¹

Causes and triggers

Trigeminal neuralgia is caused by compression of the trigeminal nerve. All three branches may be affected, but usually it affects the maxillary and mandibular nerve branches of the trigeminal nerve. The compression may be due to various reasons such as aneurysm, tumor, trauma, multiple sclerosis or an expanding lesion.¹

Some of the common triggers of trigeminal neuralgia include light touch and pressure on the face, facial movements like talking, chewing or yawning, exposure to cold air or hot food, emotional stress, anxiety, physical fatigue or minor dental procedures can trigger an episode of neuralgic pain.

Symptoms

Pain symptoms usually last for seconds, minutes, or hours. The pain appears to be shooting, stabbing, electric shock-like pain that becomes unbearable. It also occurs in short intervals with periods of remission and usually affects one side of the face, although rarely it affects both sides.¹

Pharmacological pain management

Anticonvulsants

Anticonvulsant medications may reduce the frequency of attacks by blocking pain impulses. They specifically help by changing the electrical activity of calcium, sodium, potassium and chloride ion channels present in the cell membrane. Some of the medications are gabapentin,oxcarbazepine, topiramate, oxcarbazepine, lamotrigene, carbamazepine and pregabalin.²

Antispasmodic agents

Baclofen, and other muscle relaxants, can be administered with or without carbamazepine. Drowsiness, nausea, and disorientation are possible side effects. It works by acting on the nerves of the spinal cord, which reduces the frequency and intensity of pain in the muscles caused by multiple sclerosis or trigeminal neuralgia.²

Antidepressants

Trigeminal neuralgia patients may occasionally be offered tricyclic antidepressants for alleviation. It acts on two neurotransmitter molecules found in nerves: serotonin and noradrenaline, thus, reducing pain-transmitting signals to the brain. The most often given antidepressants are amitriptyline, nortriptyline, desipramine and maprotiline.^5,2

Analgesics

Analgesics play a supportive role in managing trigeminal neuralgia, though they are not primarily indicated. Non-steroidal anti-inflammatory drugs (NSAIDs) and opioid analgesics can be used to alleviate pain, but their effectiveness is limited. However, since pain is primarily due to nerve dysfunction, these analgesics often need to be combined with anticonvulsants like carbamazepine.²

Non-pharmacological pain management

Nerve blocks

Drug treatments can occasionally cause people to become refractory. In certain situations, medications could be injected subcutaneously to reduce pain right away. The benefit of peripheral trigeminal nerve branch blocking is that it has an instantaneous effect that lasts for at least two weeks. Commonly used local anesthetics are bupivacaine and lidocaine.³

Physical therapy

Some of the techniques that may help relieve pain are:

• Patients with trigeminal neuralgia can be treated with continuous transcutaneous electrical nerve stimulation. Electrodes will be placed before the ear and at the end of the nerve 
• A moist hot pack can be used to reduce muscle spasm, and isometric neck exercises can be done to relax the muscles
• Deep breathing exercises and distraction techniques can be performed to reduce the anxiety related to trigeminal neuralgia

Psychological support

Patients with chronic pain frequently exhibit anxiety, despair, and sleep disturbances that exacerbate their discomfort. Thus, cognitive behavioral therapy (CBT) has been shown to be a successful method of treating pain. CBT alters the way that patients feel about pain by lowering stress and anxiety. When paired with medical treatments, CBT improves mental health and improves the overall management of TN by addressing negative thought patterns and reducing anxiety.⁴

Lifestyle modifications

In patients with trigeminal neuralgia, a vegan diet might be beneficial because it often reduces the high-fat animal products linked to recurrence. Also, it reduces inflammation, which is a highlight of this diet. Food rich in healthy fats, carbohydrates, and low in gelatin can be followed by the patients.

Surgical interventions

When pain medications fail to relieve a patient's chronic pain, more permanent surgical procedures are indicated. Before considering surgery, the patient should be treated with medications for at least a year. 

Microvascular decompression (MVD)

Microvascular decompression is an invasive surgical procedure used to treat trigeminal neuralgia, which relieves pressure on the trigeminal nerve. This procedure is performed by repositioning the blood vessels compressing the nerve, which is often the cause of the intense facial pain. This procedure also reduces the rate of recurrence.⁵

Since it is an invasive procedure, it also has some side effects, which include leakage of spinal fluid, infection, loss of hearing, facial numbness and difficulty in speaking or swallowing.⁶

Percutaneous rhizotomy techniques

These percutaneous procedures are indicated for those who are not suitable candidates for more invasive surgical procedures. The types of rhizotomy procedures are:

• Radiofrequency rhizotomy: Trigeminal neuralgia pain can be relieved using a less-invasive technique called trigeminal radiofrequency rhizotomy. Radiofrequency or electricity is used to numb the branches of the trigeminal nerve. This procedure can relieve pain for a considerable amount of time. Patients with trigeminal neuralgia due to multiple sclerosis, those deemed unsuitable for brain surgery, and those experiencing recurrence of pain following alternative treatment techniques find this procedure to be optimal
• Percutaneous balloon compression: A balloon is inflated after being injected with a needle into the trigeminal nerve. Thus, the severe pain is relieved temporarily by this compression, which also interrupts the pain pathways. This has the advantage of being fast with a relatively short recovery time. However, some individuals may develop a recurrence⁷
• Glycerol rhizotomy: A small amount of glycerol is injected into the trigeminal cavity close to the nerve to damage the nerve fibers that transmit pain signals. By stopping the pain pathways, this controlled destruction relieves the excruciating facial pain linked to TN⁸ 

Gamma knife surgery

Gamma knife radio surgery (GKRS) is the least invasive procedure that focuses on radiation and targeting the trigeminal nerve, eliminating pain-transmitting signals. High-dose radiation is precisely applied to the nerve root where it leaves the brainstem. The goal is to minimise damage to surrounding tissues, while producing a lesion on the nerve that stops pain from being transmitted. This surgery gives pain relief with lower risk of adverse effects.⁹

Alternative therapies

Neuromodulation

Neuromodulation for trigeminal neuralgia involves electrical stimulation to change nerve activity and reduce pain. When alternative therapies have failed, techniques like motor cortex stimulation or peripheral nerve stimulation are taken into consideration as a less invasive way to address persistent neuralgic pain.¹⁰

Acupuncture

Acupuncture is another method to treat trigeminal neuralgia that shows lower side effects. Manual acupuncture or electroacupuncture can stimulate the body's pain sites and release blockages, thereby reducing pain. 

Dietary supplements

Supplements such as those containing omega-3 fatty acids, magnesium, and vitamin B12 help enhance nerve function and lower inflammation, which reduces pain. They can be used along with medications or other treatment options.¹¹

Summary

Trigeminal neuralgia is a rare chronic pain disorder with moderate to severe pain, although it occurs occasionally. There are many treatment options, from medications to conventional surgical procedures. Thus, the treatment relies on the severity of the condition, and the response to medications. Newer approaches to relieve pain are being developed and future advancements might help improve patients’ quality of life.