Generality
Trigeminal neuralgia is a neuropathic disorder, manifested by intense facial pain. An attack of trigeminal neuralgia can occur without warning and be triggered by stimulating specific areas of the face, even during simple daily actions, such as brushing your teeth, talking or chewing. The pain lasts from a few seconds to several minutes and affects one or more branches of the trigeminal nerve (also called the fifth cranial nerve). Trigeminal neuralgia is diagnosed with medical history, physical examination and imaging techniques. The latter are often useful to exclude other causes of facial pain (cancer, aneurysm, multiple sclerosis, etc.), conditions that must be managed and treated properly. Trigeminal neuralgia is a chronic (long-term) disease; if left untreated, it often tends to worsen over time, with attacks followed by increasingly shorter periods of remission. Although trigeminal neuralgia is not currently curable, several treatments are available that can effectively relieve pain.
Treatment options for trigeminal neuralgia include:
- Pharmacological therapy ;
- Surgical therapy ;
- Complementary approaches .
The first approach is drug therapy. In many cases, anticonvulsant and antidepressant drugs are prescribed, as they are often shown to improve neuropathic pain. However, drug therapy only provides temporary relief over time and some patients may become refractory to drugs. If trigeminal neuralgia is severe, or if the drug is not effective or causes unpleasant side effects, the option of surgery may be considered. The purpose of neurosurgery is to eliminate the causes that trigger neuralgia by acting on the blood vessels that compress the trigeminal nerve or on the nerve cells responsible for pain. Research shows that surgery provides effective long-term symptomatic relief, so that in 70-90% of cases treated, trigeminal neuralgia is unlikely to recur. This last possibility depends mainly on the type of surgery used. Moreover, since it is still an invasive treatment, before adopting this solution the potential side effects, such as hearing loss or numbness of the face, must also be considered. If trigeminal neuralgia is secondary, therefore determined by other causes such as multiple sclerosis or a tumor, the doctor will treat the basic condition.
drugs
Medications can provide temporary relief from the symptoms of trigeminal neuralgia, decreasing or blocking pain signals sent to the brain. The first line therapy includes the prescription of anticonvulsants (normally used to treat epilepsy), which act mainly by slowing down the electrical impulses that pass through the trigeminal nerve. Carbamazepine is usually the first choice anticonvulsant drug. This medicine is effective in trigeminal neuralgia treatment, as it reduces the pain symptoms. However, carbamazepine can cause various side effects and toxic reactions, which can make it difficult to manage trigeminal neuralgia in some patients. Also for this reason, anticonvulsants must be taken under strict medical supervision. If carbamazepine decreases its effectiveness, the doctor may increase the dose or change the treatment protocol.
The possible side effects of carbamazepine are described below:
| Very common side effects | Less common side effects | Uncommon side effects |
Nausea and / or vomiting; Dizziness; Feeling sick and tired; Leukopenia (reduction in the number of white blood cells); Alteration of liver enzyme levels. | Increased risk of bruising or bleeding; Weight gain and fluid retention; Confusion; Headache; Vision disorders (blurred or double vision); Dry mouth. | Involuntary movements (example: tremors); Abnormal eye movements; Diarrhea; Constipation. |
If carbamazepine is not tolerated by the patient, other anticonvulsant drugs (oxcarbazepine, clonazepam and gabapentin) may be prescribed. However, in general, the anticonvulsants adopted for trigeminal neuralgia could lose their effectiveness over time, because they are effective only in alleviating pain but do not act on the underlying cause.
Second line treatment
- Other drugs include some muscle relaxants such as baclofen, which can be taken alone or in combination with carbamazepine. Side effects can include confusion, nausea and drowsiness.
- Low doses of some tricyclic antidepressants, such as amitriptyline or nortriptyline, may be effective in treating neuropathic pain, but their use is often limited to treating depression associated with chronic pain.
- Painkillers, such as paracetamol and NSAIDs, are not effective in trigeminal neuralgia treatment (they can only be used in very mild cases).
If the drug fails to relieve pain or produces intolerable side effects, surgical treatment may be recommended.
Surgery
Several neurosurgical procedures are now available for trigeminal neuralgia treatment. The choice between the various options is made based on the patient's state of health and his medical history, considering previous surgical procedures, the possible presence of multiple sclerosis and the area of involvement of the trigeminal nerve.
In particular, surgery may be recommended for trigeminal neuralgia, if:
- The patient complains of severe facial pain and severe muscle spasms, despite ongoing drug therapy;
- Any of the bodily senses is influenced by neuralgia;
- The anticonvulsants are no longer effective in controlling pain;
- Conventional therapy has led to the onset of serious side effects;
- The patient is under 40 years old.
The goal of surgery applied to neuralgia is to correct the position or structure of the blood vessel that compresses the trigeminal and damages it, causing it to malfunction in the transmission of signals.
The surgical options for trigeminal neuralgia are:
- Microvascular decompression;
- Ablative treatments.
Some procedures are performed on an outpatient basis, while others may require a more complex operation that requires general anesthesia. After most of these surgical procedures, the onset of some degree of facial numbness, which may be temporary or permanent, is common. Pain can return after months or years, despite the initial success of the therapy. Depending on the procedure, other surgical risks are possible, including hearing loss, balance problems, infections and strokes.
Microvascular decompression
Microvascular decompression is the most invasive surgical procedure for trigeminal neuralgia treatment, but it is also the one that offers the lowest probability that the pain can return. This procedure allows to relieve the pressure that the blood vessels exert on the trigeminal nerve.
For many people, microvascular decompression can eliminate or reduce pain successfully and - among all available interventions - seems to provide the most lasting outcome. It has been seen, for example, that in over 70% of people operated, pain relief was still present 10 years after surgery. However, this type of surgery has some risks (unusual and often temporary), including a decrease in hearing (in less than 3% of cases), loss of facial sensitivity and vision disorders. Very rarely, this type of surgery can cause stroke, hydrocephalus, meningitis or even death.
Stereotactic radiosurgery
Stereotactic radiosurgery uses a concentrated beam of highly focused radiation to the trigeminal branch, to try to reduce or eliminate the pain signals that travel along the course of the nerve.
Other possible procedures
The rhizotomy can be used to treat trigeminal neuralgia and involves the destruction of selected nerve fibers in order to stop the pain.
Several forms of rhizotomy are available for the treatment of trigeminal neuralgia:
- Glycerol injection: this is an outpatient procedure in which the patient is sedated intravenously. The doctor inserts a thin needle at the level of the cheek, near the mouth, which is guided towards the trigeminal ganglion, in the base of the skull (where the three branches of the trigeminal nerve are reunited). The doctor guides the needle into the trigeminal cistern, a small sac of spinal fluid that surrounds the nerve and part of its root. Doctors inject a small amount of sterile glycerol, which damages the trigeminal nerve and blocks pain signals. This procedure temporarily relieves pain for about 6-12 months.
- Balloon compression. The procedure is performed under general anesthesia. The surgeon inserts a hollow needle (cannula) through the patient's face, which is guided along a branch of the trigeminal nerve. A thin and flexible catheter, with a balloon positioned at the end, is inserted through the cannula and is inflated with sufficient pressure to damage the trigeminal nerve and block the pain signals. After 1 minute the balloon is deflated and removed, together with the catheter and the cannula. The damage created by the balloon successfully controls pain in most people, at least for a period of time, however some patients may experience temporary or permanent weakness of the chewing muscles.
- Radiofrequency trigeminal termorizotomy. Electrical stimulation is used to selectively damage the nerve endings associated with pain. The patient is anesthetized and a hollow needle is passed through the cheek to the trigeminal ganglion. Once the needle is in place, the patient is awakened by sedation and a slight electrical current is sent through the tip of the electrode. This stimulus causes a tingling in the area where pain typically occurs. The patient is again sedated and the part of the nerve involved is gradually heated with an electrode, until it damages the nerve fibers. If the pain is not eliminated, the doctor may create further injuries. Radiofrequency trigeminal termorizotomy usually results in some temporary numbness of the face after the procedure.
Research has shown that around 90% of people will gain immediate pain relief after radiofrequency trigeminal thermorizing, glycerol injection or balloon compression. However, 50% of patients may permanently lose sensitivity in the area being treated. Other complications may include blurred or double vision, chewing problems, dysesthesia (annoying numbness) and very rarely painful anesthesia. The advantages of surgery must always be carefully weighed against the risks. Although a large percentage of patients with trigeminal neuralgia report pain relief after surgery, there is no guarantee that the intervention will definitively resolve the condition.
Complementary therapies
Some patients choose to manage trigeminal neuralgia using complementary techniques, usually in combination with drug treatment. Alternative therapies for trigeminal neuralgia offer varying degrees of success and include acupuncture, electrical nerve stimulation, meditation and other relaxation techniques. Few clinical studies have so far been conducted on the efficacy of these alternative treatments, so there is still no evidence to support their use for trigeminal neuralgia.
Continue: Trigeminal Neuralgia Cures »
