Trigeminal Neuralgia
Trigeminal neuralgia or trigeminal neuralgia is a chronic condition that constitutes pain that stands as a disease in itself. Although the causes aren’t unique, their study and treatment depend on the correct identification of the condition as such.
The quintessential sign is pain, which appears sporadically and spreads throughout the innervation area of the nerve in question–the trigeminal nerve–, which is found on both sides of the face. According to estimates, the prevalence of this disease is around one person for every 10 inhabitants, approximately.
The pain of this neuropathy intensifies when there are trigger actions, that is, situations that are capable of unleashing the discomfort with greater power. As its location is facial, touching the cheek may be sufficient to trigger sensations similar to stinging or an electric shock.
What is the trigeminal nerve?
The trigeminal nerve, the site where neuralgia settles, is a structure of the cranial nerves. These are a set of 12 neural formations that originate in the skull and fulfill different functions. The fifth pair is the one we’re talking about, which isn’t just limited to one branch, but branches out into 3.
Among the multiple innervations that it encompasses, it has sensory and motor actions. This means that the same pair is capable of carrying information to the brain, but also transferring certain orders from the central nervous system to the tissues. As for its sensory capabilities, it collects data from the skin and the mucous membranes of the face. At the same time, as a motor nerve, it stimulates the chewing muscles.
The branches of the trigeminal nerve
One of the three branches is ophthalmic. This is sensitive in its entirety and takes information from the scalp, the paranasal sinuses, the cornea, and the nostrils of the nose. The second branch is the maxilla, which is also sensitive and collects data from the eyelids, paranasal sinuses, nasal cavity, cheeks, upper lip, and maxilla, as well as the buccal mucosa.
Finally, the third branch of the trigeminal nerve is the mandibular. In this case, sensory and motor actions are combined. It transmits information from the ear, the buccal mucosa, the tongue, the teeth, the lower lip, and the cheeks while at the same time regulating the movement of certain masticatory muscles, as well as others present in the inner ear.
This anatomical distribution denotes the places where pain can be present when there’s neuralgia. Although it may be more frequent in the cheek region, patients usually perceive the stimulus that settles in the ophthalmic branch as more painful, as it involves the eyeball.
The symptoms of trigeminal neuralgia
Of course, the most powerful and noticeable symptom of trigeminal neuralgia is pain. Those affected describe it in different ways, but there’s an abundant agreement in referring to it as stinging or electricity that runs through the face. The stinging burns as if the inside of the face were on fire. Electricity, for its part, simulates small discharges that are more or less intense during the day or over the weeks.
As we’ve mentioned, the pain becomes more present in the face of trigger actions. They’re not the cause of the neuropathy but are related to the symptoms, as they increase the burning and electricity or trigger it out of nowhere. Among the situations that most frequently act as triggers we have the following:
- Shaving
- Rubbing against another part of the body, such as the hand
- Washing your face
- Cold from the environment, from a fan or air conditioning, either from the house or from the car
- Tooth brushing
- Chewing
None of these actions need to be performed violently to trigger the pain. On the contrary, the sensitivity is so increased that a slight touch is enough to start the cycle of neuralgia or exacerbate an already present discomfort.
The duration of attacks
The duration of the attacks is highly variable. While there are patients who suffer for a few minutes or hours and then go through long periods of latency, there are also others who suffer for months or even years from a burning sensation that doesn’t stop and doesn’t calm down with analgesics or hygienic measures.
Regardless of cycle lengths, there are always times of remission. This means plateaus will be traversed without discomfort. In any case, it’s logical to expect an increase in seizure episodes with the passage of time and aging. It’s not yet clear why it worsens as it evolves, but it’s a fact based on the experience of patients.
What are the causes of trigeminal neuralgia?
Trigger actions are just that: Pain triggers. But the causes or etiology are different things in the case of trigeminal neuralgia. Although we know that the nerve of the fifth cranial nerve is the protagonist, there’s no clarity about the mechanisms that lead to already established neuropathy.
In the most benign situations, it can be attributed to a blood vessel that presses on the nerve, either due to a bad anatomical position or due to an enlargement of the artery or vein that leads to squeezing. This could be understood as a small aneurysm in the area of the skull through which the trigeminal passes.
Another etiological option would be the loss of myelin from the cranial nerve. This condition is common and forms part of the evolution of diseases like multiple sclerosis, but the possibility of the demyelination of specific segments of this nerve in patients is being considered. Myelin is the fatty sheath that allows rapid transmission of the nerve impulse; its loss alters that communication, generating symptoms.
Traumas that access the trigeminal and damage it would explain the appearance of pain in people who begin to suffer from it after a dental intervention or a traffic accident, for example. It’s also not unusual in those who have undergone cranial, nasal, or oral surgeries.
Finally, it’s worth noting tumors, whether or not they’re malignant. Tumors that impinge on the trigeminal pathway cause pain by the same mechanism of blood vessels that press on neurons.
Treatment of the disorder
The treatment of trigeminal neuralgia can be done with medication, but the result isn’t always effective nor does it always produce the desired effects. The chronic condition of the disorder and its tendency to worsen with time make it difficult to approach it in the medium and long term.
Analgesics and anti-inflammatories are the first choice. Among them, there’s a range of options that range from steroids and non-steroids to morphine. These can be combined with others that have complementary relief actions, such as muscle relaxants.
A special case is the use of antidepressants for neuropathic pain. Tricyclics are perhaps the most studied and prescribed in the protocols for herpetic neuralgia, for example.
Once the non-interventionist instances have been exhausted, the next step is surgical. Several options have been tried and are still used in clinical practice to try to bring relief to patients. We’ll review the most used.
Radiosurgery
This consists of the irradiation of the nerve by means of a device designed for this purpose. First, images are taken to plan the incidence of the rays and then sessions are scheduled in which the trigeminal zone is affected, especially in its brain origin.
A variant is gamma knife radiosurgery. The principle is similar, using a kind of knife that converges radiation beams on the area to be treated.
Radiofrequency
In radiofrequency, a needle is incised and directed to the trigeminal. This is done with the patient under anesthesia. Once inside the body, the needle is capable of transmitting heat through electrodes, which would cause changes in neurons, improving symptoms.
Glycerol
The use of glycerol is with intracranial injections. The professional inserts the needle into the base of the skull and directs it to the origin of the nerve. The substance would then be capable of inhibiting the transmission of painful signals by being deposited in that anatomical area, where a tiny sac with spinal fluid resides.
Vascular decompression
This technique is the most complex, but scientific studies report higher effectiveness than the rest. It’s used when there’s an artery that’s compressing the trigeminal nerve. With the procedure, this compression is released in the same place, influencing and relieving the tightening. Anesthesia, a trained surgical team, and days of hospitalization are required for recovery.
In the event that the neurosurgeon doesn’t find an artery during the process, they may choose to complete the procedure with a neurectomy. This involves removing a part of the nerve where the pain appears to originate so that the discomfort disappears. As we say, it’s a second attempt.
The approach to trigeminal neuralgia is difficult
Living with trigeminal neuralgia is difficult, but not only for the patient. Family and close ones must adjust to a person with chronic pain. In the same way, the professionals involved face a problem that puts their diagnostic and treatment capacities to the test.
All therapeutic approaches have their shortcomings. Sometimes they work and other times they don’t. The choice of surgery, radiotherapy, or trying solutions with oral medications will depend on the particular clinical situation.
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