Neuralgia is characterized by repeated crises of localized pain in the distribution territory of one or more nerves.
The most frequent is trigeminal neuralgia. Its incidence is 8-13 per 100,000 inhabitants/year and increases with age, affecting more women than men.
Trigeminal neuralgia is often confused with other headaches such as migraine or tension headache, which are completely different.
Symptoms
The patient reports attacks of intense stabbing pain or pain similar to an electric shock, lasting a few seconds to two minutes, usually unilateral and localized in the distribution of one or more nerve branches.
In the case of trigeminal neuralgia (the trigeminal has three branches), it is usually the second or third branch, affecting the area of the nasal and maxillary wing or the jaw, although sometimes it can manifest itself in several branches.
The pain can appear spontaneously, or triggered by tactile stimuli, cold, heat, chewing, etc., over certain areas called “trigger zones”.
Typically the patient tries not to talk or chew, touch his face or brush his teeth to avoid the pain.
Types of neuralgia
Depending on their cause, they can be essential, idiopathic (unknown cause) or secondary (due to tumors, aneurysms, arteriovenous malformations, trauma, alcohol, diabetes, infections, inflammatory causes, etc.).
If we consider the affected nerve, the most frequent are cranial neuralgias: trigeminal, glossopharyngeal, or occipital neuralgia, among others. Postherpetic neuralgia caused by shingles, also very common, can affect any nerve trunk of the body and usually appears after shingles.
Causes
The so-called essential forms have no apparent cause leading to nerve damage. Secondary neuralgia is due to the existence of a lesion that invades or compresses the nerve, such as a tumor, vascular malformations, demyelinating diseases (e.g. multiple sclerosis), infectious diseases (such as that produced by the herpes zoster virus) or others.
In the case of trigeminal neuralgia, it has been observed that in many patients who have undergone surgery for supposedly essential neuralgia, there were actually blood vessels compressing the trigeminal root.
The explanation of how pain is produced would be the hyperexcitability of the nerve fibers and the transmission of stimuli from the fibers that convey touch to others that conduct pain, due to a loss of the substance that surrounds the fibers (myelin) which favors the contact of the axons (the prolongation of the neurons that conduct the nerve impulse).
Treatments
In the case of secondary neuralgia, the treatment of choice is that of the originating cause (resection of tumors, aneurysms, treatment of infections, etc.).
In the case of primary, essential or idiopathic neuralgia, the treatment of choice is pharmacological, the most used and effective drugs are antiepileptic drugs.
Sometimes there are cases of essential neuralgia that do not respond to drugs, in which case surgical treatment would be indicated, in an attempt to free the nerve from possible vascular compressions, or to injure the fibers that conduct the pain.
The most commonly used in trigeminal neuralgia are: thermocoagulation, balloon compression, microvascular decompression of the trigeminal root, radiosurgery with gamma-knife, section of the trigeminal root, or the so-called peripheral neurolysis.
Sometimes it is necessary to resort to both types of treatment: medical and surgical.