Even a caress can turn into unbearable pain if you suffer from trigeminal neuralgia, the chronic-relapsing disease which, according to data from the SIN (Italian Society of Neurology) affects 5 inhabitants out of 100,000. Few, but not very few, if we consider that trigeminal neuralgia seriously compromises daily activities, from work to sport, from travel to social relationships. A life full of limitations, in short, because of a acute malaise difficult to control with drugs. Here’s the news to knock him out.
Trigeminal neuralgia, the symptoms: intense and debilitating
A stab or an electric shock. Thus patients with trigeminal neuralgia describe the crippling pain they experience when they are “under attack”. It is due to the sudden and violent inflammation of the trigeminal nerve, a very important sensory nerve rich in nociceptors, the pain receptors. It is also called the “fifth cranial nerve” and is the longest of the 12 nerves that cross the face and braincase, running both to the left and right of the facial hemisphere.
“The painful twinges are warned at cheeks, cheekbones, jaw, gums and even teeth that suddenly become hypersensitive,” explains the doctor Susanna Usai, neurologist at the Neurology 3 Unit of the Besta Neurological Institute in Milan. “The excruciating pangs last a few seconds but are repeated several times during the day and are exacerbated by any movement of the face, such as talking, chewing, brushing the teeth, and by external stimuli such as the wind or the touch of the fingers”.
Trigeminal neuralgia: causes still shrouded in mystery
Trigeminal neuralgia can be secondary to major diseases such as multiple sclerosis or the Herpes Zoster infections, the varicella virus which under conditions of stress (and consequent lowering of the immune defences) can reactivate. Most of the time, however, these are forms due to the so-called “neurovascular conflict”: MRI (magnetic resonance) and magnetic resonance angiography (which visualizes the intracranial vessels) show the mechanical compression of the trigeminal nerve by a nearby facial arteriole which ends up irritating it and damaging the myelin sheath that covers it. Fact that accentuates the sensitivity of the nerve fibers.
Trigeminal neuralgia, therapy in the acute phase and as prophylaxis
«As with all pains of neuropathic origin, i.e. transmitted through nerve fibers, in the first instance the neurologist prescribes painkillers and anti-inflammatories non-steroidal drugs (the so-called NSAIDs, such as indomethacin) to be taken as needed to quell the attack», clarifies Dr. Usai. «These are symptomatic molecules that must always be associated with long-term prophylactic therapy, aimed at reducing the frequency and intensity of attacks. The administration of is implemented neuromodulatory drugs (gabapentin, pregabalin, carbamazepine) which must be taken twice a day for several months, until the attacks disappear». Having side effects, from dizziness to drowsiness, they must be taken under strict medical supervision, scrupulously respecting times and dosage.
The two non-pharmacological novelties
In the crosshairs of research, fortunately even trigeminal neuralgia can nowadays take advantage of two new non-pharmacological treatments, which are also effective in the long term. I’m there radio frequency and the neurostimulation.
“In the first case, the power of an electromagnetic field is exploited, which is conveyed in the nerve by small needles, to reduce the sensitivity of the nerve fibers”, explains Dr. Usai. “Under local anesthesia, the needle is inserted and high-frequency electrical impulses are sent, in pulsed or continuous mode, intended to hit the fibers responsible for transmitting pain to the brain”. As with all chronic inflammatory diseases, radiofrequency it works in about 70 percent of cases but the results are greater in the case of continuous impulses which carry out a real neurolysis: they free the nerve from compression, with benefits that are maintained for up to three years (then the treatment is repeated).
In the event of very intense pain, which cannot be resolved with either pharmacological therapy or radiofrequency, the neurostimulation card is played. It involves a small surgery under local anesthesia and, possibly, general sedation to install microscopic electrodes connected to a current generator placed under the skin and the size of a postage stamp at the perineural level (ie around the trigeminal nerve). This generator sends constant impulses to the nerve in order to desensitize the fibers and thus be able to keep pain under control, also preventing close crises.
Trigeminal neuralgia, when to resort to surgery
In about 10 percent of cases it is advisable to opt for a definitive solution, resorting to a small neurosurgery. «With the term of trigeminal thermorhizotomy a minimally invasive intervention is indicated, which takes place percutaneously through 3-4 mm incisions», warns Dr. Susanna Usai. «Thanks to an electric scalpel, the surgeon “burns” some nerve fibers, partially interrupting the transmission of pain signals from the nerve to the brain. A second type of intervention is the microvascular decompression (MVD), useful for treating pain and facial spasm refractory to medical therapies, clearly due to the anatomical proximity of an arteriole which, by pulsating, irritates the nerve. In this case the surgeon, passing through a small incision behind the ear, inserts a patch or a microballoon in spongy material which has the purpose of distancing the nerve roots of the trigeminal arteriole, avoiding any painful contact». And it is thanks to the interposition of this “separator” that the person suffering from neuralgia starts living again, finally free from pain.
