[Clinical Presentation] Trigeminal neuralgia is a rare, episodic facial pain that presents as electric shock-like, lightning-like, or knife-like pain, and the face can be distorted or frozen when the pain attack is severe. Because the pain is located in two lower branches of the trigeminal nerve, it is often misdiagnosed as a dental condition, resulting in patients receiving unnecessary dental treatment and even causing some irreversible damage. Pain relief is more effective if some small dose of an antiepileptic drug (e.g., carbamazepine) is administered early rather than any pain medication. However, up to 10% of for antiepileptic drugs are ineffective in treating trigeminal neuralgia. In cases of neuropathic pain, trigeminal neuralgia can seriously affect daily life and activities and can even lead to suicide.
Diagnosis
Location of pain
The pain occurs unilaterally in the trigeminal nerve distribution area. Bilateral pain occurs in only 3% of patients and rarely occurs simultaneously on both sides.
Periodicity
The pain occurs suddenly, lasts for a few seconds or minutes, and then stops suddenly. There is a period of inactivity for each pain. The pain may enter a period of remission that lasts for weeks or months; the interval between pain-free episodes gradually decreases with time.
Pain characteristics
Electric shock-like, lightning-like, or knife-like pain
Pain level
Severe pain, but relieved by drug administration
Pain influencing factors
Light touch on the face, eating, cold wind, or vibration
Trigeminal neuralgia tends to occur suddenly and with time, the pain relief becomes shorter and the pain attack becomes longer.
[Drug treatment].
All drugs currently available for the treatment of trigeminal neuralgia were originally developed for indications other than trigeminal neuralgia, mostly epilepsy, and only a very few small sample randomized controlled trials have studied drugs for trigeminal neuralgia, many of which are outdated and methodologically flawed. International guidelines, Cochrane systematic reviews, and clinical evidence point to key treatments for trigeminal neuralgia (see Table 2 below).
Table 2: Drugs commonly used in the treatment of trigeminal neuralgia
Drug
Note
Carbamazepine
Note drug interactions; the only drug licensed in the UK for the treatment of trigeminal neuralgia
Oxcarbazepine
High risk of hyponatremia at high doses; equivalent dose to carbamazepine and oxcarbazepine is approximately 1:1.5
Gabapentin
Only one small randomized controlled trial has been conducted to study its effectiveness
Pregabalin
Long-term cohort studies have shown effectiveness
The drug of choice remains carbamazepine, with approximately 70% of patients initially achieving 100% pain relief. However, most patients experience side effects after taking the drug, mainly affecting the central nervous system, such as fatigue, poor concentration, and a high risk of drug interactions.
Surgical treatment measures]
Surgical treatment of trigeminal neuralgia is generally microvascular decompression, which is designed to decompress the trigeminal nerve and treat 95% of trigeminal neuralgia not caused by damage/lesions (see Figure 3). However, the procedure is risky and invasive, and patients are often fearful.
Figure 3: Trigeminal nerve compression in the posterior cranial fossa and microvascular decompression
[Minimally invasive interventional measures
Palliative disruption usually involves partial damage to the trigeminal nerve root to relieve pain, although there is a risk of trigeminal nerve numbness, and palliative disruption can be performed for various causes of trigeminal neuralgia, including non-blood pressure compression. Trigeminal neuralgia caused by non-pressure.
Summary]
Compared with other surgical treatment modalities, radiofrequency disruption of the trigeminal meningeal nerve has the advantages of being minimally invasive, safe, widely indicated, and highly effective. It is accepted by more and more patients.
Case presentation] The patient, female, 83 years old, had right-sided facial pain for more than 4 years, ranging from right maxillary, paranasal, upper teeth and mandibular areas, with electric shock-like pain, which was relieved by oral carbamazepine, the dose of which was gradually increased. Recently, the pain gradually worsened and he was admitted to the hospital. Intraoperatively, the trigeminal nerve was accurately punctured to the trigeminal hemimelia site and the pain was accurately replicated. The patient was put to sleep under intravenous anesthesia and radiofrequency ablation was given, and the procedure was completed in a few minutes, and the patient woke up and the pain disappeared. The patient was discharged happily on the third postoperative day. There was no recurrence of pain at the 3-month postoperative follow-up. The curative effect was remarkable.