The typical symptoms of trigeminal neuralgia are attacks of extremely severe, lightening-like shooting pain in the face. Usually these only last for a few seconds. In between the individual bouts of pain there are asymptomatic intervals. Even the slightest touch or movement in the face can trigger this kind of pain attack. However, these attacks often also occur spontaneously.
The cause of the pain is an irritation of the fifth cranial nerve (trigeminal nerve), which divides into three main branches with different perfusion areas in the face.
With classical trigeminal neuralgia the pain attacks are almost always confined to one half of the face. It is mainly the area of the second and third trigeminal branch (cheek and lower jaw region) that are affected. The classical form rarely occurs before the age of 40 and becomes more common as age increases. As a general rule it is triggered by pathological contact between the trigeminal nerve and a blood vessel (nerve-blood vessel contact), which leads to segmental damage of the nerve sheath (demyelination) on the trigeminal nerve. 
By contrast, symptomatic trigeminal neuralgia, as an accompanying symptom of an underlying disease, also occurs in younger people, is more often bilateral and also more frequently affects the first trigeminal branch (forehead). It is not uncommon for a dull pain to remain between the pain attacks. Diseases such as multiple sclerosis and various tumours or vascular diseases can be considered as possible causes.
The neurologist initially records the nature, duration, distribution and frequency of the attacks of severe facial pain and carries out further examinations in order to assess the nature of the headache or facial pain. By performing further examinations he rules out diseases such as multiple sclerosis and tumours.
As prophylactic treatment for the prevention of attacks of pain the patient receives treatment with medication. If the individually adjusted dose does not appear sufficient or is associated with excessively severe side-effects, an operative procedure is also possible. The following procedures may be considered:
- Percutaneous procedure in or on the trigeminal ganglion
Three different techniques are commonly used:
- Temperature-controlled coagulation
- Glycerol rhizolysis
- Balloon compression
- Microvascular decompression of the trigeminal nerve (under general anaesthesia with endotracheal intubation)
- Radiosurgical treatment
If an operation under general anaesthesia with endotracheal intubation and close to the brainstem represents too high a risk for the patient, according to the guideline "Trigeminal Neuralgia" the best experiences are found with thermocoagulation.  This can be performed using the sfm radiofrequency/thermolesion needle. This procedure can be controlled precisely and shows good efficacy. The early success rate is more than 90 per cent. In addition, with about 50 per cent there is still lasting success after five years. The percutaneous thermocoagulation method is also used successfully with multiple sclerosis patients.
With the use of fluoroscopy guidance, percutaneous access is achieved under intravenous short anaesthesia via the foramen ovale, an opening in the sphenoid bone in the skull. A radiofrequency probe is introduced through the sfm radiofrequency/thermolesion needle for temperature-controlled denervation of the trigeminal nerve (60–70 °C for 60–70 seconds).
Benefits of thermocoagulation with trigeminal neuralgia using the sfm radiofrequency/thermolesion needle:
- Longest and best experiences with thermocoagulation in patients, for whom an operation under general anaesthesia with endotracheal intubation and close to the brainstem represents too high a risk 
- Can be controlled precisely 
- Early success rate of more than 90 per cent 
- Low penetration force thanks to optimum bevel geometry and a smooth transition to the coated needle region
- Minimisation of pain sensation and posttraumatic stress due to the smooth transition to the coated needle
- Best possible navigation to targeted coagulation thanks to the hub design and its realization
- Optimum adjustment of the coagulation field thanks to the large number of design variations
- Treatment can be repeated several times
- Trigeminal Neuralgia. From: Hans-Christoph Diener, Christian Weimar (eds.) Guidelines for Investigations and Treatment in Neurology. Published by the Committee "Guidelines" of the German Society for Neurology. Thieme Medical Publishers, Stuttgart, September 2012