Pain originating from the V. cranial nerve, the trigeminal nerve, is one of the most intense pain experiences of all. Trigeminal is the Latin word for triplet. The three main branches of the nerve supply important facial sections with sensibility, such as the forehead (V1) and the adjacent head area, eyes and nose (V2) as well as the regions around the upper jaw, lower jaw and chin (V3). In addition, they are responsible for the activity (motor function) of the chewing and temporal muscles, for example.
Causes
We distinguish trigeminal neuralgia without an identifiable cause ("idiopathic trigeminal neuralgia") from trigeminal neuralgia as a result of another disease
At idiopathic trigeminal neuralgia it is assumed that the neuralgia is caused by the pulsating pressure of a tortuous arterial blood vessel crossing the nerve. (see therapy)
At the symptomatic trigeminal neuralgia neuralgia occurs in the context of an underlying disease such as the inflammatory focus of multiple sclerosis or due to the pressure of an often slowly growing brain tumor. Often, in addition to the pain, there is a sensory disturbance in one of the three branches of the trigeminal nerve.
Symptoms
The pain is usually sharp and stabbing on one side, mainly on the surface of the chin and cheek, especially on the crease from the nose to the mouth, but the teeth can also hurt. The attacks often last only seconds and can occur several times in a row at short intervals during one day. This is followed by longer, pain-free phases until the next attack occurs. For a few sufferers, a dull continuous feeling of pain remains in between. Often it is certain events that trigger the lightning-like pain, so-called triggers, such as a draft, a touch on the face, brushing teeth, chewing or talking, but also stressful situations. In the course of a pain attack, there are sometimes also muscle spasms on the affected side of the face.
Diagnosis
The diagnosis is made by neurological examination, laboratory tests and imaging techniques (MRI, CCT) (link), rarely also by a nerve fluid sample (CSF examination (link), e.g. in case of suspected MS or Lyme disease).
Therapy
If there is no identifiable underlying disease, drugs are initially available. Painkillers do not help because the attacks are too short. Drugs for the treatment of epilepsies (e.g. carbamazepine, lamotrigine) have proven effective. They can prevent the pain attacks, as they also affect the excitability and conductivity of pain-sensitive nerve tracts.
Doctors only consider surgery if medication cannot help, the patient is young and is expected to be ill for a long time, or the cause of the pain suggests surgery, for example in the case of a tumour.
Surgical measures are primarily aimed at relieving the irritated or pressurized nerve (decompression). Here, a piece of tissue is placed between the nerve and the pulsating artery. A modern technique for V-neuralgia triggered by a tumour is neurosurgical treatment with the so-called Gamma-Knife, recently also Cyber-Knife. Here, a special radiation device, in the case of the Cyber-Knife a kind of surgical robot, focuses radiation energy precisely on the tissue. In a sense, the tissue is removed or eliminated with razor-sharp precision, but without a scalpel.
The elimination of the nerve or its ganglion by heat (thermocoagulation) or alcohol by injection is rarely performed today because of the high recurrence rate.