Irritation | Trigeminal nerve

Irritation

In some cases there is a permanent irritation of the trigeminal nerve. Among other things, this nerve is responsible for transmitting pain in the facial area to the brain.In case of a permanent irritation, the trigeminal nerve reports strong pain to the brain, although no damage to the face is visible. This clinical picture is called trigeminal neuralgia and the pain it causes is one of the strongest pains a person can feel.

It is characterized by sudden, violent attacks of pain in the face, which usually last only a few minutes, but recur frequently (up to 100 times a day). Between the individual pain attacks, the affected person usually has no pain. A twitching of the facial muscles can also be caused by trigeminal neuralgia.

Because of the severe pain and the resulting helplessness and limitations, trigeminal neuralgia is often accompanied by depression. Certain fragrances that activate the pain receptors (e.g. acetic acid) can also irritate a branch of the trigeminal nerve. This type of trigeminal irritation plays an important role in the detection of a complete loss of olfaction (anosmia).

The trigeminal nerve is involved in the masseter and corneal reflexes and reacts in a reflex pattern when stimulated accordingly. A reduced or increased reflex reaction can indicate damage. An increased masseter reflex, possibly up to the masseter clonus, can indicate many infarctions that have occurred in the brain stem (status lacunaris).

A reduced or even extinguished masseter reflex can be based on a peripheral double-sided trigeminal paralysis. If the corneal reflex is weakened, this may be due to damage to the trigeminal nerve (afferent leg of the reflex arc) or damage to the spinal trigeminal nucleus or damage to the facial nerve (efferent leg of the reflex arc). The causes of neuralgia include brain tumors and aneurysms, which exert increased pressure on the nerve, strokes and diseases such as multiple sclerosis, in which the insulating layer surrounding the nerve is damaged.

Often, however, no cause can be identified; in such cases, one speaks of a classic trigeminal neuralgia. In the case of spatial demands that press on the nerve, it is often necessary to perform surgery to relieve the symptoms. If this is not the case, the neuralgia is treated with medication.

Various diagnostic options can provide information about the cause of trigeminal neuralgia. These include magnetic resonance imaging (MRI), computed tomography (CT), a lumbar puncture to detect or rule out multiple sclerosis, and angiography, which examines the blood vessels in the skull and can detect possible malformations. The normal pain medication (such as ibuprofen) is usually ineffective in the severe pain of trigeminal neuralgia.

The permanent administration of stronger painkillers is then necessary. As a rule, the anti-epileptic drug carbamazepine is used for therapy to prevent further pain attacks. Phenytoin is another alternative medication.

Misoprostol is used to treat trigeminal neuralgia caused by multiple sclerosis. The drug dose is gradually increased until pain relief is achieved. If no improvement can be achieved by the administration of medication, or if there is a known cause, surgery may be necessary.

There are three different procedures. In the classic surgical procedure, sponges are inserted between the trigeminal nerve and the vessel to counteract permanent irritation. Percutaneous thermocoagulation consists of the destruction of pain fibers of the nerve by heat under X-ray control with the help of a probe. In the radiosurgical procedure, pain fibers of the nerve are destroyed by a so-called gamma knife through a high radiation dose. Each of these surgical procedures has its advantages and disadvantages, so it must be decided individually which method is to be used.