A neuroma is a tumor that develops in the protective sheath of the nerves. The most common form is the acoustic neuroma which affects the vestibulocochlear nerve, that is to say the cranial nerve involved in hearing and the sense of balance. While neuromas are benign tumors in the majority of cases, some can cause complications. Support may be essential.

Definition of neuroma

A neuroma is a tumor that grows in the nerves. This tumor develops more exactly from Schwann cells present in the protective sheath surrounding the nerves. It is for this reason that a neuroma is also called a schwannoma.

The most common form is acoustic neuroma, also called vestibular schwannoma. This neuroma affects the vestibular nerve, one of the branches of the VIII cranial nerve involved in hearing and the sense of balance.

Causes du neurinome

Like many other types of tumors, neuromas have an origin that is still poorly understood. However, some cases of acoustic neuroma have been found to be a sign of type 2 neurofibromatosis, a disease caused by a genetic mutation.

Diagnostic du neurinome

A neuroma can be suspected due to certain clinical signs but can also be discovered incidentally during a medical examination. This tumor can indeed be asymptomatic in some cases, that is to say without apparent symptoms.

The diagnosis of acoustic neuroma is initially based on hearing tests such as:

• an audiogram which is carried out in all cases in order to identify a hearing loss characteristic of the acoustic neuroma;
• tympanometry which is sometimes done to determine if sound can pass through the eardrum and middle ear;
• an auditory evoked potentials (AEP) test, which measures nerve impulses in the brainstem from sound signals from the ears.

To confirm and deepen the diagnosis, a magnetic resonance imaging (MRI) exam is then performed.

Neuromas are rare tumors. They represent on average between 5 and 8% of brain tumors. The annual incidence is approximately 1 to 2 cases per 100 people.

In some cases, the neuroma is poorly developed and does not cause any noticeable symptoms.

Typical signs of acoustic neuroma

The development of an acoustic neuroma can manifest itself by several typical signs:

• hearing loss which is progressive in most cases but can sometimes be sudden;
• tinnitus, which is noise or ringing in the ear;
• a feeling of pressure or heaviness in the ear;
• earache or ear pain;
• headaches or headaches;
• imbalance and dizziness.

Note: Acoustic neuroma is usually unilateral but can sometimes be bilateral.

Risk of complications

Neuromas are benign tumors in the majority of cases. However, sometimes these tumors are cancerous.

In the case of acoustic neuroma, the tumor in the cranial nerve VIII can cause complications when it grows and increases in size. It tends to compress other cranial nerves, which can cause:

• facial paresis by compression of the facial nerve (cranial nerve VII), which is a partial loss of motor skills in the face;
• trigeminal neuralgia due to trigeminal compression (cranial nerve V), which is characterized by severe pain affecting the side of the face.

A neuroma does not necessarily require treatment, especially if the tumor is small, does not grow in size, and does not cause symptoms. However, regular medical monitoring is in place to limit the risk of complications.

On the other hand, a management of the neuroma can become essential if the tumor grows, enlarges and presents a risk of complications. Two treatment options are generally considered:

• surgery to remove the tumor;
• radiation therapy, which uses radiation to destroy the tumor.

The choice of treatment depends on many parameters including tumor size, age, state of health and severity of symptoms.

The origin of neuromas is not clear. No preventive measure has been established to date.