Let's learn about the amazing nerve that controls your tongue! (Hypoglossal Nerve)

Have you ever wondered how exactly we pronounce words, swallow food, or even control our tongue when we just stick it out and open our mouths? Our tongue is a key player behind all of this. But the tongue can't do these things on its own. It needs to receive the right signals from the brain. Today we're talking about a special nerve that brings those important signals to the tongue. That's the hypoglossal nerve, or `(Hypoglossal Nerve)`.

What is the Hypoglossal Nerve?

Simply put, this is one of 12 special pairs of nerves that come directly from our brain. In medicine, we call these 12 nerves the cranial nerves. It's like 12 special messengers coming from the brain, which is the main office of our body. The twelfth of these (12th cranial nerve) is the hypoglossal nerve.

The meaning of this name is that in Greek, "hypo" means "underneath." "glossal" means "tongue." That is, the name refers to the nerve located "under the tongue."

The most important thing is that this is a motor nerve . That means it doesn't carry sensation, but rather controls movement. This nerve works like a wire that sends commands from the brain to the muscles of the tongue to "move this way," "contract this way," and "move forward."

What are the main functions of this nerve?

Imagine, you are eating a delicious meal. The tongue helps you move the food around in your mouth, chew it, mix it well with saliva, and then send it down your throat, that is, swallow it. Also, when we pronounce letters like "ல, ர, ந, ன" how many different ways does the tongue move? All these movements, all these subtle actions, are controlled by signals coming from this hypoglossal nerve.

The main things this nerve helps us with are:

• Speak: Enunciate words clearly and move the muscles of the tongue precisely.
• Swallow food: Form a ball of food in your mouth and push it toward your throat.
• Move things around in your mouth: For things like moving food between your teeth when chewing, and moving water around your mouth when rinsing your mouth.
• Make different sounds with your mouth: This nerve also helps some people make things like the 'click' sound they make with their tongue.

How this nerve travels in our body (Anatomy)

This nerve starts at the base of our brain, near where the spinal cord begins. We call this area the brainstem. From there, this nerve travels a long way to the tongue.

This is like a little highway from the brain to the tongue. On its way:

1. First, we come down the cervical part of our spine.

2. Then, two very important large blood vessels in the neck (the carotid artery and the jugular vein) are carefully passed.

3. From there, it comes from the back of the throat and reaches the bottom of the mouth, that is, where the tongue is.

4. Eventually, small branches branch off and connect to the various muscles in the tongue, each of which receives messages from the brain.

If there is an accident, pressure, or illness anywhere along this path, the function of this nerve can be disrupted.

What diseases can damage this nerve?

Unfortunately, various medical conditions and accidents can damage this important nerve. When that happens, the function of the tongue begins to deteriorate. Let's take a look at the main causes.

What are the symptoms of damage?

When the hypoglossal nerve is damaged, its effects are directly felt in the tongue. Most of the time, this nerve is damaged on only one side (right or left). This causes weakness on that side of the tongue .

The main and most easily recognizable feature is:

The reason for this is that the muscles on the good side of the tongue (the left side) are only being pushed, causing the tongue to be pushed on the weak side (the right side).

Other symptoms may include:

• Difficulty speaking (Dysarthria): Words become slurred and cannot be pronounced properly.
• Difficulty swallowing (Dysphagia): Feeling like you are choking when swallowing food or drink.
• Atrophy of the tongue muscles: Over time, the muscles on the damaged side of the tongue gradually shrink and become thinner due to the lack of nerve signals.
• Fasciculations: The muscles on the surface of the tongue twitch, as if they are being moved by worms. This is especially common in diseases like ALS.

Warning: If these symptoms are accompanied by sudden severe neck or head pain, it may be a sign of damage to a major blood vessel in the neck (the ``internal carotid artery``). In such cases, it is essential to immediately go to a hospital's Emergency Department (ETU) .

How does a doctor check this?

When you go to see a doctor with symptoms like these, he will first do a simple physical examination.

• They ask you to put your tongue forward: Here, they check to see if the tongue is pulled to one side.
• You are asked to press your tongue against your cheek: You are asked to press your tongue against one side of your cheek, and the doctor places his hand on the outside and checks the amount of pressure. The strength of both sides is compared.
• The tongue is observed: The tongue muscles are carefully examined for atrophy or fasciculations.

After this initial examination, further tests may be ordered to determine the exact cause of the symptoms.

• MRI scan (Magnetic Resonance Imaging): This helps to check for brain damage, tumors, or other damage.
• Spinal Tap / Lumbar Puncture: This test may be done if there is a suspicion of an infection or cancer cells in the brain or spinal cord.

Treatment methods and how do we protect this nerve?

Treatment for hypoglossal nerve damage depends on the underlying cause . This means that treating the underlying condition is more important than treating the nerve itself.

For example:

• If the cause is paralysis, paralysis-related treatment and rehabilitation are provided.
• If the cause is cancer, treatment options include surgery, radiation therapy, or chemotherapy.
• If the cause is an infection, appropriate antibiotics or other medications will be given.

How do we protect this precious nerve?

Some causes, such as accidents, are difficult for us to prevent. However, we can reduce the risk of many diseases. This indirectly protects these nerves.

• A healthy lifestyle: Eating a balanced diet and exercising regularly can reduce the risk of stroke and high blood pressure.
• Maintaining a healthy weight: Controlling your body weight can reduce the risk of developing sleep apnea.
• Avoid smoking and alcohol: Both of these habits are major risk factors for head and neck cancer.
• Chronic disease management: If you have a disease like ALS, you can manage the disease by following your doctor's instructions exactly.