Trigeminal Neuralgia Causes

Trigeminal Neuralgia – The most likely cause is a “normal” blood vessel

The most common cause of trigeminal neuralgia is a blood vessel pressing on the trigeminal nerve.  To understand how a “normal” blood vessel can press on a “normal” cranial nerve and make that nerve irritated and painful, you need to understand a few things…

Let’s review the basics – Brain Anatomy 101

First, we all have a right and left trigeminal nerve. The trigeminal nerve is one of twelve, paired cranial nerves that have specific “jobs” they all do. We have 12 cranial nerves that are numbered from the top (#1 – olfactory nerve – smell) all the way to the bottom (#12 – hypoglossal nerve – moves one side of the tongue).

The trigeminal was given the number 5 and is also referred to as the “fifth cranial nerve”.

The trigeminal nerve’s primary “job” is to feel your face, teeth, cornea, etc. As such, it’s mostly a “sensory nerve”, meaning it feels all kinds of sensations such as sharp pain, heat, dull pain, aching pain, dust in the eye, cavities, etc. Like a tree, the nerve has three big branches that feel three specific zones of one side of the face.

One branch is responsible for your forehead (V1 or ophthalmic branch), another feels your cheek (V2 or maxillary branch), and one branch feeld your jaw (V3 or mandibular branch).

First, we all have a right and left trigeminal nerve. The trigeminal nerve is one of twelve, paired cranial nerves that have specific “jobs” they all do. We have 12 cranial nerves that are numbered from the top (#1 – olfactory nerve – smell) all the way to the bottom (#12 – hypoglossal nerve – moves one side of the tongue).

The trigeminal was given the number 5 and is also referred to as the “fifth cranial nerve”.

The trigeminal nerve’s primary “job” is to feel your face, teeth, cornea, etc. As such, it’s mostly a “sensory nerve”, meaning it feels all kinds of sensations such as sharp pain, heat, dull pain, aching pain, dust in the eye, cavities, etc. Like a tree, the nerve has three big branches that feel three specific zones of one side of the face.

One branch is responsible for your forehead (V1 or ophthalmic branch), another feels your cheek (V2 or maxillary branch), and one branch feeld your jaw (V3 or mandibular branch).

The V's

Back in the day when people started naming cranial nerves, they used the Roman Numeral system. As such, the Roman Numeral for the #5 is “V”. That’s why the first branch is called “V1”, the second branch is called “V2” and the lower branch is called “V3”.

What’s going on inside the trigeminal nerve when I feel pain?

Part 1 - How the system SHOULD work

Like all nerves, there are thousands of wires on the inside of every cranial nerve.  Each wire has a specific type of sensation that it feels.  For example, there are a bunch of wires (called nerve fibers) inside the trigeminal nerve that feel sharp pain bundled next to another set of wires that feel heat or cold stuff.  Under normal conditions, when something cold touches your left cheek, the wires for cold sensation “light up” or “fire” an impulse from your face to your brain through the left V2 branch (cheek territory) of the left trigeminal nerve.  As a result, you experience a cold sensation on your left cheek.  All good!

Now, let’s talk about a typical or classic trigeminal neuralgia attack.  Let’s take the same scenario where something cold touches your left cheek.  Here, a cold breeze hits your left cheek and the wires that sense cold stuff FIRE!  Immediately, an electrical signal travels down the V2 branch to the brain.  This time, the electrical impulses traveling down the cold wires “short out” on the bundle of wires that are responsible for feeling SHARP pain only.  This “sharp” bundle of wires ALSO fires immediately after the cold wires fire.  This causes pain signals to be sent to your brain by mistake.  This results in you experiencing a really sharp pain, stabbing pain, or burning sensation in one side or area of your face!!  This is how a vicious pain episode can be TRIGGERED by something as simple as a cold breeze.  The technical term for the “shorting out” process is called “ephaptic transmission”.

If you’ve ever cut open an electrical wire, you’ll see that there is often a sheath of plastic or rubber material around the metal wire.  This is a form of insulation that prevents the metal wires from “shorting out” on each other.  This insulation is really important for the lamp or switch to work properly.  Many of our nerves come with their own insulation in the form of a natural substance called MYELIN.  The myelin sheath is insulation for our nerve fibers.  With a complete myelin sheath in place, wires can fire quickly and precisely with no mistakes.

In people with trigeminal neuralgia, the myelin sheath is breaking down.  It’s literally falling apart over time.  In most cases, a “normal” blood vessel is found pressing on, pulsating on, and overheating the nerve.  This is like a constant hot fist punching the nerve with every heartbeat, negatively affecting the nerve.  Eventually, the nerve can’t take the pressure or the heat from the blood vessel and the myelin starts to fade.  As time passes, the pain episodes become more frequent and more intense as a result of myelin sheath (insulation) break down.

Although a blood vessel pressing on the trigeminal nerve and resulting in myelin breakdown is most commonly the cause of trigeminal neuralgia, other culprits can also cause facial pain.  Many patients with MULTIPLE SCLEROSIS experience trigeminal neuralgia without a blood vessel pushing on their trigeminal nerve.  This is due to the fact that, with MS, myelin breaks down in multiple places throughout the nervous system.  

Sometimes, the trigeminal nerve can be compressed or pushed on by a mass like a benign tumor or a malformation of blood vessels (also called an arteriovenous malformation).  

In some instances, trauma or previous viral infections can also result in injury to the trigeminal nerve resulting in myelin breakdown and facial pain.  All of these things can cause damage to the trigeminal nerve and result in all different types of facial pain, including trigeminal neuralgia.

Now that you understand the cause, how can you find pain relief?

There are a variety of treatments for trigeminal neuralgia.  You should work closely with an expert team of providers, doctors and surgeons to figure out which pain relief treatments might be best for you.  Treatments include, but are not limited to:

  • Medications

    • Carbamazepine
    • Oxcarbazepine
    • Gabapentin
    • Neurontin
    • Baclofen
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