Gamma Knife and Trigeminal Neuralgia – Is it an option?
Gamma Knife treatment is absolutely an option for patients with trigeminal neuralgia (TN). In fact, Gamma Knife Radiosurgery is a procedure that almost any patient can tolerate. The Gamma Knife procedure is performed at a medical center, but no overnight stay is needed and no actual “knife” is ever used.
No general anesthesia is used. No ventilator is needed!
In fact, patients go home on the same day as treatment, so it’s a very nice minimally invasive option for patients with trigeminal neuralgia. Now let’s back up a bit and talk about when, why and how a person might consider Gamma Knife as the best treatment option for her trigeminal neuralgia.
Trigeminal Neuralgia Basics – What is TN?
Trigeminal neuralgia comes in a “classic” form (Type I) and an “atypical” form (Type II). In both types, patients experience “sharp”, “electrical” or “stabbing” pain on one side of the face. The pain comes in sudden, short bursts, that last a few seconds and are extremely painful. People often avoid doing certain things like brushing their teeth, washing their face or talking because these simple “triggers” can bring on a flare up of a series of attacks.
Inside our brains, we have a trigeminal nerve on the right side and a trigeminal nerve on the left side.
The nerve is like a tree with three big branches (V1, V2 and V3) that are responsible for feeling our faces. When one trigeminal nerve “misfires”, patients get hit with horrific facial pain even though nothing “on the outside” actually happened.
Trigeminal Neuralgia – Why is this happening to me?
In most cases of TN, an MRI scan will reveal that a “normal” blood vessel is pushing on the trigeminal nerve on the same side as the facial pain. This situation is called “neurovascular conflict”. The blood vessel is hot and pulsatile and is likely irritating the nerve. But that’s not the entire picture.
On a microscopic level (something an MRI scan cannot “see”) the trigeminal nerve is likely a bit weak or unstable for one reason or another. In some situations, the insulation inside the nerve (also called myelin) is breaking down. When the insulation within the nerve weakens, small nerve fibers are believed to start “shorting out” on each other. This process is called “ephaptic transmission”.
When a trigeminal nerve starts to “short out” on the inside, from time to time this causes a painful wire to FIRE even when something painless is going on (like brushing your teeth). When you combine INSULATION BREAKDOWN with BLOOD VESSEL COMPRESSION, an “imperfect storm” is created within a trigeminal nerve. This is when the pain episodes flare up.
On a microscopic level (something an MRI scan cannot “see”) the trigeminal nerve is likely a bit weak or unstable for one reason or another. In some situations, the insulation inside the nerve (also called myelin) is breaking down. When the insulation within the nerve weakens, small nerve fibers are believed to start “shorting out” on each other. This process is called “ephaptic transmission”.
When a trigeminal nerve starts to “short out” on the inside, from time to time this causes a painful wire to FIRE even when something painless is going on (like brushing your teeth). When you combine INSULATION BREAKDOWN with BLOOD VESSEL COMPRESSION, an “imperfect storm” is created within a trigeminal nerve. This is when the pain episodes flare up.
In Search of Facial Pain Relief – What are my Treatment Options?
As you likely already know, most Trigeminal Neuralgia treatment options start with medications. For a more detailed discussion of medication treatments, try this article. Often times, medications “do the trick” resulting in adequate pain relief for many patients, especially at the beginning of their trigeminal neuralgia diagnosis.
But what are the trigeminal neuralgia treatment options when medications fail you? Well, there are a variety of options that patients can pursue if the medications are not working. These options include microvascular decompression surgery (MVD), stereotactic radiosurgery (i.e.Gamma Knife Radiosurgery), percutaneous rhizotomy, pain stimulation, and alternative therapies. For the purposes of this article, let’s focus on Gamma Knife Radiosurgery.
Gamma Knife Radiosurgery – Is this procedure “right” for my facial pain?
“Gamma Knife” is a bit of a misleading name for this minimally invasive treatment option for trigeminal neuralgia. Why is it misleading?
The “shot” can be as small as 4 millimeters (mm).
When we use Gamma Knife to treat someone with trigeminal neuralgia, all we need is a small 4mm “shot” to do the trick.
Here’s how a gamma knife treatment day for trigeminal neuralgia works:
Gamma Knife Results
Gamma knife is 70-80% effective at eliminating or significantly improving pain as an upfront treatment for type I TN.
Gamma knife carries a risk of one-sided facial numbness that can be about 5-10%.
This is not weakness, but being numb is considered a complication. You should ask your doctor about their specific experience to get accurate numbers from your treating center. For patients who have a good result, they often notice pain relief about 6 weeks after their gamma knife treatment day (on average). If the pain tries to come back years after the gamma knife (long term), then a second gamma knife procedure can be performed. It’s also important to note that Gamma Knife can be performed in patients who might be older or have a medical history that makes other more invasive surgical procedures too risky.