Radiofrequency Ablation for Trigeminal Neuralgia

What is Trigeminal Neuralgia?

Trigeminal neuralgia (TN) is a painful condition associated with the face. It is a disease of the trigeminal nerve that supplies the nerves to the face. 

The trigeminal nerve has three branches: 

• V1, which innervates the eyes and forehead
• V2 which supplies cheeks, and nose
• V3 that gives nerve supply to inside of the ear, tongue, chin, and lower lip

The pathophysiology of TN is unclear. Studies suggest that the pain is caused by pressure on the trigeminal nerve root at the entry of the pontine region of the brainstem. Compression by a tumor or blood vessels can cause local stress, which can lead to demyelination of the trigeminal nerve.

This nerve is responsible for transmitting the temperature signals of touch and pain associated with the facial organs to the jaws, gums and head of the brain. This condition is characterized by intense burning pain like shock for an interval of a few seconds. Pain usually appears on the face around the lips and eyes. 

There are mainly two types:

• Typical Trigeminal Neuralgia
• Atypical Trigeminal Neuralgia

The typical form of this disorder results in certain episodes of severe, sudden, shock-like pain in one side of the face, which lasts for seconds to few minutes.

What are the symptoms of Trigeminal Neuralgia?

Trigeminal Neuralgia may have symptoms which include: 

Some episodes of severe,

• Shooting pain which may seem like an electric shock.
• A person might come across spontaneous attacks of pain or even attacks which might get triggered by certain things like touching the face, chewing, speaking or even while brushing the teeth.

What causes Trigeminal Neuralgia?

The definite reasons of trigeminal neuralgia are unknown. However, its effect can disrupt the function of the trigeminal nerve. The trigeminal nerve is a set of three nerves responsible for transporting information from the facial area to the brain. When this nerve is compressed for any reason, a person may experience symptoms of pain. Sometimes the outer covering of the nerve, which is called myelin sheath, can cause severe pain in the facial muscles.

An individual experiences pain when performing activities such as brushing their teeth, eating, or touching their face for any reason. Trigeminal neuralgia usually triggers pain on both sides of the patient’s face or in some cases. The pain may reappear at different times of the hour, for a few hours. Sometimes the pain lasts for months together. This condition is more common in women than in men.

The reasons in most of the cases can be due to: 

1. Tumor or a lump which presses on the nerve causing wear of the trigeminal nerve
2. A cyst, fluid-filled sac which causes pressure on the trigeminal nerve
3. Arterio-venous abnormality leads to disruption of the nerve to cause pain
4. Multiple sclerosis or MS which is a disease of central nervous system

What is Radiofrequency Ablation for Trigeminal Neuralgia?

Ablation is the medical term used to refer to the removal of tissue. Radiofrequency ablation, or RFA, is a surgical technique that directs high-frequency heat to the targeted areas like nerves, to specific tissues, tumors, and nerves that cause chronic pain in the body. RFA is used to target the trigeminal nerve, destroying the brain’s ability to transmit pain signals.

An individual with trigeminal neuralgia should consult a neurosurgeon who uses radiofrequency ablation to stimulate the trigeminal nerve, thereby destroying the nerve’s ability to receive pain signals that are transmitted to the brain.

To see how the patient responds, the first line of treatment for trigeminal neuralgia prescribed by a neurosurgeon is medication. If the person is suffering from severe pain in the face and does not show any improvement with the medication, the doctor may recommend that they have to undergo radiofrequency ablation surgery.

Radiofrequency ablation (RFA) targets the trigeminal nerve, altering the brain’s ability to transmit pain signals and thereby reduce pain. This is a common percutaneous procedure used to treat trigeminal neuralgia, especially so  in elderly patients and high risk groups .

RFA has unique advantages over other methods. It can be treated as pulsatile or as an injury. Intraoperative sensory and motor tests can be performed. The needle is smaller and therefore less painful. It is performed in one day and patients are recovering well enough to return home the same day.

How is the procedure performed?

During the radiofrequency ablation for trigeminal neuralgia, the patient wakes up and falls asleep at different times. The process include:

• When the patient is sleeping under the influence of mild sedation, a neurosurgeon carefully places a needle in the corner of the mouth to reach the triangular nerve at the base of the skull.
• Then, after the x-rays confirm that the needle is correct, the neurosurgeon awakens the patient, stimulates the nerve, and asks if they are correctly feeling the stimulus at the pain site.
• This particular step ensures that the doctor hits the correct position.
• When the patient falls asleep again, the doctor uses radiofrequency heat to at least injure the nerve, which is enough to induce a feeling of numbness in the face in conjunction with acupuncture, thereby relieving the pain.

References:

• Treatment of trigeminal neuralgia: role of radiofrequency ablation, NCBI, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3033033/. Accessed on 6th February 2021
• Radiofrequency Ablation, UCLA Health, https://www.uclahealth.org/neurosurgery/dbs/radiofrequency-ablation. Accessed on 6th February 2021
• Trigeminal Neuralgia, University of California San Francisco, https://neurosurgery.ucsf.edu/trigeminal-neuralgia-faq. Accessed on 7th February 2021
• Trigeminal Neuralgia Surgery, Medscape, https://emedicine.medscape.com/article/248933-overview. Accessed on 7th February 2021

About Author –

Dr. Ravi Suman Reddy, Senior Neuro & Spine surgeon, Yashoda Hospitals – Somajiguda

MCH (NIMHANS), Advanced training in Stereotactic Radiosurgery (Brain Lab Academy – Germany). His expertise includes frameless stereotactic neurosurgery, minimally invasive spine surgery, spine stabilization, nerve radiofrequency ablation, cranial micro neurosurgery, cranio-spinal trauma, and endoscopic surgery.