Trigeminal Neuralgia – Radiosurgery
What is Trigeminal Neuralgia?
Trigeminal neuralgia (also called TN or tic douloureux) is a neurological condition characterized by sudden, sharp, stabbing or lancinating pain in the face, usually localized to one side. The pain usually lasts a few seconds, but it can become constant over time. Episodes are often triggered by touch or sensory stimuli, and everyday activities can cause trigeminal neuralgia pain – such as touching the face, brushing one’s teeth, kissing, eating, or shaving.
What Causes Trigeminal Neuralgia?
Trigeminal neuralgia has an annual incidence of 4/100,000. It is caused by irritation to the trigeminal nerve – the large sensory nerve that sends sensory information from the face to the brain. The trigeminal nerve is usually irritated by a large blood vessel that pinches the nerve as it exits the brain stem. Other rarer forms of trigeminal nerve irritation occur from MS plaques in patients with multiple sclerosis or by compressing brain tumors.
The trigeminal nerve is the fifth of twelve cranial nerves and is often referred to using the Roman numeral “V”. It begins at the base of the skull and extends upward in three branches. The first branch, V1, provides sensation to the scalp, forehead and eye; V2 covers the cheek, teeth, and gums; and the third, V3, innervates the lower jaw. Typically, only one or two branches are affected that results in the concentration of pain to a particular part of the face on one side (though all three branches may also be affected).
“Trigeminal neuralgia is a debilitating disease that may no longer respond to medical therapy. It is important for patients to know all their treatment options so they can make an informed decision. Radiosurgery is often used as a non-surgical option at the JD Lipani Radiosurgery Institute. When this procedure is performed by our experienced clinicians, it often ( > 98%) results in a tremendous benefit to our patients.”– Dr. Lipani
Treatment and Surgery Options
There are a number of ways of treating trigeminal neuralgia, even if doctors are unable to determine a specific cause. Some patients can tolerate the pain with the help of oral medication such as Tegretol, Baclofen, Neurontin or others. In extreme cases, or in patients who cannot tolerate medication, trigeminal neuralgia surgery may be necessary to provide relief of pain for the patient.
Surgical options include decompressing the trigeminal nerve from the offending compressing vessel at the skull base, referred to as microvascular decompression (MVD). This procedure requires microsurgical exploration of the trigeminal nerve root entry zone into the brain stem usually via posterior fossa craniectomy (brain surgery).
Other surgical procedures involve blocking transmission of pain signals by injuring portions of the trigeminal nerve referred to as trigeminal rhizotomy. Trigeminal nerve rhizotomies are usually performed percutaneously (injections through the skin) and can be performed in a variety of ways such as using glycerol injections (AKA glycerol rhizotomy), radiofrequency thermocoagulation (AKA radiofrequency rhizotomy), or mechanotrauma (AKA percutaneous microcompression rhizolysis).
Other non-invasive or minimally invasive rhizotomies may be performed using Gamma Knife or Cyberknife radiosurgery; knifeless surgical techniques (despite their name) that use high dose radiation delivered to a small section of the trigeminal nerve within the brain.
Other less common treatment options include traditional surgery to cut portions of the trigeminal nerve or portions of the brain stem via brain surgery.
Summary of Common Treatment Options for Trigeminal Neuralgia
- Microvascular decompression (MVD) to decompress the trigeminal nerve from an offending compressing blood vessel using brain surgery. Recommended to patients
- Removal of tumors via brain surgery if tumors are responsible for the pressure on the trigeminal nerve.
- Treatment of multiple sclerosis if found to be the cause of TN
- Glycerol rhizotomy, radiofrequency rhizotomy, microcompression rhizolysis to destroy part of the nerve.
- Stereotactic Radiosurgery for trigeminal neuralgia is a non-invasive or knifeless technique that utilizes high dose radiation beams that focus precisely on a small portion of the trigeminal nerve within the brain. The radiation interferes with the ability of the trigeminal nerve to transmit pain signals to the brain. The two most common radiosurgery tools used to treat trigeminal neuralgia are Gamma Knife and CyberKnife.
Gamma Knife Treatment
Gamma knife trigeminal neuralgia radiosurgery is a minimally-invasive procedure that uses a number of converging radiation beams that are designed to deliver a high level of radiation to a small portion of the trigeminal nerve without harming sensitive tissues surrounding it. The treatment is safe, effective, and minimally-invasive. The patient’s head is fixed to a stereotactic head frame which is attached to the treatment table for targeting purposes. Treatment is delivered in a single session or treatment fraction.
CyberKnife trigeminal neuralgia radiosurgery is a non-invasive procedure that utilizes a LINAC attached to a robotic arm that delivers several precise consecutive radiation beams to a small portion of the trigeminal nerve without harming sensitive tissues surrounding it. Rigid head fixation is not required as in Gamma Knife. Treatment is delivered in a single session or treatment fraction. Both Gamma Knife and CyberKnife are performed as an outpatient treatment.