Surgical and injection procedures are recommended in trigeminal neuralgia (TN) patients with intolerable pain, after adequate treatment with medications in various combinations and dosages have been tried and failed. The common surgeries and injections performed to treat TN are discussed below.
Microvascular Decompression Surgery for Trigeminal Neuralgia
Microvascular decompression, also called MVD or Jannetta procedure, is a cranial surgery performed to find and fix an offending blood vessel that is injuring or compressing the trigeminal nerve. This procedure involves making a small opening in the lower back portion of the skull, locating the blood vessel, and inserting a small pad (Teflon sponge or shredded Teflon felt) to keep the blood vessel and nerve apart. In most cases, the causative blood vessel is an artery.
Microvascular decompression has almost immediate pain relief with high success rates of approximately 73%-80% of people experiencing pain-free periods up to 5 years.1 The potential risks of this procedure are meningitis, cerebrospinal fluid leaks, hearing loss, brain swelling/bleeding, and facial numbness/paralysis among others.
Gamma Knife Surgery for Trigeminal Neuralgia
In gamma knife surgery, focused beams of cobalt-60 radiation are directed on a particular area of the brain to cut off the trigeminal nerve’s blood supply, causing scarring and death of the nerve tissue. This procedure involves the patient wearing a frame on their head and receiving radiation through a gamma knife unit. Gamma knife surgery is a radiosurgery and no actual incision is made, making it the least invasive surgical option. Gamma knife surgery is a common procedure for patients who cannot tolerate surgery and/or those who have unsuccessful treatments with medications.
The success rates of gamma knife surgery for TN include an estimated 52%-69% of people experiencing pain-free lives from up to 3 years.1 The pain relief from this procedure may be delayed by at least a month in most cases. Common side effects include paresthesia, sensory loss, and/or facial numbness. Gamma knife surgery is also highly expensive, which may be a reason it is not widely used.
Percutaneous Procedures for Trigeminal Neuralgia
Percutaneous procedures for TN are injections administered by piercing the skin of the cheek to reach the trigeminal ganglion or gasserian ganglion, where the three branches of the trigeminal nerve come together. These procedures are usually performed under fluoroscopy (x-ray guidance). Pain relief from these procedures are seen in 90% of people immediately following treatment, however, a long-term follow up by 5 years may vary. Sensory loss and/or numbness in the face are among the possible side effects of these procedures. The 3 percutaneous procedures for TN are described below.
- Radiofrequency thermocoagulation. This procedure involves heating the trigeminal nerve with a radiofrequency needle to create a heat lesion. This resulting lesion prevents the nerve from sending pain signals to the brain.
- Glycerol rhizotomy. This is a procedure in which pure anhydrous glycerol injection is administered in the trigeminal ganglion. Glycerol causes nerve damage by disintegration of the nerve’s myelin sheath. This nerve injury in turn prevents the nerve from sending pain signals to the brain.
- Balloon compression. This technique controls TN pain by squeezing the trigeminal nerve. A large needle is inserted into the trigeminal ganglion, and a tiny balloon is inflated at its tip with a small amount of liquid. The goal is to squeeze the nerve against the bony tissue and cause enough damage to disrupt the pain signals. The balloon is then deflated, and the needle is removed. Sensory loss, numbness in the face and/or eyes, and tingling and/or crawling sensations in the face are some of the possible side effects of percutaneous procedures in the trigeminal ganglion.
While some surgeries, such as microvascular decompression treat the underlying cause of TN, most other invasive methods superficially injure the nerve to stop pain signals. Even after a successful surgery the pain can return with milder or more severe symptoms than before. As a general rule, it is always advisable to treat trigeminal neuralgia with medications before opting for surgery or other invasive procedures.