Featuring The Department of Neurosurgery’s John Y.K. Lee, MD, Assistant Professor of Neurosurgery and Medical Director of the Penn Gamma Knife Center. Dr. Lee is committed to the comprehensive treatment of patients with craniofacial neuralgias, including trigeminal neuralgia, glossopharyngeal neuralgia, and hemifacial spasm. Dr. Lee uses minimally invasive, fully endoscopic surgical procedures including microvascular decompression (Jannetta procedure) and stereotactic radiosurgery to cure these disorders.

The expert neurosurgeons at Penn provide the most advanced cranial nerve treatment options. Through an extensive and collaborative team approach, Penn Neurosurgeons ensure a thorough consideration of both surgical and nonsurgical treatments. Our program develops a surgical treatment plan that is individually-tailored to each patient’s medical situation and specific needs.

Types of Cranial Nerve Disorder Treatment Options

Penn Neurosurgeons are pioneers in cranial nerve treatment techniques – including Gamma Knife Perfexion and microvascular decompression. The types of treatment options for cranial nerve disorders include:

Medication

The first line of treatment for cranial never disorders is to help relieve the pain of trigeminal neuralgia is usually medication therapy. The drugs most commonly used for treating trigeminal neuralgia are anti-convulsants, which are medications that were originally developed for the treatment of epilepsy. This class of medications has also been found to be quite effective in treating nerve pain, including trigeminal neuralgia when taken on an on-going basis.

Very often, however, these medications do not eliminate the pain and/or can produce significant side effects which can be potentially harmful or disruptive to the functions of daily living. If medical therapy is unsuccessful, surgical procedures can be performed to eliminate the pain.

Microvascular Decompression (MVD)

Also known as the Jannetta procedure, microvascular decompression is a surgical procedure to relieve the symptoms of trigeminal neuralgia. In this procedure, the neurosurgeon surgically opens the skull, (a craniectomy), exposing the nerve at the base of the brainstem to insert a tiny sponge between the compressing vessel and the trigeminal nerve. This sponge isolates the nerve from the pressure and pulsating of the blood vessel. By alleviating and removing the neurovascular compression, the trigeminal nerve recovers and painful symptoms are relieved. The process does not damage or destroy the nerve.

This procedure was pioneered by Peter Jannetta, MD, who graduated from medical school at the University of Pennsylvania. Dr. Jannetta successfully performed his first procedure in 1966 and eliminated the facial pain of a 41-year-old man. It took a long time before the medical community accepted and adopted this procedure. However, once it was adopted, many of the neurosurgeons performing the procedure were trained by Dr. Jannetta, including Dr. Lee.

Microvascular decompression (MVD) surgery is performed under general anesthesia, through an incision and small thumbprint sized bony opening behind the ear. The surgeon peers into the opening through an operative microscope, looks around the cerebellum, and visualizes the trigeminal nerve as it arises from the brain stem.

Micro-instruments are used to mobilize the offending vessels away from the trigeminal nerve root. The decompression is permanently maintained by inert implants between the vessels and nerve.

Following the microvascular decompression, the bone and incision are closed. Most patients then remain in the hospital for two or three days, and gradually return to full activities within a few weeks.

Pain relief is usually immediate, and medications are gradually discontinued over two weeks following surgery. If pain does recur, it may be more easily treated with medications than before, or retreated with any of the neurosurgical procedure options.

Gamma Knife® Perfexion™ Radiosurgery

Gamma Knife Perfexion Radiosurgery is one of the most precise, powerful, and proven treatments for brain disorders, including cranial nerve disorders. It is also a preferred treatment for dysfunctions, such as trigeminal neuralgia.

The Gamma Knife Perfexion is a highly advanced machine that delivers a powerful dose of radiation to a precise target in the brain. The Gamma Knife Perfexion delivers 201 beams of extremely focused radiation to a precise target in the brain. Individually, the beams are too weak to damage healthy tissue. Together, they converge to deliver powerful treatment to a single point. Patients experience little or no discomfort during the procedure, usually go home the same day, and are generally able to resume normal activities.

Before the Gamma Knife Perfexion procedure, a team of physicians creates detailed maps of the patient's brain, precisely pinpointing the tumor or malformation. During the procedure, a focused, “custom-designed” dose of radiation targets the thin, retrogasserian portion of the trigeminal nerve.

Unlike microvascular decompression, which is considered a non-ablative procedure, Gamma Knife Perfexion radiosurgery is an ablative procedure. It is designed to target the trigeminal nerve and to disrupt the pain pathways. Patients generally need only one treatment to get results, and the benefits of the procedure are usually experienced by the patient at one month after the procedure.

Pennsylvania Hospital’s Gamma Knife Perfexion is robotically controlled, which allows our surgeons to deliver radiation more precisely and safely than ever before. And it features enhanced communication capabilities – a built-in audio and video system allows physicians to see and talk to patients, and patients to talk to physicians – throughout the treatment.

Supra Orbital and Infra Orbital Peripheral Nerve Stimulation

Supra Orbital and Infra Orbital Peripheral Nerve Stimulation is a new modulatory technique that has value in patients with neuralgias that are not consistent with trigeminal neuralgia.

For example, patients with refractory post-herpetic neuralgia or post-traumatic neuralgia can benefit from the placement of these electrodes.

The procedure is usually performed in two stages. The first stage is a trial that usually lasts one week. During this time, patients gauge whether it is providing relief. If sufficient relief is achieved with the trial, then patients can proceed to the final stage which involves the placement of wires and batteries under the skin. The patient can turn on the stimulator and has access to multiple different programming modes.

As compared to microvascular decompression, Gamma Knife Perfexion is an easier, outpatient procedure. Although it is less invasive than microvascular decompression, it does not appear to have the same long-lasting benefit as the more invasive surgical procedure. Hence, Gamma Knife Perfexion is especially useful in older patients and those who are less able to tolerate conventional surgery.

Percutaneous Glycerol Rhizotomy

Percutaneous Glycerol Rhizotomy is a minimally-invasive procedure that is usually performed as an outpatient procedure. The procedure usually takes approximately one hour and is performed under local anesthesia. This procedure is also an ablative procedure that disrupts the pain pathway of the trigeminal nerve, thus relieving the pain.

A needle is inserted in the skin beside the mouth, and directed through an opening at the base of the skull. A harmless dye may be injected to confirm the needle is in the precise location, as seen on an x-ray. The chemical glycerol is then injected into the space surrounding the Gasserian ganglion. This glycerol produces a relatively mild injury to the nerve with minimal risk of permanent facial numbness. The entire nerve is not destroyed. The majority of patients achieve early relief of trigeminal neuralgia pain with this technique. The long-term benefit of the procedure is similar to that of the Gamma Knife radiosurgical procedure.

Research and Clinical Trials

Researchers in the Penn Center for Cranial Nerve Disorders are pushing the boundaries of medical research. Penn Neurosurgery is currently participating in a company sponsored multi-centric trial to do cranial nerve stimulation. This trial involves a surgical implant, Stimwave CranioFacial, that provides direct stimulation of the nerve to alleviate the symptoms in patients who are not good candidates for regular surgery.  

In addition, Dr. John Lee has received grants to pursue the minimally invasive surgery of cranial nerve disorders. He has authored multiple papers on the topic and has authored a book titled "Fully Endoscopic Cerebellopontine Angle Surgery."

For more information, visit Neurosurgery Research and Clinical Trials.

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