REVIEW OF NEUROSTIMULATION FOR NEUROPATHIC FACIAL PAIN

This review includes neurostimulation procedures for trigeminal neuropathic pain (TNP), anesthesia dolorosa (AD), post herpetic neuralgia, and occipital neuralgia. Neurostimulation is used for the conditions described below, but these procedures are not used to treat trigeminal neuralgia.

NOTE: Portions of this article are based on anecdotal information from patient calls and a TNA Sixth National Conference panel.

By Alana Greca, BSN, RN

Former TNA Director of Patient Support

At the TNA 6th national conference last fall, there were 5 sessions devoted to education and discussion about treatment for the constant burning pain associated with nerve damage or neuropathic pain. This review includes neurostimulation procedures for trigeminal neuropathic pain, trigeminal deaffrentation pain, anesthesia dolorosa (AD), post herpetic neuralgia, and occipital neuralgia.

NEUROPATHIC FACIAL PAIN DISORDERS

Neurosurgeon and member of the TNA Medical Advisory Board, Kim Burchiel, has proposed a classification system that divides neuropathic facial pain according to the cause of damage to the trigeminal nerve.

 OHSU Facial Pain Classification System

This classification system was used in the book, Striking Back, and will be used here to provide continuity in terminology. Please be aware that other medical providers may use different terms for the same problems.

Trigeminal neuropathic pain (TNP)---facial pain which is  due to unintentional injury from such things as:

• facial trauma
• dental procedure
• complication of  sinus surgery or other ear, nose or throat operation
• side effects of stroke or diabetes.

Symptoms:

• if triggered, the pain is usually in the trigger area
• pain described as constant, dull, burning, aching, or boring
• numbness and tingling may also be present
• intermittent sharp stabbing pain may also occur

http://www.spineuniverse.com/displayarticle.php/article391.html

Trigeminal deaffrentation pain (TDP)---This is pain that occurs when parts of the nerve are severely injured and have little or no function as a result of intentional injury.

TDP occurs as a complication from surgeries done to treat TN pain, such as:

• Alcohol or glycerol injections
• Radiofrequency lesioning
• Balloon compression
• Neurectomies
• Radiosurgery

Deafferentation pain symptoms

Generally, continuous aching, burning quality – usually with numbness, tingling and/or hypersensitivity in the affected area. (“burning numbness.”)

In Striking Back! The Trigeminal Neuralgia and Face Pain Handbook, it is stated that “symptoms may even go beyond the trigeminal system….arm pain, shoulder pain, chest pain and even queasiness…”

Intermittent sensations like itching, crawling, pulling or pressure may occur.  If TN pain has been relieved, these symptoms will occur alone or in addition to TN pain, if the surgery is ineffective.

http://www.umanitoba.ca/cranial_nerves/trigeminal_neuralgia/manuscript/types.html

http://www.cedars-sinai.edu/3983.html

Anesthesia dolorosa

“…This is a seemingly impossible combination of both dense numbness and severe pain in the same area following an injury to that area.” There are several theories as to why pain would be felt in a profoundly numb area. The first is that somehow the touch nerve fibers were destroyed, but the pain fibers are still functioning. The second is that the brain center which monitors and interprets the nerve signals either remembers or substitutes signals when it is no longer is receiving impulses from the non-functioning nerve.

Facial Neuralgia Resources - AD

Center for Cranial Nerve Disorders - AD

Post herpetic neuralgia (PHN)--- This is pain which follows an attack of shingles (herpes zoster), and is a result of viral damage to the nerve. If it affects the glossopharyngeal nerve, it gives throat pain; hearing difficulties result if the aucoustic nerve is damaged; drooping or paralysis of the face may occur when the facial nerve is involved; damage to the trigeminal nerve (usually the first branch area) presents as facial pain.

Symptoms

• Pain tends to be more constant than classic TN
• different descriptions of pain---sharp & jabbing; burning pain; deep and aching, dull and borimg

• Along with the pain there is often skin sensitivity and sometimes an itching or numb feeling.

Facial Neuralgia Resources - PHN

E-Medicine/Web MD - PHN

Mayo Clinic- PHN

http://www.ccjm.org/PDFFILES/Nagel7_07.pdf

Occipital Neuralgia

Although called a neuralgia, this disorder is actually related to nerve damage to the greater or lesser occipital nerves. It presents as one sided pain which begins at the back of the head and may then radiate up toward the forehead. The pain is described as a constant aching or throbbing, and does not have a trigger.

It can be the result of injury to the head or neck, or compression of the nerve by a tumor or blood vessel or neck lesion.

http://facial-neuralgia.org/conditions/occiptal.html

http://www.neurosurgerytoday.org/what/patient_e/occipital_neuralgia_06.asp

http://www.ninds.nih.gov/disorders/occipitalneuralgia/occipitalneuralgia.htm

DIAGNOSIS OF NEUROPATHIC FACIAL PAIN

It is important that neuropathic pain be differentiated from trigeminal neuralgia. Diagnosis is made based on:

Description of symptoms---the quality, characteristics, occurrence of pain is the most important means of accomplishing this.

Medical history prior to the onset of the pain should include one of the causative factors listed above for the neuropathic pain disorders.

SURGICAL TREATMENT FOR NEUROPATHIC FACIAL PAIN

The following surgical procedures are not usually done for neuropathic pain because they could increase the chance of complications, such as deaffrentation pain and anesthesia dolorosa:

• Ablative or destructive surgeries which would cut or sever the trigeminal nerve Neurosurgeon and TNA Medical Advisory Board (MAB) co-chairman, Jeffrey Brown, at the recent Richmond regional conference advised anyone with facial pain to get a second opinion when cutting the nerve has been recommended to them. 

• radiosurgery procedures, including: Gamma Knife, Cyber Knife, Novalis, etc.

• percutaneous procedures (radiofrequency, balloon compression, glycerol injection)

NEUROSTIMULATION FOR NEUROPATHIC FACIAL PAIN

General Considerations

Each neurostimulation system consists of:

• One or two leads or electrodes which deliver electrical stimulation to the targeted area

• A wire which transfers the electrical impulses from the power source to the lead

• A battery which generates the electrical stimulation

Most neurostimulator procedures are done in two stages:

• The electrodes are implanted and connected via wire to an external battery in order to do a trial period, during which different settings (rate, intensity, etc.) are tried in order to determine the effectiveness of stimulation for pain management. This screening period will usually be between one and five days.

• If the trial is considered successful, then the wire is placed under the skin and a pouch is created in the chest or abdomen to hold the battery. The battery area may be seen as a bulge under the skin, but should not be visible through clothing.

NOTE: A successful trial period confirms that stimulation may be helpful, but it does not assure that long term use of the stimulator will be successful.

http://www.medtronic.com/neuro/paintherapies/pain_treatment_ladder

Neurostimulation, is used to treat other conditions, such as Parkinson’s Disease, but this review will focus only on its use for facial pain management. Since it does not damage the nerve, it is ideal for those who already have nerve damage, and is generally used for those with chronic debilitating neuropathic facial pain who are not responsive to medical treatments. Neurostimulation therapy uses electrical stimulation to cause changes in the nervous system—impulses to block the pain messages to the brain.

The power source for the stimulator can be adjusted both during the trial period and after implantation through the use of an external programming device. Alterations in the strength and area of coverage can be made through changes in various pulse forms, amplitudes, pulse widths and frequencies.

http://www.answers.com/topic/neuromodulation?cat=health

Posted 8-14-07