Journal of Neuroscience Nursing:
The Surgical Treatment of Trigeminal Neuralgia: Overview and Experience at the University of Florida
Ritter, Pamela M.; Friedman, William A.; Bhasin, R. Rick
William A. Friedman, MD, is the chairperson of neurosurgery at the McKnight Brain Institute, University of Florida, Gainesville, FL.
R. Rick Bhasin, MD, is the chief resident neurosurgery at the McKnight Brain Institute, University of Florida, Gainesville, FL.
Questions or comments about this article may be directed to Pamela M. Ritter, MSN ARNP-BC, at Rittepm@neurosurgery.ufl.edu. She is a neurosurgical nurse practitioner at the McKnight Brain Institute, University of Florida, Gainesville, FL.
Trigeminal neuralgia, also called tic douloureux, is a commonly misdiagnosed disorder characterized by intense facial pain. It is a chronic pain disorder that affects the fifth cranial nerve, usually in the fifth to seventh decade of life. Medication is the first line of treatment but frequently fails over time. At that point, many patients seek surgical intervention. This study reviews 108 patients treated over a 1-year period at the University of Florida with one of two surgical procedures: radiofrequency lesioning and microvascular decompression. The short-term results of this experience are reviewed and discussed.
Trigeminal neuralgia (TN) is a chronic pain disorder that affects the fifth cranial nerve. Incidence is 4.5 in 100,000 individuals, and women are affected more than men (2:1). Patients generally complain of very severe, unilateral, sharp, stabbing, electrical pain in the face. The pain is episodic, and patients generally have no symptoms between exacerbations. This disorder may be seen in younger patients but generally affects patients between the fifth and seventh decade of life. TN is seldom familial. The pain is usually unilateral but may also occur bilaterally in a small percentage of patients. Bilateral TN is most frequently seen in patients with underlying multiple sclerosis (Sarlani, Grace, Balciunas, & Schwarta, 2005). Most patients have trigger points. These include touching of the face, cold air, shaving, chewing, movement of the mouth, or brushing of the teeth.
Medications are generally effective in the treatment of TN. Carbamazepine (Tegretol) is the most effective (Eisenberg, River, Shifrin, & Krivoy, 2007). Other effective medications include gabapentin (Neurontin), phenytoin (Dilantin), pregabalin (Lyrica), and baclofen. Opioids are seldom effective in controlling the pain of TN (Lewis, Sankar, De Laatt, & Benoliel, 2007). This may be related to the inability of opiates to relieve neuropathic pain. Carbamazepine is so effective for TN that failure to relieve pain usually indicates an incorrect diagnosis. Unfortunately, medications usually become less effective over time. Significant side effects such as somnolence, mental confusion, and ataxia occur with higher doses. Many patients complain of allergic reactions such as rash or erythema or severe side effects that prevent long-term medical therapy.
When medication becomes ineffective, surgical therapy should be considered. This article presents 1 year of clinical experience with this disorder at the University of Florida and discusses the best available treatment options.
Surgical Treatment Options
Surgical treatment options are available when conservative management fails. One minimally invasive surgical treatment is called radiofrequency lesioning (RFL). This outpatient procedure involves insertion of a hollow needle through the cheek into the trigeminal nerve where it exits from the skull (Fig 1). The patient is temporarily anesthetized while an electrical current is passed through the needle to burn the nerve. The patient is awakened to assess effectiveness. This procedure leaves the patient with permanent facial numbness in the area supplied by that particular branch of the nerve. If V1 is anesthetized, the patient's vision will not be affected, but they will not feel any eye trauma. As a result, the patient's eye must be monitored daily for erythema, a possible indication of corneal abrasion or infection. Although RFL is quite effective for short-term relief of pain associated with TN, the nerve grows back in approximately 50% of cases, requiring repeat operation. In addition, some patients find the numbness very uncomfortable-this is called painful numbness or anesthesia dolorosa. Other side effects include temporary weakness of the masseter muscle on that side of the face and temporary ear fullness as a result of fluid in the eustachian tube (Kanpolat, Savas, Bekar, & Berk, 2001; Latchaw, Hardy, Forsythe, & Cook, 1983).
The most effective surgical treatment of TN is microvascular decompression (MVD) of the trigeminal nerve. This procedure requires general anesthesia and exposure of the trigeminal nerve. Entry is made through the suboccipital area, on the affected side (Fig 2). After a small piece of bone is removed, the brain is retracted to allow exposure of the cranial nerves at the base of the skull. If an artery is found to be compressing the nerve, it is moved away from the nerve and a small spongy material is positioned to prevent friction on the nerve (Fig 3). The superior cerebellar artery is the most common cause of compression. Next is the anterior inferior cerebellar artery. Occasionally, an ectatic basilar artery is involved. Postoperative care includes management of nausea and surgical pain. The facial pain is usually relieved immediately. Most patients remain in the hospital 24-48 hours and complete their recovery at home over the course of about 2 weeks. This procedure results in the most desirable outcome without facial numbness.
Other surgical treatments include balloon compression, glycerol injection, and radiosurgery. Balloon compression is another method used to damage the trigeminal nerve. A soft catheter with a balloon tip is inserted into the area where the nerve exits the base of the brain. Although the patient is anesthetized, the balloon is inflated to compress the nerve. Glycerol injection of the nerve may also be used. During this procedure, a needle is inserted through the cheek into the cistern around the trigeminal nerve, leading to pain relief (McLeod & Patton, 2007; North, Kidd, Plantadosi, & Carson, 1990). Radiosurgery is an outpatient treatment where hundreds of small beams of radiation are focused on the trigeminal nerve, usually resulting in short-term pain relief.
Materials and Methods
From January 4, 2005, to December 14, 2005, 108 patients were surgically treated for TN at the University of Florida. After obtaining permission from the institutional review board, these patients' charts were retrospectively reviewed to determine the characteristics of their disease and surgical outcomes as noted at the last clinic visit.
All procedures were performed by two surgeons. Sixty patients, 29 women and 31 men, underwent RFL. The median age was 75 years (range = 26-92 years). The median duration of pain prior to surgery was 8.5 years. The distribution of pain is noted in Table 1. Forty-eight (80%) patients had pain relief on follow-up (without medication). Five patients experienced no postoperative pain relief. Six patients experienced recurrence of pain after initial postoperative relief. The time to recurrence was 1, 7, 9, 9, 10, and 12 months after the initial procedure. Complications included anesthesia dolorosa (painful numbness) in 3 patients, diplopia in 1 patient, corneal anesthesia in 1 patient, and subarachnoid hemorrhage in 1 patient.
Of the 48 patients undergoing MVD, 33 were women and 15 were men. The median age was 58 years (range = 31-85 years). The median duration of pain was 5 years. The distribution of pain is noted in Table 1. At last follow-up, 33 patients (69%) had complete pain relief without medication. Eight patients had no postoperative pain relief. Four patients experienced recurrence after initial postoperative relief. Complications included anesthesia dolorosa in 2 patients, diplopia in 1 patient, cerebrospinal fluid leakage in 2 patients, hydrocephalus in 2 patients, and facial weakness in 3 patients (2 patients were delayed onset and were both transient). Hydrocephalus after MVD is due to blood products in the cerebrospinal fluid from surgery.
Unfortunately, the quality of data reporting for TN treatment is generally poor, often lacking critical follow-up information. Of the 175 articles reviewed by Zakrzewska and Thomas (1993), only 4 could be used to evaluate rates of complete pain relief after RFL. Those 4 studies are examined in Table 2. RFL appears to have an early success rate in the 70%-90% range. Nerve regrowth or other issues lead to a steady drop in long-term success rate to about 50%. Many RFL patients will require repeat lesioning procedures.
Seven studies of MVD were felt worthy of further analysis because of success rates. They are listed in Table 3. Early success rates are reported in the 80%-90% range. Longer term success rates are around 70%. It appears that the MVD has a higher long-term success rate than that of RFL. It rarely causes facial numbness (which is the goal of RFL) and is associated with low complication rates. Most authors noted that finding an artery distorting the trigeminal nerve was a favorable prognostic factor. Most authors performed a partial sensory rhizotomy when an arterial compression was not evident.
The University of Florida study supports the use of MVD as the most efficacious treatment of TN. This procedure is recommended for patients who are otherwise healthy and able to tolerate general anesthesia. RFL is also very effective and recommended for patients with multiple sclerosis or medical comorbidities but leaves the patient with facial numbness. The goal of this article was to provide information to healthcare providers regarding diagnosis and treatment modalities for a problem that is life altering. Patients will present to their primary care facility for help in pain management before the disease is diagnosed. Early diagnosis will have major implications on quality-of-life issues.
Barker, F. G., Jannetta, P. J., Bissonette, D., Larkins, M. V., & Jho, H. J. (1996). The long-term outcome of microvascular decompression for trigeminal neuralgia. New England Journal of Medicine, 334(17), 1078-1082.
Bederson, J. B., & Wilson, C. B. (1989). Evaluation of microvascular decompression and partial sensory rhizotomy in 252 cases of trigeminal neuralgia. Neurosurgery, 71(3), 359-367.
Burchiel, K., Clark, H., Haglund, M., & Loeser, J. (1988). Long term efficacy of microvascular decompression in trigeminal neuralgia. Neurosurgery, 69(1), 35-38.
Cutbush, K., & Atkinson, R. (1994). Treatment of trigeminal neuralgia by posterior fossa microvascular decompression. Australian and New Zealand Journal of Surgery, 64(3), 173-176.
Eisenberg, E., River, Y., Shifrin, A., & Krivoy, N. (2007). Antiepileptic drugs in the treatment of neuropathic pain. Drugs, 67
Kanpolat, Y., Savas, A., Bekar, A., & Berk, C. (2001). Percutaneous controlled radiofrequency trigeminal rhizotomy for the treatment of idiopathic trigeminal neuralgia: 25-Year experience with 1600 patients. Neurosurgery, 48
Latchaw, J. P., Hardy, R. W., Forsythe, S. D., & Cook, A. F. (1983). Trigeminal neuralgia treated by radiofrequency coagulation. Journal of Neurosurgery, 59
Lewis, M., Sankar, V., De Laatt, A., & Benoliel, R. (2007). Management of neuropathic orofacial pain. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontics, 103
McLeod, N. M., & Patton, D. W. (2007). Peripheral alcohol injections in the management of trigeminal neuralgia. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontics, 104
Mendoza, N., & Illingworth, R. (1995). Trigeminal neuralgia treated by microvascular decompression: A long term follow-up study. British Journal of Neurosurgery, 9
North, R. B., Kidd, D. H., Plantadosi, S., & Carson, B. S. (1990). Percutaneous retrogasserian glycerol rhizotomy. Predictors of success and failure in treatment of trigeminal neuralgia. Journal of Neurosurgery, 72
Oturai, A., Jansen, K., Erikson, J., & Madsen, F. (1996). Neurosurgery for trigeminal neuralgia: Comparison of alcohol block, neurectomy and radiofrequency coagulation. Clinical Journal of Pain, 12
Piatt, J. H., & Wilkins, R. H. (1984). Microvascular decompression for TIC douloureux. Neurosurgery, 15
Sarlani, E., Grace, E., Balciunas, B., & Schwarta, A. (2005). Trigeminal neuralgia in a patient with multiple sclerosis and chronic demyelinating polyneuropathy. Journal of American Dental Association, 136
Zakrzewska, J., Jassim, S., & Bulman, J. (1999). A prospective, longitudinal study on patients with trigeminal neuralgia who underwent radiofrequency hermocoagulation of the Gasserian ganglion. Pain, 79(1), 51-58.
Zakrzewska, J., & Thomas, D. (1993). Patient assessment of outcomes after three surgical procedures for the management of trigeminal neuralgia. Acta Neurochirurgica, 122
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