Trigeminal neuralgia

The article "Surgical treatment of trigeminal neuralgia" is the basis for this AORN Journal independent study. The behavioral objectives and examination for this program were prepared by Rebecca Holm, RN, MSN, CNOR, clinical editor, with consultation from Susan Bakewell, RN, MS, education program professional, Center for Perioperative Education.

Participants receive feedback on incorrect answers. Each applicant who successfully completes this study will receive a certificate of completion. The deadline for submitting this study is Nov 30, 2006.

Complete the examination answer sheet and learner evaluation found on pages 761-762 and mail with appropriate fee to

BEHAVIORAL OBJECTIVES

After reading and studying the article on surgical treatment of trigeminal neuralgia, perioperative nurses will be able to

1. describe how the symptoms of trigeminal neuralgia adversely affect the lives of patients with the condition,

2. identify the pathophysiology of trigeminal neuralgia,

3. explain treatment options available to patients with trigeminal neuralgia,

4. describe perioperative care provided for patients undergoing trigeminal nerve microvascular decompression (MVD), and

5. discuss potential postoperative complications patients recovering from trigeminal nerve MVD may experience.

Trigeminal neuralgia is unilateral electric shock or knifelike pain occurring in one or more branches of the trigeminal nerve, usually the first (ie, mandibular) or second (ie, maxillary) branch. Paroxysms may last seconds or several minutes, and they may be so severe that the patient winces, which is why this condition also is called tic douloureux. Classically, the pain is evoked by stimulation of the face, lips, or gums caused by activities such as shaving, brushing the teeth, or moving trigger zones (ie, chewing, talking, yawning); however, pain may occur spontaneously. The pain is abrupt in onset and termination, with periods of remission and relapse. Paroxysms occur frequently both day and night for several weeks at a time. Patients with this condition have an aversion to being touched, and their speech is guarded. Some patients complain of almost continuous discomfort, itching, and facial sensitivity. This response is regarded as atypical, although it is not infrequent Patients usually have no sensory or motor impairment. (1-4)

HISTORICAL OVERVIEW

In the second century AD, Aretaeus of Cappadocia identified what may have been a condition similar to trigeminal neuralgia, describing it as a facial spasm that distorts a person's countenance. An 11th century Arabic physician, Jujani, wrote about patients experiencing unilateral facial pain that caused spasms and anxiety. He suggested that the pain was caused by the proximity of the artery to the nerve. (1) In 1756, a French physician, Nicholas Andre, named this condition tic douloureux, which means painful wince. Before this time, trigeminal neuralgia was described as pain that gave patients the facial appearance of a dog about to bark. (2)

The relation of vascular compression to trigeminal neuralgia is believed to have been introduced in modern neurosurgery in 1925 by Walter Dandy, MD. In 1959, W. James Gardner, MD, was the first to perform microvascular decompression (MVD) of the fifth cranial nerve. A major shift in neurosurgical practice began to appear in the 1970s after a large case study of MVDs was published. (1)

ETIOLOGY

It generally is accepted that classic trigeminal neuralgia is a consequence of vascular compression and demyelination of the trigeminal nerve as it exits the pons. (2) A blood vessel pressing against time nerve eventually wears off the nerve's insulation, leaving a bare wire that is hypersensitive to sensory stimuli. (2,5)

DIAGNOSIS

Diagnosis of trigeminal neuralgia is made clinically because neither radiological nor physiological studies can confirm or refute vascular compression. A thorough neurological examination with careful evaluation of the fifth cranial nerve, therefore, is of primary importance for diagnosis. A magnetic resonance imaging (MRI) scan should be ordered to exclude mass lesions, vascular abnormalities, or multiple sclerosis in patients with neurological deficits or bilateral or atypical trigeminal neuralgia. (1)

Fewer than 1% of all patients with trigeminal neuralgia have an associated intracranial mass. (2) Bilateral symptoms are more common in patients with multiple sclerosis. (2) Some radiology facilities report that an MRI, performed with 1-mm axial, oblique, and sagittal views through the trigeminal nerve at pontine level, can identify vascular compression from looping of the nearby superior cerebellar artery. Results vary from institution to institution; however, compression can occur from other adjacent smaller arteries, as well as veins. (6) This is a common disorder of middle age and later life and is more common in women than men. (2,4)

ANATOMY

The fifth trigeminal nerve root consists of a larger sensory root and a smaller medially-situated motor root. It arises from the lateral aspect of the pons and courses in a laterally anterior and slightly superior direction through the anterior part of the cerebellopontine angle in the pontocerebellar cistern (Figure 1). The superior cerebellar artery usually passes above the root, and the anterior inferior cerebellar artery passes below. This relationship is not constant because of frequent anatomic variations and loops of vessels. The petrosal vein is lateral and posterior to the trigeminal root. The trigeminal (ie, crescent-shaped) or Gasserian ganglion occupies a shallow bony recess on the anterior aspect of the petrous apex, also known as Meckel's cave. (7)

[FIGURE 1 OMITTED]

TREATMENT

Medical and surgical approaches are available for treatment of trigeminal neuralgia. Several medications currently are available for treating trigeminal neuralgia. Carbamazepine, the usual initial medical therapy, also is diagnostic because most patients with classic trigeminal neuralgia respond to this treatment. Initially, 100 mg per day is prescribed and increased as needed. Some patients experiencing severe pain have been able to tolerate as much as 1,200 mg per day. Carbamazepine may cause dose-dependent bone marrow depression, so complete blood counts (CBCs) must be monitored. Other side effects include mental slowing, dizziness, imbalance, and sedation. Side effects often preclude chronic use, especially in patients whose jobs require concentration or dexterity. (2,3) Fifty percent of patients treated with carbamazepine become tolerant during a period of years. (4) Other medications used alone or in partnership with carbamazepine are baclofen, phenytoin, and, recently, gabapentin. Medical therapy gradually becomes less effective because of the progressive nature of trigeminal neuralgia; therefore, patients should be prepared for eventual surgical treatment. Surgical treatment consists of neurodestructive procedures, stereotactic radiosurgery, and MVD. Peripheral neurectomy, peripheral and ganglionic alcohol blocks, and cryotherapy have not proven as efficacious as other procedures and, therefore, will not be discussed.

NEURODESTRUCTIVE PROCEDURES. There are three percutaneous rhizotomy procedures used to treat trigeminal neuralgia: glycerol, balloon compression, and radiofrequency. These procedures result in partial numbness of the patient's face and risk of corneal denervation with secondary keratitis.

Glycerol rhizotomy is an outpatient procedure performed under fluoroscopy with local anesthesia and mild sedation. A needle is placed via a percutaneous approach through the foramen ovale into the trigeminal cistern. Patients then are asked if they feel typical trigeminal neuralgia pain. If they respond affirmatively, a small test dose of a neurotoxic substance, such as glycerol, is injected, after which additional small doses are injected incrementally. Patients usually perceive the injection as tingling or burning along the affected divisions of the nerve. Initial pain relief occurs in more than 80% of patients and usually is immediate, but 12-month recurrence rates vary from 10% to 50%. (6)

Balloon compression rhizotomy, which is performed as an inpatient procedure under general anesthesia with fluoroscopic control, inserts a guide needle via a percutaneous approach into the patient's foramen ovale. A balloon catheter is advanced through the needle into Meckel's cave. The balloon is filled slowly with contrast solution until it occupies the cave, ensuring adequate compression of the ganglion. Compression times vary from one to six minutes. On emergence from anesthesia, nearly all patients experience immediate pain relief and mild sensory loss. Six percent to 15% of patients report troublesome dysesthesia (ie, odd, unfamiliar feelings, including burning sensations) after the procedure. (1,5) These range from significant discomfort to pain requiring medical treatment. Patients usually are discharged the morning after surgery. Recurrence is reported in 6% to 14% of patients in the first year. (1-3)

Radiofrequency rhizotomy is a procedure that typically requires an overnight stay admission. The patient undergoes general anesthesia and intermittent fluoroscopy as the surgeon percutaneously inserts a radiofrequency needle through the foramen ovale into Meckel's cave. The relationship of the trigeminal rootlets to the foramen ovale is such that with stepwise advancement of the needle, the third, second, and first divisions are stimulated in succession. After the needle has traveled the preplanned distance, patients are allowed to awaken, the stylet is replaced by an electrode, and the nerve root is stimulated. The pain elicited must conform to that of the patient's original neuralgia; otherwise the needle must be repositioned. When appropriate pain has been elicited, patients are reanesthetized, and the retrogasserian rootlets are thermocoagulated using radiofrequency currents. After each thermocoagulation, patients are awakened and manual sensory testing of the face is carried out. Additional thermocoagulations are performed until definitive hypalgesia (ie, perception of a painful stimulus that varies significantly from a normal perception of the same stimulus) has ensued. A large percentage of typical patients experience immediate pain relief, but by three years, one-third of patients have recurrent neuralgia. Long-term, annoying paresthesias (ie, paroxysmal pain, including pins and needles) is experienced by 5% to 10% of patients treated. (1-3)

STEREOTACTIC RADIOSURGERY. Stereotactic radiosurgery also is called gamma knife. The gamma knife is a focused array of 201 intercepting beams of gamma radiation. Using local anesthesia, a stereotactic frame is secured to the patient's head, after which an MRT is performed to identify the trigeminal nerve. Under IV or oral sedation, the trigeminal nerve is irradiated. Most patients only need an overnight stay. Follow up at one year demonstrates that 70% of patients treated were pain free. (1-3) Loss of facial sensation is rare. Treatment results differ from other procedures because pain relief is not immediate and takes four to six weeks to occur.

MICROVASCULAR DECOMPRESSION. Failure of medical therapy or other surgical interventions may indicate the need for

MVD. Some physicians consider trigeminal nerve MVD the best initial procedure for patients who are not responsive to oral medication. The failure rate of MVD for trigeminal neuralgia is higher in patients who previously have had neurodestructive procedures. The patient must be healthy and not pose a general anesthetic risk. The target area is the nerve-pons junction. This procedure provides pain relief with decreased risk of facial numbness and anesthesia dolorosa (ie, burning numbness). A craniotomy is performed under general anesthesia. The trigemihal nerve is exposed at the cerebellopontine angle. The vessel compressing the nerve is dissected off the nerve and padded. The procedure takes three to four hours, and patients usually wake free of pain and are discharged in four to five days.

PREOPERATIVE ASSESSMENT

Before proceeding with the MVD surgery, the neurosurgeon evaluates the patient, performs a complete neurological examination, takes a medical history, and reviews the patient's MRI films. He or she then explains file surgical procedure, potential complications, and side effects to the patient and his or her family members. Because of the age group of these patients and the seriousness of the surgery, most patients need medical clearance, which includes blood tests (eg, CBC, prothrombin time, partial thromboplastin time, electrolytes), electrocardiogram (ECG), and chest x-ray. Some surgeons also order preoperative brain stem auditory-evoked potentials and otological testing for both pure tone and speech discrimination. If not performed already, an MRI is ordered to rule out cerebellopontine angle tumors. Patients typically are more than 50 years old and have been dealing with progressively worsening paroxysmal facial pain because medication no longer controls the pain. Many patients practically are housebound because ordinary stimuli (eg, breath of wind, smiling) cause excruciating spasm, pain, or both. If a patient wishes to proceed, the surgeon schedules the patient for elective surgery.

The anesthesia care provider interviews the patient, ascertains whether he or she is an acceptable anesthetic risk, and explains the anesthetic treatment plan. He or she instructs the patient not to have anything to eat or drink after midnight the night before surgery. No other special preparations are necessary.

DAY OF SURGERY

The patient arrives at the preoperative unit on the morning of surgery, one to one and one-half hours before the scheduled surgery time. The preoperative admission nurse instructs the patient to change into a hospital gown. The nurse measures the patient's vital signs; reviews the chart for laboratory results, EKG, chest x-ray, MRI, and history and physical examination; and verifies the availability of two units of packed red blood cells. The nurse also reviews the necessary informed consent forms. The nurse then performs a systems assessment of the patient. This includes determining the patient's general health, previous surgeries, existing medical conditions or disabilities, and routine medications used, including over-the-counter medications or herbal remedies. The nurse questions the patient regarding allergies to medication, foods, and latex. The nurse then asks the patient to indicate the incisional site. If the patient does not know the site, it is clarified with the surgeon, at which point all agree and mark the site together. The nurse shaves the incisional area, minimizing the area to be shaved as much as possible and adhering to recommended practices. The nurse asks the patient to remove all jewelry, dentures, contact lenses, hearing aids, or other prostheses, although hearing- or visually-impaired patients may keep their hearing aids or glasses until after induction. When possible, all belongings are given to a family member for safekeeping. The anesthesia care provider starts an IV line.

OR SETUP. The perioperative nurse ensures that the OR is prepared for a craniotomy procedure and the more detailed microvascular portion of the procedure before leaving the room to interview the patient. Routine craniotomy setup includes a

* craniotomy set,

* drill for making burr holes and turning a small bone flap,

* unipolar electrosurgical unit, and

* irrigating bipolar electrosurgical unit. Special instrumentation and equipment required for MVD include

* aneurysms clips,

* microvascular instruments,

* microscope,

* self-retaining retractor that attaches to the three-point headrest,

* small endoscopes,

* special chairs for microsurgery, and

* towers containing the microscope and endoscope equipment.

Medications on the field include

* antibiotic irrigating solution,

* antibiotic ointment,

* fibrin glue,

* hemostatic sponge agents, and

* local medications containing epinephrine

INTRAOPERATIVE CARE

Preoperatively, the circulating nurse greets the patient, explains the anticipated procedure, and reviews the preoperative assessment form. The anesthesia care provider lightly sedates the patient and, cooperatively with the circulating nurse, transports the patient to the OR. After anesthetizing and intubating the patient, the anesthesia care provider inserts an arterial line, a central line, and an oral gastric tube. He or she lubricates the patient's eyes and protects them by taping cotton eye pads in place over closed eyelids. The anesthesia care provider tapes a precordial doppler in place to listen for any air that could enter the venous system through an open sinus. Meanwhile, the circulating nurse inserts a temperature-monitoring Foley catheter and places antiembolism stockings and sequential compression devices on the patient.

INTRAOPERATIVE NEUROPHYSIOLOGICAL MONITORING. Intraoperatively, neurophysiological monitoring is used to record electrical signals at different levels of the neuraxis or at different muscle groups. Using intraoperative neurophysiological monitoring helps detect changes that might presage irreversible damage (ie, pressure or stretching of the ganglion or eighth cranial nerve can cause temporary or permanent deafness). This allows the surgeon to alter surgical technique whenever possible to reduce morbidity and mortality. The underlying assumptions of intraoperative neurophysiological monitoring are that

* it can detect changes resulting from surgical manipulation of brain tissue;

* such a change will be detected quickly enough to prevent permanent injury; and

* the information can be used by the surgeon to stop or change the surgical procedure.

POSITIONING. After the technologist places the neurophysiological monitoring electrodes, surgical team members place the patient in a modified lateral position. The anesthesia care provider places a lumbar spinal drain to control intracranial pressure. Frequently, up to 50 mL or more of cerebrospinal fluid (CSF) is drained to provide more surgical space. Team members reposition the patient to a modified lateral position, by bringing the shoulder and lower arm over the edge of the OR bed. The lower axilla must be heavily padded with foam to prevent brachial plexus injury. The surgeon secures the patient's head in the neurosurgical three-point headrest and turns the patient's head away from where he or she will stand during the procedure. The surgeon also laterally flexes the patient's head toward the floor and toward the patient's body. A gel-filled, full-length, table pad is pulled well up toward the head of the bed to make a padded sling to support the lower arm (Figure 2). The patient's lower leg is padded with foam, and pillows are placed between the patient's legs. The patient is secured to the OR bed with wide tape at the chest, hips, and legs. The patient's skin should be protected with towels. The circulating nurse pads the patient's upper axilla and side with foam and gently pulls the patient's upper shoulder toward the foot of the bed while the surgeon tapes the patient's arm in place, again protecting the patient's skin with towels. The circulating nurse checks to ensure that all bony prominences are padded and places an electrosurgical unit (ESU) dispersive pad on the patient's upper, lateral thigh. The circulating nurse places a temperature-regulating blanket on the patient from shoulders to toes. The neurophysiological monitoring technologist places final electrodes around the incision and in the patient's ear. Excessive retraction can cause hearing loss. Monitoring brain stem-evoked potentials can reveal excessive retraction and indicate that the retractor needs to be adjusted.

[FIGURE 2 OMITTED]

The circulating nurse preps the patient, after which the surgeon, scrub person, and assistant drape the patient. The scrub person places the irrigating bipolar ESU and suctions on the field, and hands off the opposite ends to the circulating nurse.

TRIGEMINAL NERVE MICROVASCULAR DECOMPRESSION

The surgeon and assistant perform a craniotomy while the scrub person sterilely drapes the surgeon's and assistant's chairs and the microscope. When the dura is exposed, the circulating nurse assists the scrub person in bringing the microscope and chairs into position. The circulating nurse brings two monitoring towers into position and turns off the room lights. He or she places a tower with both an endoscopic screen and a screen displaying the microscope picture directly across from the surgeon. The circulating nurse places the other tower, displaying only a microscope picture so the scrub person can see the screen. The anesthesia care provider and neurophysiological monitoring technologist also must have a good view of one of the screens.

The surgeon uses the microscope to open the dura, after which he or she drains the lateral cerebellomedullary cistern and gently places a retractor lateral to the eighth cranial nerve. The surgeon inspects the petrosal venous complex. If the veins are prominent, they must be cauterized and occluded. The surgeon opens the arachnoid membrane dorsal to the seventh and eighth nerves and continues the opening upward to the fourth nerve.

A retractor is placed just posterior to the root entry zone of the trigeminal nerve, dissecting the cerebellum away from the area. Compression of the nerve usually is caused by the superior cerebellar artery; however, other large arteries or small arterioles or veins that drain into the superior petrosal sinus near Meckel's cave also may cause compression. The surgeon mobilizes the entire compressive artery (Figure 3) and then places shredded pieces of polytetrafluorethylene felt between the artery and the nerve. Some surgeons, however, believe that placing felt may cause scarring, which could result in recurrence. Sometimes a 7-0 polypropylene suture is used to hang or sling the decompressed artery from the tentorium (Figure 4). If veins are causing compression, they are cauterized and divided. The trigeminal nerve must be thoroughly explored from Meckel's cave all the way to the root entry zone at the pons.

[FIGURES 3-4 OMITTED]

When decompression is believed to be complete, the circulating nurse attaches the light source and camera to the endoscope and defogs and white balances it. The surgeon uses 0[degrees] and 30[degrees], 2-mm endoscopes and can press a button on the hand control of the microscope to see the endoscopic view. The surgeon inspects the nerve on all sides, looking for other veins or arteries that might cause a problem.

The surgeon closes the dura, frequently with fibrin glue, to help prevent CSF leaks. The surgeon replaces the bone flap using screws and plates and a bone substitute, such as hydroxyapatite cement, to fill in defects. He or she closes the scalp, after which, the surgical team removes the patient from the neurosurgical stabilizing headrest and wraps the patient's head with antibiotic ointment, dressing sponges, and two to four woven cotton roll bandages in a standard head dressing.

POSTOPERATIVE CARE

The anesthesia care provider awakens and extubates the patient and removes the oral gastric tube. Surgical team members move the patient to a postoperative bed, with the head of the bed elevated 30[degrees] to 45[degrees]. The anesthesia care provider, circulating nurse, and surgeon transport the patient to the postanesthesia care unit (PACU). Patients who have undergone a MVD procedure generally remain in the PACU for several hours. Most patients awaken from anesthesia with their neuralgia gone. Nursing care of these patients is similar to that for any patient recovering from craniotomy and general anesthesia. The PACU nurse measures vital signs and performs neurological checks every 15 minutes times four and then 30 minutes times two. Neurological checks include

* level of consciousness,

* size of pupils and reactivity to light,

* intact vision,

* movement and strength of extremities, and

* speech.

Of particular concern for patients undergoing trigeminal nerve MVD are facial sensations; hearing because of eighth cranial nerve retraction; symmetry of smile (ie, presence or absence of droop); eye movements; and clenching of teeth (ie, motor component of fifth cranial nerve). When the patient is awake and stable, usually within two hours, he or she is transferred to the neurosurgery unit.

Nurses on this unit continue to closely monitor the patient, measuring vital signs and performing neurological checks every one hour for four hours, every two hours for eight hours, and every four hours thereafter. The lumbar drain was clamped intraoperatively and remains so unless signs of increased intracranial pressure are present. The surgeon removes the drain 24 hours after surgery if no increases in intracranial pressure are noted. The nurse removes the indwelling Foley catheter the first postoperative day when the patient is ambulating.

Nurses monitor the patient closely for unbalanced fluid volume related to increased intracranial pressure or diuresis. The patient is weighed daily, and nurses carefully maintain the patient's intake and output. Nurses also monitor the patient's respiratory function because ineffective breathing patterns can occur with postoperative cerebral edema. Additionally, nurses carefully watch older patients who are vulnerable for pneumonia if they are not breathing deeply enough. Nurses also assess for venous thrombosis, although, the patient wears sequential compression stockings and ambulates the day after surgery. (8,9) The patient is discharged on the fourth postoperative day if no complications are encountered.

No activity limitations are required, and patients are instructed to return to the surgeon's office for a postoperative appointment seven to 10 days later for suture removal.

COMPLICATIONS

Complications resulting from the procedure include bleeding from the petrosal vein or other cerebellar draining veins, hearing loss, cerebellar contusions, and postoperative CSF leak. These complications occur in fewer than 5% of patients undergoing this surgery when the procedure is performed by experienced surgeons and surgical team members. Eighty-five percent of patients do not experience complications and are afforded pain relief without facial numbness. The incidence of recurrence is 15% to 20% after MVD within a five-year period. Recurrent trigeminal neuralgia can be treated by repeating the surgical procedure.

CASE STUDY

Mrs R, a retired, 69-year-old woman with trigeminal neuralgia since 1986, experienced sharp, electric shock-like, facial pain brought on by talking, eating, touching her face, or brushing her teeth. Even a breath of cold air incited the pain, which lasted a few seconds. She experienced several remissions, some lasting for months, but the pain worsened steadily. The pain was slightly relieved with medications; however, five tablets each of carbamazepine and gabapentin did not provide complete relief. Six tablets of each produced severe side effects (eg, dizziness, diplopia). Mrs R's primary care physician suggested gamma knife radiation, rhizotomy, or MVD. After researching her options via the Internet and through a trigeminal neuralgia support group, Mrs R chose MVD.

Mrs R had a history of chest pain relieved by nitroglycerin, so she needed a complete cardiac workup to clear her for a general anesthetic. She also was on medication for hypertension. On neurological examination, Mrs R demonstrated severe facial pain. Her higher functions, cranial nerve examination, and motor and sensory examinations were all within normal limits. Mrs R's cerebellar examination revealed tandem gait impairment. Her MRI examination revealed no abnormalities except for some hypodense areas in the white matter on MRI images.

Mrs R was cleared for surgery. She reported to the preoperative unit the morning of her scheduled elective surgery, having been NPO since midnight. Preoperatively, the anesthesia care provider administered phenytoin to reduce the chance of postoperative seizures and dexamethasone to reduce cerebral edema, Intraoperatively, the anesthesia care provider administered mannitol to produce diuresis, which helped reduce CSF, and antibiotics to decrease the risk of infection. Mrs R's surgery was uneventful and lasted four hours.

When Mrs R awakened in the PACU, her neuralgia was gone. She remained in the PACU for three hours and then was transferred to the neurosurgery unit. Her lumbar drain and indwelling Foley catheter was removed the morning after surgery, and she ambulated in the hall later that morning. Mrs R was discharged on the fourth postoperative day, with no obvious sensory deficits or neuralgia. The surgeon tapered Mrs R's carbamazepine for nine days from the day of surgery, after which it was discontinued. Mrs R returned to the surgeon's office in five days for suture removal. Mrs R remains asymptomatic and pain free today, two years after surgery.

CONCLUSION

Trigeminal neuralgia is a debilitating disease. Patients frequently are house bound because even the wind can act as a triggering stimulus for their pain. When medical therapy fails, trigeminal nerve MVD frequently is the treatment of choice providing pain relief with a decreased risk of facial numbness and anesthesia dolorosa when the procedure is performed by an experienced surgeon and surgical team members. The majority of patients undergoing this procedure experience immediate pain relief.

AORN Home Study

This program meets criteria for CNOR and CRNFA recertification as well as other continuing education requirements.

A minimum score of 70% on the multiple-choice examination is necessary to earn 3 contact hours for this independent study.

Purpose/Goal: To educate perioperative nurses about surgical treatment options for trigeminal neuralgia.

Editor's note: The author acknowledges Laligam Sekhar, MD, North Shore University Hospital, Great Neck, NY, and Ramin Rak, MD, for their generous help and contributions to this article.

NOTES

(1.) T J Nurmikko, P R Eldridge, "Trigeminal neuralgia: Pathophysiology, diagnosis and current treatment," British Journal of Anaesthesia 87 (July 2001) 117-132.

(2.) J A Brown, "Trigeminal neuralgia," in Conn's Current Therapy, R E Rakel, E T Bope, eds, (Philadelphia: W B Saunders, 2001) 973-975.

(3.) M F Beal, S L Hauser, "Common disorders of the cranial nerves," in Harrison's Principles of Internal Medicine, 15th ed, E Braunwald et al, eds (New York: McGraw-Hill, Medical Publishing Division, 2001) 2421-2424.

(4.) M Victor, A H Ropper, "Diseases of cranial nerves," in Adams and Victor's Principles of Neurology, seventh ed (New York: McGraw-Hill, Medical Publishing Division, 2001)

(5.) L N Sekhar, E de Oliveira, Cranial Microsurgery: Approaches and Techniques (New York: Thieme Medical Publishing, 1999) 23-31, 354-359, 373-375.

(6.) J M Taha, J M Tew, Jr, "Treatment of trigeminal neuralgia by percutaneous radio-frequency rhizotomy," Neurosurgery Clinics of North America 8 (January 1997) 31-39.

(7.) W Mosiman, "Taking the sting out of trigeminal neuralgia," Nursing 31 (March 2001) 86.

(8.) L S Brunner, S C Smeltzer, S C O'Connell-Smeltzer, eds, Brunner and Suddarth's Textbook of Medical Surgical Nursing, 10th ed (Philadelphia: Lippincott, Williams & Wilkins Publishers, 2003) 1866-1870.

(9.) J V I Hickey ed, The Clinical Practice of Neurological and Neurosurgical Nursing, fifth ed (Philadelphia: Lippincott, 2003) 705.

Cassi Brown, RN, CRNFA, is a clinician II in the main OR at Inova Fairfax Hospital, Arlington, Va.

Examination Surgical treatment of trigeminal neuralgia

1. Trigeminal neuralgia often is called tic douloureux because the painful paroxysms sometimes are so severe that the patient winces.

a. true

b. false

2. The pain of trigeminal neuralgia typically is evoked by

a. lifting and other activities of the shoulder girdle.

b. stimulation of the face, lips, or gums.

c. bending over or placing the head lower than the waist.

d. directional movements of the head.

3. Trigeminal neuralgia is a consequence of vascular -- and -- of the trigeminal nerve as it exits the pons.

a. compression/denervation

b. decompression/denervation

c. compression/demyelination

d. decompression/demyelination

4. Side effects of carbamazepine include all of the following except

a. dose-dependent bone marrow depression.

b. mental slowness and sedation.

c. slurred speech and unsteady gait.

d. dizziness and imbalance.

5. All of the following types of percutaneous rhizotomy procedures are used to treat trigeminal neuralgia except

a. formaldehyde blocks.

b. balloon compression.

c. glycerol.

d. radiofrequency.

6. Anesthesia dolorosa is defined as

a. burning numbness.

b. inability to differentiate between the right side and the left side of the face.

c. excruciating spasms.

d. paroxysmal facial pain.

7. The anesthesia care provider uses a precordial doppler to

a. monitor for abnormal heart rate and rhythm.

b. ensure that the patient's respirations remain shallow, thus preventing unnecessary movement.

c. listen for any air that could enter the venous system through an open sinus.

d. monitor, prevent, or treat hiccups that result from hyperventilation.

8. All of the following assumptions regarding intraoperative neurophysiological monitoring are correct except

a. it can detect changes resulting from surgical manipulation of brain tissue.

b. changes will be detected quickly enough to prevent permanent injury.

c. information about changes can be used to stop or change the surgical procedure.

d. changes can be documented to prevent future legal litigation.

9. The dura is closed, frequently with --, to help prevent cerebrospinal fluid leaks.

a. fibrin glue

b. gelfoam

c. raney clips

d. suture

10. Procedural complications include all of the following except

a. decreased sense of smell.

b. bleeding from the petrosal vein or other cerebellar draining veins.

c. hearing loss.

d. cerebellar contusions.

COPYRIGHT 2003 Association of Operating Room Nurses, Inc.
COPYRIGHT 2003 Gale Group