Dizziness: Surgical Treatment John W. House, MD Los Angeles, California
The purpose of ths paper is to discuss the various surgical procedures which are available for the treatment of dizziness and vertigo. Special emphasis will be placed on the indications for these operations and the advantages of each. Dizziness is a common complaint of patients seen by general medical physicians and otolaryngologists. At the Otologic Medical Group in Los Angeles about one third of our new patients seek assistance because of dizziness. The etiologies of these various types of dizziness are multiple. It is not the intent of this paper to discuss the differential diagnosis or methods of evaluation. However, it is important to understand the various types of etiological factors as they are important in successful treatment. Conservation Surgery The various operations for the control of dizziness can be divided into three categories: (1) conservative, (2) destructive, and (3) neurosection. The conservative operations are performed in order to attempt to restore normal function to the ear, thus conserving its normal physiology. The destructive type of operations are those which cause a lesion in the balance and often affect the hearing apparatus. Neurosections are an attempt to selectively section the offending nerve in order to prevent the symptoms of dizziness. Presented at the 82nd Annual Convention of the National Medical Association, Los Angeles, California, August 1, 1977. Requests for reprints should be addressed to Dr. John W. House, The Otologic Medical Group and The Ear Research Institute, 2122 W 3rd Street, Los Angeles, CA 90057.
There have been many discussions over the years as to the exact etiology of Meniere's disease. Hallpike and Cairns' discuss the observations of pathologic temporal bones in cases of Meniere's syndrome. They describe the dilatation of the endolymphatic spaces. The exact reason for distention is not entirely clear. It appears to be related to either the overproduction of endolymph or its poor resorption. The resorption of endolymph occurs in the endolymphatic sac which is located adjacent to the posterior fossa dura. Portmann2 first described the surgical decompression of the endolymphatic sac in order to relieve patients of their recurrent vertigo. House,3 in 1962, described the endolymphatic drainage operation whereby a plastic tube is inserted into the endolymphatic
JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 70, NO. 4, 1978
sac. The contents are drained into the posterior subarachnoid space. This procedure is called the endolymphatic subarachnoid shunt operation. The advantage of this type of surgery is that it is an attempt to restore the ear to a more normal physiologic state. This is achieved by providing drainage of the excess endolymphatic fluid. In addition to controlling the vertigo, this operation may help to conserve hearing, and in some cases, improve it. House,4 in 1965, discusses the results of a group of 146 patients with Meniere's disease who underwent endolymphatic subarachnoid shunt surgery. The postoperative period varied from four months to four years. House found that the symptoms of vertigo had been totally relieved in 50 percent of cases. The patients' tinnitus had been relieved in 34 percent and hearing had been improved in about 12 percent. Further deterioration of hearing occurred in only ten percent of patients. Subsequent experience with the endolymphatic subarachnoid shunt has shown that about 60 percent of patients experience complete relief of the symptoms of episodic vertigo. About one half of the patients have stabilization of their hearing, while some experience improvement in hearing. Other conservative operations are also based on the theory of draining the excess endolymphatic fluid. These techniques include ultrasound applica247
tion to the promontory or horizontal semicircular canal and a cryosurgery, in which a freezing probe is applied to the promontory. Cryosurgery had been performed at the Otologic Medical Group up until about five years ago. This procedure was abandoned because of the tendency of recurrence of symptoms. House5 reported, in 1966, that initially about 70 percent of the patients undergoing cryosurgical treatment had relief of their vertigo. Subsequent experiences have indicated that these patients tend to have recurrent symptoms in time. Another drainage procedure is described by Fick.'; He advocates puncturing the saccule by a transfootplate approach. Fick describes using a sharp needle to pierce the dilated saccule in the vestibule. In the Fick procedure, a high percentage of the patients have relief of vertigo. However, about 80 percent suffer permanent hearing damage following the procedure. At the Otologic Medical Group, we use the Fick operation in patients who have previously undergone endolymphatic subarachnoid shunts and have failed to respond, or in those whose hearing is not salvageable, but who have continued episodes of vertigo. This operation is highly successful in eliminating vertigo in patients with Meniere's disease. It must be emphasized that these drainage operations work only in cases of vertigo caused by Meniere's disease and not in vertigo from other etiologies. It is difficult to generalize as to when a patient's hearing is not salvageable. This must be decided on an individual basis and carefully discussed with the patient. We prefer to use the endolymphatic subarachnoid shunt operation in cases of Meniere's disease when the hearing can be considered salvageable. The endolymphatic subarachnoid shunt operation is peformed under general anesthesia. The patient is in the hospital for three days following surgery. The operation is peformed through a postauricular incision where a complete mastoidectomy is performed. The endolymphatic sac is located adjacent to the posterior fossa dura of the mastoid. The sac is opened on its anterior surface, thus exposing the lumen following which the posterior surface is opened and a tube placed into the opening. The tube then enters the subarachnoid space of the cerebel248
lopontine angle and is secured in the lumen of the sac. A muscle plug is placed on top of the sac. Postoperatively, the patients generally feel well. They stay in the hospital for three days to be observed for possible fever or cerebrospinal fluid leak.
Destructive Procedures The most common destructive procedure is labyrinthectomy. The operation may be performed in one of several ways. The classical labyrinthectomy is performed through a transcanal approach whereby the eardrum is elevated, the stapes removed from the oval window, and the contents of the vestibule removed. This operation has been modified so that the ampule of the superior, lateral, and posterior canals are removed, in addition to the saccule and utricle. This is accomplished by opening widely the oval window with a small cutting burr. At the termintion of the procedure the vestibule is packed with gel-foam moistened with an ototoxic drug such as polymyxin-Bneomycin-hydrocortisone (Cortisporin). This is felt to help cause further destruction of the neuron. The operation is performed under local anesthesia and the patient generally leaves the hospital in one to two days. The operation results in a total hearing loss. This operation is generally reserved for those who have poor vestibular function as well as poor hearing. Other indications for surgery are patients who have constant unsteadiness due to a low-grade activity of a partially destroyed labyrinth. Occasionally, the classic transcanal labyrinthectomy does not completely relieve dizziness because of the regeneration of the vestibular nerves. At pathological sections of these cases a traumatic neuroma may form at the end of the cut vestibular nerve. For this reason, a transmastoid labyrinthectomy and sectioning of the vestibular nerves is often the best approach. In this operation a translabyrinthine approach to the internal auditory canal is created by postauricular incision. This operation is performed under general anesthesia. Both the superior and inferior vestibular nerves are sectioned proximal to Scarpa's ganglion. In this way, regeneration of the vestibular nerves does not occur. The vestibular nerves will then degenerate back to the vestibular nuclei in the brainstem. Pa-
tients are generally in the hospital for about one week after a translabyrinthine section of the vestibular nerves. The indications for this operation are persistent vertigo or dizziness in a person with a nonfunctional ear. This operation, also, will result in total hearing destruction. Unlike the endolymphatic shunt, or the other types of operations which have been previously discussed, this procedure is performed for dizziness of any etiology. Most commonly, patients who undergo this type of surgery have had some type of traumatic lesion to the vestibular apparatus as a result of head trauma, drug therapy, or previous surgical procedures.
Neurosection In 1961, House7 first described the surgical approach to the internal auditory canal through the middle fossa. This approach has revolutionized otologic surgery. It has allowed the otologic surgeon to approach the internal auditory canal without sacrificing hearing. It was originally described for decompression of the internal auditory canal and for the removal of small acoustic neuromas. Since that time, House8 has described this operation for selective section of the superior and inferior vestibular nerves. Occasionally, we see patients who have had some type of trauma or infection of the vestibular divisions of the 8th cranial nerve. These patients may have normal hearing, yet have a constant unsteadiness or recurrent dizziness associated with a reduced vestibular response in the affected ear. If these patients fail to respond to medical management, then surgical intervention is necessary. The ideal approach for this type of problem is through the middle cranial approach. In this approach, both the superior and inferior vestibular nerves are sectioned proximal to Scarpa's ganglion. In most cases, hearing can be preserved with a 90 percent chance of complete relief of dizziness or vertigo. In our hands, approximately six percent of patients undergoing this procedure will suffer some hearing loss as a result of manipulation of the internal auditory artery and vestibular nerves. This operation is performed under general anesthesia. An incision is made slightly anterior to the tragus and superior to the ear. A 2 x 2 inch piece
JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 70, NO. 4, 1978
of bone is removed from the area over the temporal lobe. The temporal lobe dura is then elevated off the floor of the middle cranial fossa. The internal auditory canal is located by identifying various landmarks. These landmarks include the greater superficial petrosal nerve, the superior semicircular canal, and the geniculate ganglion. When the geniculate ganglion is identified, the facial nerve is traced proximal to its entry into the lateral portion of the internal auditory canal. The internal auditory canal can then be opened widely, thus exposing the superior and inferior vestibular nerves. Careful identification and differentiation between the facial nerve and the superior vestibular nerve is imperative in order to avoid injury to the facial nerve. With selective sectioning of the superior vestibular nerve only, approximately 30 percent of patients will have a recurrence or persistence of their dizziness. For this reason, it is necessary to section both the superior and inferior nerves in order to offer the patient a greater opportunity of relief from dizziness.
Discussion
Conclusion
Many surgical procedures are now available for the relief of vertigo and dizziness. It is imperative that the patients undergo a complete otologic and neuro-otologic evaluation in order to determine the exact etiology of the dizziness. Tumors must be ruled out, as well as other otologic or neurologic problems. It is necessary that patients be tried on various medications, including tincture of time. As most physicians know, patients usually recover from their dizziness without specific treatment or with minimal supportive care. It is the rare patient who would require surgical intervention. Fortunately, those few problem patients who have persistent dizziness, unsteadiness, or recurrent vertigo can obtain relief through surgery. The type of procedure to be performed must be carefully determined by the otologist to maximize the best results and minimize complications or problems postoperatively. This situation must be thoroughly explained to the patient as to the advantages to be gained and the complications which may occur.
Vertigo usually responds to medical management. However, selected cases of vertigo can now be treated through various surgical means. In many cases hearing can be preserved, or even improved, with such surgery. The patient with recurrent vertigo or persistent dizziness can seek relief through surgical means. Literature Cited 1. Hallpike CS, Cairns H: Observations on the pathology of Meniere's syndrome. J Laryngol 53:625-655, 1938 2. Portmann G: Vertigo. Surgical treatment by opening the saccus endolymphaticus. Arch Otolaryngol 6:309-319, 1927 3. House WF: Subarachnoid shunt for drainage of endolymphatic hydrops: A preliminary report. Laryngoscope 72:713-729, 1962 4. House WF: Subarachnoid shunt for drainage of hydrops: A report of 146 cases. Laryngoscope 75:1547-1551, 1965 5. House WF: Cryosurgical treatment of Meniere's disease. Arch. Otolaryngol 84:616629, 1966 6. Fick IA: Decompression of the labyrinth. Arch Otolaryngol 79:447, 1964 7. House WF: Surgical exposure of the internal auditory canal and its contents through the middle cranial fossa. Laryngoscope 71:1363-1385, 1961 8. House WF: Middle cranial approach to the petrous pyramid: A report of 50 cases. Arch Otolaryngol 78:469, 1963
Conference on Credentialing of Health Manpower and the Public Interest Under the auspices of the National Health Council a conference on the above subject was held January 3031, 1978, at Stouffer's International Hotel Center, Arlington, Va, considered the implications of the report Credentialing Health Manpower released by the US Department of Health, Education, and Welfare in July 1977. The purpose of the Conference was to provide a forum for NHC member associations and other concerned organizations in the health field to consider the implications of the DHEW report and improve national dialog on communications among participating groups. JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 70, NO. 4, 1978
249
The purpose of ths paper is to discuss the various surgical procedures which are available for the treatment of dizziness and vertigo. Special emphasis will be placed on the indications for these operations and the advantages of each. Dizziness is a common complaint of patients seen by general medical physicians and otolaryngologists. At the Otologic Medical Group in Los Angeles about one third of our new patients seek assistance because of dizziness. The etiologies of these various types of dizziness are multiple. It is not the intent of this paper to discuss the differential diagnosis or methods of evaluation. However, it is important to understand the various types of etiological factors as they are important in successful treatment. Conservation Surgery The various operations for the control of dizziness can be divided into three categories: (1) conservative, (2) destructive, and (3) neurosection. The conservative operations are performed in order to attempt to restore normal function to the ear, thus conserving its normal physiology. The destructive type of operations are those which cause a lesion in the balance and often affect the hearing apparatus. Neurosections are an attempt to selectively section the offending nerve in order to prevent the symptoms of dizziness. Presented at the 82nd Annual Convention of the National Medical Association, Los Angeles, California, August 1, 1977. Requests for reprints should be addressed to Dr. John W. House, The Otologic Medical Group and The Ear Research Institute, 2122 W 3rd Street, Los Angeles, CA 90057.
There have been many discussions over the years as to the exact etiology of Meniere's disease. Hallpike and Cairns' discuss the observations of pathologic temporal bones in cases of Meniere's syndrome. They describe the dilatation of the endolymphatic spaces. The exact reason for distention is not entirely clear. It appears to be related to either the overproduction of endolymph or its poor resorption. The resorption of endolymph occurs in the endolymphatic sac which is located adjacent to the posterior fossa dura. Portmann2 first described the surgical decompression of the endolymphatic sac in order to relieve patients of their recurrent vertigo. House,3 in 1962, described the endolymphatic drainage operation whereby a plastic tube is inserted into the endolymphatic
JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 70, NO. 4, 1978
sac. The contents are drained into the posterior subarachnoid space. This procedure is called the endolymphatic subarachnoid shunt operation. The advantage of this type of surgery is that it is an attempt to restore the ear to a more normal physiologic state. This is achieved by providing drainage of the excess endolymphatic fluid. In addition to controlling the vertigo, this operation may help to conserve hearing, and in some cases, improve it. House,4 in 1965, discusses the results of a group of 146 patients with Meniere's disease who underwent endolymphatic subarachnoid shunt surgery. The postoperative period varied from four months to four years. House found that the symptoms of vertigo had been totally relieved in 50 percent of cases. The patients' tinnitus had been relieved in 34 percent and hearing had been improved in about 12 percent. Further deterioration of hearing occurred in only ten percent of patients. Subsequent experience with the endolymphatic subarachnoid shunt has shown that about 60 percent of patients experience complete relief of the symptoms of episodic vertigo. About one half of the patients have stabilization of their hearing, while some experience improvement in hearing. Other conservative operations are also based on the theory of draining the excess endolymphatic fluid. These techniques include ultrasound applica247
tion to the promontory or horizontal semicircular canal and a cryosurgery, in which a freezing probe is applied to the promontory. Cryosurgery had been performed at the Otologic Medical Group up until about five years ago. This procedure was abandoned because of the tendency of recurrence of symptoms. House5 reported, in 1966, that initially about 70 percent of the patients undergoing cryosurgical treatment had relief of their vertigo. Subsequent experiences have indicated that these patients tend to have recurrent symptoms in time. Another drainage procedure is described by Fick.'; He advocates puncturing the saccule by a transfootplate approach. Fick describes using a sharp needle to pierce the dilated saccule in the vestibule. In the Fick procedure, a high percentage of the patients have relief of vertigo. However, about 80 percent suffer permanent hearing damage following the procedure. At the Otologic Medical Group, we use the Fick operation in patients who have previously undergone endolymphatic subarachnoid shunts and have failed to respond, or in those whose hearing is not salvageable, but who have continued episodes of vertigo. This operation is highly successful in eliminating vertigo in patients with Meniere's disease. It must be emphasized that these drainage operations work only in cases of vertigo caused by Meniere's disease and not in vertigo from other etiologies. It is difficult to generalize as to when a patient's hearing is not salvageable. This must be decided on an individual basis and carefully discussed with the patient. We prefer to use the endolymphatic subarachnoid shunt operation in cases of Meniere's disease when the hearing can be considered salvageable. The endolymphatic subarachnoid shunt operation is peformed under general anesthesia. The patient is in the hospital for three days following surgery. The operation is peformed through a postauricular incision where a complete mastoidectomy is performed. The endolymphatic sac is located adjacent to the posterior fossa dura of the mastoid. The sac is opened on its anterior surface, thus exposing the lumen following which the posterior surface is opened and a tube placed into the opening. The tube then enters the subarachnoid space of the cerebel248
lopontine angle and is secured in the lumen of the sac. A muscle plug is placed on top of the sac. Postoperatively, the patients generally feel well. They stay in the hospital for three days to be observed for possible fever or cerebrospinal fluid leak.
Destructive Procedures The most common destructive procedure is labyrinthectomy. The operation may be performed in one of several ways. The classical labyrinthectomy is performed through a transcanal approach whereby the eardrum is elevated, the stapes removed from the oval window, and the contents of the vestibule removed. This operation has been modified so that the ampule of the superior, lateral, and posterior canals are removed, in addition to the saccule and utricle. This is accomplished by opening widely the oval window with a small cutting burr. At the termintion of the procedure the vestibule is packed with gel-foam moistened with an ototoxic drug such as polymyxin-Bneomycin-hydrocortisone (Cortisporin). This is felt to help cause further destruction of the neuron. The operation is performed under local anesthesia and the patient generally leaves the hospital in one to two days. The operation results in a total hearing loss. This operation is generally reserved for those who have poor vestibular function as well as poor hearing. Other indications for surgery are patients who have constant unsteadiness due to a low-grade activity of a partially destroyed labyrinth. Occasionally, the classic transcanal labyrinthectomy does not completely relieve dizziness because of the regeneration of the vestibular nerves. At pathological sections of these cases a traumatic neuroma may form at the end of the cut vestibular nerve. For this reason, a transmastoid labyrinthectomy and sectioning of the vestibular nerves is often the best approach. In this operation a translabyrinthine approach to the internal auditory canal is created by postauricular incision. This operation is performed under general anesthesia. Both the superior and inferior vestibular nerves are sectioned proximal to Scarpa's ganglion. In this way, regeneration of the vestibular nerves does not occur. The vestibular nerves will then degenerate back to the vestibular nuclei in the brainstem. Pa-
tients are generally in the hospital for about one week after a translabyrinthine section of the vestibular nerves. The indications for this operation are persistent vertigo or dizziness in a person with a nonfunctional ear. This operation, also, will result in total hearing destruction. Unlike the endolymphatic shunt, or the other types of operations which have been previously discussed, this procedure is performed for dizziness of any etiology. Most commonly, patients who undergo this type of surgery have had some type of traumatic lesion to the vestibular apparatus as a result of head trauma, drug therapy, or previous surgical procedures.
Neurosection In 1961, House7 first described the surgical approach to the internal auditory canal through the middle fossa. This approach has revolutionized otologic surgery. It has allowed the otologic surgeon to approach the internal auditory canal without sacrificing hearing. It was originally described for decompression of the internal auditory canal and for the removal of small acoustic neuromas. Since that time, House8 has described this operation for selective section of the superior and inferior vestibular nerves. Occasionally, we see patients who have had some type of trauma or infection of the vestibular divisions of the 8th cranial nerve. These patients may have normal hearing, yet have a constant unsteadiness or recurrent dizziness associated with a reduced vestibular response in the affected ear. If these patients fail to respond to medical management, then surgical intervention is necessary. The ideal approach for this type of problem is through the middle cranial approach. In this approach, both the superior and inferior vestibular nerves are sectioned proximal to Scarpa's ganglion. In most cases, hearing can be preserved with a 90 percent chance of complete relief of dizziness or vertigo. In our hands, approximately six percent of patients undergoing this procedure will suffer some hearing loss as a result of manipulation of the internal auditory artery and vestibular nerves. This operation is performed under general anesthesia. An incision is made slightly anterior to the tragus and superior to the ear. A 2 x 2 inch piece
JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 70, NO. 4, 1978
of bone is removed from the area over the temporal lobe. The temporal lobe dura is then elevated off the floor of the middle cranial fossa. The internal auditory canal is located by identifying various landmarks. These landmarks include the greater superficial petrosal nerve, the superior semicircular canal, and the geniculate ganglion. When the geniculate ganglion is identified, the facial nerve is traced proximal to its entry into the lateral portion of the internal auditory canal. The internal auditory canal can then be opened widely, thus exposing the superior and inferior vestibular nerves. Careful identification and differentiation between the facial nerve and the superior vestibular nerve is imperative in order to avoid injury to the facial nerve. With selective sectioning of the superior vestibular nerve only, approximately 30 percent of patients will have a recurrence or persistence of their dizziness. For this reason, it is necessary to section both the superior and inferior nerves in order to offer the patient a greater opportunity of relief from dizziness.
Discussion
Conclusion
Many surgical procedures are now available for the relief of vertigo and dizziness. It is imperative that the patients undergo a complete otologic and neuro-otologic evaluation in order to determine the exact etiology of the dizziness. Tumors must be ruled out, as well as other otologic or neurologic problems. It is necessary that patients be tried on various medications, including tincture of time. As most physicians know, patients usually recover from their dizziness without specific treatment or with minimal supportive care. It is the rare patient who would require surgical intervention. Fortunately, those few problem patients who have persistent dizziness, unsteadiness, or recurrent vertigo can obtain relief through surgery. The type of procedure to be performed must be carefully determined by the otologist to maximize the best results and minimize complications or problems postoperatively. This situation must be thoroughly explained to the patient as to the advantages to be gained and the complications which may occur.
Vertigo usually responds to medical management. However, selected cases of vertigo can now be treated through various surgical means. In many cases hearing can be preserved, or even improved, with such surgery. The patient with recurrent vertigo or persistent dizziness can seek relief through surgical means. Literature Cited 1. Hallpike CS, Cairns H: Observations on the pathology of Meniere's syndrome. J Laryngol 53:625-655, 1938 2. Portmann G: Vertigo. Surgical treatment by opening the saccus endolymphaticus. Arch Otolaryngol 6:309-319, 1927 3. House WF: Subarachnoid shunt for drainage of endolymphatic hydrops: A preliminary report. Laryngoscope 72:713-729, 1962 4. House WF: Subarachnoid shunt for drainage of hydrops: A report of 146 cases. Laryngoscope 75:1547-1551, 1965 5. House WF: Cryosurgical treatment of Meniere's disease. Arch. Otolaryngol 84:616629, 1966 6. Fick IA: Decompression of the labyrinth. Arch Otolaryngol 79:447, 1964 7. House WF: Surgical exposure of the internal auditory canal and its contents through the middle cranial fossa. Laryngoscope 71:1363-1385, 1961 8. House WF: Middle cranial approach to the petrous pyramid: A report of 50 cases. Arch Otolaryngol 78:469, 1963
Conference on Credentialing of Health Manpower and the Public Interest Under the auspices of the National Health Council a conference on the above subject was held January 3031, 1978, at Stouffer's International Hotel Center, Arlington, Va, considered the implications of the report Credentialing Health Manpower released by the US Department of Health, Education, and Welfare in July 1977. The purpose of the Conference was to provide a forum for NHC member associations and other concerned organizations in the health field to consider the implications of the DHEW report and improve national dialog on communications among participating groups. JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 70, NO. 4, 1978
249
