The canalith repositioning procedure: For treatment of benign paroxysmal positional vertigo JOHN M. EPLEY, MD, Portland, Oregon
The Canalith Repositioning Procedure (CRP) is designed to treat benign paroxysmal positional vertigo (BPPV) through induced out-migration of free-moving pathological densities in the endolymph of a semicircular canal, using timed head maneuvers and applied vibration. This article describes the procedure and its rationale, and reports the results in 30 patients who exhibited the classic nystagmus of BPPV with Hallpike maneuvers. CRP obtained timely resolution of the nystagmus and positional vertigo in 100%. Of these, 10% continued to have atypical symptoms, suggesting concomitant pathology; 30% experienced one or more recurrences, but responded well to retreatment with CRP. These results also support an alternative theory that the densities that impart gravity-sensitivity to a semicircular canal in BPPV are free in the canal, rather than attached to the cupula. CRP offers significant advantages over invasive and other noninvasive treatment modalities in current use. (OTOLARYNGOL HEAD NECK SURG 1992;107:399.)
First described by Barany' in 1921, the entity of benign paroxysmal positional vertigo (BPPV) was more fully defined in 1952 by Dix and Hallpike.,' who originated the provocative test now generally referred to as the "Hallpike maneuver." This elicits a pathognomonic "classic" nystagmus characterized by: predominantly rotatory motion with the fast phase directed toward the undermost side, latency, limited duration, reversal on return to upright, and response decline on repetition of the provocative maneuver. Dix and Hallpike/ also localized the source of BPPV to the undermost ear in the Hallpike maneuver, leading the way to destructive surgical procedures. 3,4 These usually provided relief of symptoms, but involved significant risk and postoperative morbidity. Thus, there has been a search for an effective noninvasive treatment. McClure and Willett" found antivertiginous medications ineffective in controlling BPPY. Cawthorne" advocated "vestibular habituation therapy" (VHT), whereby patients assumed head positions that provoked the symptoms of vertigo, an approach primarily aimed at increasing their tolerance to the vertigo rather than eliminating its cause. Brandt and Daroff' described a more specific exercise, which purportedly dispersed
From the Portland Otologic Clinic. Received for publication Oct. 23, 1991; revision received Feb. 17, 1992; accepted March 5, 1992. Reprint requests: John M. Epley, MD, Portland Otologic Clinic, 545 N.E. 47th Ave., Suite 314, Portland, OR 97213.
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heavy debris within labyrinth. Toupet and Semont" developed a more aggressive approach termed the "liberatory maneuver," based on the theory that it freed the cupula of heavy debris. Norre and Beckers? reported only 52% of 23 BPPV patients treated with the liberatory maneuver were free of vertigo after 1 week, but Semont et al.'? claimed "positive results" in 92.68%. All of these methods, however, have significant drawbacks. VHT and other exercise treatments often extend for weeks and temporarily augment symptoms, causing patients to abandon treatment. An alternative of hospitalization with treatment under sedation is impractical. The violent character of the liberatory maneuver is of concern in a litigious society. Pathophysiologic mechanism of BPPV. In 1962, Schuknecht" presented what has become known as the "cupulolithiasis" or "heavy cupula" theory, which held that the posterior semicircular canal (PSC) is rendered sensitive to gravity by dense particles attached to or impinging on its cupula. II Whereas the PSC localization has been verified," the "heavy cupula" concept has been brought into question. Paramount are studies showing that when a heavy cupula is created by alcohol or deuterium ingestion,'>" the resulting nystagmus, in a particular head position, is sustained for long periods of time, rather than transient as in the classic nystagmus. An alternative explanation holds that at least some BPPV cases result from free-moving densities in the endolymph of the PSC. 14 , 15 This is strongly supported by the direct surgical observation by Pames and Mcf lure " of free densities, resembling accumulations
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of displaced otoconia, in the PSC of two BPPV patients. Other studies suggest that the differential density can also be created by a nonhomogenous layering of endolymph" or a single calcified mass." Treatment Based on Canalith Theory
The Canalith Repositioning Procedure (CRP) was developed in response to the need for a better-tolerated and more effective noninvasive treatment for BPPY. It is based on the premise that the transient nystagmus is exclusively caused by densities ("canaliths") moving freely in the endolymph of a semicircular canal. Incases with classic nystagmus, they would be in the segment of the PSC between the ampulla and the common crus. Cupular deflection, and the accompanying nystagmus and vertigo, is assumed to occur while these canaliths are gravitating longitudinally through the canal and creating a hydrodynamic drag sufficient to overcome cupular elasticity. CRP was instituted at the Portland Otologic Clinic (POC) in 1979 as the treatment of choice for BPPV, and has been applied to more than 200 patients. Moreover, the technique has been widely taught by the author":" since 1979 and is used routinely by a number of physicians and clinics. It has been modified since its inception, with subsequent improvement in results. Rationale. CRP was designed, with the use of head maneuvers and induced vibration, to cause free canaliths (postulated) to migrate by gravitation completely out of the PSC, by way of the common crus, to the utricle, where they no longer would affect the dynamics of the semicircular canals. The canal is rotated ampullopetally while its orientation is maintained co-planar with gravity, so that any canaliths present would move in the opposite direction. Optimally, this achievement would involve complete inversion of the patient's head using a suspension apparatus, but the procedure reported herein, designed for a simple examining table, has proved effective for most cases. Our laboratory tests indicated that the approximate distance heavy particles will gravitate in a curved, fluidfilled tube, held stationary and co-planar with gravity, is through that portion subtended by an angle of 90 degrees. Thus, each sequential position was designed to rotate the PSC through 90 degrees or less. Timing of these maneuvers is based on ongoing observation of the induced nystagmus, which reflects the direction and rate of induced canalith migration. An oscillating device is applied throughout the procedure to minimize adherence of the canaliths and decrease their angle of repose relative to the side walls of the semicircular canal.
METHODS
The present study selected all patients with the classic findings of BPPV and treated with CRP at the POC during the 30-month period from January I, 1988 to July I, 1990. (Two patients were excluded because their initial CRP had been done before this.) This resulted in a series of 30 patients, ranging in age from 31 to 82 years. They had undergone a thorough history and neurotologic examination, including (when indicated) electronically monitored tests of vestibular function. Procedure Preliminary. The target semicircular canal is predetermined by Hallpike maneuvers, and is the PSC of the undermost ear when classic nystagmus is provoked. The sum of the latency and duration of the induced nystagmus is also noted. This provides an estimate of the time required for the canalith bolus to gravitate through 90 degrees. Preparation. Patients are premedicated with a transdermal scopalamine patch the previous night, or 5 mg diazepam given orally I hour earlier. They are seated on an examining table (or treatment chair) so that when brought to the Hallpike position the head will extend beyond the end. The operator is located directly behind the patient, an assistant at the patient's side. Maneuvers. The 5-position cycle for treatment of BPPV with classic nystagmus is illustrated in Fig. 1. This is repeated until no nystagmus is observed during the last cycle, or until no progress is apparent in the last two cycles. If induced nystagmus is present as a result of a change from one position to the next, the slowing of this nystagmus is taken to indicate that the canalith bolus has neared the end of its descent, whereupon the head is maneuvered to the next position. Typical time in each position is 6 to 13 seconds. When nystagmus is not observed after a given position is achieved, timing is based on the last observed nystagmus duration, and the remainder of the positioning cycle is completed. This is done because canaliths may still be present in the target canal but temporarily too dispersed to elicit nystagmus. Whereas the induced rotatory nystagmus is minimally affected by visual fixation, direct observation is usually adequate for monitoring eye movement during the procedure. Vibration. A standard electromagnetic bone conduction vibrator driven by a square-wave generator at 700 Hz is applied to the ipsilateral mastoid area through at least one positioning cycle. Then, a hand-held vibrator (Oster, Model No. 126-11A) with a frequency of approximately 80 Hz is applied throughout at least
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"CD • '1,. dQ
@
\
Endolymphatic duct
Fig. 1. Positions for CRP, targeting left PSc. Dark figure, side view; boxes, operator's exposed view of left labyrinth, showing gravitating ccncliths. Semicircular canals are labeled. S (Start), Patient is seated, operator behind, oscillator applied, 1, Head is placed over the end of the table, 45 degrees to the left (canaliths gravitate to center of PSC]. 2, While head is kept tilted downward, it is rotated to 45 degrees right (canaliths reach common crus), 3, Head and body are rotated until facing downward 135 degrees from supine position (canaliths traverse common crus), 4, While head is kept turned right, patient is brought to sitting position (canaliths enter utricle), 5, Head is turned forward, chin down 20 degrees, General: Pause at each position until induced nystagmus approaches termination, or T sec (latency + duration) if no nystagmus, Keep repeating entire series (1 through 5) until no nystagmus any position.
one cycle. In some cases, the latter mode of vibration will momentarily reactivate the nystagmus, presumably indicating that adherent canaliths have been mobilized. Followup. After completion of a treatment session, patients are advised to keep their heads relatively upright for 48 hours so that loose debris will not gravitate back into the PSc. eRP is repeated as necessary at weekly intervals until vertigo symptoms have cleared and the Hallpike maneuver is negative.
RESULTS
Response to treatment was categorized as follows: I. All vertigo (and nystagmus) resolved. II. BPPV resolved, other vertigo remains: Free of positional vertigo and induced rotatory nystagmus, but nonpositional vertigo still present. III. Partially resolved: Positional vertigo symptoms significantly improved, though still present. IY. Same or worse: (none in this study). The results are documented in Table I and summarized
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Table 1. Patients with classical nystagmus of BPPV treated by the canalith repositioning procedure Case no.
Age (years)/sex
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
75/M 55/M 47/M 77/M 34/F 56/F 51/M 83/F 51/F 65/F 82/F 391M 77/M 80/F 26/F 63/F 69/M 69/M 37/F 26/F 63/M 59/F 40/M 371M 70/F 80/F 59/F 69/F 311M
47/M
Supposed etiology P Fistula E Hydrops Unknown Trauma Unknown Unknown Trauma Unknown Trauma Unknown P Fistula Unknown Trauma Trauma Unknown G Forces Unknown Unknown Unknown Unknown Trauma Unknown Unknown Unknown Trauma Unknown Unknown Unknown Trauma Unknown
Duration (mo.) 36.0 1.0 8.0 2.0 12.0 1.2 4.0 0.3
mOt 180.0 240 24.0 48.0 48.0 24.0 2.0 0.7 60.0 1.5 8.0 240 0.5 4.0 0.3 48.0 48.0 24.0 5.0 48.0 48.0
Side/treatments' L 1 L2 L 1 L 1 R1 R1 R1 L5 R1 R1 R1 L2 L 1 R1 L 1 L 1 L2 R1 L 1 L 1 R1 R1 R1 L2 L 1 R1 R1 R1 R2 R1
Initial resultt
Time til recurrence (mo.) (repeat C~P result) 4(11)
4(1)
1(1),6(1) 8(1) 9(111)
2(1) 10(1),4(1),4(1),8(1)
4(1),3(1) 2(1)
"Number of weekly treatment sessions required to obtain initial result. tSee text.
in Table 2. Recurrences are shown in the last column of Table 1, with the time in months since the previous CRP treatment, and the results of retreatment. A recurrence is defined as renewed symptoms after an asymptomatic month. Note that after initial treatment, all results were in category I or II, representing resolution of the classic BPPV symptoms and nystagmus. BPPV recurred at least once in nine (30%) patients. Of 14 CRP treatments for recurrence, only one did not have a category I or II resolution. Thus, 43 (97.7%) of 44 courses of treatment with CRP resulted in resolution of BPPY. One patient (case 25) experienced four recurrences, and surgery was offered as an option but not accepted. No patients treated with CRP in this series (or since 1979 at the POC) have been permanently worse or had any long-term complications. However, early experience indicated that significant nausea could be temporarily generated by the procedure. This was effec-
tively controlled by antivertiginous pre-medication in the present series. The time course and direction of the observed nystagmus during CRP maneuvers were generally consistent with the assumed movement of canaliths in a semicircular canal. CASE REPORT
This 55-year-old metal worker (case 3) reported a continuous propensityfor vertigoprovokedby positionchange since an exercise class 8 months earlier. There was no history of head injury or previous dizziness. He had consulted a neurologist who, in view of a negative MRI and his failure to improve with transdermal scopalamine and vestibular exercises, referred him to the POc. Ear examination was negative. Frenzel's glasses examination revealed no gaze or spontaneous nystagmus. Hearing was normalexcept for a 3000Hz dip on the left. The Romberg (eyes-closed) and Hennebert tests were negative. The right Hallpike maneuver produced, after a latency of 5 seconds,
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Table 2. Results in 30 patients during 3D-month period Result category I. Ail vertigo resolved
Initial treatment result
Recurrence retreatment results
27 (90%)
12 (85.7%)
3 (10%)
1 (7.1%) 1 (7.1%)
All treatment results 39 (88.6%) } 97.7%*
II. BPPV resolved/Other Remains III. Partially resolved IV. Same or worse Total treatment courses TOTAL PATIENTS
*Category I
+
o
4 (91%) 1 (2.3%)
o
...Q
...Q
30 30
14 9
44 (100%) 30
II = resolution ot BPPV.
severe counter-clockwise rotatory nystagmus of IS-second duration, accompanied by intense vertigo. He had reversal of nystagmus on return to upright, and response decline on repeated positioning. The left Hallpike maneuver was negative. CRP was carried out on February 1, 1989, addressing the right PSc. Immediately after the procedure he reported no dizziness or nausea. At followup 10 days later he reported complete freedom from vertigo since the CRP treatment, and Hallpike maneuvers generated neither nystagmus nor subjective symptoms. When contacted more than 2 years later, he reported continued freedom from vertigo.
DISCUSSION
The question of a subjective placebo effect after CRP was ruled out in this study by the requirement that resolution of BPPV be confirmed in each case by objectively negative Hallpike maneuvers. This was considered essential because of our observation that BPPV patients typically learn to avoid the provocative position, and may continue to do so habitually long after apparent remission. Thus, they may claim resolution because their symptoms are improved, yet demonstrate typical nystagmus when tested with the Hallpike maneuver. Inasmuch as BPPV often undergoes spontaneous remission, it was also necessary to demonstrate that resolution after CRP had not been merely fortuitous. This was accomplished by virtue of the rapid elimination of both symptoms and nystagmus in a large number of cases despite months or years of previous continuous proclivity to positional vertigo. Thus, 24 (80.0%) were cleared of vertigo and nystagmus immediately after the initial procedure; 19 of these had experienced symptoms for 4 months or more before initial treatment, and 14 had previous symptoms for 1 year or more. Thus, these patients had acted as their own controls during the symptomatic period before treatment. Comparing the results of this study with those of Norre and Beckers" for either VHT or the liberatory
maneuver, CRP is the superior method of treatment. In addition, CRP avoids violent manipulation, prolonged sedation, or active participation of the patient. Those with category II results were deemed to have concomitant vestibular pathology, and CRP served to simplify a complicated clinical picture. Recurrence. The recurrence rate noted in this series may represent an aberration on the high side, inasmuch as only two of the approximately 150 patients treated with CRP during the previous 8-year period returned for treatment during the 30-month period of the study. Because CRP is a low-risk, low-morbidity procedure, the possibility of recurrence does not significantly degrade its value. Recommendation for surgery. Attesting to the effectiveness of CRP is the fact that, during the 2 years before its introduction in 1979 at the POC, 11 of 23 patients diagnosed with BPPV underwent singular neurectomy. During the 30-month period of this study, no surgery was done for BPPV on any of the 30 patients, although it was offered in case 25. Generally, the decision to elect surgery is reached not because of short-term CRP failure, but because of the disability that can result from multiple, unpredictable recurrences over the long term. Although singular neurectomy has been the surgery of choice in the past, the PSC occlusion procedure of Parnes and McClure,21 or as modified by Anthony, 22 theoretically promises less morbidity and risk. Support for the canalith hypothesis. Although it cannot be directly shown that CRP acts through actually mobilizing canaliths out of the semicircular canal as envisioned, the fact that carrying out a procedure designed with that objective has proved very effective in control of BPPV lends support to this premise. In addition, observations during CRP of the induced nystagmatic response have been consistent with this assumption. The limited success of other noninvasive treatment modalities may be explained by their probable gradual dispersion of canaliths within the semicircular
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canal without their effective elimination from the canal. The highly consistent short-term results with CRP in this study suggest that the classic clinical characteristics of BPPV are exclusively caused by densities that are free in the semicircular canal, in contradiction to the "heavy cupula" concept. If similar results are achieved by others, the pathophysiologic condition causing BPPV would be more appropriately termed canalithiasis. Suboptimal technique. CRP requires critical judgements based on ongoing observations and knowledge of the pathophysiology. Its attempted deployment with less than optimal technique may result in a lower rate of resolution than reported here. However, if there is a contraindication, such as perilymph fistula or retinal detachment, to the application of vibration, the maneuvers alone can be sufficiently effective to warrant a trial. Refinements in technique and apparatus are planned at the POC, directed at reducing recurrence and managing patients who tolerate the maneuvers poorly for physical reasons. CONCLUSION
CRP should be the initial procedure of choice for treatment of BPPY. It is cost-effective and provides timely resolution in a high percentage of cases. The morbidity and stress to the patient are minimized, and surgery is usually obviated. In those patients who may experience later recurrence, this benign procedure can be repeated as necessary. REFERENCES I. Barany R, cited by Dix R, Hallpike CS. Diagnose von Krankheitserscheinungen im Bereiche des Otolithenapparates. Acta Otolaryngol 1921;2:434-7. 2. Dix R, Hallpike CS. The pathology, symptomatology, and diagnosis of certain common disorders of the vestibular system. Proc R Soc Med 1952;54:341-54. 3. Schuknecht HF. Positional vertigo: clinical and experimental observations. Trans Am Acad Ophthalmol Otolaryngol 1962;66:319-32.
4. Gacek R. Transection of the posterior ampullary nerve for the relief of benign paroxysmal positional nystagmus. Ann Otol Rhinol Laryngol 1974;83:596-605. 5. McClure lA, Willett 1M. Lorazepam and diazepam in the treatment of benign paroxysmal vertigo. 1 Otolaryngol 1980;9: 472-7. 6. Cawthorne T. The physiologic basis for head exercises. 1 Chart Soc Physiother 1944;30:106-7. 7. Brandt T, Daroff RB. Physical therapy for benign paroxysmal positional vertigo. Arch Otolaryngol 1980;106:484-5. 8. Toupet M, Semont A. La physiotherapie du vertige paroxystique benin. In: Hausler R, ed. Les vertige d'origine peripherique et centrale. Paris: Ipsen, 1985:21'-7. 9. Nom: ME, Beckers A. Exercise treatment for paroxysmal positional vertigo: comparison of two types of exercises. Arch Otolaryngol 1987;244:291-4. 10. Semont A, Freyss G, Vitte E. Curing the BPPV with a liberatory maneuver. Adv Otorhinolaryngol 1988;42:290-3. II. Schuknecht HF, Ruby RF. Cupulolithiasis. Adv Otorhinolaryngol 1973;20:434-43. 12. Money KE, Johnson WH, Carlett BA. Role of semicircular canals in positional alcohol nystagmus. Am 1 Physiol 1970;208: 1065-70. 13. Money KE, Myles WS. Heavy water nystagmus and effects of alcohol. Nature 1974;247:404-5. 14. Hall SF, Ruby RRF, McClure lA. The mechanics of benign paroxysmal vertigo. 10tolaryngol 1979;8:151-8. 15. Epley 1M. New dimensions of benign paroxysmal positional vertigo. OTOLARYNGOL HEAD NECK SURG 1980;88:599-605. 16. Parnes LS, McClure lA. Free-floating endolymph particles: a new operative finding during posterior canal occlusion. Presented at the Meeting of the Eastern Section of the American Laryngological, Rhinological, and Otological Society, Philadelphia, Pa., Feb. 1991. 17. McClure lA. Horizontal canal BPY. 1 Otolaryngol 1985;14: 30-5. 18. Vyslonzil E. Uber eine umschriebene anasmmlung von Otokien in hinteren hautigen Bogengange. Monatsschr Ohrenheilkd 1963;97:63. 19. Epley 1M, Hughes DW. Positional vertigo: new methods of diagnosis and treatment. Instruction Course. Annual Meeting of the American Academy of Otolaryngology-Head and Neck Surgery, 1980. 20. Epley 1M. Inner ear surgery course. Colorado Otologic Research Center, 1983. 21. Parnes LS, McClure lA. Posterior semicircular canal occlusion in the normal ear. OTOLARYNGOL HEAD NECK SURG 1991;104: 52-7. 22. Anthony PF. Partitioning of the labyrinth: Application in benign paroxysmal positional vertigo. Am 1 Otol 1991;12:388-93.
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News and Announcements
held July 26-30, 1993, at the Tamarron Resort in Durango, Colorado. This 28 hour review and update will encompass all the clinically important areas of MR imaging. Important new concepts and pathological/imaging correlations in the body, musculoskeletal system, ENT, head and neck, brain, and spine will be explored. Daily case presentations will supplement these lectures and will serve to test the registrants' diagnostic abilities in MR imaging. This complete review of MR imaging will be presented by nationally recognized leaders in magnetic resonance imaging. As a result of this comprehensive review, registrants will become familiar with current applications of MR imaging and will be able to integrate many of these applications directly into their practice. Program chairmen for this presentation will be Robert Quencer, MD (University of Miami), Victor Haughton, MD (Medical College of Wisconsin). Twenty-eight credits of Category I will be available. For further information, please contact Marti Carter, CME, Inc., 11011 West Nort Ave., Milwaukee, Wisconsin 53226, or call (414) 771-9520. Ear, Nose, and Throat Diseases: 1993 Update
Children's Hospital of Pittsburgh will hold its 18th Annual Symposium, "Ear, Nose, and Throat Diseases in Children: A 1993 Update." This symposium will be held July 30-31, 1993. CME credits will be awarded.
For further information, please contact the Department of Pediatric Otolaryngology, Children's Hospital of Pittsburgh, 3705 Fifth Avenue at DeSoto St., Pittsburgh, Pennsylvania 15213, or call (412) 692-8577. Twenty-fifth Annual Meeting - Head and Neck Oncologists
The Association of Head and Neck Oncologists of Great Britain will sponsor the Twenty-fifth Annual Meeting of Head and Neck Oncology, to be held in Edinburgh, Scotland, United Kingdom, on August 23-26, 1993. International and local faculty will present extensive social and family programs. For further information, please contact Mr. P. J. Bradley, Honorary Secretary, Department of Otorhinolaryngology-Head and Neck Surgery, University Hospital, Queens Medical Centre, Nottingham, NG7 2UH, England, or phone 0602421421. Sixth International Congress on Interventlonal Ultrasound
The Sixth International Congress on Interventional Ultrasound will be held in Copenhagen, Denmark, on September 7-10, 1993. For further information, please contact Christian Nolsoe, Congress Secretary, Department of Ultrasound, Herlev Hospital, University of Copenhagen, DK-2730 HerlevDenmark, or call + 45/ 44 53 53 00 ext. 3240.
CORRECTION
The Supplement to the December 1992 issue of the JOURNAL (Volume 107, Number 6, Part 2), incorrectly listed Dr. Bruce R. Gordon as Chief of Otolaryngology at the Massachusetts Eye and Ear Institute. Dr. Joseph Nadol is Chief of Otolaryngology at the Massachusetts Eye and Ear Infirmary. Dr. Gordon is Chief of Otolaryngology at Cape Cod Hospital.
The Canalith Repositioning Procedure (CRP) is designed to treat benign paroxysmal positional vertigo (BPPV) through induced out-migration of free-moving pathological densities in the endolymph of a semicircular canal, using timed head maneuvers and applied vibration. This article describes the procedure and its rationale, and reports the results in 30 patients who exhibited the classic nystagmus of BPPV with Hallpike maneuvers. CRP obtained timely resolution of the nystagmus and positional vertigo in 100%. Of these, 10% continued to have atypical symptoms, suggesting concomitant pathology; 30% experienced one or more recurrences, but responded well to retreatment with CRP. These results also support an alternative theory that the densities that impart gravity-sensitivity to a semicircular canal in BPPV are free in the canal, rather than attached to the cupula. CRP offers significant advantages over invasive and other noninvasive treatment modalities in current use. (OTOLARYNGOL HEAD NECK SURG 1992;107:399.)
First described by Barany' in 1921, the entity of benign paroxysmal positional vertigo (BPPV) was more fully defined in 1952 by Dix and Hallpike.,' who originated the provocative test now generally referred to as the "Hallpike maneuver." This elicits a pathognomonic "classic" nystagmus characterized by: predominantly rotatory motion with the fast phase directed toward the undermost side, latency, limited duration, reversal on return to upright, and response decline on repetition of the provocative maneuver. Dix and Hallpike/ also localized the source of BPPV to the undermost ear in the Hallpike maneuver, leading the way to destructive surgical procedures. 3,4 These usually provided relief of symptoms, but involved significant risk and postoperative morbidity. Thus, there has been a search for an effective noninvasive treatment. McClure and Willett" found antivertiginous medications ineffective in controlling BPPY. Cawthorne" advocated "vestibular habituation therapy" (VHT), whereby patients assumed head positions that provoked the symptoms of vertigo, an approach primarily aimed at increasing their tolerance to the vertigo rather than eliminating its cause. Brandt and Daroff' described a more specific exercise, which purportedly dispersed
From the Portland Otologic Clinic. Received for publication Oct. 23, 1991; revision received Feb. 17, 1992; accepted March 5, 1992. Reprint requests: John M. Epley, MD, Portland Otologic Clinic, 545 N.E. 47th Ave., Suite 314, Portland, OR 97213.
23/1/37658
heavy debris within labyrinth. Toupet and Semont" developed a more aggressive approach termed the "liberatory maneuver," based on the theory that it freed the cupula of heavy debris. Norre and Beckers? reported only 52% of 23 BPPV patients treated with the liberatory maneuver were free of vertigo after 1 week, but Semont et al.'? claimed "positive results" in 92.68%. All of these methods, however, have significant drawbacks. VHT and other exercise treatments often extend for weeks and temporarily augment symptoms, causing patients to abandon treatment. An alternative of hospitalization with treatment under sedation is impractical. The violent character of the liberatory maneuver is of concern in a litigious society. Pathophysiologic mechanism of BPPV. In 1962, Schuknecht" presented what has become known as the "cupulolithiasis" or "heavy cupula" theory, which held that the posterior semicircular canal (PSC) is rendered sensitive to gravity by dense particles attached to or impinging on its cupula. II Whereas the PSC localization has been verified," the "heavy cupula" concept has been brought into question. Paramount are studies showing that when a heavy cupula is created by alcohol or deuterium ingestion,'>" the resulting nystagmus, in a particular head position, is sustained for long periods of time, rather than transient as in the classic nystagmus. An alternative explanation holds that at least some BPPV cases result from free-moving densities in the endolymph of the PSC. 14 , 15 This is strongly supported by the direct surgical observation by Pames and Mcf lure " of free densities, resembling accumulations
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of displaced otoconia, in the PSC of two BPPV patients. Other studies suggest that the differential density can also be created by a nonhomogenous layering of endolymph" or a single calcified mass." Treatment Based on Canalith Theory
The Canalith Repositioning Procedure (CRP) was developed in response to the need for a better-tolerated and more effective noninvasive treatment for BPPY. It is based on the premise that the transient nystagmus is exclusively caused by densities ("canaliths") moving freely in the endolymph of a semicircular canal. Incases with classic nystagmus, they would be in the segment of the PSC between the ampulla and the common crus. Cupular deflection, and the accompanying nystagmus and vertigo, is assumed to occur while these canaliths are gravitating longitudinally through the canal and creating a hydrodynamic drag sufficient to overcome cupular elasticity. CRP was instituted at the Portland Otologic Clinic (POC) in 1979 as the treatment of choice for BPPV, and has been applied to more than 200 patients. Moreover, the technique has been widely taught by the author":" since 1979 and is used routinely by a number of physicians and clinics. It has been modified since its inception, with subsequent improvement in results. Rationale. CRP was designed, with the use of head maneuvers and induced vibration, to cause free canaliths (postulated) to migrate by gravitation completely out of the PSC, by way of the common crus, to the utricle, where they no longer would affect the dynamics of the semicircular canals. The canal is rotated ampullopetally while its orientation is maintained co-planar with gravity, so that any canaliths present would move in the opposite direction. Optimally, this achievement would involve complete inversion of the patient's head using a suspension apparatus, but the procedure reported herein, designed for a simple examining table, has proved effective for most cases. Our laboratory tests indicated that the approximate distance heavy particles will gravitate in a curved, fluidfilled tube, held stationary and co-planar with gravity, is through that portion subtended by an angle of 90 degrees. Thus, each sequential position was designed to rotate the PSC through 90 degrees or less. Timing of these maneuvers is based on ongoing observation of the induced nystagmus, which reflects the direction and rate of induced canalith migration. An oscillating device is applied throughout the procedure to minimize adherence of the canaliths and decrease their angle of repose relative to the side walls of the semicircular canal.
METHODS
The present study selected all patients with the classic findings of BPPV and treated with CRP at the POC during the 30-month period from January I, 1988 to July I, 1990. (Two patients were excluded because their initial CRP had been done before this.) This resulted in a series of 30 patients, ranging in age from 31 to 82 years. They had undergone a thorough history and neurotologic examination, including (when indicated) electronically monitored tests of vestibular function. Procedure Preliminary. The target semicircular canal is predetermined by Hallpike maneuvers, and is the PSC of the undermost ear when classic nystagmus is provoked. The sum of the latency and duration of the induced nystagmus is also noted. This provides an estimate of the time required for the canalith bolus to gravitate through 90 degrees. Preparation. Patients are premedicated with a transdermal scopalamine patch the previous night, or 5 mg diazepam given orally I hour earlier. They are seated on an examining table (or treatment chair) so that when brought to the Hallpike position the head will extend beyond the end. The operator is located directly behind the patient, an assistant at the patient's side. Maneuvers. The 5-position cycle for treatment of BPPV with classic nystagmus is illustrated in Fig. 1. This is repeated until no nystagmus is observed during the last cycle, or until no progress is apparent in the last two cycles. If induced nystagmus is present as a result of a change from one position to the next, the slowing of this nystagmus is taken to indicate that the canalith bolus has neared the end of its descent, whereupon the head is maneuvered to the next position. Typical time in each position is 6 to 13 seconds. When nystagmus is not observed after a given position is achieved, timing is based on the last observed nystagmus duration, and the remainder of the positioning cycle is completed. This is done because canaliths may still be present in the target canal but temporarily too dispersed to elicit nystagmus. Whereas the induced rotatory nystagmus is minimally affected by visual fixation, direct observation is usually adequate for monitoring eye movement during the procedure. Vibration. A standard electromagnetic bone conduction vibrator driven by a square-wave generator at 700 Hz is applied to the ipsilateral mastoid area through at least one positioning cycle. Then, a hand-held vibrator (Oster, Model No. 126-11A) with a frequency of approximately 80 Hz is applied throughout at least
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"CD • '1,. dQ
@
\
Endolymphatic duct
Fig. 1. Positions for CRP, targeting left PSc. Dark figure, side view; boxes, operator's exposed view of left labyrinth, showing gravitating ccncliths. Semicircular canals are labeled. S (Start), Patient is seated, operator behind, oscillator applied, 1, Head is placed over the end of the table, 45 degrees to the left (canaliths gravitate to center of PSC]. 2, While head is kept tilted downward, it is rotated to 45 degrees right (canaliths reach common crus), 3, Head and body are rotated until facing downward 135 degrees from supine position (canaliths traverse common crus), 4, While head is kept turned right, patient is brought to sitting position (canaliths enter utricle), 5, Head is turned forward, chin down 20 degrees, General: Pause at each position until induced nystagmus approaches termination, or T sec (latency + duration) if no nystagmus, Keep repeating entire series (1 through 5) until no nystagmus any position.
one cycle. In some cases, the latter mode of vibration will momentarily reactivate the nystagmus, presumably indicating that adherent canaliths have been mobilized. Followup. After completion of a treatment session, patients are advised to keep their heads relatively upright for 48 hours so that loose debris will not gravitate back into the PSc. eRP is repeated as necessary at weekly intervals until vertigo symptoms have cleared and the Hallpike maneuver is negative.
RESULTS
Response to treatment was categorized as follows: I. All vertigo (and nystagmus) resolved. II. BPPV resolved, other vertigo remains: Free of positional vertigo and induced rotatory nystagmus, but nonpositional vertigo still present. III. Partially resolved: Positional vertigo symptoms significantly improved, though still present. IY. Same or worse: (none in this study). The results are documented in Table I and summarized
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Table 1. Patients with classical nystagmus of BPPV treated by the canalith repositioning procedure Case no.
Age (years)/sex
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
75/M 55/M 47/M 77/M 34/F 56/F 51/M 83/F 51/F 65/F 82/F 391M 77/M 80/F 26/F 63/F 69/M 69/M 37/F 26/F 63/M 59/F 40/M 371M 70/F 80/F 59/F 69/F 311M
47/M
Supposed etiology P Fistula E Hydrops Unknown Trauma Unknown Unknown Trauma Unknown Trauma Unknown P Fistula Unknown Trauma Trauma Unknown G Forces Unknown Unknown Unknown Unknown Trauma Unknown Unknown Unknown Trauma Unknown Unknown Unknown Trauma Unknown
Duration (mo.) 36.0 1.0 8.0 2.0 12.0 1.2 4.0 0.3
mOt 180.0 240 24.0 48.0 48.0 24.0 2.0 0.7 60.0 1.5 8.0 240 0.5 4.0 0.3 48.0 48.0 24.0 5.0 48.0 48.0
Side/treatments' L 1 L2 L 1 L 1 R1 R1 R1 L5 R1 R1 R1 L2 L 1 R1 L 1 L 1 L2 R1 L 1 L 1 R1 R1 R1 L2 L 1 R1 R1 R1 R2 R1
Initial resultt
Time til recurrence (mo.) (repeat C~P result) 4(11)
4(1)
1(1),6(1) 8(1) 9(111)
2(1) 10(1),4(1),4(1),8(1)
4(1),3(1) 2(1)
"Number of weekly treatment sessions required to obtain initial result. tSee text.
in Table 2. Recurrences are shown in the last column of Table 1, with the time in months since the previous CRP treatment, and the results of retreatment. A recurrence is defined as renewed symptoms after an asymptomatic month. Note that after initial treatment, all results were in category I or II, representing resolution of the classic BPPV symptoms and nystagmus. BPPV recurred at least once in nine (30%) patients. Of 14 CRP treatments for recurrence, only one did not have a category I or II resolution. Thus, 43 (97.7%) of 44 courses of treatment with CRP resulted in resolution of BPPY. One patient (case 25) experienced four recurrences, and surgery was offered as an option but not accepted. No patients treated with CRP in this series (or since 1979 at the POC) have been permanently worse or had any long-term complications. However, early experience indicated that significant nausea could be temporarily generated by the procedure. This was effec-
tively controlled by antivertiginous pre-medication in the present series. The time course and direction of the observed nystagmus during CRP maneuvers were generally consistent with the assumed movement of canaliths in a semicircular canal. CASE REPORT
This 55-year-old metal worker (case 3) reported a continuous propensityfor vertigoprovokedby positionchange since an exercise class 8 months earlier. There was no history of head injury or previous dizziness. He had consulted a neurologist who, in view of a negative MRI and his failure to improve with transdermal scopalamine and vestibular exercises, referred him to the POc. Ear examination was negative. Frenzel's glasses examination revealed no gaze or spontaneous nystagmus. Hearing was normalexcept for a 3000Hz dip on the left. The Romberg (eyes-closed) and Hennebert tests were negative. The right Hallpike maneuver produced, after a latency of 5 seconds,
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Table 2. Results in 30 patients during 3D-month period Result category I. Ail vertigo resolved
Initial treatment result
Recurrence retreatment results
27 (90%)
12 (85.7%)
3 (10%)
1 (7.1%) 1 (7.1%)
All treatment results 39 (88.6%) } 97.7%*
II. BPPV resolved/Other Remains III. Partially resolved IV. Same or worse Total treatment courses TOTAL PATIENTS
*Category I
+
o
4 (91%) 1 (2.3%)
o
...Q
...Q
30 30
14 9
44 (100%) 30
II = resolution ot BPPV.
severe counter-clockwise rotatory nystagmus of IS-second duration, accompanied by intense vertigo. He had reversal of nystagmus on return to upright, and response decline on repeated positioning. The left Hallpike maneuver was negative. CRP was carried out on February 1, 1989, addressing the right PSc. Immediately after the procedure he reported no dizziness or nausea. At followup 10 days later he reported complete freedom from vertigo since the CRP treatment, and Hallpike maneuvers generated neither nystagmus nor subjective symptoms. When contacted more than 2 years later, he reported continued freedom from vertigo.
DISCUSSION
The question of a subjective placebo effect after CRP was ruled out in this study by the requirement that resolution of BPPV be confirmed in each case by objectively negative Hallpike maneuvers. This was considered essential because of our observation that BPPV patients typically learn to avoid the provocative position, and may continue to do so habitually long after apparent remission. Thus, they may claim resolution because their symptoms are improved, yet demonstrate typical nystagmus when tested with the Hallpike maneuver. Inasmuch as BPPV often undergoes spontaneous remission, it was also necessary to demonstrate that resolution after CRP had not been merely fortuitous. This was accomplished by virtue of the rapid elimination of both symptoms and nystagmus in a large number of cases despite months or years of previous continuous proclivity to positional vertigo. Thus, 24 (80.0%) were cleared of vertigo and nystagmus immediately after the initial procedure; 19 of these had experienced symptoms for 4 months or more before initial treatment, and 14 had previous symptoms for 1 year or more. Thus, these patients had acted as their own controls during the symptomatic period before treatment. Comparing the results of this study with those of Norre and Beckers" for either VHT or the liberatory
maneuver, CRP is the superior method of treatment. In addition, CRP avoids violent manipulation, prolonged sedation, or active participation of the patient. Those with category II results were deemed to have concomitant vestibular pathology, and CRP served to simplify a complicated clinical picture. Recurrence. The recurrence rate noted in this series may represent an aberration on the high side, inasmuch as only two of the approximately 150 patients treated with CRP during the previous 8-year period returned for treatment during the 30-month period of the study. Because CRP is a low-risk, low-morbidity procedure, the possibility of recurrence does not significantly degrade its value. Recommendation for surgery. Attesting to the effectiveness of CRP is the fact that, during the 2 years before its introduction in 1979 at the POC, 11 of 23 patients diagnosed with BPPV underwent singular neurectomy. During the 30-month period of this study, no surgery was done for BPPV on any of the 30 patients, although it was offered in case 25. Generally, the decision to elect surgery is reached not because of short-term CRP failure, but because of the disability that can result from multiple, unpredictable recurrences over the long term. Although singular neurectomy has been the surgery of choice in the past, the PSC occlusion procedure of Parnes and McClure,21 or as modified by Anthony, 22 theoretically promises less morbidity and risk. Support for the canalith hypothesis. Although it cannot be directly shown that CRP acts through actually mobilizing canaliths out of the semicircular canal as envisioned, the fact that carrying out a procedure designed with that objective has proved very effective in control of BPPV lends support to this premise. In addition, observations during CRP of the induced nystagmatic response have been consistent with this assumption. The limited success of other noninvasive treatment modalities may be explained by their probable gradual dispersion of canaliths within the semicircular
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canal without their effective elimination from the canal. The highly consistent short-term results with CRP in this study suggest that the classic clinical characteristics of BPPV are exclusively caused by densities that are free in the semicircular canal, in contradiction to the "heavy cupula" concept. If similar results are achieved by others, the pathophysiologic condition causing BPPV would be more appropriately termed canalithiasis. Suboptimal technique. CRP requires critical judgements based on ongoing observations and knowledge of the pathophysiology. Its attempted deployment with less than optimal technique may result in a lower rate of resolution than reported here. However, if there is a contraindication, such as perilymph fistula or retinal detachment, to the application of vibration, the maneuvers alone can be sufficiently effective to warrant a trial. Refinements in technique and apparatus are planned at the POC, directed at reducing recurrence and managing patients who tolerate the maneuvers poorly for physical reasons. CONCLUSION
CRP should be the initial procedure of choice for treatment of BPPY. It is cost-effective and provides timely resolution in a high percentage of cases. The morbidity and stress to the patient are minimized, and surgery is usually obviated. In those patients who may experience later recurrence, this benign procedure can be repeated as necessary. REFERENCES I. Barany R, cited by Dix R, Hallpike CS. Diagnose von Krankheitserscheinungen im Bereiche des Otolithenapparates. Acta Otolaryngol 1921;2:434-7. 2. Dix R, Hallpike CS. The pathology, symptomatology, and diagnosis of certain common disorders of the vestibular system. Proc R Soc Med 1952;54:341-54. 3. Schuknecht HF. Positional vertigo: clinical and experimental observations. Trans Am Acad Ophthalmol Otolaryngol 1962;66:319-32.
4. Gacek R. Transection of the posterior ampullary nerve for the relief of benign paroxysmal positional nystagmus. Ann Otol Rhinol Laryngol 1974;83:596-605. 5. McClure lA, Willett 1M. Lorazepam and diazepam in the treatment of benign paroxysmal vertigo. 1 Otolaryngol 1980;9: 472-7. 6. Cawthorne T. The physiologic basis for head exercises. 1 Chart Soc Physiother 1944;30:106-7. 7. Brandt T, Daroff RB. Physical therapy for benign paroxysmal positional vertigo. Arch Otolaryngol 1980;106:484-5. 8. Toupet M, Semont A. La physiotherapie du vertige paroxystique benin. In: Hausler R, ed. Les vertige d'origine peripherique et centrale. Paris: Ipsen, 1985:21'-7. 9. Nom: ME, Beckers A. Exercise treatment for paroxysmal positional vertigo: comparison of two types of exercises. Arch Otolaryngol 1987;244:291-4. 10. Semont A, Freyss G, Vitte E. Curing the BPPV with a liberatory maneuver. Adv Otorhinolaryngol 1988;42:290-3. II. Schuknecht HF, Ruby RF. Cupulolithiasis. Adv Otorhinolaryngol 1973;20:434-43. 12. Money KE, Johnson WH, Carlett BA. Role of semicircular canals in positional alcohol nystagmus. Am 1 Physiol 1970;208: 1065-70. 13. Money KE, Myles WS. Heavy water nystagmus and effects of alcohol. Nature 1974;247:404-5. 14. Hall SF, Ruby RRF, McClure lA. The mechanics of benign paroxysmal vertigo. 10tolaryngol 1979;8:151-8. 15. Epley 1M. New dimensions of benign paroxysmal positional vertigo. OTOLARYNGOL HEAD NECK SURG 1980;88:599-605. 16. Parnes LS, McClure lA. Free-floating endolymph particles: a new operative finding during posterior canal occlusion. Presented at the Meeting of the Eastern Section of the American Laryngological, Rhinological, and Otological Society, Philadelphia, Pa., Feb. 1991. 17. McClure lA. Horizontal canal BPY. 1 Otolaryngol 1985;14: 30-5. 18. Vyslonzil E. Uber eine umschriebene anasmmlung von Otokien in hinteren hautigen Bogengange. Monatsschr Ohrenheilkd 1963;97:63. 19. Epley 1M, Hughes DW. Positional vertigo: new methods of diagnosis and treatment. Instruction Course. Annual Meeting of the American Academy of Otolaryngology-Head and Neck Surgery, 1980. 20. Epley 1M. Inner ear surgery course. Colorado Otologic Research Center, 1983. 21. Parnes LS, McClure lA. Posterior semicircular canal occlusion in the normal ear. OTOLARYNGOL HEAD NECK SURG 1991;104: 52-7. 22. Anthony PF. Partitioning of the labyrinth: Application in benign paroxysmal positional vertigo. Am 1 Otol 1991;12:388-93.
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News and Announcements
held July 26-30, 1993, at the Tamarron Resort in Durango, Colorado. This 28 hour review and update will encompass all the clinically important areas of MR imaging. Important new concepts and pathological/imaging correlations in the body, musculoskeletal system, ENT, head and neck, brain, and spine will be explored. Daily case presentations will supplement these lectures and will serve to test the registrants' diagnostic abilities in MR imaging. This complete review of MR imaging will be presented by nationally recognized leaders in magnetic resonance imaging. As a result of this comprehensive review, registrants will become familiar with current applications of MR imaging and will be able to integrate many of these applications directly into their practice. Program chairmen for this presentation will be Robert Quencer, MD (University of Miami), Victor Haughton, MD (Medical College of Wisconsin). Twenty-eight credits of Category I will be available. For further information, please contact Marti Carter, CME, Inc., 11011 West Nort Ave., Milwaukee, Wisconsin 53226, or call (414) 771-9520. Ear, Nose, and Throat Diseases: 1993 Update
Children's Hospital of Pittsburgh will hold its 18th Annual Symposium, "Ear, Nose, and Throat Diseases in Children: A 1993 Update." This symposium will be held July 30-31, 1993. CME credits will be awarded.
For further information, please contact the Department of Pediatric Otolaryngology, Children's Hospital of Pittsburgh, 3705 Fifth Avenue at DeSoto St., Pittsburgh, Pennsylvania 15213, or call (412) 692-8577. Twenty-fifth Annual Meeting - Head and Neck Oncologists
The Association of Head and Neck Oncologists of Great Britain will sponsor the Twenty-fifth Annual Meeting of Head and Neck Oncology, to be held in Edinburgh, Scotland, United Kingdom, on August 23-26, 1993. International and local faculty will present extensive social and family programs. For further information, please contact Mr. P. J. Bradley, Honorary Secretary, Department of Otorhinolaryngology-Head and Neck Surgery, University Hospital, Queens Medical Centre, Nottingham, NG7 2UH, England, or phone 0602421421. Sixth International Congress on Interventlonal Ultrasound
The Sixth International Congress on Interventional Ultrasound will be held in Copenhagen, Denmark, on September 7-10, 1993. For further information, please contact Christian Nolsoe, Congress Secretary, Department of Ultrasound, Herlev Hospital, University of Copenhagen, DK-2730 HerlevDenmark, or call + 45/ 44 53 53 00 ext. 3240.
CORRECTION
The Supplement to the December 1992 issue of the JOURNAL (Volume 107, Number 6, Part 2), incorrectly listed Dr. Bruce R. Gordon as Chief of Otolaryngology at the Massachusetts Eye and Ear Institute. Dr. Joseph Nadol is Chief of Otolaryngology at the Massachusetts Eye and Ear Infirmary. Dr. Gordon is Chief of Otolaryngology at Cape Cod Hospital.
