The Epley (canalith repositioning) manoeuvre for benign paroxysmal positional vertigo (Unknown)

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1 The Epley (canalith repositioning) manoeuvre for benign paroxysmal positional vertigo (Unknown) Hilton M, Pinder D This is a reprint of a Cochrane unknown, prepared and maintained by The Cochrane Collaboration and published in The Cochrane Library 2001, Issue 4 (Unknown).

2 T A B L E O F C O N T E N T S ABSTRACT SYNOPSIS BACKGROUND OBJECTIVES CRITERIA FOR CONSIDERING STUDIES FOR THIS REVIEW SEARCH STRATEGY FOR IDENTIFICATION OF STUDIES METHODS OF THE REVIEW DESCRIPTION OF STUDIES METHODOLOGICAL QUALITY RESULTS DISCUSSION REVIEWER S CONCLUSIONS POTENTIAL CONFLICT OF INTEREST SOURCES OF SUPPORT REFERENCES TABLES Characteristics of included studies Characteristics of excluded studies GRAPHS Comparison 01. Epley versus placebo manoeuvre: conversion of positive to negative Dix-Hallpike test..... Comparison 02. Epley versus placebo manoeuvre: subjective symptom resolution COVER SHEET COMMENTS AND CRITICISMS GRAPHS AND OTHER TABLES Comparison 02. Conversion of positive to negative Dix-Hallpike test Comparison 02. Subjective report of complete symptom resolution i

3 The Epley (canalith repositioning) manoeuvre for benign paroxysmal positional vertigo Hilton M, Pinder D Status: Commented This record should be cited as: Hilton M, Pinder D.. The Cochrane Database of Systematic Reviews (Complete Reviews), Issue. Art. No.: CD DOI: / CD This version first published online: 25 October 2001 in Issue,. Date of most recent substantive amendment: 25 October 2001 A B S T R A C T Background Benign paroxysmal positional vertigo (BPPV) is a syndrome characterised by short-lived episodes of vertigo in association with rapid changes in head position. It is a common cause of vertigo presenting to primary care and specialist otolaryngology clinics. Current treatment approaches include rehabilitative exercises and physical manoeuvres including the Epley manoeuvre. Objectives To assess the effectiveness of the Epley manoeuvre compared to other treatments available for posterior canal benign paroxysmal positional vertigo, or no treatment. Search strategy The Cochrane Controlled Trials Register (Cochrane Library, Issue ), MEDLINE (1966 onwards), EMBASE (1974 onwards), and reference lists of identified publications. Date of the most recent search was June Selection criteria Randomised trials of adults diagnosed with posterior canal BPPV (including a positive Dix-Hallpike test). Comparisons sought: Epley manoeuvre versus placebo Epley manoeuvre versus untreated controls Epley manoeuvre versus other active treatment Outcome measures that were considered include: frequency and severity of attacks of vertigo; proportion of patients improved by each intervention; and conversion of a positive Dix-Hallpike test to a negative Dix-Hallpike test Data collection and analysis Both reviewers independently extracted data and assessed trials for quality. Main results Eleven trials were identified but nine studies were excluded because of a high risk of bias, leaving two trials in the review. Trials were mainly excluded because of inadequate concealment during randomisation, or failure to blind outcome assessors. Both studies included in the review (Lynn 1995, Froehling 2000) addressed the efficacy of the Epley manoeuvre against a sham manoeuvre by comparing the proportion of subjects in each group who had complete resolution of their symptoms, and who converted from a positive to negative Dix-Hallpike test. Individual and pooled data showed a statistically significant effect in favour of the Epley manoeuvre over controls. There were no serious adverse effects of treatment. 1

4 Reviewer s conclusions There is some evidence that the Epley manoeuvre is a safe effective treatment for posterior canal BPPV, although this is based on the results of only two small randomised controlled trials with relatively short follow up. There is no good evidence that the Epley manoeuvre provides a long term resolution of symptoms. There is no good evidence comparing the Epley manoeuvre with other physical, medical or surgical therapy for posterior canal BPPV. S Y N O P S I S The Epley manoeuvre can help spinning and dizziness on moving the head (benign paroxysmal positional vertigo) in the short term but more research is needed. Benign paroxysmal positional vertigo (BPPV) is caused by a rapid change in head movement. The person feels they or their surroundings are moving or rotating. Common causes are head trauma or ear infection. BPPV can be caused by debris in the semicircular canal of the ear that continues to move after the head has stopped moving. This causes a sensation of ongoing movement that conflicts with other sensory information. The review of trials found the Epley manoeuvre (four specific movements of the head and body designed to move the debris out the ear canal) is safe and effective. More research is needed. B A C K G R O U N D Benign paroxysmal positional vertigo (BPPV) is a syndrome characterised by short-lived episodes of vertigo (a sensation of instability, often with a sensation of rotation) in association with rapid changes in head position. It is a common cause of vertigo presenting to primary care and specialist otolaryngology, neuro-otology, neurology and audiological clinics. There are a number of aetiologies associated with BPPV. Common causes appear to be head trauma (17%) and vestibular neuritis (inflammation or infection of the nerve supplying the vestibule; an important part of the balance system) (15%) (Baloh 1987). Other putative causes include vertebrobasilar ischaemia (reduced blood flow in the area of the brain supplied by the basilar artery), labyrinthitis (inflammation or infection of the inner ear), as a complication of middle ear surgery, and following periods of prolonged bed rest. However, most cases appear to be idiopathic (without known cause). Incidence and Prevalence The peak incidence of idiopathic BPPV is between 50 and 70 years of age, although the condition is found amongst all age groups. The incidence of idiopathic BPPV ranges from per 100,000 per year (Mizukoshi 1988, Froehling 1991), increases by approximately 38% per decade of life and is twice as common in females as males. Sex distribution is about equal for post-traumatic and post-vestibular neuritis (Baloh 1987, Katsarkas 1978). Aetiology Balance is normally achieved by brain centres that monitor and synthesize information from the eyes, the vestibular system (part of the inner ear), and position sensors in major joints. Angular acceleration (i.e. turning movements) is detected by the semicircular canals. There are 3 semicircular canals set in orthogonal planes in each ear (6 semicircular canals in total: each ear providing reciprocal information) and they are therefore well placed to detect angular acceleration in any plane of head movement. The lateral semicircular canals are filled with a fluid called endolymph. The main sense organ in each canal is called the crista which is stimulated by movement of the cupula. Head rotation causes relative movement of the endolymph in the semicircular canal which bends the cupula and the embedded hairs of the hair cells and causes stimulation of the relevant vestibular nerve. The cause of benign positional vertigo is believed to be canalithiasis principally affecting the posterior semicircular canal. In canalithiasis, free floating debris in the semicircular canal is hypothesised to act like a plunger, causing continuing movement of the endolymph even after head movement has ceased. This causes movement of the cupula, bending of the hairs of the hair cells, and provokes vertigo. An alternate theory, cupulolithiasis, asserts that canal debris becomes attached to the cupula whose specific gravity is normally the same as endolymph but with attached debris would become heavier: thus responding to any change in gravitational position of the head (rather than angular acceleration). The latter theory has become less favoured, in part, with the introduction of positioning techniques to treat BPPV. With free floating debris (canalithiasis), successively turning the head should continue to provoke nystagmus (repeated jerky movements of the eyes) in the same direction if the direction of rotation remains constant: the debris sinks to the most gravitationally dependent position of the canal each time. However, cupulolithiasis would predict a change in direction of the nystagmus as the head continues to turn. The heavy cupula under the influence of gravity should deviate in the opposite direction as the crista of the 2

5 semicircular canal passes through the vertical plane. Clinical observation during positional manoeuvres confirms that when the direction of rotation is constant the direction of the nystagmus remains the same. The horizontal and anterior canals may also be affected by canalithiasis, although less frequently. When the aetiology is secondary to a labyrinthitis or end organ ischaemic injury (reduced blood supply causing damage to vital sensory cells) other components of the vestibular system in addition to a discrete posterior semicircular canal lesion may be affected. Symptoms Patients with posterior canal BPPV typically have episodic vertigo in association with a rapid change in head position, particularly movement relative to gravity and involving neck extension. The vertigo typically lasts for anything from a few seconds to one minute. Attacks may be associated with nausea, and the nausea may persist for much longer than the sensation of vertigo: sometimes for a few hours. Typical manoeuvres provoking vertigo include lying down in bed, extending the neck to reach up for objects on high shelves, bending over, and sitting up from supine. A patient s balance is usually normal between episodes. Exceptions to this would be those situations in which BPPV occurs in association with a partial vestibular paresis e.g. following vestibular neuronitis or labyrinthitis, where sudden head movements of any sort may provoke momentary sense of vertigo, or aetiologies such as ischaemic end organ damage that compromise other vestibular receptors. Horizontal canal BPPV typically causes vertigo when turning over in bed from side to side. Many cases of BPPV resolve spontaneously within a few weeks or months. Attacks tend to occur in clusters and symptoms may recur after an apparent period of remission. It is important to distinguish BPPV from central positional vertigo (which may occur with multiple sclerosis, cerebellar disease, and brainstem ischaemia) in which one of more of the classical features of BPPV will be absent: there may be no latent period, no fatiguability of the nystagmus, nystagmus which is not classically rotatory and the provocation is not always associated with nausea or a sensation of vertigo, which is typically quite intense for patients with BPPV. Diagnosis The Dix-Hallpike test (Hallpike manoeuvre) (Dix 1952), or the lateral head-trunk tilt (Brandt 1999) are used to confirm the diagnosis of posterior canal BPPV. A positive test provokes vertigo and nystagmus when a patient is rapidly moved from a sitting position to lying with the head tipped 45 degrees below the horizontal, 45 degrees to the side, and with the side of the affected ear (and semicircular canal) downwards. The nystagmus typically has a latency of a few seconds before onset and fatigues after approximately seconds. The nystagmus is rotatory with the fast phase beating towards the lower ear (geotropic). The nystagmus adapts with repeated testing. Optic fixation (the eyes being able to fix on a specific object) may reduce the severity of the nystagmus and it is possible to test patients wearing Frenzel glasses (glasses with strong prisms for lenses, that remove the ability of the eyes to focus on an object). However, increasing the sensitivity of the Hallpike manoeuvre by wearing Frenzel glasses will reduce its specificity, since asymptomatic normal subjects can develop positional nystagmus on positional testing when optic fixation is removed. A proportion of patients with a typical history of posterior canal BPPV who have a negative Hallpike manoeuvre on the first occasion, may demonstrate a positive test on retesting after a period of a few days, or have reproducible symptoms and paroxysmal nystagmus when testing with positional electronystagmography. (ENG involves a special headset worn by the patient during positional movements. Any eye movements are objectively measured and recorded by electrodes placed around the eyes) (Norre 1995). There are no other specific investigations which can confirm or exclude the diagnosis of BPPV. Treatment Options There are a number of treatment options available for posterior canal BPPV. In many cases, spontaneous remission occurs before medical advice is sought, and patients may simply seek an explanation for their symptoms without needing or demanding treatment. Regular medication (e.g. betahistine hydrochloride, prochlorperazine) is rarely prescribed as a treatment since there is no pathophysiological rationale for these agents to be effective, although vestibular suppressants and antihistamines may provide partial relief of nausea that can persist after acute attacks. Brandt-Daroff exercises (Brandt 1980) and canalith repositioning manoeuvres (Epley 1992, Semont 1988) are the main therapies for most patients who seek active treatment for their symptoms. They are purported to act by dispersion of the canal debris from the posterior semicircular canal into the utricle, where it is inactive. These modalities of treatment all have a sequence of head and/or trunk positioning manoeuvres as a common factor. In recent years the Epley manoeuvre (Epley 1992) has become particularly popular. The technique involves a series of four movements of the head and body from sitting to lying, rolling over and back to sitting. The technique can be modified by the addition of a headband which vibrates: putatively to encourage the movement of the particles through the semicircular canals (Li 1995). In extreme circumstances, patients with frequent episodes of intractable vertigo showing no sign of spontaneous remission, may require or seek surgical treatment. This includes vestibular neurectomy where the singular nerve which selectively supplies the posterior semicircular canal is divided. Although the debris may continue to cause abnormal deflection of the cupula, the resulting sensory signal can no longer reach the brainstem for higher processing. In posterior semicircular canal obliteration surgery the posterior semicircular canal is exposed by drilling away part of the mastoid bone, and then packed firmly to obliterate the endolymphatic channel, thus also effectively removing the ability of the semicircular canal to produce aberrant sensory information. 3

6 O B J E C T I V E S To assess the effectiveness of the Epley manoeuvre compared to other treatments available for posterior canal benign paroxysmal positional vertigo, or no treatment. C R I T E R I A F O R C O N S I D E R I N G S T U D I E S F O R T H I S R E V I E W Types of studies Randomised or quasi-randomised controlled trials. Types of participants Participants should be adults (age greater than 16 years) who have a clinical diagnosis of benign paroxysmal positional vertigo. The clinical diagnosis must state that the patient had a positive Dix- Hallpike positional test with clear and classical features of positional nystagmus. Types of intervention Epley manoeuvre (either as classically described or with mastoid oscillation). Comparison interventions: Placebo Medication Positional exercises S E A R C H S T R A T E G Y F O R I D E N T I F I C A T I O N O F S T U D I E S See: search strategy Trials were identified from the Cochrane Controlled Trials Register (Cochrane Library, Issue ), and by searching the MEDLINE (1966 onwards) and EMBASE (1974 onwards) databases. Reference lists of retrieved articles were scrutinised for other trials. The date of the most recent search was June MEDLINE and EMBASE were searched using the highly sensitive search strategies designed by the Cochrane Collaboration for identifying randomised controlled trials (see the Cochrane Handbook, Appendix 5c) in combination with the following specific terms: #1 vertig* or dizziness or benign or paroxysmal #2 Epley* #3 canalith* #4 particle* #5 position* #6 #1 and (#2 or #3 or #4 or #5) A total of 282 trials were identified by the combined MEDLINE and EMBASE searches. One reviewer scanned the search results to identify 14 trials that appeared to broadly address the subject of the review and the full text of these articles was scrutinised for eligibility. One further trial was identified from the Cochrane Controlled Trials Register. Four of these trials were not relevant to the review, leaving 11 trials for consideration. Other canalith repositioning procedures Vestibular neurectomy M E T H O D S O F T H E R E V I E W Posterior semicircular canal obliteration surgery Comparisons sought: Epley manoeuvre versus placebo Epley manoeuvre versus untreated controls Epley manoeuvre versus other active treatment Types of outcome measures Frequency of attacks of vertigo Severity of attacks of vertigo Proportion of patients improved by each intervention Conversion of a positive Dix-Hallpike test to a negative Dix-Hallpike test. (Although this could be considered a spurious outcome measure since it has no relevance to a patient s perception of their condition, it is the only relatively objective sign of improvement). QUALITY ASSESSMENT The 11 trials were independently assessed by the two reviewers. There was no disagreement between the reviewers about inclusion/exclusion of studies. The studies were assessed for the following characteristics based on the method of Schulz et al (Schulz 1995): 1. the reliability of the diagnosis of BPPV 2. the adequacy of randomisation process 3. the adequacy of blinding of the outcome assessors 4. the quality of outcome assessment, including the reporting of post-treatment Dix-Hallpike test. 5. the minimisation of performance bias DATA EXTRACTION Data from the studies were independently extracted by two reviewers using standardised data forms. 4

7 D E S C R I P T I O N O F S T U D I E S M E T H O D O L O G I C A L Q U A L I T Y The methodological quality of the 11 identified studies was generally low, and nine of the studies were excluded because of concern about a high probability of bias. Reliability of diagnosis In all studies a clinical diagnosis of BPPV was based on clinical history and examination including a positive Dix-Hallpike test. Where the inclusion criteria did not explicitly state a positive Dix-Hallpike test for inclusion, the application of a negative Dix-Hallpike test as an outcome suggested that a positive test was implicit in the diagnosis of BPPV for inclusion, and this was assumed. bias The quality of randomisation was poor in the majority of studies. Only one study (Lynn 1995) reported a robust strategy with sealed envelopes that were opened only after counselling and consent to partake was obtained. was inadequate in several studies (Blakley 1994, Steenerson 1996, Wolf 1999, Radtke 1999, Cohen 1999) and unclear in others (Li 1995, Herdman 1993, Massoud 1996, Froehling 2000). Blinding of outcome assessors Only two studies (Lynn 1995, Froehling 2000) reported blinding of outcome assessors, where patients were interviewed and tested by a clinician who had not administered their original treatment. Both reports explicitly state that returning patients were asked not to describe or discuss their first treatment when they returned for follow up. Quality of outcome assessment Seven of the trials reported results of a post-treatment Dix- Hallpike test in patients (rated as either positive or negative) (Lynn 1995, Asawavich. 2000, Li 1995, Wolf 1999, Radtke 1999, Froehling 2000, Massoud 1996). All trials reported on subjective resolution of symptoms. Most trials used broad categorical classification of symptom improvement e.g. complete resolution ; improved or no different/worse. Two trials (Lynn 1995, Radtke 1999) involved patients keeping a daily diary of symptoms. Follow up periods were generally short. Three trials report data on follow up of 1-2 weeks only (Radtke 1999, Froehling 2000, Herdman 1993). There were only three trials that reported follow up data up to six months (Asawavich. 2000, Wolf 1999, Cohen 1999). Only two trials imposed a minimum duration of symptoms as an inclusion criteria for entry to the trial. The trial by Lynn (Lynn 1995) used two months as the criteria. The trial by Wolf (Wolf 1999) used one month. All other trials included patients who may have had symptoms for a very short period of time. Asawavichianginda (Asawavich. 2000) recruited 85 patients to their trial, but 62% of these had symptoms for less than two weeks. Lynn 1995 This trial was a prospective, well randomised study of 36 patients. The outcome assessment was done by an audiologist who was blinded to the patient s treatment. Outcome assessment relied on objective measures, with conversion from a positive to a negative Dix-Hallpike test, and subjective rating of symptoms by keeping a daily diary. The trial compared the Epley manoeuvre with a sham manoeuvre. There was no performance bias and explicit reporting of the three patients who did not complete the study. Froehling 2000 This was a prospective randomised study of 50 patients. The technique of randomisation was not explicit in the report, although the participants were stratified in the randomisation by age and sex suggesting the strategy is unlikely to be quasi-randomisation (alternate patients, odd/even day allocation). The authors failed to reply to two requests for further detail. The outcome assessor was blinded to the patient s treatment. Outcome assessment relied on the conversion from a positive to a negative Dix-Hallpike test, and the single question do you feel that the dizziness has completely resolved? The trial compared the Epley manoeuvre with a sham manoeuvre. There was no performance bias between the groups. No patient was lost to follow up. Both studies used the modified version of the Epley manoeuvre in which no mastoid vibration is applied, and no premedication is given. Post-treatment instructions were very similar for both studies: to sleep sitting upright for two nights, avoid sleeping with the affected side down for one week, and to minimise head movements during the week after treatment. R E S U L T S The two included trials comprised a total of 86 patients. Complete data are available for 83 patients. EPLEY MANOEUVRE VERSUS SHAM (PLACEBO) MA- NOEUVRE SYMPTOM IMPROVEMENT Both trials report symptom outcome as a dichotomous variable, where success was defined as complete resolution of symptoms. No attempt was made to analyse differences in groups of patients who were improved but still had symptoms, or patients who failed to improve. A statistically significant difference in symptom resolution in favour of the treatment group was observed in each trial. Pooled trial data yields an odds ratio of 4.92 (95% C.I ) in favour of treatment. CONVERSION FROM A POSITIVE TO A NEGATIVE HALLPIKE MANOEUVRE In both trials there was a statistically significant difference in conversion from a positive to a negative Hallpike manoeuvre in favour 5

8 of the treatment group. Pooled trial data yields an odds ratio of 5.67 (95% C.I ) in favour of treatment. No eligible trials were identified to address the comparison of the Epley manoeuvre with either untreated controls, or alternative active treatments for posterior canal BPPV. D I S C U S S I O N The 11 studies identified by the search strategy as being trials of the Epley manoeuvre in the treatment of posterior canal BPPV were generally of low methodological quality, particularly in the key areas of allocation concealment and blinding of assessors to outcome. The principal patient-orientated outcome variable is subjective: resolution of a patient s symptoms of vertigo. Assessor blinding was therefore considered to be a key issue in the inclusion of trials in the review. Conversion to a negative Hallpike manoeuvre is the only objective marker of any physiological change resulting from treatment and is therefore included as an important outcome variable. Two studies were included in the review (Lynn 1995, Froehling 2000), and these both compared the efficacy of the Epley manoeuvre against a sham manoeuvre. Individual and pooled data showed a statistically significant effect in favour of the Epley manoeuvre over controls The natural resolution of BPPV is an extremely important issue. In the two included studies 20% of control patients had resolution of their symptoms and 27% (Lynn 1995) and 38% (Froehling 2000) of control patients were found to have a negative Hallpike manoeuvre at follow up. This emphasises that the natural history of posterior canal BPPV is for spontaneous resolution over time. The study by Asawavichianginda (Asawavich. 2000) was excluded because although well randomised it was unblinded. Nonetheless, it does not seem inappropriate to note that after three months 84% of the control group (N=25) who received no treatment had converted to a negative Hallpike manoeuvre. The majority of subjects recruited in this study had symptoms for less than two weeks before inclusion in the trial. This would suggest that trials which include patients very early in the course of their disease and have only modest numbers may report no benefit of treatment if a large spontaneous resolution rate overshadows a genuine benefit of treatment (a type II statistical error: failing to demonstrate a real difference between treatment and control). This is precisely the circumstance where meta-analysis may clarify a treatment effect which is not explicit from individual randomised controlled trials. If more trials are included in future up-dates of this review, a sensitivity analysis examining the effect size stratified by mean (or median) symptom duration will be considered. It might seem attractive to consider a minimum duration of symptoms as a specific requirement for patient or trial inclusion in the review. However, such a decision would inevitably introduce a rather arbitrary inclusion criterion; there is no well-founded basis for choosing a specific time period. Furthermore, imposing this type of criterion does not reflect day-to-day clinical practice. Most practitioners would offer a patient with BPPV treatment with the Epley manoeuvre at their first presentation, rather than deferring treatment to allow for the possibility of spontaneous resolution, irrespective of the duration of their symptoms. If one accepts that the mechanism producing symptoms of posterior canal BPPV is similar for patients irrespective of symptom duration (as seems intuitive), there is no obvious reason why the Epley manoeuvre should be more or less effective at different times between the onset of the disease and its natural resolution. What is perhaps surprising is that the condition resolves spontaneously at all. ADVERSE EFFECTS OF TREATMENT There were few reported adverse side effects, and no serious complications of treatment. The only reported problems were inability to tolerate the positioning manoeuvres because of cervical spine problems, and emesis (vomiting) during the treatment (Froehling 2000). Absence of serious side effects is particularly important for a treatment that is targeted at a condition which would be expected to resolve spontaneously over time in the majority of individuals. CONFOUNDING FACTORS Long term follow up was lacking in both included studies. Lynn (Lynn 1995) assessed patients one month after treatment completion, and Froehling (Froehling 2000) assessed patients between one and two weeks after completion. On the basis of these trials it is not therefore possible to comment on whether the Epley manoeuvre provides a permanent relief of BPPV, or a temporary remission from symptoms. R E V I E W E R S Implications for practice C O N C L U S I O N S There is some evidence that the Epley manoeuvre is a safe, effective treatment for posterior canal BPPV, although this is based on the results of only two small randomised controlled trials with relatively short follow up. There is no evidence that the Epley manoeuvre provides a long term resolution of symptoms. There is no evidence comparing the Epley manoeuvre with other physical, medical or surgical therapy for posterior canal BPPV. Implications for research Further research in this field should consider the following criteria: 1. The use of a rigorous randomisation technique with respect to adequate pre-allocation concealment. 2. Stratified randomisation of participants based on duration of symptoms. This may help address the concern that a high proportion of patients with short symptom duration may experience spontaneous remission of the disease during the study period. 6

9 3. The blinding of outcome assessors. 4. The inclusion of a post-treatment Hallpike manoeuvre as part of the reported results. 5. Long term follow up of patients. P O T E N T I A L I N T E R E S T C O N F L I C T O F None known S O U R C E S O F S U P P O R T External sources of support No sources of support supplied Internal sources of support No sources of support supplied R E F E R E N C E S References to studies included in this review Froehling 2000 {published data only} Froehling DA, Bowen JM, Mohr DN, Brey RH, Beatty CW, Wollan PC, et al. The canalith repositioning procedure for the treatment of benign paroxysmal positional vertigo: a randomized controlled trial. Mayo Clinic Proceedings 2000;75(7): Lynn 1995 {published data only} Lynn S, Pool A, Rose D, Brey R, Suman V. Randomized trial of the canalith repositioning procedure. Otolaryngology Head and Neck Surgery 1995;113(6): References to studies excluded from this review Asawavich Asawavichianginda S, Isipradit P, Snidvongs K, Supiyaphun P. Canalith repositioning for benign paroxysmal positional vertigo: a randomized, controlled trial. Ear, Nose, and Throat Journal 2000;79 (9):732-4, Blakley 1994 Blakley BW. A randomized, controlled assessment of the canalith repositioning maneuver [see comments]. Otolaryngology Head and Neck Surgery 1994;110(4): Cohen 1999 Cohen HS, Jerabek J. Efficacy of treatments for posterior canal benign paroxysmal positional vertigo. Laryngoscope 1999;109(4): Herdman 1993 Herdman SJ, Tusa RJ, Zee DS, Proctor LR, Mattox DE. Single treatment approaches to benign paroxysmal positional vertigo. Archives of Otolaryngology Head & Neck Surgery 1993;119(4): Li 1995 Li JC. Mastoid oscillation: a critical factor for success in the canalith repositioning procedure. Otolaryngology Head and Neck Surgery 1995; 112: Massoud 1996 Massoud EA, Ireland DJ. Post-treatment instructions in the nonsurgical management of benign paroxysmal positional vertigo. Journal of Otolaryngology 1996;25(2): Radtke 1999 Radtke A, Neuhauser H, von Brevern M, Lempert T. A modified Epley s procedure for self-treatment of benign paroxysmal positional vertigo. Neurology 1999;53(6): Steenerson 1996 Steenerson RL, Cronin GW. Comparison of the canalith repositioning procedure and vestibular habituation training in forty patients with benign paroxysmal positional vertigo. Otolaryngology Head and Neck Surgery 1996;114(1):61-4. Wolf 1999 Wolf M, Hertanu T, Novikov I, Kronenberg J. Epley s manoeuvre for benign paroxysmal positional vertigo: a prospective study. Clinical Otolaryngology 1999;24(1):43-6. Additional references Baloh 1987 Baloh RW, Honrubia V, Jacobson K. Benign positional vertigo: clinical and oculographic features in 240 cases. Neurology 1987;37(3): Brandt 1980 Brandt T, Daroff RB. Physical therapy for benign paroxysmal positional vertigo. Archives of Otolaryngology 1980;106(8):

10 Brandt 1999 Brandt T. In: Büttner U, editor(s). Vestibular dysfunction and its therapy. Vol. 55 Advances in Otorhinolaryngology, Basel: Karger, 1999: Dix 1952 Dix R, Hallpike CS. The pathology, symptomatology and diagnosis of certain common disorders of the vestibular system. Annals of Otology, Rhinology and Laryngology 1952;6: Epley 1992 Epley JM. The canalith repositioning procedure: for treatment of benign paroxysmal positional vertigo. Otolaryngology Head and Neck Surgery 1992;107(3): Froehling 1991 Froehling DA, Silverstein MD, Mohr DN, Beatty CW, Offord KP, Ballard DJ. Benign positional vertigo: incidence and prognosis in a population-based study in Olmsted County, Minnesota. Mayo Clinic Proceedings 1991;66(6): Katsarkas 1978 Katsarkas A, Kirkham TH. Paroxysmal positional vertigo - a study of 255 cases. Journal of Otolaryngology 1978;7(4): Mizukoshi 1988 Mizukoshi K, Watanabe Y, Shojaku H, Okubo J, Watanabe I. Epidemiological studies on benign paroxysmal positional vertigo in Japan. Acta Oto-Laryngologica Suppl 1988;447: Norre 1995 Norre ME. Reliability of examination data in the diagnosis of benign paroxysmal positional vertigo. American Journal of Otology 1995;16 (6): Schulz 1995 Schulz KF, Chalmers I, Hayes RJ, Altman DG. Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials. Journal of the American Medical Association 1995;273(5): Semont 1988 Semont A, Freyss G, Vitte E. Curing the BPPV with a liberatory maneuver. Advances in Otorhinolaryngology 1988;42: T A B L E S Characteristics of included studies Study Froehling 2000 Methods Participants Interventions Outcomes Notes Prospective randomised controlled trial. Randomisation stratified by age and sex. 50 patients greater than 18y old (18 males, 32 females). Median symptom duration 43 days for the experimental group, 35 days for the sham group. Modified Epley manoeuvre versus sham manoeuvre (lying on the affected side for 5 minutes). 1. Conversion of Dix-Hallpike test from positive to negative. 2. Subjective improvement by question; do you feel your dizziness has completely resolved? Follow up only at 1-2 weeks after treatment. No long term assessment. 8

11 concealment B Study Lynn 1995 Methods Participants Interventions Outcomes Notes concealment Prospective randomised controlled trial. Sealed envelope randomisation strategy. 36 patients between 23y and 90y (9 males, 24 females). Symptom duration for minimum 2 months. Modified Epley manoeuvre versus sham manoeuvre (lying in the first lateral position of the Semont manouevre for 5 minutes). 1. Conversion of Dix-Hallpike test from positive to negative. 2. Daily diary of symptoms. Report of vertigo in the 7 days prior to reassessment at 1 month was failure. Follow up only at 1 month after treatment. No long term assessment. A Both trials applied a modified Epley manoeuvre: the sequence of positioning was as originally described by Epley 1992, but without the addition of mastoid oscillation or premedication. Characteristics of excluded studies Study Asawavich Blakley 1994 Cohen 1999 Herdman 1993 Li 1995 Massoud 1996 Reason for exclusion 1. No blinding of outcome assessors 2. Performance bias: control group received no exposure to clinical staff during the trial other than assessments, compared to frequent attendance in experimental group Participants Short duration of symptoms: 62% of cohort reported symptoms of less than 2 weeks duration 1. Inadequate randomisation strategy 3. Performance bias: control group received less exposure to clinical staff Outcomes Outcome only by subjective measures 1. Inadequate randomisation strategy - sequential allocation 3. Risk of attrition bias: complete follow up on only 58 of 87 subjects Outcomes Outcome only by subjective measures 1. Unclear randomisation strategy Outcomes Objective outcome measures (Dix-Hallpike test) reported in only 48% of subjects 1. Unclear randomisation strategy 1. Unclear randomisation strategy 9

12 Characteristics of excluded studies (Continued) Radtke 1999 Steenerson 1996 Wolf Inadequate randomisation: 20% of the study population were allocated to receive the Epley manoeuvre because they had previously failed with rehabilitation exercises: which was the control treatment. Remaining patients were allocated alternately. 1. Inadequate randomisation: alternative allocation to 2 treatment groups. Control group were patients who refused active treatment. Outcomes No objective outcome measure 1. Inadequate randomisation: first 22 patients allocated by date of examination (odd; even). Remaining 19 patients all received active treatment. 3. Performance bias: control group received less exposure to clinical staff. G R A P H S Comparison 01. Epley versus placebo manoeuvre: conversion of positive to negative Dix-Hallpike test Outcome title Conversion of positive to negative Dix-Hallpike test No. of No. of studies participants Statistical method Effect size 2 83 Odds Ratio (Fixed) 95% CI 5.67 [2.21, 14.56] Comparison 02. Epley versus placebo manoeuvre: subjective symptom resolution Outcome title Subjective report of complete symptom resolution No. of No. of studies participants Statistical method Effect size 2 83 Odds Ratio (Fixed) 95% CI 4.92 [1.84, 13.16] Title Authors Contribution of author(s) Issue protocol first published 2001/3 C O V E R S H E E T Hilton M, Pinder D Date of most recent amendment 18 November 2003 Date of most recent SUBSTANTIVE amendment What s New DOI Cochrane Library number The reviewers contributed equally to searching, selection of trials, quality assessment and data extraction 25 October 2001 Information not supplied by author / CD CD

13 Editorial group Editorial group code Cochrane Ear, Nose and Throat Disorders Group HM-ENT C O M M E N T S A N D C R I T I C I S M S Herxheimer 2003 Summary Describe the Epley manoeuvre 1. The review is very valuable. It would be still more useful if it included or was linked to a detailed description of the Epley manoeuvre, and illustrated with one or more diagrams. The references to Epley s original paper and to the two trials reviewed are in rather obscure and not easily accessible places. 2. The coversheet states that various dates have no been supplied by the reviewer. Surely most of this information must be in the editorial office or easily obtained by the CRG. I certify that I have no affiliations with or involvement in any organisation or entity with a direct financial interest in the subject matter of my criticisms. AH Author s reply Contributors Andrew Herxheimer London N3 2NL UK andrew_herxheimer@compuserve.com G R A P H S A N D O T H E R T A B L E S Comparison 02. Conversion of positive to negative Dix-Hallpike test Review: Comparison: 01 Epley versus placebo manoeuvre: conversion of positive to negative Dix-Hallpike test Outcome: 01 Conversion of positive to negative Dix-Hallpike test Study Treatment Control Odds Ratio (Fixed) Weight Odds Ratio (Fixed) n/n n/n 95% CI (%) 95% CI Froehling /24 10/ [ 1.00, ] Lynn /18 4/ [ 3.41, ] Yimtae /25 13/ [ 0.87, ] Total (95% CI) [ 2.30, ] Total events: 54 (Treatment), 27 (Control) Test for heterogeneity chi-square=3.10 df=2 p=0.21 I =35.4% Test for overall effect z=4.01 p= Favours control Favours treatment 11

14 Comparison 02. Subjective report of complete symptom resolution Review: Comparison: 02 Epley versus placebo manoeuvre: subjective symptom resolution Outcome: 01 Subjective report of complete symptom resolution Study Treatment Control Odds Ratio (Fixed) Weight Odds Ratio (Fixed) n/n n/n 95% CI (%) 95% CI Froehling /24 5/ [ 1.19, ] Lynn /18 3/ [ 1.29, ] Yimtae /25 7/ [ 0.97, ] Total (95% CI) [ 1.96, 9.08 ] Total events: 39 (Treatment), 15 (Control) Test for heterogeneity chi-square=0.40 df=2 p=0.82 I =0.0% Test for overall effect z=3.69 p= Favours control Favours treatment 12

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