Critical review of the evidence for each question
1. Liberatory manoeuvres
Which liberatory manoeuvre is the most effective for patients with BPPV to free the typical posterior canal of the causative heavy clot:
Semont’s, Epley’s, or Brandt/Daroff’s manoeuvre?
Effectiveness of the manoeuvres
Everyone who uses the liberatory manoeuvres is convinced of their efficacy. It is generally assumed that they are highly effect-ive for the common posterior canal BPPV in 80–99% of patients [5,6,8,23,24], and that they are also very cost-effective procedures [25].
There is, however, no real class I evidence (i.e. quality of evidence ratings for therapeutic modalities following Brainin et al. [26]; class I evidence is provided by one or more well-designed randomized-controlled clinical trials) on the effec-tiveness of the different manoeuvres or on a comparison of the three manoeuvres.
In our search for BPPV treatment studies published since 1995 in PubMed and Medline, we found 55 studies that exam-ined the efficacy of various manoeuvres in patients with BPPV of the posterior canal. Only two studies, however, had a prospective, controlled, and single-blinded design.
Simhadri et al. [23] evaluated (in only 40 patients) the efficacy of a modified Epley manoeuvre, proposed by Parnes Chapter 8: Vertigo and dizziness 61
and Price-Jones [27]. They showed that it had a success rate of 95% (versus 15% in the control group) after 1 week. After 6 months the success rate was still 95% (versus 25%) and after 1 year, 90% (versus 15%). Previously Lynn et al. [24]
had assessed the effectiveness of the Epley manoeuvre with-out mastoid vibration and medical treatment in 18 patients with 1-month follow-up and found a success rate of 88.9%.
An overview of both trials is presented in Table 8.2. Since both studies defined success as absence of vertigo and nystag-mus during the Dix–Hallpike test, the success rates could be averaged. This yielded a value of 90% for a total 38 patients.
Eleven further randomized-controlled prospective studies [28–38] evaluated the efficacy of Epley’s (10 trials), Semont’s (4 trials), Brandt and Daroff’s (2 trials), or habituation
manoeuvres (1 trial). They are listed in Table 8.2 but were not included in the meta-analysis presented above because of substantial methodological deficits. Despite their differences in definitions of success, follow-up time, and manoeuvres, we averaged the cited success rates and obtained a value of approximately 70% for 500 evaluated cases of BPPV (range 51–94% success). Even though this result has marginal explanatory power, it nevertheless indicates that positioning manoeuvres in the treatment of BPPV are very efficacious.
Studies that were not of randomized-controlled design are not listed.
A recent critical meta-analysis [39] of the Epley manoeuvre also pointed to the absence of sufficient trials on this topic:
‘The 11 studies identified by the search strategy as being trials 62 Part 2: Neurological symptoms/problems
Table 8.2 Liberatory manoeuvre for patients with benign paroxysmal positioning vertigo.
Study Type of study N (female:male)/ Median Follow-up Type of manoeuvre Success Duration of treatment impaired canal age (years) (N) rate Number of manoeuvres
(%) Carried out by
Simhadri et al. [23] Single blinded, 40 (1:1)/ 41 12 months PRM [27] (20) 90 1 week
randomized controlled, posterior canal Every 3rd hour while
prospective awake
Patients themselves
Lynn et al. [24] Single blinded, 33 (24:9)/ 68 1 month Epley (18) 89 One session
randomized controlled, posterior canal Mostly four cycles
prospective Audiologist
Li [28] Randomized controlled, 60 n.s./ n.s. 7 days Epley, partially with 51 Not specified
prospective posterior canal mastoid vibration
(37)
Salvinelli et al.[29] Randomized controlled, 80 (54:26)/ 60 6 months Semont (40) 88 1–3 manoeuvres prospective posterior canal
Angeli et al. [30] Randomized controlled, 47 (26:21)/ 74 1 month Modified 64 One session
prospective posterior canal Epley (28) 1–3 manoeuvres
Soto Varela et al. [31] Randomized controlled, 106 (73:33)/ 59 3 months Brandt Daroff (11) 62 3/day patients
prospective posterior canal Semont (12) 77 Not specified repeated
Epley (13) 93 if necessary Sherman and Randomized controlled, 71 (53:18)/ 54 12 months PRM [27] (18) 83 Not specified
Massoud [32] prospective posterior canal
Wolf et al. [33] Randomized controlled, 41 (23:18)/ 46 6 months Epley (31) 94 Titration manoeuvre
prospective posterior canal performed weekly
Cohen and Kimball [34] Randomized controlled, 124 (76:48)/ 58 6 months Brandt Daroff (25) – Various parameters
prospective posterior canal CRP (Epley) (24) – analysed
LM (Semont) (25) – Habituation – exercise (25)
Motamed et al. [35] Randomized controlled, 84 (70:14)/ 49 1–1.5 Epley, partially with 68 Not specified
prospective posterior canal months mastoid vibration
(79)
Asawavichianginda Randomized controlled, 85 (56:29)/ 50 6 months Epley (42) 92 Not specified
et al. [36] prospective posterior canal Physician
Herdman et al. [37] Randomized controlled, 60 (44:16)/ 58 4 months Semont (30) 70 Not specified
prospective posterior canal Epley (30) 57
Froehling et al. [38] Randomized controlled, 50 (32:18)/ 64 10 days Epley (24) 67 Titration prospective posterior canal
of the Epley manoeuvre in the treatment of posterior canal BPPV were generally of low methodological quality, particu-larly in the key areas of allocation concealment and blinding of the assessors to outcome. Nine of the studies were excluded because of concern about a high probability of bias. Only two trials [24,38] were judged to be of sufficient methodological quality to be included in the review’ [39]. The meta-analysis of a total of 83 patients in this study revealed that patients who perform the Epley manoeuvre are more likely to have com-plete resolution of their symptoms (odds ratio 4.92 (95% con-fidence interval 1.84 –13.16)) and more likely to convert from a positive to a negative Dix–Hallpike test (odds ratio 5.67 (95%
confidence interval 2.21–14.56)). The authors concluded that further research in this field should consider using a rigorous randomization technique with respect to adequate pre-allocation concealment, the blinding of the outcome assessors, the inclusion of the post-treatment Hallpike manoeuvre as an efficacy criterion, and a long-term follow-up of the patients [39].
In a very careful meta-analysis by White et al. [40] on the Epley manoeuvre a total of nine randomized-controlled trials were identified and included in their analysis; three had a blinded follow-up (141 patients). The nine trials consisted of a total of 505 patients with a mean follow-up time of 16 days.
The risk of persistence of BPPV without treatment was 69%, the risk after a single canalith repositioning manoeuvre was 28% (P 0.00001; relative risk reduction 61%). The authors concluded from their analysis that the Epley manoeuvre is a safe and effective treatment of BPPV. A single treatment ses-sion resolves BPPV in 72% of the cases.
The following studies dealt with the comparison of different positioning manoeuvres. A recent retrospective study on 840 patients with posterior canal BPPV compared the effectiveness of Epley’s with Semont’s manoeuvre [41]. The Epley ‘reposi-tioning’ manoeuvre was performed on 607 (66%) patients;
the mean number of treatment sessions was 2.98 (range 1–12), 409 (67%) became symptom free, 164 (27%) were sig-nificantly improved, and 34 (6%) had no change of their symptoms; Semont’s liberatory manoeuvre was performed on 233 (25%) patients. The mean number of treatment ses-sions was 4.34 (range 1–19). In this group 144 (62%) of the patients became symptom free, 83 (36%) were significantly improved, and 6 (2%) did not experience any change in their symptoms.
In another study the efficacy of the three manoeuvres was compared in 106 patients 1 week, 1 month, and 3 months after treatment. The success rate after 1 week was 74% with Semont’s, 71% with Epley’s, and 24% with Brandt–Daroff’s manoeuvres and after 3 months 77% with Semont’s, 93%
with Epley’s, and 62% with Brandt–Daroff’s manoeuvres [31].
One study on 62 patients retrospectively evaluated whether the success rate of Epley’s manoeuvre depends on the aetiology of the BPPV and demonstrated that it was lower in secondary BPPV, for example, due to head injury, MD, or VN [42].
A very recent controlled study compared the efficacy of the Epley, Semont, Brandt and Daroff, and sham manoeuvres and habituation exercises in 124 patients (each group with 24–25 patients, follow-up of 6 months) [34]. It showed that the decrease of vertigo after Epley, Semont, Brandt and Daroff manoeuvres was significantly better than in the sham group (with no difference between the three treatment groups). The effect of habituation exercises was not significantly different neither from the treatment nor the sham group.
Finally, the efficacy of the Epley versus Semont manoeuvre for self-treatment of posterior canal BPPV was evaluated in 70 patients with posterior canal BPPV [43]. The response rate after 1 week was 95% in the Epley group and 58% in the Semont group (P 0.01). Treatment failure, however, was due to incorrect performance of the Semont manoeuvre (see below). This indicates that detailed instruction and monitor-ing of the correct manoeuvre are necessary in all patients.
All in all, the following conclusions can be drawn: first, so far only a few methodologically high-quality studies on the effectiveness of the different liberatory manoeuvres in BPPV are available; second, the success rate after the first man-oeuvre seems to be lower and the recurrence rate higher than previously reported; and third, prospective, randomized, con-trolled studies in this field are necessary in the future.
Supplementary procedures to the manoeuvres Li [28] found in a randomized-controlled survey that the suc-cess rate improved if the procedure is combined with mastoid vibration; this, however, was not confirmed in a more recent study [44], mainly because the success rate without vibration was already very high in the second study. Semont [6] recom-mended having the patient maintain the upright position for 48 h following liberation, but we have not found this to be nec-essary. Our view is supported by two prospective and at least partially controlled studies that showed that post-manoeuvre restrictions are not necessary in posterior canal BPPV to improve effectiveness [45,46].
Side effects of the manoeuvres
A possible complication of liberatory manoeuvres is that the clot leaves the posterior canal but instead of staying in the utricular cavity enters the anterior (via the common crus) or the horizontal canal. Thus, posterior BPPV may convert to horizontal or anterior BPPV. This occurred in 5 of 85 patients who originally had typical posterior BPPV (horizontal canal: 3, anterior canal: 2) after they had undergone libera-tory manoeuvres [47]. ‘Canalith jam’ is another speculative description of hitherto unexplained transient phenomena that rarely occur during physical treatment [48]. Despite suc-cessful liberatory manoeuvres, many patients complain of postural vertigo and dizziness when standing and walking after the liberatory manoeuvres. This may last a few or several weeks and can be explained by the partial repositioning of the otoconia towards the otolith organs, namely the utricle (i.e.
Chapter 8: Vertigo and dizziness 63
most likely an otolithic vertigo). Patients should be informed in advance about this side effect of the manoeuvres, which disappears spontaneously within a few days due to central compensation and can be improved by exercises.
Failure of manoeuvre treatment
There are several reasons for the failure of treatment with the manoeuvres described above. First, the diagnosis may have been wrong, that is, the patient suffered from central pos-itioning or positional vertigo or nystagmus, bilateral BPPV, or BPPV of the horizontal or (very rarely) anterior semicircular canal (see below). Second, the patient may not have per-formed the manoeuvres correctly, for example, the head rota-tion in Semont’s liberatory manoeuvre is often performed incorrectly when the patient moves the body 180° to the non-affected side or this body movement is performed too slowly so that the clot moves in the ‘wrong direction’ within the poste-rior canal. In such cases, the patient should be re-instructed, and if the symptoms persist, he should be admitted to a hospi-tal for a few days until the symptoms resolve.