Research Review By Gary J. Maguire©

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Date Posted:

March 2011

Study Title:

Effectiveness of Particle Repositioning Maneuvers in the Treatment of Benign Paroxysmal Positional Vertigo: A Systematic Review

Authors:

Helminski JO et al.

Author's Affiliations:

Department of Physical Therapy, Midwestern University, Downers Grove, IL, USA

Publication Information:

Physical Therapy 2010; 90(5): 663-678.

Background Information:

Benign paroxysmal positional vertigo (BPPV) is the most common vestibular conditions in the general population accounting for one third of vestibular diagnoses. The lifetime prevalence of BPPV is 2.4% and 1-year incidence is 0.6%. This condition is characterized by brief periods of vertigo triggered by a change in the position of a person’s head relative to gravity. Patients with BPPV often experience delays in diagnosis and treatment (an average delay of 92 weeks has been reported!) and are usually treated (inappropriately) with vestibular suppressant medications. BPPV can greatly diminish quality of life and lead to reduced ability to perform ADLs, falls and even depression.

BPPV results from abnormal mechanical stimulation of 1 or more of the 3 semicircular canals within the inner ear. These fluid-filled canals normally detect rotation of the head via deflection of sensory hair cells that are embedded in a gelatinous membrane. In BPPV, calcite particles (called otoconia) which are normally weighted in the gelatinous membrane (the cupula) become dislodged and form ‘sediment’ in the canals, leading to dynamic changes and aberrant signaling within the canals.

Inner Ear
Two primary theories exist to explain BPPV:
  1. Cupulolithiasis is when the dislodged otoconia directly attach to the cupula, weighting the membrane. Reorientation of the canal relative to gravity deflects the cupula creating excitation or inhibition of the ampullary organ.
  2. Canalithiasis involves the otoconia forming a free ‘sediment’ in the canals. Reorientation of the canals causes the otoconia to move to the lowest part of the canals. This creates a drag on the endolymph and resulting fluid pressure on the cupula. This causes activation of the ampullary organ which can lead to aberrant signals.
The Dix-Hallpike maneuver or Dix-Hallpike Test (DHT) is the standard diagnostic procedure to identify posterior canal BPPV and differentiate it from other conditions (1). The diagnostic criteria for PC BPPV are:
  • vertigo associated with characteristic ocular nystagmus that is torsional (toward the dependent ear) and directed upward;
  • consistent with the excitation of the ampullary organ of the PC;
  • 1 to 40 second latency before the onset of vertigo and nystagmus; and
  • vertigo and nystagmus with duration of less than 60 seconds.
With repeated positioning, PC BPPV temporarily becomes less intense and can even disappear.

For the DHT, the estimated sensitivity and specificity are 79% (95% confidence interval [CI] = 65-94) and 75% (CI = 33-100), respectively. When interpreting the direction of eye movement interrater reliability ranges from a mean percentage of agreement of 43% (fair) to a mean percentage of agreement of 81% (substantial). This depends on the level of expertise of the examiner.

PIC This systematic review evaluated the effectiveness of several particle repositioning maneuvers, primarily the canalith repositioning procedure (CRP – familiar to most as the ”Epley’s” maneuver), the liberatory maneuver (also known as ”Semont’s maneuver”), and self-administered variants aimed at treating PC BPPV. Inclusion criteria consisted on focusing on the quality of the performance of the intervention and the appropriateness of the tests and measures used.

EDITOR’S NOTE: If you need to review the steps for Epley’s and Semont’s - a quick search on the internet will guide you to videos showing you how to do these tests.

Pertinent Results:

  • The CRP is more effective than a control treatment of PC BPPV. Only 2 studies met the criteria for quantitative synthesis and as a result a meta-analysis was not conducted. It was concluded that greater variability in the quasi-RCTs may have been due to the clinical expertise of the study personnel or to a difference in the patient populations. Interrater reliability for interpreting the direction of eye movement varied depending on the level of expertise. The low odds ratio (OR) may reflect the lack of experience of the trained professionals in evaluating eye movements and may support the need for experienced professionals to treat BPPV needed to minimize delays in treatment as well as reduce health care costs.
  • The liberatory maneuver is an effective treatment for PC BPPV and is deemed as effective (quasi-RCTs findings) as the CRP. The authors though recommend that RCTs need to be performed to determine whether the liberatory maneuver is more effective for PC BPPV than a sham treatment and whether there is a correlation between the speed that the maneuver is performed and the success of the maneuver (2).
  • The use of the self-administered CRP was more effective than the self-administered liberatory maneuver in the treatment of PC BPPV. More patients performed the liberatory maneuver incorrectly than performed the self-administered CRP incorrectly. Unfortunately the Brandt-Daroff exercises had little or no effect on resolving symptoms.
  • To optimize functional outcomes, all patients should receive illustrated instructions with specific exercises for the affected ear, perform the exercises under the supervision of an experienced clinician as well as be asked to perform the maneuver at the time of follow-up to assess the accuracy of performance.
  • Clinicians should note that there is a 2.5% to 6% chance of causing a transient worsening of the patient’s condition through a “canal conversion” from the PC to the lateral canal. Clinicians should be well versed in the ability to recognize and treat lateral canal BPPV should this occur (although often the complication resolves on its own). Patients who perform the maneuvers on their own should also be aware of this complication with canal conversion. Currently there are no RCTs regarding lateral canal BPPV.
  • The time interval between treatment and outcome assessment is considered critical. To separate the effects of active treatment from a fatigue response, outcome should be assessed 24 hours or more after treatment. It is important to note that repeated positioning may cause a fatigue response that can mimic successful treatment. Usually within 7 days of PC BPPV symptom onset, 30% of patients will experience spontaneous remission.

Clinical Application & Conclusions:

Results from existing randomized controlled trials suggest that the CRP is the most effective treatment in resolving benign paroxysmal positional nystagmus (BPPN) in patients with PC BPPV. The authors also concluded that evidence for the use of other particle repositioning maneuvers in the treatment of PC BPPV is weak due to limited numbers of studies and no RCTs. Individual results suggested that the liberatory (Semont’s) maneuver was more effective than a control.

There also appears to be no significance in the effectiveness of the liberatory maneuver and the effectiveness of the CRP. The self-administered CRP was more effective than the self-administered liberatory maneuver and the CRP was more effective than the CRP administered alone. The Brandt-Daroff exercises appear to have no data on their outcome effects relevant to patients and as a result are considered to be the least effective of the various maneuvers.

The Epley’s design is to use the forces associated with gravity to treat Canalithiasis of the PC. Semont’s maneuver is designed to use both inertia and gravity to treat cupulolithiasis of the PC. The mechanism of BPPV may be determined on the basis of the characteristic nystagmus parameters of latency to onset, duration and amplitude. Due to the nystagmus parameters not being reported for the particle repositioning maneuvers, correlations between the mechanism of BPPV and the outcome of the maneuvers could not be determined and requires further research.

Study Methods:

The literature search utilized MEDLINE, EMBASE and CINAHL. Abstracts were screened for relevant studies. If a study was an RCT or a quasi-RCT and the study population was diagnosed with PC BPPV, then the article was obtained and reviewed. To assess the outcome of each study, the effect size was calculated. The successful outcome of a particle repositioning maneuver was defined as the conversion of a positive positional test to a negative positional test (no BPPN). The patient’s report of vertigo was not qualitatively analyzed. The odds ratio and the 95% CI were calculated to determine the odds of a successful outcome of a negative positional test.

The selection of trials in which randomized treatment assignments and a clearly defined control group were used and were considered. Statistical analysis of the data was performed with SAS/STAT with all tests of significance performed at an ? level of .05.

Study Strengths / Weaknesses:

Initially 868 records were identified; 24 full text articles were assessed for eligibility, only 10 articles met inclusion and only 2 RCTs compared the effectiveness of the CRP and the effectiveness of a control in the treatment of PC BPPV. The limited number of studies prevented the authors from including the articles in a quantitative synthesis or meta-analysis.

Overall the studies reviewed showed low methodological quality and the probability of bias was high focusing on the effectiveness of the liberatory maneuver and self-administered variants. This restricted interpretation due to limited data. Randomized controlled trials investigating the effectiveness of the liberatory maneuver and self-administered variants need to be conducted.

Additional References:

  1. Dix MR et al. The pathology, symptomatology, and diagnosis of certain common disorders of the vestibular system: Proc R Soc Med 1952; 45: 341-354.
  2. Faldon et al. Head accelerations during particle repositioning manoeuvres. Audiol Neurootol 2008; 13: 345-356.