The lack of differences among groups indicates that some variations in treatment methodology do not reduce the effectiveness of care. CRP has been shown to be significantly more effective than a sham treatment and slightly more effective than Brandt Daroff exercise. 15
This study shows that modifying the CRP, performing CRP plus a home program, or having involvement of a second semicircular canal does not change treatment effectiveness. One week of the self-CRP exercise is as effective as the modified Brandt Daroff exercise or three trials of CRP and its variations. Thus, self-CRP is an effective home program. It may be preferred for patients who have limited ability to sit up quickly.
This study replicated previous findings showing that CRP is effective in reducing vertigo and responses to the Dix-Hallpike maneuver. 8,15,21,22
and improving posturography and VADL scores.15
Previous work 23, 24
supports the finding that CRP plus a home program does not improve the outcome. By contrast, Tanimoto et al found that CRP, alone, was less effective than CRP plus self-CRP at home, 11
perhaps due to paradigm differences.
Consistent with previous research15
subjects in Groups 1,2,3 and 4 were all treated at T1
and did not receive CRP at subsequent dates. Since some patients may need a second or third treatment 25
the finding that some subjects were still symptomatic at T2
is not surprising. Also, some patients may have had subclinical Dix-Hallpike responses without concomitant vertigo. The underlying pathophysiology in such cases may have been residual otoconial matter in the semicircular canals. Anatomical work has shown that otoconial matter may be present in the semicircular canals of people who had not complained of vertigo in life. 26
Groups 3 and 5 practiced home exercise for a week. With the availability of the Internet some patients may try to treat themselves with instructions for exercises that they find on-line. Therefore, an important area for future research might be to determine the optimal treatment for subjects who self-treat with exercise.
The relationship between vertigo frequency and intensity changes over time. Before treatment vertigo frequency and intensity are weakly related. After treatment vertigo frequency and intensity are strongly related, suggesting that they co-vary with improvement after care. This finding provides indirect support for the theory that BPPV is caused by otoconial matter displaced into the semicircular canal. If the particles become relocated to the utricle then the frequency of episodes and the intensity of sensation should decrease as fewer particles remain in the involved canal.
CRP is a robust treatment technique. As performed in this study CRP is as effective as the liberatory maneuver, 4
CRP without the second 90° turn, and CRP with additional “shaking” head motions, 15, 27
with other variations on CRP with medication and compared to a no-treatment control group, 28
compared to a different sham group than that used by Cohen and Kimball 21
for more than 3 trials, 8
or with variations in the duration of each position. 21
Some investigators have used cervical collars, 22
but CRP is effective without them. Vibration and postural restrictions do not influence effectiveness. 29, 30
Repositioning treatments appear to be efficacious, regardless of minor differences among maneuvers. If the head is moved in the appropriate motions, and rapidly enough -- approximately 55°/second to 75°/second, 14
the treatment is likely to be effective. Thus, minor variations in technique may not substantially influence the outcome of treatment and the clinician can be confident in using repositioning treatments with a wide variety of patients.
The clinician has several options for care and may tailor the treatment plan to meet the needs of the individual patient as long as the basic requirements for head movement are met. Several trials of CRP given in the out-patient clinic may be preferable because CRP takes only a few minutes but a home program takes several days. Therefore, the clinician need not feel obligated to recommend a home program, especially when musculoskeletal limitations make a home exercise program contraindicated.
The home-based repositioning exercises described here are effective, but with a caveat. The patient must be instructed properly. Patients do not learn exercises from printed directions. In this study, the senior author explained the premise of the exercise, demonstrated it herself, had the patient practice it, reiterated the instructions, give the patient written instructions to take home, and than had the patient repeat the instructions and ask questions. This process takes time. During treatment planning the clinician should decide if she has time to instruct the patient in home exercise or if office-based CRP would be as effective and more efficient. The recurrence rate for BPPV is high 24
so some patients may have recurrences. The clinician could use CRP in the office and then give a home exercise for use initially in the case of a recurrence. The patient could be encouraged to return for out-patient care if the home-based exercise does not resolve the symptoms.