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Approach to bilateral benign paroxysmal positioning vertigo
American Journal of Otolaryngology – Head and Neck Medicine and Surgery 27 (2006) 91 – 95 www.elsevier.com/locate/amjoto
Approach to bilateral benign paroxysmal positioning vertigo Lea Pollak, MDa,T, Rafael Stryjer, MDb, Mark Kushnir, MD, Shlomo Flechter, MDa a
Department of Neurology, Assaf Harofeh Medical Center, Zerifin, Israel b Department D, Mental Health Hospital, Beer-Yaacov, Israel Received 8 April 2005
Abstract
Background: Bilateral benign paroxysmal positioning vertigo (bBPPV) is rather rare, accounting for up to 10% in the reported benign paroxysmal positioning vertigo (BPPV) series. Inappropriate head positioning during testing in unilateral BPPV causes the otolith debris in the uppermost ear to move toward the cupula, resulting in an inhibitory nystagmus and mimicking bBPPV. Purpose: We analyzed the clinical data of patients with bilaterally positive Dix-Hallpike maneuver and compared them with the characteristics of patients with unilateral BPPV. We further tried to propose a simple schematic approach to the treatment of patients with bilaterally positive DixHallpike maneuver. Materials and methods: Medical records of 232 patients treated for BPPV at our dizziness clinic during 1999 to 2003 were reviewed. An algorithm used for the treatment of patients with bilaterally positive BPPV is discussed. Results: Twenty-eight patients with bilaterally positive Dix-Hallpike test were found. Sixteen were diagnosed with bBPPV, and 12 were diagnosed with unilateral mimicking bBPPV. Thirty patients with unilateral posterior canal BPPV served as control subjects.No difference in age, sex distribution, duration of symptoms, number of treatments per ear, and recurrence was found between bBPPV and unilateral BPPV. The female sex appeared to be predisposed for more treatments. The total duration of BPPV symptoms obtained by history was found to correlate with the number of recurrences after treatment. Conclusions: We conclude that bBPPV can be readily distinguished from unilateral mimicking bBPPV. Patients with bBPPV do not differ from patients with unilateral BPPV in clinical characteristics. The mechanism of otolith debris dislodgment appears to be the main cause of bilaterality, trauma being a more common trigger than other known causes of BPPV. D 2006 Elsevier Inc. All rights reserved.
1. Background Bilateral benign paroxysmal positioning vertigo (bBPPV) is rather rare, accounting for 6% to 26% in the reported benign paroxysmal positioning vertigo (BPPV) series [1-3]. It was reported to often be of traumatic origin and is considered to have a less favorable prognosis than unilateral BPPV [4-6]. Steddin and Brandt [7] described the entity of unilateral mimicking bilateral benign paroxysmal positioning vertigo
T Corresponding author. 4 Kibutz Galuyot St., Nes Ziona 74012, Israel. Tel.: +972 8 9404747; fax: +972 8 9401995. E-mail address: [email protected] (L. Pollak). 0196-0709/$ – see front matter D 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.amjoto.2005.07.012
(umbBPPV) where inappropriate head positioning during testing of the unaffected ear causes displacement of the affected canal from its perpendicular position. This makes the otolith debris move gravitationally toward the cupula evoking an inhibitory nystagmus. This nystagmus is directed to the unaffected ear and leads thus to the impression of bilateral posterior canal BPPV (Fig. 1). The inhibitory nystagmus usually has a lower amplitude and frequency than the excitatory nystagmus of the affected ear, and patients report less symptoms when the unaffected ear is tested. However, clinically, it is often difficult to distinguish between true bBPPV and umbBPPV and to decide which side should be treated first. We analyzed the clinical data of patients with bilaterally positive
92
L. Pollak et al. / American Journal of Otolaryngology – Head and Neck Medicine and Surgery 27 (2006) 91 – 95
Fig. 1. Unilateral mimicking bilateral left BPPV according to Steddin and Brandt [7]. r, right; l, left; A, anterior; H, horizontal; P, posterior; +, excitatory stimulus; -, inhibitory stimulus.
Dix-Hallpike maneuver and tried to suggest a simple schematic approach to the treatment.
2. Patients and methods Medical records of patients who were diagnosed and treated for posterior canal variant BPPV at our dizziness clinic during the years 1999 to 2003 were reviewed. The clinical characteristics of patients with bilaterally positive
Dix-Hallpike maneuver were analyzed and compared with characteristics of patients with unilateral posterior canal BPPV. All patients had a detailed clinical neurotological examination, which included examination of eye movements, the head-thrust test, the head shaking test using Frenzel’s glasses, examination of stance and gait, and positioning testing. The latter consisted of the Dix-Hallpike test, horizontal canal test, and head-down test. Patients with positive horizontal canal test were excluded from the study. Patients were treated by the repositioning maneuver of Epley and seen once weekly until the symptoms and signs cleared [8-11]. The following approach for treatment of patients with bilaterally positive Dix-Hallpike test is proposed (Fig. 2): If the obtained nystagmus is asymmetric, that is, on 1 side, it is of higher amplitude, faster, of shorter duration, and causes more vertigo, this is probably due to umbBPPV, and this side should be treated until disappearance of symptoms and signs. However, when it is difficult to decide which side is more symptomatic and/or the nystagmus presents rather symmetrically, a head down test, that is, extension of the head directly backward from the sitting to the supine straight head hanging position [12], might be helpful. Appearance of vertical upbeat nystagmus suggests true bBPPV. During the head down test, both posterior canals get irritated and the torsional component of the nystagmus, which has opposite directions, is cancelled, whereas the vertical component,
Fig. 2. Bilaterally positive Hallpike test. (A) Asymmetric nystagmus. (B) Symmetric nystagmus. aExtension of the head from the sitting to the supine head hanging position (see Methods). Ny, nystagmus; umb BPPV, unilateral mimicking bilateral BPPV; bBPPV, bilateral BPPV.
L. Pollak et al. / American Journal of Otolaryngology – Head and Neck Medicine and Surgery 27 (2006) 91 – 95
which shares the same direction, persists. However, if the nystagmus retains its rotational component, this is probably a case of umbBPPV and the direction of the rotation indicates the affected ear. 3. Statistical methods The characteristics of patients with bBPPV, umbBPPV, and BPPV were analyzed. Sex distribution and recurrence rate among the 3 groups were tested by the Pearson v 2. One-way analysis of variance was used to compare the mean age, present duration of symptoms, total duration of symptoms, and the time of recurrence after treatment. An LN of the total duration time was performed to obtain a normal distribution of data. Because the number of treatments per ear showed an abnormal distribution, the nonparametric Kruskal-Wallis test was applied to compare the treatment outcome in each group. In a similar way, we compared the data between the group of bBPPV and the group of umbBPPV and the posterior canal BPPV group together using the t test for age and duration of symptoms. The nonparametric MannWhitney test was applied for comparison of the number of treatments per ear between both groups. We further looked for correlation between the number of treatments per ear and the clinical characteristics of patients (age, present duration of symptoms, and total duration of symptoms) by the Pearson correlation test. Correlation between sex and treatment was examined by the MannWhitney test. Association between recurrence and other data was examined by comparing the means of the distinct parameters of patients with and without recurrence by the t test (for continuous parameters) and the v 2 test (for sex). 4. Results The data of patients with bilaterally positive DixHallpike test are summarized in Table 1. Among 232 patients treated for BPPV, we found 28 with bilaterally positive Dix-Hallpike maneuver. Sixteen patients (6%) were diagnosed with bBPPV and 12 (5%) with umbBPPV using the previous algorithm. Thirty patients with unilateral posterior canal BPPV served as control subjects. The mean age of patients with bBPPV was 60.2 years, and that of patients with umbBPPV was 50.8 years. The mean age of the control group was 56.9 years. Of 16 patients with bBPPV, 11 were women, whereas 8 of 12 patients with umbBPPV and 15 of 30 patients with BPPV were women. The mean duration of the present attack was 1.5 months in patients with bBPPV, and 1.1 months and 2.5 months in the umbBPPV and BPPV groups, respectively. The bBPPV group had a history of previous vertigo attacks during the last 6.3 years, and the umbBPPV group and the BPPV groups had a history of previous attacks during the last 2.6
93
Table 1 Characteristics of patients with bilateral and unilateral BPPV
Mean age (y) Range (y) Sex (men) Mean duration of present attack (mo) Range (mo) Mean of total duration (mo) Range (mo) Mean number of treatments per ear Range Recurrence (%)
bBPPV (n = 16)
umbBPPV (n = 12)
BPPV (n = 30)
P
60.2 F 12.7 35 –79 5 1.5 F 1.4
50.8 F 8.2 31– 62 4 1.1 F 1.6
56.9 F 13.9 33 – 82 15 2.5 F 3.3
NS NS NS
0.25 –5 76 F 139
0.1– 6 30.6 F 63.4
0.1–12 40.4 F 85.4
NS
0.25 – 432 1.4 F 0.6
0.25 –228 2.1 F 1.5
0.1– 360 1.6 F 1.2
NS
1–3 25
1–5 8
1–7 33
NS
NS indicates not statistically significant.
and 3.4 years, respectively. The mean number of treatments per ear was 1.4 in the bBPPV group, 2.1 in the umbBPPV group, and 1.6 in the BPPV group of patients. No statistical difference in age, sex distribution, duration of symptoms, and number of treatments was found between the 3 groups. The mean follow-up period was 17.6 months (range, 8-39 months). Recurrence after treatment was also similar in each group: symptoms and signs reoccurred in 4 patients with bBPPV (25%), in 1 patient with umbBPPV (8%), and in 10 patients with BPPV (33%) (Table 1). Only in 1 patient with bBPPV did the signs reoccur in both ears. A similar analysis was performed between the bBPPV and unilateral BPPV (umbBPPV + BPPV) groups. No statistical differences were found between either of the parameters. We looked for a correlation between the number of treatments per ear and other clinical characteristics. The female sex appeared to be predisposed for more treatments (mean of 1.9 treatments vs 1.2 in men) ( P = .048). Age, duration of symptoms, or total duration of symptoms did not influence treatment. We further looked for association between the recurrence rate and other variables: total duration of symptoms was found to be correlated with recurrences ( P = .052), whereas age, sex, duration of symptoms before first treatment, or number of treatments did not influence recurrence. In 4 patients (2 with bBPPV), positional vertigo appeared after a head trauma; in 1 patient, with umbBPPV it followed vestibular neuronitis; and in the remainder, it was idiopathic. 5. Discussion In this study, we analyzed the characteristics of patients with bBPPV and compared them with the characteristics of patients with unilateral BPPV. Patients with umbBPPV were considered separately. We found 6.8% of patients with bBPPV among 232 patients treated for BPPV during a period of 4 years. This number is consistent with the rate of bBPPV reported in
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L. Pollak et al. / American Journal of Otolaryngology – Head and Neck Medicine and Surgery 27 (2006) 91 – 95
other series [1-4]. We did not find differences in age, sex, duration of symptoms, or treatment responsiveness either between bBPPV and unilateral BPPV or between bBPPV, umbBPPV, and BPPV when compared separately. However, many more patients with bBPPV than unilateral BPPV were of traumatic origin (12.5% vs 0.9%) [4]. This allows us to conclude that bilaterality of BPPV is probably a result of the mechanism that causes the debris dislodgment and is not influenced by other factors such as age or duration of the symptoms. Females needed more treatments per ear than men. This is difficult to explain because we retreat only patients with a positive Hallpike test, that is, when the typical nystagmus is still present on follow-up examinations. Recurrence was encountered in 26% of all BPPV and in 25% of patients with bBPPV, which is in agreement with the reported recurrence rate of previous studies [8,13]. Among patients with umbBPPV, the recurrence rate was only 8%, but this might be due to the low number of patients in this subgroup. Positive correlation was found between recurrence of BPPV after treatment and total duration of symptoms, that is, period since positional vertigo occurred for the first time in life until it was recognized and treated. This might suggest that successful treatment of a BPPV attack does not influence its recurrence and that the clinical course of the disease is self-limited. We also tried to propose a simple approach for the treatment of bilateral posterior canal BPPV. Our approach is in accordance with principle of bnystagmus-based strategyQ of Epley while taking into consideration that when performing the provoking maneuver, the semicircular canal plane does not always lie in the ideal position [14]. This is due to the fact that the head is put into the required plane by the examiner only approximately by beye judgment.Q Moreover, the head positioning can be influenced by limitation of the patient’s neck movement, his skull form, or hairstyle [15]. Patients with a typical unilateral posterior canal BPPV report vertigo spells not only on lying down or bending but also when turning the head to sideways. The posterior canal is stimulated by movement in all planes except for the plane that is perpendicular to the pitch (vertical plane) of movement [7]. In a similar vein, patients with horizontal canal BPPV report vertigo not only when turning the head while supine but also when lying down or bending. We found the head down test to be helpful in distinguishing a true bBPPV from umbBPPV. However, if the head positioning is not performed in the proper vertical plane, false-positive unilateral nystagmus may appear. The bilateral involvement becomes obvious later if after the treatment of that side, nystagmus on the opposite side persists. The lack of optimal positioning of the semicircular canals is also the cause in cases when horizontal canalithiasis mimics a uni- or bilaterally positive Dix-Hallpike test. However, here, the nystagmus has a clearly horizontal
component and should be easily recognized by the examiner. Patients with a positive horizontal canal test were excluded from our study. It should be also mentioned that features of nystagmus of posterior canal origin change according to the eyeball position: they have a more prominent rotational component when the eye looks in the direction of the affected ear and a vertical character when the eye looks in the opposite direction [16]. Our algorithm can be applied only when the patient’s eye is in midposition during the testing. We conclude that bBPPV is rather rare and can be readily distinguished from umbBPPV using a simple treatment approach. Patients with bBPPV do not differ from unilateral BPPV in clinical characteristics. The main predictor of bilaterality is the cause of otolithic debris dislodgment, trauma being a more common trigger than other known causes of BPPV. It appears also that successful treatment does not influence the reoccurrence of an attack and that the clinical course of the disease is self-limited. Despite the quite large amount of information about the mechanism of BPPV today, the cause of BPPV is known only in a small proportion of patients. Further studies for elucidation of the causes that lead to displacement of otoliths in cases of idiopathic BPPV are certainly justified.
References [1] Korres S, Balatsouras DG, Kaberos A, et al. Occurrence of semicircular canal involvement in benign paroxysmal positional vertigo. Otol Neurotol 2002;23:926 - 32. [2] Petrone D, De Candia N, Cassano P. La cupulolitiasi bilaterale. Acta Otorhinolaryngol Ital 1997;17:215 - 8. [3] Gacek RR. Technique and results of singular neurectomy for the management of benign paroxysmal positional vertigo. Acta Otolaryngol 1995;115:154 - 7. [4] Katsarkas A. Benign paroxysmal positional vertigo (BPPV): idiopathic versus post-traumatic. Acta Otolaryngol 1999;119:745 - 9. [5] Macias JD, Lambert KM, Massingale S, et al. Variables affecting treatment in benign paroxysmal positional vertigo. Laryngoscope 2000;110:1921 - 4. [6] McClure JA, Parnes LS. A cure for benign positional vertigo. Baillieres Clin Neurol 1994;3:537 - 45. [7] Steddin S, Brandt T. Unilateral mimicking bilateral benign paroxysmal positioning vertigo. Arch Otolaryngol Head Neck Surg 1994; 120:1339 - 41. [8] Epley JM. The canalith repositioning procedure: for treatment of benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg 1992;107:399 - 404. [9] Radtke A, Neuhauser H, von Brevern M, et al. A modified Epley’s procedure for self-treatment of benign paroxysmal positional vertigo. Neurology 1999;53:1358 - 60. [10] Lempert T, Wolsley C, Davies R, et al. Three hundred sixty–degree rotation of the posterior semicircular canal for treatment of benign positional vertigo: a placebo-controlled trial. Neurology 1997;49: 729 - 33. [11] Froehling DA, Bowen JM, Mohr DN, Brey RH, et al. The canalith repositioning procedure for the treatment of benign paroxysmal positional vertigo: a randomized controlled trial. Mayo Clin Proc 2000;75:695 - 700. [12] Bertholon P, Bronstein AM, Davies RA, et al. Positional down beating nystagmus in 50 patients: cerebellar disorders and possible anterior
L. Pollak et al. / American Journal of Otolaryngology – Head and Neck Medicine and Surgery 27 (2006) 91 – 95 semicircular canal canalithiasis. J Neurol Neurosurg Psychiatry 2002;72:366 - 72. [13] Bronstein AM. Benign paroxysmal positional vertigo: some recent advances. Curr Opin Neurol 2003;16:1 - 3. [14] Epley JM. Human experience with canalith repositioning maneuvers. Ann N Y Acad Sci 2001;942:179 - 91.
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[15] Blanks RHI, Curthoys IS, Markham CH. Planar relationships of the semicircular canals in man. Acta Otolaryngol 1975;80:185 - 96. [16] Brandt T. Benign paroxysmal positioning vertigo. Vertigo. Its multisensory syndromes. 2nd ed. London7 Springer Verlag; 1999. p. 254.
Approach to bilateral benign paroxysmal positioning vertigo Lea Pollak, MDa,T, Rafael Stryjer, MDb, Mark Kushnir, MD, Shlomo Flechter, MDa a
Department of Neurology, Assaf Harofeh Medical Center, Zerifin, Israel b Department D, Mental Health Hospital, Beer-Yaacov, Israel Received 8 April 2005
Abstract
Background: Bilateral benign paroxysmal positioning vertigo (bBPPV) is rather rare, accounting for up to 10% in the reported benign paroxysmal positioning vertigo (BPPV) series. Inappropriate head positioning during testing in unilateral BPPV causes the otolith debris in the uppermost ear to move toward the cupula, resulting in an inhibitory nystagmus and mimicking bBPPV. Purpose: We analyzed the clinical data of patients with bilaterally positive Dix-Hallpike maneuver and compared them with the characteristics of patients with unilateral BPPV. We further tried to propose a simple schematic approach to the treatment of patients with bilaterally positive DixHallpike maneuver. Materials and methods: Medical records of 232 patients treated for BPPV at our dizziness clinic during 1999 to 2003 were reviewed. An algorithm used for the treatment of patients with bilaterally positive BPPV is discussed. Results: Twenty-eight patients with bilaterally positive Dix-Hallpike test were found. Sixteen were diagnosed with bBPPV, and 12 were diagnosed with unilateral mimicking bBPPV. Thirty patients with unilateral posterior canal BPPV served as control subjects.No difference in age, sex distribution, duration of symptoms, number of treatments per ear, and recurrence was found between bBPPV and unilateral BPPV. The female sex appeared to be predisposed for more treatments. The total duration of BPPV symptoms obtained by history was found to correlate with the number of recurrences after treatment. Conclusions: We conclude that bBPPV can be readily distinguished from unilateral mimicking bBPPV. Patients with bBPPV do not differ from patients with unilateral BPPV in clinical characteristics. The mechanism of otolith debris dislodgment appears to be the main cause of bilaterality, trauma being a more common trigger than other known causes of BPPV. D 2006 Elsevier Inc. All rights reserved.
1. Background Bilateral benign paroxysmal positioning vertigo (bBPPV) is rather rare, accounting for 6% to 26% in the reported benign paroxysmal positioning vertigo (BPPV) series [1-3]. It was reported to often be of traumatic origin and is considered to have a less favorable prognosis than unilateral BPPV [4-6]. Steddin and Brandt [7] described the entity of unilateral mimicking bilateral benign paroxysmal positioning vertigo
T Corresponding author. 4 Kibutz Galuyot St., Nes Ziona 74012, Israel. Tel.: +972 8 9404747; fax: +972 8 9401995. E-mail address: [email protected] (L. Pollak). 0196-0709/$ – see front matter D 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.amjoto.2005.07.012
(umbBPPV) where inappropriate head positioning during testing of the unaffected ear causes displacement of the affected canal from its perpendicular position. This makes the otolith debris move gravitationally toward the cupula evoking an inhibitory nystagmus. This nystagmus is directed to the unaffected ear and leads thus to the impression of bilateral posterior canal BPPV (Fig. 1). The inhibitory nystagmus usually has a lower amplitude and frequency than the excitatory nystagmus of the affected ear, and patients report less symptoms when the unaffected ear is tested. However, clinically, it is often difficult to distinguish between true bBPPV and umbBPPV and to decide which side should be treated first. We analyzed the clinical data of patients with bilaterally positive
92
L. Pollak et al. / American Journal of Otolaryngology – Head and Neck Medicine and Surgery 27 (2006) 91 – 95
Fig. 1. Unilateral mimicking bilateral left BPPV according to Steddin and Brandt [7]. r, right; l, left; A, anterior; H, horizontal; P, posterior; +, excitatory stimulus; -, inhibitory stimulus.
Dix-Hallpike maneuver and tried to suggest a simple schematic approach to the treatment.
2. Patients and methods Medical records of patients who were diagnosed and treated for posterior canal variant BPPV at our dizziness clinic during the years 1999 to 2003 were reviewed. The clinical characteristics of patients with bilaterally positive
Dix-Hallpike maneuver were analyzed and compared with characteristics of patients with unilateral posterior canal BPPV. All patients had a detailed clinical neurotological examination, which included examination of eye movements, the head-thrust test, the head shaking test using Frenzel’s glasses, examination of stance and gait, and positioning testing. The latter consisted of the Dix-Hallpike test, horizontal canal test, and head-down test. Patients with positive horizontal canal test were excluded from the study. Patients were treated by the repositioning maneuver of Epley and seen once weekly until the symptoms and signs cleared [8-11]. The following approach for treatment of patients with bilaterally positive Dix-Hallpike test is proposed (Fig. 2): If the obtained nystagmus is asymmetric, that is, on 1 side, it is of higher amplitude, faster, of shorter duration, and causes more vertigo, this is probably due to umbBPPV, and this side should be treated until disappearance of symptoms and signs. However, when it is difficult to decide which side is more symptomatic and/or the nystagmus presents rather symmetrically, a head down test, that is, extension of the head directly backward from the sitting to the supine straight head hanging position [12], might be helpful. Appearance of vertical upbeat nystagmus suggests true bBPPV. During the head down test, both posterior canals get irritated and the torsional component of the nystagmus, which has opposite directions, is cancelled, whereas the vertical component,
Fig. 2. Bilaterally positive Hallpike test. (A) Asymmetric nystagmus. (B) Symmetric nystagmus. aExtension of the head from the sitting to the supine head hanging position (see Methods). Ny, nystagmus; umb BPPV, unilateral mimicking bilateral BPPV; bBPPV, bilateral BPPV.
L. Pollak et al. / American Journal of Otolaryngology – Head and Neck Medicine and Surgery 27 (2006) 91 – 95
which shares the same direction, persists. However, if the nystagmus retains its rotational component, this is probably a case of umbBPPV and the direction of the rotation indicates the affected ear. 3. Statistical methods The characteristics of patients with bBPPV, umbBPPV, and BPPV were analyzed. Sex distribution and recurrence rate among the 3 groups were tested by the Pearson v 2. One-way analysis of variance was used to compare the mean age, present duration of symptoms, total duration of symptoms, and the time of recurrence after treatment. An LN of the total duration time was performed to obtain a normal distribution of data. Because the number of treatments per ear showed an abnormal distribution, the nonparametric Kruskal-Wallis test was applied to compare the treatment outcome in each group. In a similar way, we compared the data between the group of bBPPV and the group of umbBPPV and the posterior canal BPPV group together using the t test for age and duration of symptoms. The nonparametric MannWhitney test was applied for comparison of the number of treatments per ear between both groups. We further looked for correlation between the number of treatments per ear and the clinical characteristics of patients (age, present duration of symptoms, and total duration of symptoms) by the Pearson correlation test. Correlation between sex and treatment was examined by the MannWhitney test. Association between recurrence and other data was examined by comparing the means of the distinct parameters of patients with and without recurrence by the t test (for continuous parameters) and the v 2 test (for sex). 4. Results The data of patients with bilaterally positive DixHallpike test are summarized in Table 1. Among 232 patients treated for BPPV, we found 28 with bilaterally positive Dix-Hallpike maneuver. Sixteen patients (6%) were diagnosed with bBPPV and 12 (5%) with umbBPPV using the previous algorithm. Thirty patients with unilateral posterior canal BPPV served as control subjects. The mean age of patients with bBPPV was 60.2 years, and that of patients with umbBPPV was 50.8 years. The mean age of the control group was 56.9 years. Of 16 patients with bBPPV, 11 were women, whereas 8 of 12 patients with umbBPPV and 15 of 30 patients with BPPV were women. The mean duration of the present attack was 1.5 months in patients with bBPPV, and 1.1 months and 2.5 months in the umbBPPV and BPPV groups, respectively. The bBPPV group had a history of previous vertigo attacks during the last 6.3 years, and the umbBPPV group and the BPPV groups had a history of previous attacks during the last 2.6
93
Table 1 Characteristics of patients with bilateral and unilateral BPPV
Mean age (y) Range (y) Sex (men) Mean duration of present attack (mo) Range (mo) Mean of total duration (mo) Range (mo) Mean number of treatments per ear Range Recurrence (%)
bBPPV (n = 16)
umbBPPV (n = 12)
BPPV (n = 30)
P
60.2 F 12.7 35 –79 5 1.5 F 1.4
50.8 F 8.2 31– 62 4 1.1 F 1.6
56.9 F 13.9 33 – 82 15 2.5 F 3.3
NS NS NS
0.25 –5 76 F 139
0.1– 6 30.6 F 63.4
0.1–12 40.4 F 85.4
NS
0.25 – 432 1.4 F 0.6
0.25 –228 2.1 F 1.5
0.1– 360 1.6 F 1.2
NS
1–3 25
1–5 8
1–7 33
NS
NS indicates not statistically significant.
and 3.4 years, respectively. The mean number of treatments per ear was 1.4 in the bBPPV group, 2.1 in the umbBPPV group, and 1.6 in the BPPV group of patients. No statistical difference in age, sex distribution, duration of symptoms, and number of treatments was found between the 3 groups. The mean follow-up period was 17.6 months (range, 8-39 months). Recurrence after treatment was also similar in each group: symptoms and signs reoccurred in 4 patients with bBPPV (25%), in 1 patient with umbBPPV (8%), and in 10 patients with BPPV (33%) (Table 1). Only in 1 patient with bBPPV did the signs reoccur in both ears. A similar analysis was performed between the bBPPV and unilateral BPPV (umbBPPV + BPPV) groups. No statistical differences were found between either of the parameters. We looked for a correlation between the number of treatments per ear and other clinical characteristics. The female sex appeared to be predisposed for more treatments (mean of 1.9 treatments vs 1.2 in men) ( P = .048). Age, duration of symptoms, or total duration of symptoms did not influence treatment. We further looked for association between the recurrence rate and other variables: total duration of symptoms was found to be correlated with recurrences ( P = .052), whereas age, sex, duration of symptoms before first treatment, or number of treatments did not influence recurrence. In 4 patients (2 with bBPPV), positional vertigo appeared after a head trauma; in 1 patient, with umbBPPV it followed vestibular neuronitis; and in the remainder, it was idiopathic. 5. Discussion In this study, we analyzed the characteristics of patients with bBPPV and compared them with the characteristics of patients with unilateral BPPV. Patients with umbBPPV were considered separately. We found 6.8% of patients with bBPPV among 232 patients treated for BPPV during a period of 4 years. This number is consistent with the rate of bBPPV reported in
94
L. Pollak et al. / American Journal of Otolaryngology – Head and Neck Medicine and Surgery 27 (2006) 91 – 95
other series [1-4]. We did not find differences in age, sex, duration of symptoms, or treatment responsiveness either between bBPPV and unilateral BPPV or between bBPPV, umbBPPV, and BPPV when compared separately. However, many more patients with bBPPV than unilateral BPPV were of traumatic origin (12.5% vs 0.9%) [4]. This allows us to conclude that bilaterality of BPPV is probably a result of the mechanism that causes the debris dislodgment and is not influenced by other factors such as age or duration of the symptoms. Females needed more treatments per ear than men. This is difficult to explain because we retreat only patients with a positive Hallpike test, that is, when the typical nystagmus is still present on follow-up examinations. Recurrence was encountered in 26% of all BPPV and in 25% of patients with bBPPV, which is in agreement with the reported recurrence rate of previous studies [8,13]. Among patients with umbBPPV, the recurrence rate was only 8%, but this might be due to the low number of patients in this subgroup. Positive correlation was found between recurrence of BPPV after treatment and total duration of symptoms, that is, period since positional vertigo occurred for the first time in life until it was recognized and treated. This might suggest that successful treatment of a BPPV attack does not influence its recurrence and that the clinical course of the disease is self-limited. We also tried to propose a simple approach for the treatment of bilateral posterior canal BPPV. Our approach is in accordance with principle of bnystagmus-based strategyQ of Epley while taking into consideration that when performing the provoking maneuver, the semicircular canal plane does not always lie in the ideal position [14]. This is due to the fact that the head is put into the required plane by the examiner only approximately by beye judgment.Q Moreover, the head positioning can be influenced by limitation of the patient’s neck movement, his skull form, or hairstyle [15]. Patients with a typical unilateral posterior canal BPPV report vertigo spells not only on lying down or bending but also when turning the head to sideways. The posterior canal is stimulated by movement in all planes except for the plane that is perpendicular to the pitch (vertical plane) of movement [7]. In a similar vein, patients with horizontal canal BPPV report vertigo not only when turning the head while supine but also when lying down or bending. We found the head down test to be helpful in distinguishing a true bBPPV from umbBPPV. However, if the head positioning is not performed in the proper vertical plane, false-positive unilateral nystagmus may appear. The bilateral involvement becomes obvious later if after the treatment of that side, nystagmus on the opposite side persists. The lack of optimal positioning of the semicircular canals is also the cause in cases when horizontal canalithiasis mimics a uni- or bilaterally positive Dix-Hallpike test. However, here, the nystagmus has a clearly horizontal
component and should be easily recognized by the examiner. Patients with a positive horizontal canal test were excluded from our study. It should be also mentioned that features of nystagmus of posterior canal origin change according to the eyeball position: they have a more prominent rotational component when the eye looks in the direction of the affected ear and a vertical character when the eye looks in the opposite direction [16]. Our algorithm can be applied only when the patient’s eye is in midposition during the testing. We conclude that bBPPV is rather rare and can be readily distinguished from umbBPPV using a simple treatment approach. Patients with bBPPV do not differ from unilateral BPPV in clinical characteristics. The main predictor of bilaterality is the cause of otolithic debris dislodgment, trauma being a more common trigger than other known causes of BPPV. It appears also that successful treatment does not influence the reoccurrence of an attack and that the clinical course of the disease is self-limited. Despite the quite large amount of information about the mechanism of BPPV today, the cause of BPPV is known only in a small proportion of patients. Further studies for elucidation of the causes that lead to displacement of otoliths in cases of idiopathic BPPV are certainly justified.
References [1] Korres S, Balatsouras DG, Kaberos A, et al. Occurrence of semicircular canal involvement in benign paroxysmal positional vertigo. Otol Neurotol 2002;23:926 - 32. [2] Petrone D, De Candia N, Cassano P. La cupulolitiasi bilaterale. Acta Otorhinolaryngol Ital 1997;17:215 - 8. [3] Gacek RR. Technique and results of singular neurectomy for the management of benign paroxysmal positional vertigo. Acta Otolaryngol 1995;115:154 - 7. [4] Katsarkas A. Benign paroxysmal positional vertigo (BPPV): idiopathic versus post-traumatic. Acta Otolaryngol 1999;119:745 - 9. [5] Macias JD, Lambert KM, Massingale S, et al. Variables affecting treatment in benign paroxysmal positional vertigo. Laryngoscope 2000;110:1921 - 4. [6] McClure JA, Parnes LS. A cure for benign positional vertigo. Baillieres Clin Neurol 1994;3:537 - 45. [7] Steddin S, Brandt T. Unilateral mimicking bilateral benign paroxysmal positioning vertigo. Arch Otolaryngol Head Neck Surg 1994; 120:1339 - 41. [8] Epley JM. The canalith repositioning procedure: for treatment of benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg 1992;107:399 - 404. [9] Radtke A, Neuhauser H, von Brevern M, et al. A modified Epley’s procedure for self-treatment of benign paroxysmal positional vertigo. Neurology 1999;53:1358 - 60. [10] Lempert T, Wolsley C, Davies R, et al. Three hundred sixty–degree rotation of the posterior semicircular canal for treatment of benign positional vertigo: a placebo-controlled trial. Neurology 1997;49: 729 - 33. [11] Froehling DA, Bowen JM, Mohr DN, Brey RH, et al. The canalith repositioning procedure for the treatment of benign paroxysmal positional vertigo: a randomized controlled trial. Mayo Clin Proc 2000;75:695 - 700. [12] Bertholon P, Bronstein AM, Davies RA, et al. Positional down beating nystagmus in 50 patients: cerebellar disorders and possible anterior
L. Pollak et al. / American Journal of Otolaryngology – Head and Neck Medicine and Surgery 27 (2006) 91 – 95 semicircular canal canalithiasis. J Neurol Neurosurg Psychiatry 2002;72:366 - 72. [13] Bronstein AM. Benign paroxysmal positional vertigo: some recent advances. Curr Opin Neurol 2003;16:1 - 3. [14] Epley JM. Human experience with canalith repositioning maneuvers. Ann N Y Acad Sci 2001;942:179 - 91.
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[15] Blanks RHI, Curthoys IS, Markham CH. Planar relationships of the semicircular canals in man. Acta Otolaryngol 1975;80:185 - 96. [16] Brandt T. Benign paroxysmal positioning vertigo. Vertigo. Its multisensory syndromes. 2nd ed. London7 Springer Verlag; 1999. p. 254.