Benign paroxysmal positional vertigo predominantly affects the right labyrinth
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《神经病学神经外科学杂志》
1 Neurologische Klinik, Charité, Campus Virchow-Klinikum, Berlin, Germany
2 Robert-Koch-Institut, Berlin, Germany
3 Neurologische Abteilung, Schlosspark-Klinik, Berlin, Germany
Correspondence to:
Dr M von Brevern
michael.von_brevern@charite.de
ABSTRACT
Benign paroxysmal positional vertigo (BPPV) occurs when there are freely moving particles in a semicircular canal and the head is turned in the plane of the affected canal. The aim of the present study was to clarify whether BPPV manifests equally in both labyrinths or whether there is a preponderance for one side. We conducted a PubMed literature search of BPPV case series which specified the affected side and a retrospective chart review of 80 consecutive patients with BPPV of the posterior canal who had presented at our dizziness clinic.
Eighteen studies with a total of 3426 patients were identified. In our own series the right side was affected in 54 of 80 patients (right/left ratio 2.08). Altogether, in 3506 patients the right labyrinth was involved 1.41 times more often than the left (95% CI 1.37 to 1.45). We think that the reason for the predominant involvement of the right ear in BPPV is the habit—of most patients—of sleeping on the right side.
Abbreviations: BPPV, benign paroxysmal positional vertigo
Keywords: benign paroxysmal positional vertigo; utricle; canalolithiasis; otoconia
Benign paroxysmal positional vertigo (BPPV) is the commonest vestibular disorder, accounting for about 20% of referrals in specialist dizziness clinics. According to the widely
Theoretically, one would expect that this pathology affects both ears equally. So far this has not been systematically investigated and the aim of the present study was to clarify whether BPPV involves one ear more often than the other.
METHODS
The PubMed database was searched from 1966 to December 2002 to identify case series of patients with BPPV. Only those studies were selected which included more than 20 patients with unilateral BPPV and specified the affected side. Another requirement was confirmation of the diagnosis by observation of typical nystagmus during a provocative manoeuvre. Those studies which exclusively included patients with BPPV of the horizontal canal were excluded.
In addition, a retrospective chart review was conducted to identify the affected side in all patients with unilateral BPPV of the posterior canal who had presented to our dizziness clinic between January 2001 and September 2003.
RESULTS
The PubMed search yielded 18 case series which specified the side affected by BPPV in a total of 3426 patients (table 1).3–20 The right ear was affected in 1999 patients and the left in 1427, thus the right ear was involved 1.40 times more often than the left. Only two of 18 studies described more patients with BPPV on the left than on the right side.5,9 Of 80 patients presenting to our dizziness clinic with unilateral BPPV of the posterior canal, 54 had the right ear affected (right/left ratio 2.08). Altogether, in the 3506 patients included in this study the right labyrinth was affected 1.41 times more often than the left (95% CI 1.37 to 1.45).
Table 1 Laterality of ear affected by benign paroxysmal positional vertigo (BPPV) in 18 studies reported in the literature and patients presenting to the dizziness clinic
DISCUSSION
According to the canalolithiasis theory typical BPPV of the posterior canal is caused by otoconia that dislodge from the utricle and enter the semicircular canal where they move freely within the endolymph.1 This theory explains all features of BPPV and has been corroborated by the finding of dense particulate matter, free floating in the endolymph of the posterior canal of patients with BPPV.2 It is now known that BPPV develops in stages: first the otoconia detach from the utricular matrix, and then they enter into a semicircular canal when the head assumes a critical position. Furthermore, it has been shown by means of physiomathematical models that the prerequisites for BPPV are: (i) there should be approximately 62 otoconia within the semicircular canal and (ii) these particles have to agglomerate in order to exert a hydrodynamic effect when moving in the canal.21
Our study shows that the right ear is predominantly affected by BPPV. How can this predilection be explained on the basis of the canalolithiasis model? There are five factors which apparently predispose to BPPV: trauma to the head, other ear disease, advanced age, migraine, and bed rest.22,23 The first four factors probably account for the detachment of otoconia from the utricle by mechanical means or degenerative and ischaemic changes, but it seems unlikely that one ear is affected more often by one of these mechanisms than the other. Most studies included patients with both idiopathic and secondary BPPV. One case series also showed a preponderance of right sided BPPV in a group of patients with secondary BPPV due to inner ear disease.10 Prolonged bed rest probably facilitates agglomeration of otoconia, but again, this should apply equally to both labyrinths.
Since damage to the utricle and agglomeration of otoconia are unlikely reasons for the predominance of the right side, we suspect that the critical mechanism occurs in the last stage in the pathophysiology of BPPV: the entry of particles into a semicircular canal depending on the position of the head.
Interestingly, sleep seems to be involved in the pathophysiology of BPPV and many patients experience their first attack when moving in bed after awakening.12 Recently, it has been shown that the side affected by BPPV correlates with the preferred position in bed: in 33 of 45 patients with BPPV of the posterior canal the side of the involved semicircular canal was the side patients used to lie on. Most patients slept in the right supine position and had BPPV on the right.13 Freely moving otoconia in the labyrinth have a higher density than endolymph and follow gravity. In the right lateral supine position the openings of both the right posterior and the horizontal canals are in the lowermost position, which facilitates entry of heavy particles from the utricle. Thus one might speculate that BPPV predominantly involves the right ear because many persons prefer to sleep on the right side, possibly due to an uncomfortable awareness of the heart beat when lying on the left side. Positions during sleep have
REFERENCES
Brandt T , Steddin S. Current view of the mechanisms of benign paroxysmal positioning vertigo: cupulolithiasis or canalolithiasis? J Vestib Res 1993;3:373–82.
Welling DB, Parnes LS, O’Brien B, et al. Particulate matter in the posterior semicircular canal. Laryngoscope 1997;107:90–4.
Asawavichianginda S , Isipradit P, Snidvongs K, et al. Canalith repositioning for benign paroxysmal positional vertigo: a randomized, controlled trial. Ear Nose Throat J 2000;79:732–7.
Blakley BW. A randomized, controlled assessment of the canalith repositioning maneuver. Otolaryngol Head Neck Surg 1994;110:391–6.
Brandt T , Daroff RB. Physical therapy for benign paroxysmal positional vertigo. Arch Otolaryngol 1980;106:484–5.
Dal T , ?zlüolu LN, Ergin NT. The canalith repositioning maneuver in patients with benign positional vertigo. Eur Arch Otorhinolaryngol 2000;257:133–6.
Epley JM. The canalith repositioning procedure: for treatment of benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg 1992;107:399–404.
Froehling DA, Bowen JM, Mohr DN, 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.
Harvey SA, Hain TC, Adamiec LC. Modified liberatory maneuver: effective treatment for benign paroxysmal positional vertigo. Laryngoscope 1994;104:1206–12.
Karlberg M , Hall K, Quickert N, et al. What inner ear disease cause benign paroxysmal positional vertigo? Acta Otolaryngol 2000;120:380–5.
Katsarkas A . Benign paroxysmal positional vertigo (BPPV): idiopathic versus post-traumatic. Acta Otolaryngol 1999;119:745–9.
Korres S , Balatsouras DG, Kaberos A, et al. Occurrence of semicircular canal involvement in benign paroxysmal positional vertigo. Otol Neurotol 2002;23:926–32.
Lopez-Escámez JA, Gámiz MJ, Fiana MG, et al. Position in bed is associated with left or right location in benign paroxysmal positional vertigo of the posterior semicircular canal. Am J Otolaryngol 2002;23:263–6.
Marciano E , Marcelli V. Postural restrictions in labyrintholithiasis. Eur Arch Otorhinolaryngol 2002;259:262–5.
Nuti D , Nati C, Passali D. Treatment of benign paroxysmal positional vertigo: no need for postmaneuver restrictions. Otolaryngol Head Neck Surg 2000;122:440–4.
O’Reilly RC, Elford B, Slater R. Effectiveness of the particle repositioning maneuver in subtypes of benign paroxysmal positional vertigo. Laryngoscope 2000;110:1385–8.
Sargent EW, Bankaitis AE, Hollenbeak CS, et al. Mastoid oscillation in canalith repositioning for paroxysmal positional vertigo. Otol Neurotol 2001;22:205–9.
Serafini G , Palmieri AM, Simincelli C. Benign paroxysmal positional vertigo of posterior semicircular canal: results in 160 cases treated with Semont’s maneuver. Ann Otol Rhinol Laryngol 1996;105:770–5.
Soto Varela A , Bartual Magro J, Santos Pérez S, et al. Benign paroxysmal vertigo: a comparative prospective study of Brandt and Daroff exercises, Semont and Epley manoeuvre. Rev Laryngol Otol Rhinol 2001;122:179–83.
Wolf JS, Boyev KP, Manokey J, et al. Success of the modified Epley maneuver in treating benign paroxysmal positional vertigo. Laryngoscope 1999;109:900–3.
House MG, Honrubia V. Theoretical models for the mechanisms of benign paroxysmal positional vertigo. Audiol Neurootol 2003;8:91–9.
Epley JM. Positional vertigo related to semicircular canalithiasis. Otolaryngol Head Neck Surg 1995;112:154–61.
Ishiyama A , Jacobson KM, Baloh RW. Migraine and benign positional vertigo. Ann Otol Rhinol Laryngol 2000;109:377–80.
Leung RST, Bowman ME, Parker JD, et al. Avoidance of the left lateral decubitus position during sleep in patients with heart failure: relationship to cardiac size and function. J Am Coll Cardiol 2003;41:227–30.(M von Brevern1, T Seelig1)
2 Robert-Koch-Institut, Berlin, Germany
3 Neurologische Abteilung, Schlosspark-Klinik, Berlin, Germany
Correspondence to:
Dr M von Brevern
michael.von_brevern@charite.de
ABSTRACT
Benign paroxysmal positional vertigo (BPPV) occurs when there are freely moving particles in a semicircular canal and the head is turned in the plane of the affected canal. The aim of the present study was to clarify whether BPPV manifests equally in both labyrinths or whether there is a preponderance for one side. We conducted a PubMed literature search of BPPV case series which specified the affected side and a retrospective chart review of 80 consecutive patients with BPPV of the posterior canal who had presented at our dizziness clinic.
Eighteen studies with a total of 3426 patients were identified. In our own series the right side was affected in 54 of 80 patients (right/left ratio 2.08). Altogether, in 3506 patients the right labyrinth was involved 1.41 times more often than the left (95% CI 1.37 to 1.45). We think that the reason for the predominant involvement of the right ear in BPPV is the habit—of most patients—of sleeping on the right side.
Abbreviations: BPPV, benign paroxysmal positional vertigo
Keywords: benign paroxysmal positional vertigo; utricle; canalolithiasis; otoconia
Benign paroxysmal positional vertigo (BPPV) is the commonest vestibular disorder, accounting for about 20% of referrals in specialist dizziness clinics. According to the widely
Theoretically, one would expect that this pathology affects both ears equally. So far this has not been systematically investigated and the aim of the present study was to clarify whether BPPV involves one ear more often than the other.
METHODS
The PubMed database was searched from 1966 to December 2002 to identify case series of patients with BPPV. Only those studies were selected which included more than 20 patients with unilateral BPPV and specified the affected side. Another requirement was confirmation of the diagnosis by observation of typical nystagmus during a provocative manoeuvre. Those studies which exclusively included patients with BPPV of the horizontal canal were excluded.
In addition, a retrospective chart review was conducted to identify the affected side in all patients with unilateral BPPV of the posterior canal who had presented to our dizziness clinic between January 2001 and September 2003.
RESULTS
The PubMed search yielded 18 case series which specified the side affected by BPPV in a total of 3426 patients (table 1).3–20 The right ear was affected in 1999 patients and the left in 1427, thus the right ear was involved 1.40 times more often than the left. Only two of 18 studies described more patients with BPPV on the left than on the right side.5,9 Of 80 patients presenting to our dizziness clinic with unilateral BPPV of the posterior canal, 54 had the right ear affected (right/left ratio 2.08). Altogether, in the 3506 patients included in this study the right labyrinth was affected 1.41 times more often than the left (95% CI 1.37 to 1.45).
Table 1 Laterality of ear affected by benign paroxysmal positional vertigo (BPPV) in 18 studies reported in the literature and patients presenting to the dizziness clinic
DISCUSSION
According to the canalolithiasis theory typical BPPV of the posterior canal is caused by otoconia that dislodge from the utricle and enter the semicircular canal where they move freely within the endolymph.1 This theory explains all features of BPPV and has been corroborated by the finding of dense particulate matter, free floating in the endolymph of the posterior canal of patients with BPPV.2 It is now known that BPPV develops in stages: first the otoconia detach from the utricular matrix, and then they enter into a semicircular canal when the head assumes a critical position. Furthermore, it has been shown by means of physiomathematical models that the prerequisites for BPPV are: (i) there should be approximately 62 otoconia within the semicircular canal and (ii) these particles have to agglomerate in order to exert a hydrodynamic effect when moving in the canal.21
Our study shows that the right ear is predominantly affected by BPPV. How can this predilection be explained on the basis of the canalolithiasis model? There are five factors which apparently predispose to BPPV: trauma to the head, other ear disease, advanced age, migraine, and bed rest.22,23 The first four factors probably account for the detachment of otoconia from the utricle by mechanical means or degenerative and ischaemic changes, but it seems unlikely that one ear is affected more often by one of these mechanisms than the other. Most studies included patients with both idiopathic and secondary BPPV. One case series also showed a preponderance of right sided BPPV in a group of patients with secondary BPPV due to inner ear disease.10 Prolonged bed rest probably facilitates agglomeration of otoconia, but again, this should apply equally to both labyrinths.
Since damage to the utricle and agglomeration of otoconia are unlikely reasons for the predominance of the right side, we suspect that the critical mechanism occurs in the last stage in the pathophysiology of BPPV: the entry of particles into a semicircular canal depending on the position of the head.
Interestingly, sleep seems to be involved in the pathophysiology of BPPV and many patients experience their first attack when moving in bed after awakening.12 Recently, it has been shown that the side affected by BPPV correlates with the preferred position in bed: in 33 of 45 patients with BPPV of the posterior canal the side of the involved semicircular canal was the side patients used to lie on. Most patients slept in the right supine position and had BPPV on the right.13 Freely moving otoconia in the labyrinth have a higher density than endolymph and follow gravity. In the right lateral supine position the openings of both the right posterior and the horizontal canals are in the lowermost position, which facilitates entry of heavy particles from the utricle. Thus one might speculate that BPPV predominantly involves the right ear because many persons prefer to sleep on the right side, possibly due to an uncomfortable awareness of the heart beat when lying on the left side. Positions during sleep have
REFERENCES
Brandt T , Steddin S. Current view of the mechanisms of benign paroxysmal positioning vertigo: cupulolithiasis or canalolithiasis? J Vestib Res 1993;3:373–82.
Welling DB, Parnes LS, O’Brien B, et al. Particulate matter in the posterior semicircular canal. Laryngoscope 1997;107:90–4.
Asawavichianginda S , Isipradit P, Snidvongs K, et al. Canalith repositioning for benign paroxysmal positional vertigo: a randomized, controlled trial. Ear Nose Throat J 2000;79:732–7.
Blakley BW. A randomized, controlled assessment of the canalith repositioning maneuver. Otolaryngol Head Neck Surg 1994;110:391–6.
Brandt T , Daroff RB. Physical therapy for benign paroxysmal positional vertigo. Arch Otolaryngol 1980;106:484–5.
Dal T , ?zlüolu LN, Ergin NT. The canalith repositioning maneuver in patients with benign positional vertigo. Eur Arch Otorhinolaryngol 2000;257:133–6.
Epley JM. The canalith repositioning procedure: for treatment of benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg 1992;107:399–404.
Froehling DA, Bowen JM, Mohr DN, 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.
Harvey SA, Hain TC, Adamiec LC. Modified liberatory maneuver: effective treatment for benign paroxysmal positional vertigo. Laryngoscope 1994;104:1206–12.
Karlberg M , Hall K, Quickert N, et al. What inner ear disease cause benign paroxysmal positional vertigo? Acta Otolaryngol 2000;120:380–5.
Katsarkas A . Benign paroxysmal positional vertigo (BPPV): idiopathic versus post-traumatic. Acta Otolaryngol 1999;119:745–9.
Korres S , Balatsouras DG, Kaberos A, et al. Occurrence of semicircular canal involvement in benign paroxysmal positional vertigo. Otol Neurotol 2002;23:926–32.
Lopez-Escámez JA, Gámiz MJ, Fiana MG, et al. Position in bed is associated with left or right location in benign paroxysmal positional vertigo of the posterior semicircular canal. Am J Otolaryngol 2002;23:263–6.
Marciano E , Marcelli V. Postural restrictions in labyrintholithiasis. Eur Arch Otorhinolaryngol 2002;259:262–5.
Nuti D , Nati C, Passali D. Treatment of benign paroxysmal positional vertigo: no need for postmaneuver restrictions. Otolaryngol Head Neck Surg 2000;122:440–4.
O’Reilly RC, Elford B, Slater R. Effectiveness of the particle repositioning maneuver in subtypes of benign paroxysmal positional vertigo. Laryngoscope 2000;110:1385–8.
Sargent EW, Bankaitis AE, Hollenbeak CS, et al. Mastoid oscillation in canalith repositioning for paroxysmal positional vertigo. Otol Neurotol 2001;22:205–9.
Serafini G , Palmieri AM, Simincelli C. Benign paroxysmal positional vertigo of posterior semicircular canal: results in 160 cases treated with Semont’s maneuver. Ann Otol Rhinol Laryngol 1996;105:770–5.
Soto Varela A , Bartual Magro J, Santos Pérez S, et al. Benign paroxysmal vertigo: a comparative prospective study of Brandt and Daroff exercises, Semont and Epley manoeuvre. Rev Laryngol Otol Rhinol 2001;122:179–83.
Wolf JS, Boyev KP, Manokey J, et al. Success of the modified Epley maneuver in treating benign paroxysmal positional vertigo. Laryngoscope 1999;109:900–3.
House MG, Honrubia V. Theoretical models for the mechanisms of benign paroxysmal positional vertigo. Audiol Neurootol 2003;8:91–9.
Epley JM. Positional vertigo related to semicircular canalithiasis. Otolaryngol Head Neck Surg 1995;112:154–61.
Ishiyama A , Jacobson KM, Baloh RW. Migraine and benign positional vertigo. Ann Otol Rhinol Laryngol 2000;109:377–80.
Leung RST, Bowman ME, Parker JD, et al. Avoidance of the left lateral decubitus position during sleep in patients with heart failure: relationship to cardiac size and function. J Am Coll Cardiol 2003;41:227–30.(M von Brevern1, T Seelig1)