- Email: [email protected]
Sudden hearing loss with simultaneous posterior semicircular canal BPPV: Possible etiology and clinical implications
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI NE AN D SUR G E RY 3 5 ( 2 0 14 ) 18 0–1 8 5
Available online at www.sciencedirect.com
ScienceDirect www.elsevier.com/locate/amjoto
Sudden hearing loss with simultaneous posterior semicircular canal BPPV: Possible etiology and clinical implications Sabri El-Saied, MD⁎, Ben-Zion Joshua, MD, Nili Segal, MD, Mordechai Kraus, MD, Daniel M. Kaplan, MD Department of Otolaryngology-Head and Neck Surgery, Soroka University Medical Center and the Faculty of Health Science, Ben-Gurion University in the Negev, Beer-Sheva, Israel
ARTI CLE I NFO
A BS TRACT
Article history:
Objectives: The objectives of this study were to describe the clinical course and outcome of
Received 10 August 2013
patients with sudden sensorineural hearing loss (SSNHL) in conjunction with benign paroxysmal positional vertigo (BPPV), and hypothesize the possible pathophysiology of this entity. Study design: Retrospective study of all patients with evidence of SSNHL with any type of BPPV between 2008 and 2012. Settings: Tertiary care university hospital. Subjects and methods: Five patients aged 56 to 71 were diagnosed with unilateral profound SSNHL and BPPV. Neurotologic examination revealed an ipsilateral torsional, up-beating nystagmus on Dix–Hallpike exam. Severe or profound ipsilateral–sensorineural hearing loss was recognized on audiometry. The rest of the exam was normal; this was in keeping with the diagnosis of SSNHL with ipsilateral posterior semicircular canal BPPV. Results: All patients were treated with a modified Epley maneuver; oral steroids were administered for two weeks. In all cases vertigo resolved and the Dix–Hallpike exam became normal within several weeks. However, the hearing loss remained unchanged in two patients. Magnetic resonance imaging of the head was normal and ENG caloric test demonstrated mild ipsilateral canal paresis in two patients. Conclusions: 1. Patients with SSNHL and BPPV can have a variable clinical course and outcome. This entity may be quite common, but the diagnosis of BPPV can be missed if a complete neurological physical examination is not performed. 2. Arterial occlusions or selective multiple vascular or neural involvement may explain the pathophysiology of SSNHL with BPPV of the posterior semicircular canal. © 2014 Elsevier Inc. All rights reserved.
1.
Introduction
The annual incidence of sudden sensorineural hearing loss (SSNHL) ranges from 5 to 20 cases per 100,000 persons [1]. The causes of SSNHL are speculative and may be multifactorial.
The most common definition of sudden sensorineural hearing loss is a loss of 30 dB or more across ≥ 3 continuous frequencies within 72 h [2]. Vertigo is seen in about 30%–40% of cases of SSNHL [3] and is considered to be a poor prognostic factor for hearing recovery [4]. In one study vertigo was not an unfavorable sign of hearing
⁎ Corresponding author. Department of Otolaryngology-Head & Neck Surgery, Soroka University Medical Center, Beer-Sheva, Israel. Tel.: +972 8 640 0635; fax: + 972 8 640 3037. E-mail addresses: [email protected], [email protected] (S. El-Saied). 0196-0709/$ – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjoto.2013.08.021
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI N E AN D SUR G E RY 3 5 ( 2 0 14 ) 18 0–1 8 5
181
Table 1 – Patient clinical data. Medical history
Hearing loss
Caloric Test
F 71
HTN
Severe
M 50
DM + HTN
Profound
F61
DM
Severe
F56
Amaurosis fugax S/P mitral valve replacement
F56
MRI
Treatment
Outcome
Normal
Normal
Mild canal paresis (27%) Normal
Normal
Vertigo: resolved Hearing: no change Vertigo: resolved Hearing loss: resolved Vertigo: resolved Hearing loss: improved
Profound
Mild canal paresis (27%)
Normal
Profound
Normal
Normal
P.O. Prednisone mEM P.O. Predisone mEM P.O. Prednisone mEM IT-MP P.O. Prednisone mEM IT-MP P.O. Prednisone mEM
Normal
Vertigo: resolved Hearing: no change Vertigo: resolved Hearing loss: resolved
mEM, Modified Epley maneuver; IT-MP, intratympanic methylprednisolone; DM, Diabetes mellitus; HTN, hypertension.
recovery [5]. One explanation for this discrepancy is that vertigo is a symptom and not a specific entity, and the studies do not differentiate types of vertigo. The most common type of vertigo, in general, is benign paroxysmal positional vertigo (BPPV). Several previous studies have observed and discussed BPPV and SSNHL occurring simultaneously [6–8]. BPPV most commonly involves the posterior semicircular canal, which is characterized by typical findings on Dix–Hallpike exam—up-beating, rotional, geotropic nystagmus found on one side with a latency of 5 to 10 s, and fatiguing within 10–20 s. Other, less common types of BPPV include horizontal SCC, which is diagnosed with the roll test, and anterior SCC, which is also diagnosed by the Dix–Hallpike exam. The objective of our study was to describe a group of patients with simultaneous SSNHL and BPPV, review the possible etiology, and present conclusions on the clinical implications.
2.
Patients and methods
After approval of the hospital’s Ethic committee Files of all patients with confirmed or suspected SSNHL, who were admitted to the Department of Otolaryngology-Head & Neck Surgery were reviewed. SSNHL was defined as a hearing impairment of greater than 30 dB in three contiguous frequencies that occurred in less than 3 days in the absence of a skull fracture [2]. A complete neurological exam was performed when there were symptoms of vertigo. All patients with evidence of any type of BPPV and SSNHL between 2008 and 2012 were followed and their clinical findings were documented in the clinic. A modification of the Epley maneuver (mEM) was used for treatment of pBPPV; neither premedication nor oscillation was used during the maneuver. All patients were closely followed up in our out-patient clinic until hearing stabilized, the patients had no further symptoms of vertigo, and the medical investigation was completed.
3.
Results
Five patients with unilateral SSNHL were identified with BPPV. All the patients presented with SSNHL and a few hours later experienced positional vertigo with nausea.
In all of these patients the Dix–Hallpike exam was positive for ipsilateral up-beating and torsional geotropic–symptomatic nystagmus. The roll test for diagnosis of lateral SCC BPPV was normal, there were no gait disturbances, head impulse tests on both sides were negative, and no post-headshake nystagmus was observed. This was in keeping with the diagnosis of posterior semicircular canal BPPV. The main clinical data of these patients are presented in Table 1. Audiometry revealed severe to profound hearing loss of the affected ear, with reduced speech discrimination (40%–60%), and normal hearing in the contra-lateral ear. All patients were treated with a mEM, and oral steroids (1 mg/kg) were administered for one week, after which the dosage was gradually reduced for an additional week. Two patients (3 and 4) also received salvage intratympanic prednisolone (62.5 mg/ml) 3 times. In total, hearing remained unchanged in two patients and three patients had complete recovery of hearing (e.g., Figs. 1 and 2). All patients responded to one mEM with the DH exam normalizing and becoming asymptomatic one month following the incident. Videonystagmography (VNG) caloric exam performed between 2 and 4 weeks after presentation demonstrated a mild ipsilateral canal paresis in patients 1 and 3, with excitability differences of 27%. Post-contrast Magnetic Resonance (MR) of the head showed normal internal auditory canals and cerebellopontine angles, and no enhancement of the vestibular or cochlear nerves.
4.
Discussion
While vertigo commonly accompanies SSNHL as a symptom, there are few reports describing both SSNHL and BPPV simultaneously; [6–8] some of them hypothesized about the etiology [8]. In this report we describe five patients and discuss the possible etiology and the clinical significance of this entity. When exploring the possible etiology of simultaneous SSNHL and BPPV we must first clarify the anatomical structures involved. If the whole auditory–vestibular nerve bundle or the whole vestibular labyrinth would have been involved, we would expect severe non-positional vertigo (aside from the hearing loss) as seen in cases of vestibular
182
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI NE AN D SUR G E RY 3 5 ( 2 0 14 ) 18 0–1 8 5
Fig. 1 – Patient 3 before treatment.
neuritis, serous or even bacterial labyrinthitis. The clinical entity we are discussing could only be caused by damage to the cochlea and selective damage to the vestibular apparatus that causes migration of otoconia into the posterior SCC. According to common understanding, the source of the otoconia is the utricle, so to explain the simultaneous presentation of BPPV and SSNHL, the utricle as well as the whole cochlea would have to be involved. Interestingly, several recent studies have challenged this traditional belief, and discussed the possible involvement of the saccule in BPPV [9,10]. Since the vestibular evoked myogenic potential (VEMP) examines the function of the saccular macula, the presence of abnormal VEMPs in these patients would support involvement of the saccule in BPPV and not only of the utricle. Patients with posterior SCC BPPV had significantly higher rates of abnormal VEMPs than controls in two different controlled studies [9,10]. The function of the utricle in humans has been assessed in several studies [11]. However, to the best of our knowledge, there are no reports on the function of the utricule in BPPV. Carlberg et al. [8] reported 4 patients presenting with BPPV and SSNHL. VEMPs were performed in three patients, and only in one were they reduced in the affected side. We did not perform VEMP, an exam that is not a standard test in our healthcare system, and is not covered by medical insurance. The release of otoconia from the macular utricle secondary to vascular occlusion was previously reported by Baloh et al. [12] They concluded that vasospasm associated with migraine
possibly resulted in ischemic damage to the utricular macule, leading to the development of BPPV in children.
4.1.
Etiology and pathophysiology
How do we explain the relation between cochlear or cochlear nerve damage and pBPPV simultaneously? Based on anatomy, as well as previous animal and human studies, we propose and summarize several hypotheses for the etiology and pathophysiology of pBPPV with SSNHL.
4.2.
The vascular theory
Blood to the inner ear is supplied by the internal auditory artery [13–15] (see Fig. 3); there is no common blood vessel for the cochlea and the utricle. However, the vestibulocochlear artery does supply the saccule and the basal turn of the cochlea, and the posterior cochlear artery supplies the rest of the cochlea. So theoretically, occlusion of the common cochlear artery after the branching of the anterior vestibular artery could explain cochlear and saccular involvement. As previously reported, [12] ischemia of the macula (in this case of the saccule and not the utricle) could cause otoconia release. The hypothesis of vascular occlusion is not supported in a temporal bone study by Inagaki et al. [16] They studied the histology of the vestibular system in four patients diagnosed with sudden deafness with vertigo and sudden deafness without
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI N E AN D SUR G E RY 3 5 ( 2 0 14 ) 18 0–1 8 5
183
Fig. 2 – Patient 3 post-treatment.
vertigo. The authors failed to find vascular changes or other histological differences between the two groups of patients. Alternatively, we may attempt to explain this entity not on a direct anatomical basis. Multiple, small emboli affecting more than one of the inner ear arteries or anatomical variants of inner ear vascular supply are also a possibility [17]. Inner ear hypoperfusion, causing transient cochlear ischemia, has been suggested as a possible cause of sensorineural hearing loss during prolonged cardiopulmonary bypass [18]. Transient labyrinthine ischemia might cause a "patchy" loss of inner ear function if parts of the labyrinth differ in their sensitivity
to ischemia. Such ischemia has been suggested as a cause of otoconia release and BPPV [19].
4.3.
The Neural theory
The afferent fibers of the otolithic organs – the saccule and utricle – connect to the inferior and superior vestibular nerves, respectively, and the cochlea sends afferent fibers through the cochlear nerve. There is no common nerve supply between the cochlea and either of the otolithic organs, so a strictly neural–anatomical explanation is invalid.
Fig. 3 – Inner ear Blood Supply.
184
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI NE AN D SUR G E RY 3 5 ( 2 0 14 ) 18 0–1 8 5
Viral infection or viral reactivation within the inner ear, causing inflammation, damaging critical inner ear structures has long been suspected as a possible cause of both acuteunilateral-vestibulopathy and of SSNHL. A possible “patchy pattern” in the nerves or labyrinth, as seen in other viral diseases, and Bell’s palsy, caused by HSV I or Herpes zoster oticus (Ramsey–Hunt syndrome), may explain the simultaneous involvement [8,20]. Carlberg et al. [8] reported 4 patients presenting with BPPV and SSNHL. The caloric test was normal in all subjects; however, in our patients the caloric test was mildly abnormal in two patients, which may indicate other or additional pathogenesis in these two patients.
4.4.
Imaging
All our patients underwent a head MRI within several weeks of presentation, mainly to rule out a cerebellopontine angle tumor. A previous study demonstrated enhancement of the vestibular nerve in patients with vestibular neuritis, [21] while another failed to demonstrate such enhancement [22]. Facial nerve enhancement on MRI has been demonstrated in cases of acute facial nerve palsy and enhancement of both the facial and the cochleovestibular nerve has been demonstrated in Herpes zoster oticus [23]. In our study enhancement of nerves with gadolinium was not observed. It is possible, however, that an immediate MRI may have demonstrated enhancement of some or all parts of the vestibular and cochlear nerve and labyrinth, so we cannot rule out neuritis in our patients.
4.5.
Summary of etiology
In addition to the anatomy of the inner ear, described above, vascular occlusion, affecting the common blood supply of the saccule vestibulocochlear artery and the cochlea (vestibulocochlear and posterior cochlear artery) could cause sudden profound hearing loss with degeneration of the saccular macula. This could cause dislodgment of otoconia from the infarcted macula. Such dislodgement would take time and this could explain the delay in vestibular symptoms in relation to the hearing loss. The main anatomical obstacle in this theory, however, is that the debris would need to travel through the utricular–saccular duct in order to reach the vestibule and the semicircular canals, causing BPPV. The theory of inner ear hypoperfusion may fit the mildly abnormal canal paresis observed in two of our five patients, suggesting additional involvement of the lateral semicircular canal, as seen by the canal paresis. The pathogenesis in these two patients could be related to peripheral vascular disease, so potentially they may have suffered from atherosclerosis and microembolic events in the inner ear. This finding of canal paresis in BPPV is not uncommon and has been documented by Baloh et al., who describe canal paresis in 39% of patients with BPPV [24]. The canal paresis seen in two of our patients may have been an incidental finding, reflecting previous vestibular neuritis or labyrinthitis that the patients did not recall. As described, a "patchy pattern" of neural inflammation, possibly of viral origin, is an alternative or additional explanation. It is
also possible that more than one mechanism is responsible in different patients or even for the same patient.
4.6.
Prognosis
Limited information is available on the prognosis of SSNHL with pBPPV. Kim et al. [4] studied 90 patients diagnosed with SSNHL, 17 of whom were diagnosed with BPPV. Hearing recovery rate of the study group was 40%, which did not significantly differ from that of controls (32%). However, canal weakness was a significant risk factor for poor hearing recovery; interestingly, 65% of patients with BPPV had involvement of the lateral SCC, as demonstrated by a positive roll test and negative DH exam. In contrast, Lee et al. [3] conducted a retrospective study of 298 patients with SSNHL. Hearing outcomes were evaluated by assessment of pretreatment hearing and hearing gain. Comparative multivariate analysis between potential prognostic factors and hearing outcome was conducted. The authors concluded that BPPV in SSNHL patients was related to a poor prognosis of hearing. Among our small study group, hearing become normal in three patients and the vertigo resolved in all patients.
4.7.
Clinical significance
Even when a patient presenting with SSNHL volunteers symptoms of accompanying dizziness or vertigo, these complaints in many cases may not be thoroughly investigated. In such cases, diagnosis of a treatable disease is easily missed. We therefore stress the importance of a complete neurotological exam in patients presenting with SSNHL, especially when they volunteer or answer positive for symptoms of vertigo. Perhaps vice versa may also be true: patients who present with BPPV should all undergo audiological assessment to rule out the possibility of unnoticed SSNHL.
5.
Conclusions 1. The etiology of simultaneous pBPPV and SSNHL is still unclear and may be attributed to specific arterial occlusion of the internal auditory artery or by patchy arterial or neural involvement, with variable sensitivity to ischemia and degeneration in certain inner ear structures. 2. Simultaneous pBPPV and SSNHL may not be so rare. A complete neurotological examination of patients with SSNHL with vertigo is needed to exclude BPPV, which is an easily treatable disease.
REFERENCES
[1] Byl Jr FM. Sudden hearing loss: eight years experience and suggested prognostic table. Laryngoscope 1984;94:647–61. [2] Wilson WR. The relationship of the herpesvirus family to sudden hearing loss: a prospective clinical study and literature review. Laryngoscope 1986;96:870. [3] Moskowitz D, Lee KJ, Smith HW. Steroid use in idiopathic sudden sensorineural hearing loss. Laryngoscope 1984;94 (5 Pt 1):664–6.
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI N E AN D SUR G E RY 3 5 ( 2 0 14 ) 18 0–1 8 5
[4] Watanabe Y, Aso S, Ohi H, et al. Vestibular nerve disorder in patients suffering from sudden deafness with vertigo and/or vestibular dysfunction. Acta Otolaryngol Suppl 1993;504:109–11. [5] Saunders WH. Sudden deafness and its several treatments. Laryngoscope 1972;82:1206–13. [6] Lee NH, Ho Ban J. Is BPPV a prognostic factor in idiopathic sudden sensory hearing loss?Clin Exp Otorhinolaryngol 2010;3:199–202 [Epub 2010 Dec 22]. [7] Kim YH, Kim K-S, Choi H, et al. Benign paroxysmal positional vertigo is not a prognostic factor in sudden sensorineural hearing loss. Otolaryngol Head Neck Surg 2012;146:279–82. [8] Karlberg M, Halmagyi GM, Büttner U, et al. Sudden unilateral hearing loss with simultaneous ipsilateral posterior semicircular canal benign paroxysmal positional vertigo: a variant of vestibulo-cochlear neurolabyrinthitis? Arch Otolaryngol Head Neck Surg 2000;126:1024–9. [9] Longo G, Onofri M, Pelliccari T, et al. Benign paroxysmal positional vertigo: is vestibular evoked myogenic potential testing useful? Otoneurology 2012;132:39–43. [10] Korres S, Gkoritsa E, Giannakokou-Razelou D, et al. Vestibular evoked myogenic potentials in patients with BPPV. Med Sci Monit 2011;17:CR42–7. [11] Clarke AH, Scheonfeld U, Helling K. Unilateral examination of utricle and saccule function. J Vestibul Res-Equil 2003;13: 215–25. [12] Baloh RW, Honrubia V. Childhood onset of benign positional vertigo. Neurology 1998;50:1494–6. [13] Mazzoni A. Internal auditory canal. Arterial relations at the porus acusticus. Ann Otol Rhinol Laryngol 1969;78:797–814. [14] Axellson A. The vascular anatomy of the cochlea in the guinea pig and man. Acta Otolaryngol 1968;243(Suppl):1–134. [15] Mazzoni A. The vascular anatomy of the vestibular labyrinth in man. Acta Otolaryngol 1990;472(Suppl):1–83.
185
[16] Inagaki T. Vestibular system changes in sudden deafness with and without vertigo: a human temporal bone study. Otol Neurotol 2012;33:1151–5. [17] Sugita M, Masutani H, Moriguchi M, et al. Distribution of arteries from brain stem to inner ear around the internal auditory canal. Acta Otolaryngol Suppl (Stockh) 1991;48: 645–52. [18] Phillipps JJ, Thornton AR. Audiometric changes in patients undergoing coronary artery bypass surgery. Br J Audiol 1996;30:19–25. [19] Schuknecht HF, Ruby RR. Cupulolithiasis. Adv Otorhinolaryngol 1973;20:434–43. [20] Arbusow V, Schulz P, Strupp M, et al. Distribution of herpes simplex virus type 1 in human geniculate and vestibular ganglia: implications for vestibular neuritis. Ann Neurol 1999;46:416–9. [21] Mark AS, Seltzer S, Nelson-Drake J, et al. Labyrinthine enhancement on gadolinium-enhanced magnetic resonance imaging in sudden deafness and vertigo: correlation with audiologic and electronystagmographic studies. Ann Otol Rhinol Laryngol 1992;101: 459–64. [22] Strupp M, Jager L, Muller-Lisse U, et al. High resolution Gd-DTPA MR imaging of the inner ear in 60 patients with idiopathic vestibular neuritis: no evidence for contrast enhancement of the labyrinth or vestibular nerve. J Vestib Res 1998;8:427–33. [23] Berrettini S, Bianchi MC, Segnini G, et al. Herpes zoster oticus: correlations between clinical and MRI findings. Eur Neurol 1998;39:26–31. [24] Baloh RW, Honrubia V, Jacobson K. Benign positional vertigo: clinical and oculographic feature in 240 cases. Neurology 1987;37:371–8.
Available online at www.sciencedirect.com
ScienceDirect www.elsevier.com/locate/amjoto
Sudden hearing loss with simultaneous posterior semicircular canal BPPV: Possible etiology and clinical implications Sabri El-Saied, MD⁎, Ben-Zion Joshua, MD, Nili Segal, MD, Mordechai Kraus, MD, Daniel M. Kaplan, MD Department of Otolaryngology-Head and Neck Surgery, Soroka University Medical Center and the Faculty of Health Science, Ben-Gurion University in the Negev, Beer-Sheva, Israel
ARTI CLE I NFO
A BS TRACT
Article history:
Objectives: The objectives of this study were to describe the clinical course and outcome of
Received 10 August 2013
patients with sudden sensorineural hearing loss (SSNHL) in conjunction with benign paroxysmal positional vertigo (BPPV), and hypothesize the possible pathophysiology of this entity. Study design: Retrospective study of all patients with evidence of SSNHL with any type of BPPV between 2008 and 2012. Settings: Tertiary care university hospital. Subjects and methods: Five patients aged 56 to 71 were diagnosed with unilateral profound SSNHL and BPPV. Neurotologic examination revealed an ipsilateral torsional, up-beating nystagmus on Dix–Hallpike exam. Severe or profound ipsilateral–sensorineural hearing loss was recognized on audiometry. The rest of the exam was normal; this was in keeping with the diagnosis of SSNHL with ipsilateral posterior semicircular canal BPPV. Results: All patients were treated with a modified Epley maneuver; oral steroids were administered for two weeks. In all cases vertigo resolved and the Dix–Hallpike exam became normal within several weeks. However, the hearing loss remained unchanged in two patients. Magnetic resonance imaging of the head was normal and ENG caloric test demonstrated mild ipsilateral canal paresis in two patients. Conclusions: 1. Patients with SSNHL and BPPV can have a variable clinical course and outcome. This entity may be quite common, but the diagnosis of BPPV can be missed if a complete neurological physical examination is not performed. 2. Arterial occlusions or selective multiple vascular or neural involvement may explain the pathophysiology of SSNHL with BPPV of the posterior semicircular canal. © 2014 Elsevier Inc. All rights reserved.
1.
Introduction
The annual incidence of sudden sensorineural hearing loss (SSNHL) ranges from 5 to 20 cases per 100,000 persons [1]. The causes of SSNHL are speculative and may be multifactorial.
The most common definition of sudden sensorineural hearing loss is a loss of 30 dB or more across ≥ 3 continuous frequencies within 72 h [2]. Vertigo is seen in about 30%–40% of cases of SSNHL [3] and is considered to be a poor prognostic factor for hearing recovery [4]. In one study vertigo was not an unfavorable sign of hearing
⁎ Corresponding author. Department of Otolaryngology-Head & Neck Surgery, Soroka University Medical Center, Beer-Sheva, Israel. Tel.: +972 8 640 0635; fax: + 972 8 640 3037. E-mail addresses: [email protected], [email protected] (S. El-Saied). 0196-0709/$ – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjoto.2013.08.021
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI N E AN D SUR G E RY 3 5 ( 2 0 14 ) 18 0–1 8 5
181
Table 1 – Patient clinical data. Medical history
Hearing loss
Caloric Test
F 71
HTN
Severe
M 50
DM + HTN
Profound
F61
DM
Severe
F56
Amaurosis fugax S/P mitral valve replacement
F56
MRI
Treatment
Outcome
Normal
Normal
Mild canal paresis (27%) Normal
Normal
Vertigo: resolved Hearing: no change Vertigo: resolved Hearing loss: resolved Vertigo: resolved Hearing loss: improved
Profound
Mild canal paresis (27%)
Normal
Profound
Normal
Normal
P.O. Prednisone mEM P.O. Predisone mEM P.O. Prednisone mEM IT-MP P.O. Prednisone mEM IT-MP P.O. Prednisone mEM
Normal
Vertigo: resolved Hearing: no change Vertigo: resolved Hearing loss: resolved
mEM, Modified Epley maneuver; IT-MP, intratympanic methylprednisolone; DM, Diabetes mellitus; HTN, hypertension.
recovery [5]. One explanation for this discrepancy is that vertigo is a symptom and not a specific entity, and the studies do not differentiate types of vertigo. The most common type of vertigo, in general, is benign paroxysmal positional vertigo (BPPV). Several previous studies have observed and discussed BPPV and SSNHL occurring simultaneously [6–8]. BPPV most commonly involves the posterior semicircular canal, which is characterized by typical findings on Dix–Hallpike exam—up-beating, rotional, geotropic nystagmus found on one side with a latency of 5 to 10 s, and fatiguing within 10–20 s. Other, less common types of BPPV include horizontal SCC, which is diagnosed with the roll test, and anterior SCC, which is also diagnosed by the Dix–Hallpike exam. The objective of our study was to describe a group of patients with simultaneous SSNHL and BPPV, review the possible etiology, and present conclusions on the clinical implications.
2.
Patients and methods
After approval of the hospital’s Ethic committee Files of all patients with confirmed or suspected SSNHL, who were admitted to the Department of Otolaryngology-Head & Neck Surgery were reviewed. SSNHL was defined as a hearing impairment of greater than 30 dB in three contiguous frequencies that occurred in less than 3 days in the absence of a skull fracture [2]. A complete neurological exam was performed when there were symptoms of vertigo. All patients with evidence of any type of BPPV and SSNHL between 2008 and 2012 were followed and their clinical findings were documented in the clinic. A modification of the Epley maneuver (mEM) was used for treatment of pBPPV; neither premedication nor oscillation was used during the maneuver. All patients were closely followed up in our out-patient clinic until hearing stabilized, the patients had no further symptoms of vertigo, and the medical investigation was completed.
3.
Results
Five patients with unilateral SSNHL were identified with BPPV. All the patients presented with SSNHL and a few hours later experienced positional vertigo with nausea.
In all of these patients the Dix–Hallpike exam was positive for ipsilateral up-beating and torsional geotropic–symptomatic nystagmus. The roll test for diagnosis of lateral SCC BPPV was normal, there were no gait disturbances, head impulse tests on both sides were negative, and no post-headshake nystagmus was observed. This was in keeping with the diagnosis of posterior semicircular canal BPPV. The main clinical data of these patients are presented in Table 1. Audiometry revealed severe to profound hearing loss of the affected ear, with reduced speech discrimination (40%–60%), and normal hearing in the contra-lateral ear. All patients were treated with a mEM, and oral steroids (1 mg/kg) were administered for one week, after which the dosage was gradually reduced for an additional week. Two patients (3 and 4) also received salvage intratympanic prednisolone (62.5 mg/ml) 3 times. In total, hearing remained unchanged in two patients and three patients had complete recovery of hearing (e.g., Figs. 1 and 2). All patients responded to one mEM with the DH exam normalizing and becoming asymptomatic one month following the incident. Videonystagmography (VNG) caloric exam performed between 2 and 4 weeks after presentation demonstrated a mild ipsilateral canal paresis in patients 1 and 3, with excitability differences of 27%. Post-contrast Magnetic Resonance (MR) of the head showed normal internal auditory canals and cerebellopontine angles, and no enhancement of the vestibular or cochlear nerves.
4.
Discussion
While vertigo commonly accompanies SSNHL as a symptom, there are few reports describing both SSNHL and BPPV simultaneously; [6–8] some of them hypothesized about the etiology [8]. In this report we describe five patients and discuss the possible etiology and the clinical significance of this entity. When exploring the possible etiology of simultaneous SSNHL and BPPV we must first clarify the anatomical structures involved. If the whole auditory–vestibular nerve bundle or the whole vestibular labyrinth would have been involved, we would expect severe non-positional vertigo (aside from the hearing loss) as seen in cases of vestibular
182
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI NE AN D SUR G E RY 3 5 ( 2 0 14 ) 18 0–1 8 5
Fig. 1 – Patient 3 before treatment.
neuritis, serous or even bacterial labyrinthitis. The clinical entity we are discussing could only be caused by damage to the cochlea and selective damage to the vestibular apparatus that causes migration of otoconia into the posterior SCC. According to common understanding, the source of the otoconia is the utricle, so to explain the simultaneous presentation of BPPV and SSNHL, the utricle as well as the whole cochlea would have to be involved. Interestingly, several recent studies have challenged this traditional belief, and discussed the possible involvement of the saccule in BPPV [9,10]. Since the vestibular evoked myogenic potential (VEMP) examines the function of the saccular macula, the presence of abnormal VEMPs in these patients would support involvement of the saccule in BPPV and not only of the utricle. Patients with posterior SCC BPPV had significantly higher rates of abnormal VEMPs than controls in two different controlled studies [9,10]. The function of the utricle in humans has been assessed in several studies [11]. However, to the best of our knowledge, there are no reports on the function of the utricule in BPPV. Carlberg et al. [8] reported 4 patients presenting with BPPV and SSNHL. VEMPs were performed in three patients, and only in one were they reduced in the affected side. We did not perform VEMP, an exam that is not a standard test in our healthcare system, and is not covered by medical insurance. The release of otoconia from the macular utricle secondary to vascular occlusion was previously reported by Baloh et al. [12] They concluded that vasospasm associated with migraine
possibly resulted in ischemic damage to the utricular macule, leading to the development of BPPV in children.
4.1.
Etiology and pathophysiology
How do we explain the relation between cochlear or cochlear nerve damage and pBPPV simultaneously? Based on anatomy, as well as previous animal and human studies, we propose and summarize several hypotheses for the etiology and pathophysiology of pBPPV with SSNHL.
4.2.
The vascular theory
Blood to the inner ear is supplied by the internal auditory artery [13–15] (see Fig. 3); there is no common blood vessel for the cochlea and the utricle. However, the vestibulocochlear artery does supply the saccule and the basal turn of the cochlea, and the posterior cochlear artery supplies the rest of the cochlea. So theoretically, occlusion of the common cochlear artery after the branching of the anterior vestibular artery could explain cochlear and saccular involvement. As previously reported, [12] ischemia of the macula (in this case of the saccule and not the utricle) could cause otoconia release. The hypothesis of vascular occlusion is not supported in a temporal bone study by Inagaki et al. [16] They studied the histology of the vestibular system in four patients diagnosed with sudden deafness with vertigo and sudden deafness without
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI N E AN D SUR G E RY 3 5 ( 2 0 14 ) 18 0–1 8 5
183
Fig. 2 – Patient 3 post-treatment.
vertigo. The authors failed to find vascular changes or other histological differences between the two groups of patients. Alternatively, we may attempt to explain this entity not on a direct anatomical basis. Multiple, small emboli affecting more than one of the inner ear arteries or anatomical variants of inner ear vascular supply are also a possibility [17]. Inner ear hypoperfusion, causing transient cochlear ischemia, has been suggested as a possible cause of sensorineural hearing loss during prolonged cardiopulmonary bypass [18]. Transient labyrinthine ischemia might cause a "patchy" loss of inner ear function if parts of the labyrinth differ in their sensitivity
to ischemia. Such ischemia has been suggested as a cause of otoconia release and BPPV [19].
4.3.
The Neural theory
The afferent fibers of the otolithic organs – the saccule and utricle – connect to the inferior and superior vestibular nerves, respectively, and the cochlea sends afferent fibers through the cochlear nerve. There is no common nerve supply between the cochlea and either of the otolithic organs, so a strictly neural–anatomical explanation is invalid.
Fig. 3 – Inner ear Blood Supply.
184
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI NE AN D SUR G E RY 3 5 ( 2 0 14 ) 18 0–1 8 5
Viral infection or viral reactivation within the inner ear, causing inflammation, damaging critical inner ear structures has long been suspected as a possible cause of both acuteunilateral-vestibulopathy and of SSNHL. A possible “patchy pattern” in the nerves or labyrinth, as seen in other viral diseases, and Bell’s palsy, caused by HSV I or Herpes zoster oticus (Ramsey–Hunt syndrome), may explain the simultaneous involvement [8,20]. Carlberg et al. [8] reported 4 patients presenting with BPPV and SSNHL. The caloric test was normal in all subjects; however, in our patients the caloric test was mildly abnormal in two patients, which may indicate other or additional pathogenesis in these two patients.
4.4.
Imaging
All our patients underwent a head MRI within several weeks of presentation, mainly to rule out a cerebellopontine angle tumor. A previous study demonstrated enhancement of the vestibular nerve in patients with vestibular neuritis, [21] while another failed to demonstrate such enhancement [22]. Facial nerve enhancement on MRI has been demonstrated in cases of acute facial nerve palsy and enhancement of both the facial and the cochleovestibular nerve has been demonstrated in Herpes zoster oticus [23]. In our study enhancement of nerves with gadolinium was not observed. It is possible, however, that an immediate MRI may have demonstrated enhancement of some or all parts of the vestibular and cochlear nerve and labyrinth, so we cannot rule out neuritis in our patients.
4.5.
Summary of etiology
In addition to the anatomy of the inner ear, described above, vascular occlusion, affecting the common blood supply of the saccule vestibulocochlear artery and the cochlea (vestibulocochlear and posterior cochlear artery) could cause sudden profound hearing loss with degeneration of the saccular macula. This could cause dislodgment of otoconia from the infarcted macula. Such dislodgement would take time and this could explain the delay in vestibular symptoms in relation to the hearing loss. The main anatomical obstacle in this theory, however, is that the debris would need to travel through the utricular–saccular duct in order to reach the vestibule and the semicircular canals, causing BPPV. The theory of inner ear hypoperfusion may fit the mildly abnormal canal paresis observed in two of our five patients, suggesting additional involvement of the lateral semicircular canal, as seen by the canal paresis. The pathogenesis in these two patients could be related to peripheral vascular disease, so potentially they may have suffered from atherosclerosis and microembolic events in the inner ear. This finding of canal paresis in BPPV is not uncommon and has been documented by Baloh et al., who describe canal paresis in 39% of patients with BPPV [24]. The canal paresis seen in two of our patients may have been an incidental finding, reflecting previous vestibular neuritis or labyrinthitis that the patients did not recall. As described, a "patchy pattern" of neural inflammation, possibly of viral origin, is an alternative or additional explanation. It is
also possible that more than one mechanism is responsible in different patients or even for the same patient.
4.6.
Prognosis
Limited information is available on the prognosis of SSNHL with pBPPV. Kim et al. [4] studied 90 patients diagnosed with SSNHL, 17 of whom were diagnosed with BPPV. Hearing recovery rate of the study group was 40%, which did not significantly differ from that of controls (32%). However, canal weakness was a significant risk factor for poor hearing recovery; interestingly, 65% of patients with BPPV had involvement of the lateral SCC, as demonstrated by a positive roll test and negative DH exam. In contrast, Lee et al. [3] conducted a retrospective study of 298 patients with SSNHL. Hearing outcomes were evaluated by assessment of pretreatment hearing and hearing gain. Comparative multivariate analysis between potential prognostic factors and hearing outcome was conducted. The authors concluded that BPPV in SSNHL patients was related to a poor prognosis of hearing. Among our small study group, hearing become normal in three patients and the vertigo resolved in all patients.
4.7.
Clinical significance
Even when a patient presenting with SSNHL volunteers symptoms of accompanying dizziness or vertigo, these complaints in many cases may not be thoroughly investigated. In such cases, diagnosis of a treatable disease is easily missed. We therefore stress the importance of a complete neurotological exam in patients presenting with SSNHL, especially when they volunteer or answer positive for symptoms of vertigo. Perhaps vice versa may also be true: patients who present with BPPV should all undergo audiological assessment to rule out the possibility of unnoticed SSNHL.
5.
Conclusions 1. The etiology of simultaneous pBPPV and SSNHL is still unclear and may be attributed to specific arterial occlusion of the internal auditory artery or by patchy arterial or neural involvement, with variable sensitivity to ischemia and degeneration in certain inner ear structures. 2. Simultaneous pBPPV and SSNHL may not be so rare. A complete neurotological examination of patients with SSNHL with vertigo is needed to exclude BPPV, which is an easily treatable disease.
REFERENCES
[1] Byl Jr FM. Sudden hearing loss: eight years experience and suggested prognostic table. Laryngoscope 1984;94:647–61. [2] Wilson WR. The relationship of the herpesvirus family to sudden hearing loss: a prospective clinical study and literature review. Laryngoscope 1986;96:870. [3] Moskowitz D, Lee KJ, Smith HW. Steroid use in idiopathic sudden sensorineural hearing loss. Laryngoscope 1984;94 (5 Pt 1):664–6.
AM ER IC AN JOUR NA L OF OTOLARY NG OLOG Y –H EA D A N D N E CK ME D I CI N E AN D SUR G E RY 3 5 ( 2 0 14 ) 18 0–1 8 5
[4] Watanabe Y, Aso S, Ohi H, et al. Vestibular nerve disorder in patients suffering from sudden deafness with vertigo and/or vestibular dysfunction. Acta Otolaryngol Suppl 1993;504:109–11. [5] Saunders WH. Sudden deafness and its several treatments. Laryngoscope 1972;82:1206–13. [6] Lee NH, Ho Ban J. Is BPPV a prognostic factor in idiopathic sudden sensory hearing loss?Clin Exp Otorhinolaryngol 2010;3:199–202 [Epub 2010 Dec 22]. [7] Kim YH, Kim K-S, Choi H, et al. Benign paroxysmal positional vertigo is not a prognostic factor in sudden sensorineural hearing loss. Otolaryngol Head Neck Surg 2012;146:279–82. [8] Karlberg M, Halmagyi GM, Büttner U, et al. Sudden unilateral hearing loss with simultaneous ipsilateral posterior semicircular canal benign paroxysmal positional vertigo: a variant of vestibulo-cochlear neurolabyrinthitis? Arch Otolaryngol Head Neck Surg 2000;126:1024–9. [9] Longo G, Onofri M, Pelliccari T, et al. Benign paroxysmal positional vertigo: is vestibular evoked myogenic potential testing useful? Otoneurology 2012;132:39–43. [10] Korres S, Gkoritsa E, Giannakokou-Razelou D, et al. Vestibular evoked myogenic potentials in patients with BPPV. Med Sci Monit 2011;17:CR42–7. [11] Clarke AH, Scheonfeld U, Helling K. Unilateral examination of utricle and saccule function. J Vestibul Res-Equil 2003;13: 215–25. [12] Baloh RW, Honrubia V. Childhood onset of benign positional vertigo. Neurology 1998;50:1494–6. [13] Mazzoni A. Internal auditory canal. Arterial relations at the porus acusticus. Ann Otol Rhinol Laryngol 1969;78:797–814. [14] Axellson A. The vascular anatomy of the cochlea in the guinea pig and man. Acta Otolaryngol 1968;243(Suppl):1–134. [15] Mazzoni A. The vascular anatomy of the vestibular labyrinth in man. Acta Otolaryngol 1990;472(Suppl):1–83.
185
[16] Inagaki T. Vestibular system changes in sudden deafness with and without vertigo: a human temporal bone study. Otol Neurotol 2012;33:1151–5. [17] Sugita M, Masutani H, Moriguchi M, et al. Distribution of arteries from brain stem to inner ear around the internal auditory canal. Acta Otolaryngol Suppl (Stockh) 1991;48: 645–52. [18] Phillipps JJ, Thornton AR. Audiometric changes in patients undergoing coronary artery bypass surgery. Br J Audiol 1996;30:19–25. [19] Schuknecht HF, Ruby RR. Cupulolithiasis. Adv Otorhinolaryngol 1973;20:434–43. [20] Arbusow V, Schulz P, Strupp M, et al. Distribution of herpes simplex virus type 1 in human geniculate and vestibular ganglia: implications for vestibular neuritis. Ann Neurol 1999;46:416–9. [21] Mark AS, Seltzer S, Nelson-Drake J, et al. Labyrinthine enhancement on gadolinium-enhanced magnetic resonance imaging in sudden deafness and vertigo: correlation with audiologic and electronystagmographic studies. Ann Otol Rhinol Laryngol 1992;101: 459–64. [22] Strupp M, Jager L, Muller-Lisse U, et al. High resolution Gd-DTPA MR imaging of the inner ear in 60 patients with idiopathic vestibular neuritis: no evidence for contrast enhancement of the labyrinth or vestibular nerve. J Vestib Res 1998;8:427–33. [23] Berrettini S, Bianchi MC, Segnini G, et al. Herpes zoster oticus: correlations between clinical and MRI findings. Eur Neurol 1998;39:26–31. [24] Baloh RW, Honrubia V, Jacobson K. Benign positional vertigo: clinical and oculographic feature in 240 cases. Neurology 1987;37:371–8.