International Journal of Pediatric Otorhinolaryngology Extra 6 (2011) 410–413

Case report

Unilateral sudden sensorineural hearing loss as the presenting symptom ofmultiple sclerosis in adolescent: Neuro-otologic manifestations, pathogenesis,and localization

Wei-Ting Hsu a, Hung-Ching Lin a,b,c,*, Jon-Kway Huang d,e

a Department of Otolaryngology-Head and Neck Surgery, Mackay Memorial Hospital, Taipei, Taiwanb Department of Speech and Hearing Disorders and Sciences, National Taipei College of Nursing, Taipei, Taiwanc Department of Speech Language Pathology and Hearing, Chung Shan Medical University, Taichung, Taiwand Department of Radiology, Mackay Memorial Hospital, Taipei, Taiwane Department of Radiology, Taipei Medical University, Taipei, Taiwan

A R T I C L E I N F O

Article history:

Received 7 June 2011

Accepted 18 June 2011

Available online 20 July 2011

Keywords:

Hearing loss

Multiple sclerosis

Deafness

Adolescent

A B S T R A C T

Sudden sensorineural hearing loss (SSNHL) is a rare initial complaint of multiple sclerosis (MS) in

adolescent. We present the case of a 14-year-old girl presented with right SSNHL as an initial symptom in

MS and recovery of hearing with time compatible to the MRI finding. It clearly identified that the

pathogenesis of unilateral SSNHL in the patient with MS favors CNS demyelination, which may be

accompanied with cytogenic edema, involving the intraaxial portion of the cochlear nerve and nerve

fibers near cochlear nucleus. Besides, in adolescent with sudden hearing loss, multiple sclerosis should

be included in the differential diagnosis.

� 2011 Elsevier Ireland Ltd. All rights reserved.

Contents lists available at ScienceDirect

International Journal of Pediatric OtorhinolaryngologyExtra

jo ur n al ho m ep ag e: ww w.els evier . c om / lo cat e/ i jp o r l

1. Introduction

Multiple sclerosis (MS) is an immune-mediated inflammatorydisease that attacks myelinated axons in the central nervoussystems, destroying the myelin of the nerve sheath in variabledegrees. The disease has a slow and progressive course thatcharacteristically is irregular with fluctuating periods of exacer-bation and remission of specific symptoms. MS is more common infemale. It usually occurs in the third and fourth decades and isuncommon before ten years of age.

The reported incidence of hearing loss in patients with MS isextremely variable, ranging from as low as 1% to as high as 90%[1,2], and accurate large-scale statistics on the incidence of hearingloss due to specifically to MS are not available. ‘Acute’ hearing lossin MS, although rare, has been reported in only 1.7% (12/705) and3.5% (14/400) with MS [3,4]. However, hearing impairment isusually not an initial symptom or a prominent complaint in MS.

The US National Institute for Deafness and CommunicationDisorders specifies that sudden sensorineural hearing loss (SSNHL)may be diagnosed when there is idiopathic hearing loss of at least

* Corresponding author at: Department of Otolaryngology-Head and Neck

Surgery, Mackay Memorial Hospital, 92 Chungshan North Road, Sec. 2, Taipei

10449, Taiwan. Tel.: +886 2 25433535x2208; fax: +886 2 25433642.

E-mail address: hclin59@ms29.hinet.net (H.-C. Lin).

1871-4048/$ – see front matter � 2011 Elsevier Ireland Ltd. All rights reserved.

doi:10.1016/j.pedex.2011.06.003

30 dB over 3 or more test frequencies occurring within 3 days [5].The reported incidence of SSNHL in patients with MS is variable.There were just several case reports but only one systemic review(11 of 253 patients) recently after survey English literature inMedline, while not all the patients fulfilled the criteria for SSNHL inthe review paper [6–14].

Our presented case illustrates unilateral SSNHL as the presentsymptom in an adolescent with MS. The main point of our story isthe auditory test and MRI finding clearly identified the location ofauditory pathway damage and the pathogenesis of unilateralSSNHL in MS.

2. Case report

A 14-year-old girl presented with sudden onset of right-sidedhearing loss at our pediatric emergency department of MackayMemorial Hospital, a tertiary referral medical center in Taiwan, inDecember 2007. She also complained of headache, dizziness,ataxia, and diplopia. Medical history was significant for mixedconnective tissue disease, encephalopathy, and seizure disorder.The audiogram showed a right severe hearing loss with thresholdsat 90 dB HL (Fig. 1a). The tympanograms were normal bilaterally.Ipsilateral acoustic reflexes were normal on the left side but wereelevated threshold with 110 dB SPL at 2k Hz and absent at 4k Hz onthe right side. Bilateral contralateral acoustic reflexes were normal.Bilateral otoacoustic emissions (OAE) pass demonstrated normal

Fig. 1. Audiogram (a) 1st: during the first visit, the audiogram showed a severe right SNHL with thresholds at 90 dB. (b) 1M: one month later, the partial auditory recovery in

the right ear was seen in all frequencies after initial interferon, MTX and steroid pulse therapy. (c) 4M: four months later, hearing improved to a 38-dB loss on the right affected

side and slight increased left hearing threshold. (d) 2Y: 2 years later, right hearing remained with a 33-dB hearing loss and mild left SNHL, especially in high frequency (4k Hz,

8k Hz). (e) 2Y4M: 2 years and 4 months later, bilateral sensorineural hearing loss was obtained.

W.-T. Hsu et al. / International Journal of Pediatric Otorhinolaryngology Extra 6 (2011) 410–413 411

cochlear outer hair cell function on the both sides. Auditorybrainstem evoked response (ABR) revealed normal responses onthe left side and severe delay latency of wave III and V with mildprolong latency of the wave I on the right side (Fig. 2a).

An MRI of the brain revealed typical MS lesions located rightfrontal white matter, bilateral parietal white matter, left temporalwhite matter, callosal body, posterior limbs of bilateral internalcapsules, right lateral thalamus, right cerebral peduncle, and rightmiddle and inferior cerebellar peduncles with evidence of rightcochlear nucleus and eighth cranial nerve root-entry zonedemyelination accompanied with cytogenic edema (Fig. 3A, Cand D). Her MRI of the spinal cord also showed typicaldemyelinating lesions at the C7, T1 and T8 level. The cerebrospinalfluid analysis was abnormally increased IgG index as a value ofmore than 0.7, but negative for oligoclonal bands. She wasdiagnosed with MS according to McDonald’s criteria and specificattention was invested in the findings excluding the diagnosis ofSusac disease [15].

Fig. 2. Morphology change of the ABR. (a) 1st visit, severe prolonged latency of wave III a

and V; (c) 9 months later, poor morphology in wave III and V; (d) 1 year and 5 months la

latency of wave III and V.

She received administration of interferon beta 1b subcutaneousinjection, steroid pulse therapy and oral methotrexate (MTX) afterconfirmed diagnosis. One month after therapy, her right hearinggot partial recovery in all frequencies, particularly in lowfrequencies (Fig. 1b). Four months later, right hearing improvedto a 38 dB HL (Fig. 1c). The ABR disclosed mild prolonged latencyand poor morphology in wave III and V (Fig. 2b). In addition,follow-up brain MRI 6 months later revealed the enhancementlessened near right cochlear nucleus, nerve root-entry zone andpartial proximal part of the auditory nerve, and disappearance ofcytogenic edema (Fig. 3B). 2 years later, the right hearing remainedwith a 33 dB HL (Fig. 1d) and the ABR revealed improvement ofwaveform but still mild prolong latency in wave III and V (Fig. 2e).

Over the next 28 months, the patient suffered from another sixattacks. She had severe problem of speech articulation gradually.She had no recurrent episode of acute hearing loss, but audiogramdisclosed slowly progressive bilateral sensorineural hearing losswith 65 dB HL on the left side and 77 dB HL on the right side at the

nd V, and slightly prolonged wave I; (b) 4 months later, poor morphology in wave III

ter, slightly prolonged latency of wave III and V; (e) 2 years later, slightly prolonged

Fig. 3. MRI of the brain, T2 FLAIR image. (A) High signal intensity in right middle and inferior cerebellar peduncles with evidence of right cochlear nucleus and eighth cranial

nerve root-entry zone demyelination (arrowhead). (C) DWI shows hyperintense lesions (arrow) near cochlear nucleus with (D) decreased signal (arrow) on ADC present

cytotoxic edema. (B) 6 months later, follow-up brain image revealed the enhancement lessened near right cochlear nucleus, nerve root-entry zone and partial proximal part of

the auditory nerve.

W.-T. Hsu et al. / International Journal of Pediatric Otorhinolaryngology Extra 6 (2011) 410–413412

last follow up (Fig. 1e). Speech reception threshold revealedthreshold of 90 dB HL on the left side and 80 dB HL on the rightside. No change in last ABR was found.

3. Discussion

Sudden fluctuant sensorineural hearing loss is a rare initialcomplaint of multiple sclerosis. It can be unilateral, sequentialbilateral, or bilateral acute hearing loss [6–9,12–14]. In theprevious reports, it appeared early in the course of the disease,and presented with the unilaterality of symptoms and signs in themajority. Fluctuation of hearing loss is uncommon. It is generallyshort lasting and carries a good prognosis as our patient on theright affected ear [1,3,6–9,14]. However, she suffered frombilateral insidious hearing loss during follow up for 28 months.No change in ABR, normal threshold of ipsilateral acoustic reflex onboth sides, and bilateral otoacoustic emissions pass were obtained.We assumed that the lesions were above the midbrain as a result ofanother six attacks of MS with a slow and progressive course.

Auditory dysfunction in MS may be as a result of a lesion in thecochlear nerve itself or in the central auditory pathways, including

the root of the eighth nerve, upper brainstem, midbrain, and thecortical area of the CNS [12]. The pathogenesis is reasonablyattributed to demyelination of the nerve pathway or edema whichoccurs in the tissue around the demyelinating lesion [13].Meanwhile, initial bilateral otoacoustic emissions (OAE) passand abnormal right acoustic reflexes in our patient with MSdemonstrated normal cochlear outer hair cell function andindicated a retrocochlear lesion near brainstem.

Given the complexity and the extensive crossing of the auditorypathway, unilateral sudden hearing loss must in all likelihoodindicate a lesion at the most caudal level of the pathway, involvingthe intramedullary auditory nerve fibers prior to its bifurcation orthe cochlear nucleus [1,6]. Although there are reports of lesionswithin the peripheral part of cochlear nerve itself or above themidbrain area with both temporal lobes involvement [11,12], thecase is very rare and the likelihood seems to be smaller. Most of thecase reports where imaging was carried out failed to detectextraaxial abnormality, and rather showed demyelination ineighth cranial nerve root-entry zone, middle cerebellar pedunclewhich near cochlear nucleus, pontomedullary junction, or the ponsin MS patients with SSNHL [7,9].

W.-T. Hsu et al. / International Journal of Pediatric Otorhinolaryngology Extra 6 (2011) 410–413 413

Our patient showed slightly prolonged wave I and severeprolonged wave III and V in ABR on the right side initially. It isconsistent with a neural (retrocochlear) lesion within the brainstem and eighth cranial nerve root-entry zone. Slightly prolongedwave I indicated that central myelin of the eighth nerve, whichextends only a few millimeters extra-axially, is susceptible todemyelination.

Conclusive proof of the site of the lesion in our patient wasobtained by MRI. High signal intensity on T2 FLAIR image of thebrain MRI indicated demyelinating lesion in right middle andinferior cerebellar peduncles with involvement of right cochlearnucleus, eighth cranial nerve root-entry zone and partial proximalpart of the auditory nerve. Besides, cytotoxic edema was also foundto occur in the tissue around the demyelinating lesion. It iscompatible to the lesion site according to ABR finding. Thisenhancement on MRI lessened over six months and the righthearing recovered consequently. The MRI and audiometric findingsupported the pathogenesis of SSNHL in our patient of MS.

The audiograms showed much hearing improvement to a 38-dBHL on the right affected side after 4 months, while the ABR stilldisclosed poor morphology in wave III and V but normalizedlatency of wave I. Even after 2 years, the ABR was still notnormalized totally. It seems that abnormal ABR associated withsubjectively normal hearing threshold are common in MS. The ABR,depending on the decrease of the neural transmission in patient ofMS, can show latency and amplitude changes. A certain level ofsynchronization is sufficient for the perception of a pure tone bythe brain, but it may not be adequate to genetate discrete peaks inABR [12,13]. The delay latency or poor morphology of the wavescan be explained physiologically despite the much improvement ofhearing during the remission stage.

To conclude, our findings demonstrate that a demyelinatinglesion with cytogenic edema involving the intraaxial portion of thecochlear nerve and nerve fibers near cochlear nucleus can cause

sudden hearing loss in MS. Besides, in adolescent with suddenhearing loss, multiple sclerosis should be included in thedifferential diagnosis.

References

[1] W.T. Daugherty, Hearing loss in multiple sclerosis, Arch. Neurol. 40 (1983) 33–35.[2] J.F. Jerger, Patterns of auditory abnormality in multiple sclerosis, Audiology 25

(1986) 193–199.[3] C. Fischer, F. Mauguiere, V. Ibanez, C. Confavreux, G. Chazot, The acute deafness of

definite multiple sclerosis: BAEP patterns, Electroencephalogr. Clin. Neurophy-siol. 61 (1985) 7–15.

[4] J. de Seze, R. Assouad, T. Stojkovic, A. Desaulty, B. Dubus, P. Venmersch, Hearingloss in multiple sclerosis: clinical, electrophysiologic and radiological study, Rev.Neurol. (Paris) 157 (2001) 1403–1409 [in French].

[5] National Institute of Health, Sudden Deafness, National Institutes of Health,Bethesda, MD, 2000, NIH Publication 00-4757.

[6] M.A. Hellmann, I. Steiner, R. Mosberg-Galili, Sudden sensorineural hearing loss inmultiple sclerosis: clinical course and possible pathogenesis, Acta Neurol. Scand.123 (2011) 1600–1604.

[7] H.J. Barratt, D. Miller, P. Rudge, The site of the lesion causing deafness in multiplesclerosis, Scand. Audiol. 17 (1988) 67–71.

[8] T. Tabira, S. Tsuji, T. Nagashima, T. Nakajima, Y. Kuroiwa, Cortical deafness inmultiple sclerosis, J. Neurol. Neurosurg. Psychiatry 44 (May (5)) (1981) 433–436.

[9] Y.M. Oh, D.H. Oh, S.H. Jeong, J.W. Koo, J.S. Kim, Sequential bilateral hearing loss inmultiple sclerosis, Ann. Otol. Rhinol. Laryngol. 117 (March) (2008) 186–191.

[10] T. Yamasoba, K. Sakai, M. Sakurai, Role of acute cochlear neuritis in suddenhearing loss in multiple sclerosis, J. Neurol. Sci. 146 (March) (1997) 179–181.

[11] R. Bergamaschi, A. Romani, F. Zappoli, M. Versino, V. Cosi, MRI and brainstemauditory evoked potential evidence of eighth cranial nerve involvement inmultiple sclerosis, Neurology 48 (1997) 270–272.

[12] A. Ozunlu, N. Mus, M. Gulhan, Multiple sclerosis: a cause of sudden hearing loss,Audiology 37 (January–February) (1998) 52–58.

[13] B. Drulovic, K. Ribaric-Jankes, V. Kostic, N. Sternic, Multiple sclerosis as the causeof sudden ‘pontine’ deafness, Audiology 33 (July–August) (1994) 195–201.

[14] M.V. Rodriguez-Casero, S. Mandelstam, A.J. Kornberg, R.G. Berkowitz, Acutetinnitus and hearing loss as the initial symptom of multiple sclerosis in a child,Int. J. Pediatr. Otorhinolaryngol. 69 (January) (2005) 123–126.

[15] J. Dorr, H. Radbruch, M. Bock, J. Wuerfel, A. Bruggemann, K.P. Wandinger, D. Zeise,C.F. Pfueller, F. Zipp, F. Paul, Encephalopathy, visual disturbance and hearing loss-recognizing the symptoms of Susac syndrome, Nat. Rev. Neurol. 5 (December)(2009) 683–688.