Case Report Iranian Journal of Otorhinolaryngology, Vol.28(2), Serial No.85, Mar 2016

A Case of Undiagnosed Sleep Disorder with Hearing Difficulty and Dizziness *Fumiyuki Goto1, Miki Arai1, Mitusru Kitamura1, Tomoko Otomo1, Ryoto Nagai1, Shuujiro Minami1, Takanobu Shimada1, Tatsuo Matsunaga1, Kouichi Tsunoda1, Masato Fujii1

Abstract

Introduction: The aim of this case report was to investigate the relationship between sleep disorders and audio vestibular symptoms.

Case Report: A case of undiagnosed sleep disorder, presenting as a temporary auditory processing difficulty, is presented. The disorder was initially treated as sudden deafness with dizziness. A 23-year-old male patient complained of acute hearing disturbance despite normal results on pure tone audiometry. The patient was initially administered a steroid injection in the hospital. After treatment, his hearing symptoms improved only slightly and he reported balance difficulty with rightward spontaneous nystagmus. Vestibular rehabilitation was performed. We also suspected that his hearing symptom was due to an auditory processing difficulty. Despite steroid treatment and vestibular rehabilitation, neither of his symptoms improved. We subsequently identified the presence of insomnia. He was prescribed zolpidem 5 mg, which slightly improved his symptoms, and referred to a sleep specialist for further examination. Polysomnography was performed, which identified restless leg syndrome and sleep disturbance with delayed sleep phase syndrome. After pharmacological treatment, his sleep disturbance, hearing difficulty, and balance disorder completely resolved.

Conclusion: Sleep disorders may provoke reversible auditory processing difficulties. We should carefully evaluate patients for a potentially undiagnosed sleep disorder, even in patients chiefly complaining of intractable sensory dysfunction such as hearing or balance disturbance.

Keywords: Dizziness, Insomnia, Sleep, Vestibular.

Received date: 5 May 2015 Accepted date: 21 Jun 2015

1Department of Otorhinolaryngology, National Hospital Organization, Tokyo Medical Center, Tokyo, Japan. *Corresponding Author: Department of Otorhinolaryngology, National Hospital Organization, Tokyo Medical Center, Tokyo, Japan. E-mail: [email protected]

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Introduction organic disorder. The cause of his symptoms Auditory processing disorder (APD) is a was unclear, but because the symptoms were collection of disorders affecting the way the similar to sudden deafness, he was brain processes auditory information and is administered an injectable steroid for 7 days. not currently included in mainstream However, his hearing disturbance improved diagnostic classifications. At our facility, we only slightly and he began to experience have examined patients complaining of balance problems. Repeat examination misunderstanding verbal speech despite revealed a spontaneous nystagmus to the having normal pure tone hearing function on right and a bedside head impulse test pure tone audiometry. These patients may indicated left-sided canal paralysis. Static have an auditory processing difficulty, posturography showed a slight increase in which is similar to APD. Individuals with the total length of path (LNG) and APD usually have a hearing system with a environmental area (ENV.AREA), as shown normal structure and function. However, in (Table. 1). they cannot process the information they hear in the same way as others do, which Table 1:Static posturography performed before and leads to difficulties in recognizing and after treatment for RLS and sleep phase disorder

interpreting the sounds composing speech. It before after Eye Eye Eye Eye

is thought that these difficulties arise from open close open close dysfunction in the central nervous system LNG(cm) 69.9 98.6 53.1 61.7 ENV (1). Insomnia is a common complaint among 5.9 3.9 1.5 1.4 patients with intractable dizziness and may AREA(cm2) RLS: restless leg syndrome, LNG: total length of path be underdiagnosed (2). Recently, insomnia ENV. AREA: environmental area was proposed as a possible trigger for Meniere disease and vestibular dysfunction The Dizziness Handicap Inventory (DHI) (3,4). Restless leg syndrome (RLS) is and Hospital Anxiety and Depression Scale another important sleep disorder, but it is (HADS) scores were 82 (physical= 24, uncommon to examine a RLS patient in the emotional= 26, function= 32) and 23 Department of Otolaryngology. In this (anxiety= 12 and depression= 11). During report, we present a case of undiagnosed examination 2 weeks later, no spontaneous, sleep disorder with RLS presenting as a gaze-evoked, or positional nystagmus were reversible auditory processing difficulty with found. The Fukuda stepping test was normal dizziness. and the electronystagmogram with caloric test did not reveal any canal paralysis (5). Case Report Vestibular rehabilitation was initiated, but A 23-year-old post-graduate male student did not improve his subjective dizziness. was examined for sudden deafness. In May After carefully reviewing his clinical 2014, he was suddenly unable to hear history, we determined that he could hear clearly, although he could still hear sound. sound normally, but his ability to listen Pure tone audiometry was performed and was decreased. In addition, we found that was normal, with 7.5d B in the right ear and the patient had a sleep disturbance. 16.3d B in the left (Fig. 1A). The results of Zolpidem 5 mg was prescribed, which SDS (speech discrimination score) were improved his sleep difficulty. His normal. Despite this, he was adamant in his dizziness improved gradually, but he still complaint and was experiencing difficulty experienced dizziness and hearing listening in class. The result of his MRI was difficulty. Further investigation of his normal and we could not diagnose any sleep disorder was recommended and the

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Auditory Processing Difficulty Caused by sleep Disorder patient was referred to a sleep specialist. performance. Sleep deprivation impairs Polysomnography (PSG) was conducted. performance on the Random Gap The sleep time was 413.5 minutes over a Detection Test (RGDT) and Staggered 651-minute recording period. Therefore, the Spondaic Word Test (SSWT) (6). When a sleep efficacy was 56.6%, which was patient’s adament complaints cannot be significantly reduced. The Apnea-hypopnea clearly explained based on physical Index (AHI) was 2.3 times/hour, and the symptoms and clinical examination, we Arousal Index was 12.16 times/hour. often suspect a medically unexplained Arousal due to apnea-hypopnea and periodic symptom. This patient was first diagnosed limb movement were each 0.94 times/ hour. and treated for a medically unexplained PLM index was 4.91 times/h. Collectively, symptom. Undiagnosed depression or these findings clearly indicated insomnia anxiety is considered a common without apnea or hypopnea. RLS was component of medically unexplained suspected; therefore, pramipexole 0.125 mg symptoms (7). In this case, the HADS was prescribed. His subjective insomnia, score was 12 in anxiety and 11 in dizziness, and hearing disturbance depression. Although, this indicated the disappeared within 4 days. The pure tone existence of mild anxiety and depression, audiometry results were unchanged we did not consider an antidepressant or (Fig. 1B). anti-anxiety drug necessary. The patient complained of difficulty hearing despite having normal results on pure tone audiometry; therefore, we suspected that the patient had an auditory processing difficulty similar to APD. He first reported symptoms resembling sudden deafness but later realized that he was able to hear sound but was less able to listen. His symptoms disappeared after treating his sleep disorder and the auditory processing difficulty appeared to be reversible. Fig 1: Pure tone audiometry results in a 23-year- old man with acute hearing difficulty. (A) Initial Occasionally, we encounter patients with visit; (B) After treatment for restless leg syndrome difficulty hearing speech despite normal with pramipexole 0.125 mg. pure tone audiometry and speech discrimination ratio results. Some of these The posturography results improved, as patients may have an auditory processing shown in Table 1; however, he still disorder. The present patient initially required several hours to fall asleep complained of dizziness with spontaneous despite taking zolpidem 5 mg. Delayed nystagmus; therefore, left-sided acute sleep phase syndrome was strongly vestibular dysfunction was suspected. suspected and ramelteon 8 mg was However, the vestibular symptoms prescribed. His sleep rhythm subsequently recovered spontaneously as the caloric test improved. did not detect any canal paralysis. Unsurprisingly, conventional steroid Discussion treatment and vestibular rehabilitation did Sleep deprivation is extremely common not improve his physical symptoms. in contemporary society and is considered Reportedly, sleep apnea is closely related a frequent cause of impaired cognitive to vestibular dysfunction and Meniere

Iranian Journal of Otorhinolaryngology, Vol.28(2), Serial No.85, Mar 2016 151 Fumiyuki G, et al disease. However, a clear association pharmacological treatment alone is an between vestibular dysfunction and sleep inadequate solution. Further clinical disorders other than sleep apnea has not examination by a sleep specialist may been described. We treated the patient’s identify an important sleep disorder causing sleep disorder with zolpidem initially, the medically unexplained symptom. which slightly improved his subjective dizziness. We then treated his RLS Acknowledgement pharmacologically and identified his sleep This report was supported by grant from phase disorder. Treating all of these the mental health Okamoto 2015. problems simultaneously completely resolved his hearing and balance problems. References It is clear that the sleep disorder played an 1. Cacace AT, McFarland DJ. Central auditory important role in the onset of his processing disorder in school-aged children: a critical review. J Speech Lang Hear Res 1998; symptoms. 41(2):355-73. We seldom encounter patients with sleep 2. Goto F, Tsutumi T, Arai M, Ogawa K. [Somatic disorders other than sleep apnea in the symptoms in those hospitalized for dizziness or Department of Otolaryngology. However, vertigo]. Nihon Jibiinkoka Gakkai Kaiho 2010; it is important for clinicians to consider a 113(9):742-50. 3. Kayabasi S, Iriz A, Cayonu M, Cengiz B, Acar sleep disorder as a cause of hearing and A, Boynuegri S, et al. Vestibular functions were balance problems. Therefore, if the found to be impaired in patients with moderate-to- physical symptom does not completely severe obstructive sleep apnea. Laryngoscope resolve following conventional treatment 2015; 125(5):1244-8. by otolaryngologists, we should consider a 4. Nakayama M, Kabaya K. Obstructive sleep apnea syndrome as a novel cause for Meniere's possible sleep disorder. disease. Current opinion in otolaryngology & head If a sleep disorder is suspected, it is and neck surgery 2013;21(5):503-8. necessary not only to prescribe appropriate 5. Honaker JA, Shepard NT. Performance of medication, but also to refer the patient for Fukuda Stepping Test as a function of the severity examination by a sleep specialist. It is of caloric weakness in chronic dizzy patients. Journal of the American Academy of Audiology important to uncover hidden sleeping 2012; 23(8): 616-22. disorders that may be triggering sensory 6. Liberalesso PB, D'Andrea KF, Cordeiro ML, problems. Zeigelboim BS, Marques JM, Jurkiewicz AL. Effects of sleep deprivation on central auditory Conclusion processing. BMC Neurosci 2012;13:83. 7. Goto F, Tsutsumi T, Oishi N, Mimura M. An undiagnosed sleep disorder is an Hidden depression in otolaryngology patients with important cause of MUS and should be medically unexplained symptoms. Gen Hosp considered in cases of auditory processing Psychiatry 2012;34(2):206-8. difficulty and unexplained dizziness. When a sleep disorder is suspected,

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