Sudden hearing loss

Japanese: 突発性難聴

What kind of disease is it?

●Main symptoms and progression Sudden hearing loss with an unknown cause is called sudden hearing loss. More than 95% of patients experience hearing loss in only one ear, and the condition of "difficulty hearing" varies from being completely unable to hear sounds, to feeling like the ear is clogged, to ringing in the ears.
Dizziness occurs in 30 to 60 percent of cases, and other symptoms such as nausea and vomiting also appear, so it is important to distinguish this from similar diseases such as Meniere's disease and acoustic neuroma.
If treatment is started early, about two-thirds of patients will be completely cured or will see an improvement in symptoms. If more than one month has passed since the onset of the disease, improvement becomes difficult. Therefore, it is recommended that treatment be started as early as possible, preferably within one week.

●How the causes and symptoms of illness occurSound is transmitted as air vibrations. The human ear is made up of the outer ear, middle ear, and inner ear. Sound waves collected by the outer ear (pinna) are amplified in the ear canal, causing the eardrum at the border with the middle ear to vibrate and being transmitted to the middle ear. The sound vibrations are further amplified by the eardrum and transmitted to the inner ear. The inner ear contains an organ called the cochlea, which is responsible for hearing, and contains lymph fluid. The vibrations of the sound waves transmitted from the middle ear cause this lymph fluid to vibrate, and sensory cells convert these vibrations into electrical signals that are transmitted to the cerebrum via the nerves, and we recognize that sound has been heard.
The outer ear to the middle ear are called the conductive system because they catch and transmit sound, while the inner ear is called the sensorineural system because it detects and makes the sound recognized by the nerves and cerebrum. Hearing loss caused by some kind of disorder in the conductive system is called conductive hearing loss, and hearing loss caused by the sensorineural system not working properly is called sensorineural hearing loss.
Sudden deafness is a sensorineural hearing loss, and it is clear that some kind of disorder has occurred in the inner ear. At present, it is thought to be caused by a virus or other infection, or by a disorder in the blood vessels of the inner ear that has led to poor blood circulation.

●Characteristics of the disease It can affect a wide range of people, from children to the elderly, but is most common in people in their 40s and 50s.

EBM checks on common treatments and care

[Treatment and care] Start treatment as soon as possible [Rating] ☆☆
[Evaluation Points] Sudden hearing loss has better outcomes if treatment is started as soon as possible after onset, and it is currently said that there is little chance of recovery after one month. However, people with mild hearing loss may recover naturally without any special treatment, so it is difficult to judge whether those whose hearing has not recovered would have recovered if they had started treatment earlier. Unfortunately, there are cases where little improvement is seen no matter how hard you try. Treatment is not effective for people who have completely lost their hearing at the time of onset or for people with severe hearing loss accompanied by dizziness.

[Treatment and care] Avoid stress, both mentally and physically, and stay at rest [Rating] ☆☆
[Evaluation Points] It is important to rest sufficiently and avoid stress, regardless of the illness. However, there are no clinical studies on the relationship between rest and sudden hearing loss, so the effectiveness is unknown. In fact, hearing loss often does not improve simply by resting, so if you suddenly lose your hearing, it is important to see a doctor as soon as possible.

[Treatment and care] Refrain from watching TV or listening to the radio, and limit phone calls to the bare minimum [Rating] ☆☆
[Evaluation Points] There are no clinical studies on the relationship between lowering the volume of sounds and sudden hearing loss, so its effectiveness is unknown. It may be more stressful to turn down the volume of sounds because it is difficult to hear TV, radio, and telephones. It may be better to refrain from doing so to a degree that does not put too much strain on your mind.

[Treatment and care] Adrenal cortical steroid tapering therapy [Evaluation] ☆☆
[Evaluation Points] In cases of sudden hearing loss, oral or intravenous administration of corticosteroids is commonly used to improve blood circulation, suppress inflammation, and improve weakened nerve function. Several clinical studies have been conducted on this treatment, but none have been conclusive, and its effectiveness remains controversial. (1)(2)

[Treatment and care] Use medication to improve blood circulation in the inner ear [Rating] ☆☆
[Evaluation Points] Drugs such as alprostadil alfadex are used to improve blood circulation in the inner ear and restore its function. They are sometimes used after considering the mechanism by which hearing loss occurs, but their effectiveness has not been confirmed through reliable clinical research. (3)

[Treatment and care] Hyperbaric oxygen therapy [Rating] ☆☆☆
[Evaluation points] Hyperbaric oxygen therapy is a treatment that improves blood circulation in the inner ear by inhaling oxygen at elevated pressure in a large tank or hyperbaric chamber, sending large amounts of oxygen into the blood. Even if other treatments have not shown improvement, clinical studies have confirmed that if hyperbaric oxygen therapy is started within six weeks of the onset of the condition, there are cases in which hearing can be significantly restored. (4)(5)

Checking commonly used drugs with EBM

Corticosteroids [Drug name] Rinderon (betamethasone) (1)(2)
[Rating] ☆☆
[Drug name] Decadron (dexamethasone) (1) (2)
[Rating] ☆☆
[Drug name] Prednisone/Prednisolone (Prednisolone) (1)(2)
[Rating] ☆☆
[Evaluation points] There are clinical studies that support the effectiveness of corticosteroids for sudden hearing loss, as well as studies that reject it, and no consensus has been reached.

Medicine to improve blood circulation in the inner ear [Drug name] Neuquinon (ubidecarenone)
[Rating] ☆☆
[Drug name] Adephos Kowa/Trinosin (adenosine triphosphate disodium hydrate)
[Rating] ☆☆
[Drug name] Vitamedin-S (a mixture of vitamins _B1 , _B2 , and _B12 )
[Rating] ☆☆
[Drug name] Prostandin (alprostadil alfadex) (3)
[Rating] ☆☆
[Evaluation Points] Ubidecarenone is a drug that allows oxygen to be used efficiently, adenosine triphosphate disodium hydrate and alprostadil alfadex are drugs that dilate blood vessels, and a mixture of vitamins _B1 , _B2 , and _B12 activates cells. Although their actions are different, all of these drugs are used to improve blood circulation in the inner ear. Clinical studies have been conducted on alprostadil alfadex, but its effectiveness is unclear. There are no clinical studies showing the effectiveness of other drugs. However, considering the cause of the disease, they are supported by expert opinion and experience.

Overall, the most reliable treatment currently available <br /> Try various treatments Sudden deafness is a sensorineural hearing loss, and we know that there is some kind of problem with the inner ear, but since the cause is unclear, there are currently no treatments that have been proven effective in reliable clinical studies.
Therefore, various treatments have been attempted. Typical treatments include tapering of corticosteroids, use of drugs to improve blood circulation in the inner ear, and hyperbaric oxygen therapy. There are also reports that antiviral drugs are effective, but their effectiveness is unclear, and further research is awaited.

It is important to seek medical attention as soon as possible. It has been found that the treatment outcome for sudden hearing loss is better if treatment is started as soon as possible after the onset of the condition. At present, it is said that there is little hope of recovery after one month. The important thing is early detection and early treatment.
If you experience symptoms such as being unable to hear anything, feeling like your ears are blocked, ringing, or tinnitus, it is important to see a specialist as soon as possible. In addition, it is important to distinguish this from similar diseases such as Meniere's disease and acoustic neuroma.

Rest and avoid stress Stress is also said to be one of the causes of sudden hearing loss. Therefore, resting the body and mind (especially reducing the volume of sounds, etc.) is thought to be a good way to avoid stress, even though it may not be directly related.

(1)Stachler RJ, Chandrasekhar SS, Archer SM, et al. Clinical practice guideline: sudden hearing loss. Otolaryngol Head Neck Surg. 2012; 146:S1.
(2)Wei BP, Stathopoulos D, O'Leary S. Steroids for idiopathic sudden sensorineural hearing loss. Cochrane Database Syst Rev. 2013; 7:CD003998.
(3)Nakashima T, Kuno K, Yanagita N. Evaluation of prostaglandin E1 therapy for sudden deafness. Laryngoscope. 1989;99:542-546.
(4)Bennett MH, Kertesz T, Yeung P. Hyperbaric oxygen for idiopathic sudden sensorineural hearing loss and tinnitus. Cochrane Database Syst Rev. 2007; :CD004739.
(5)Suzuki H, Hashida K, Nguyen KH, et al. Efficacy of intratympanic steroid administration on idiopathic sudden sensorineural hearing loss in comparison with hyperbaric oxygen therapy. Laryngoscope. 2012; 122:1154.

Source: "EBM: A book that explains correct treatment" Information about the book "EBM: A book that explains correct treatment"

Japanese:

どんな病気でしょうか?

●おもな症状と経過
　突然、おこる難聴で、原因が不明なものを突発性難聴(とっぱつせいなんちょう)といいます。患者さんの95パーセント以上が片耳だけに難聴をおこし、音がまったく聞こえない、あるいは耳がつまった感じ、耳鳴りがするなど「聞こえにくさ」の状態はさまざまです。
　30～60パーセントにめまいを伴うほか、吐き気や嘔吐(おうと)などの症状が現れるので、メニエール病や聴神経腫瘍(ちょうしんけいしゅよう)など類似の病気との判別が重要となります。
　早期に治療を始めれば約3分の2の患者さんで完全に治ったり、症状の改善がみられたりします。発病から1カ月を過ぎると改善が難しくなります。したがってなるべく早く、できれば1週間以内に治療を開始することが望ましいとされています。

●病気の原因や症状がおこってくるしくみ
　音は、空気の振動として伝わります。人の耳は、外耳(がいじ)、中耳(ちゅうじ)、内耳(ないじ)からなっていて、外耳（耳介(じかい)）で集められた音波は、外耳道で増幅されながら、中耳との境目にある鼓膜(こまく)を振動させ、中耳に伝わります。鼓膜で音の振動はさらに増幅され、内耳に伝えられます。内耳には聴覚を司(つかさど)る蝸牛(かぎゅう)という器官があり、蝸牛のなかにはリンパ液が入っています。中耳から伝えられた音波の振動によって、このリンパ液が揺れ、その揺れを感覚細胞が電気信号に変え、神経から大脳に伝達し、音が聞こえたと認識します。
　外耳から中耳までは、音をキャッチして伝える役割をするので伝音系(でんおんけい)、内耳は神経・大脳に感知、認識させる働きをするので感音系(かんおんけい)と呼びます。伝音系になんらかの障害があっておこる難聴を伝音難聴、感音系がうまく働かないためにおこる難聴を感音難聴と呼びます。
　突発性難聴は感音難聴であり、内耳になんらかの障害がおこっていることだけは明らかです。現在のところ、ウイルスなどの感染、あるいは内耳の血管に障害があり血液の循環が悪化したためと考えられています。

●病気の特徴
　子どもからお年寄りまで広くおこりますが、40歳～50歳代に多いといわれています。

よく行われている治療とケアをEBMでチェック

［治療とケア］可能な限り早く治療を開始する
［評価］☆☆
［評価のポイント］　突発性難聴は、発症後なるべく早く治療を始めたほうが治療成績がよく、いまのところ1カ月を過ぎると回復の見込みはほとんどないといわれています。しかし、軽度難聴の人ではとくに治療をしなくても自然に治癒する場合もあるので、聴力が回復しなかった人が、もし早期に治療を始めていれば回復できたかどうかの判断が困難です。残念なことに、どれほど手を尽くしてもほとんど改善がみられない場合もあります。発症時に聴力が完全になくなってしまった人やめまいを伴う高度難聴の人は治療効果がよくありません。

［治療とケア］精神的にも、肉体的にもストレスを避け、安静を保つ
［評価］☆☆
［評価のポイント］　十分に静養し、ストレスを避けることは、どのような病気でも大事なことです。しかし、安静と突発性難聴との関係についての臨床研究は見あたりませんので、その効果はわかっていません。むしろ、安静にしているだけでは難聴が回復しないことが多いので、突然耳が聞こえなくなったら1日も早く受診することが大切です。

［治療とケア］テレビ・ラジオの視聴は控え、電話も必要最低限にとどめる
［評価］☆☆
［評価のポイント］　音のボリュームを下げることと突発性難聴との関係についての臨床研究は見あたりませんので、その効果はわかっていません。テレビ、ラジオ、電話の音などが聞こえにくいために、かえってストレスを感じることがあります。精神的にあまり負担がかからない程度に控えたほうがいいかもしれません。

［治療とケア］副腎皮質(ふくじんひしつ)ステロイド薬(やく)漸減(ぜんげん)療法を行う
［評価］☆☆
［評価のポイント］　突発性難聴では血液の循環をよくし、炎症を抑え、弱っている神経の機能を改善するといった目的で副腎皮質ステロイド薬の内服や点滴が一般的に行われます。この治療についてはいくつかの臨床研究が行われていますが、どれも決定的なものとはいえず、効果については議論の余地が残っています。(1)(2)

［治療とケア］内耳の血行を改善する薬を用いる
［評価］☆☆
［評価のポイント］　アルプロスタジルアルファデクスなどの薬剤は、内耳の血行を改善して内耳の機能を回復させることを目的として用いられます。難聴がおこるしくみを考えたうえで用いられることもありますが、信頼性の高い臨床研究で効果が確認されているわけではありません。(3)

［治療とケア］高圧酸素療法(こうあつさんそりょうほう)を行う
［評価］☆☆☆
［評価のポイント］　高圧酸素療法は、大きなタンクあるいは高圧室のなかに入って気圧を上げた状態で酸素を吸入することによって血液中に酸素を大量に送り込み、内耳の血行を改善する治療です。ほかの治療で改善がみられなかった場合でも、発症から6週間以内に高圧酸素療法を始めれば、聴力が著しく回復する場合があるということが臨床研究によって確かめられています。(4)(5)

よく使われている薬をEBMでチェック

副腎皮質ステロイド薬
［薬名］リンデロン（ベタメタゾン）(1)(2)
［評価］☆☆
［薬名］デカドロン（デキサメタゾン）(1)(2)
［評価］☆☆
［薬名］プレドニン／プレドニゾロン（プレドニゾロン）(1)(2)
［評価］☆☆
［評価のポイント］　副腎皮質ステロイド薬の突発性難聴に対する有効性については効果を認めるとする臨床研究と否定的な臨床研究があり、評価が定まっていません。

内耳の血行を改善する薬
［薬名］ノイキノン（ユビデカレノン）
［評価］☆☆
［薬名］アデホスコーワ／トリノシン（アデノシン三リン酸二ナトリウム水和物）
［評価］☆☆
［薬名］ビタメジン-S（ビタミンB₁・B₂・B₁₂混合剤）
［評価］☆☆
［薬名］プロスタンディン（アルプロスタジルアルファデクス）(3)
［評価］☆☆
［評価のポイント］　ユビデカレノンは酸素を効率よく利用できるようにする薬、アデノシン三リン酸二ナトリウム水和物とアルプロスタジルアルファデクスは血管を拡張させる薬、ビタミンB₁・B₂・B₁₂混合剤は細胞を活性化させる薬です。このように作用は違いますが、いずれの薬も内耳の血行を改善する目的で用いられます。アルプロスタジルアルファデクスについては臨床研究が行われていますが、効果ははっきりしていません。ほかの薬については、有効性を示す臨床研究が見あたりません。しかし、病気の原因から考えて、専門家の意見や経験から支持されています。

総合的に見て現在もっとも確かな治療法
さまざまな治療を試す
　突発性難聴は感音難聴であり、内耳になんらかの問題があることだけはわかっていますが、原因が定かではないこともあり、現在までのところ、信頼性の高い臨床研究で効果があると認められている治療は見あたりません。
　したがって、さまざまな治療が試みられています。副腎皮質ステロイド薬漸減療法、内耳の血行を改善する薬の使用、高圧酸素療法などが代表的な治療となります。抗ウイルス薬が有効であるという報告もありますが、その効果については定かではなく、今後のさらなる研究が待たれます。

できるだけ早い受診が重要
　突発性難聴は、発症後なるべく早く治療を始めたほうが治療成績がよいことがわかっています。いまのところ1カ月を過ぎると回復の見込みはほとんどないといわれています。大切なのは、早期発見、早期治療です。
　音がまったく聞こえない、あるいは耳がつまった感じ、音が響く感じ、耳鳴りがするといった症状がでたら、一刻も早く専門医に診察してもらうことが大切です。また、その際、メニエール病や聴神経腫瘍など似た病気との判別が重要になります。

安静をはかり、ストレスを回避する
　このほか、ストレスが突発性難聴の原因の一つとされています。そこで、心身の安静（とくに音のボリュームを下げるなど、音に対する安静）を図ることも、直接的には関係ないかもしれませんが、ストレス回避にはよいことだと考えられます。

出典　法研「EBM 正しい治療がわかる本」EBM 正しい治療がわかる本について　情報

<<: Exanthem subitum (Roseola infantum)

>>: Tottori Plain - Tottori Heiya