Bilateral Otitis Media Causing Atlanto-Occipital Joint Infection and Neurologic Signs

翻譯 By @寵物神經(jīng)科醫(yī)生高健

原文網(wǎng)址：

https://todaysveterinarynurse.com/neurology/bilateral-otitis-media-causing-atlanto-occipital-joint-infection-and-neurologic-signs/

Because otitis media and interna can be hard to diagnose without advanced imaging, it is important to take even subtle clinical signs seriously.

由于中耳炎和內(nèi)耳炎在沒有高階影像學(xué)檢查的情況下很難診斷，
所以即使是細微的臨床癥狀也要認真對待。

Kathleen graduated in 2007 from the Vet Tech Institute in Pittsburgh, Pennsylvania, with a degree in Veterinary Specialized Technology. In 2015, she received a Bachelor of Science degree from the University of Pittsburgh with a focus on chemistry, biology, and psychology. She has worked for 7 years in general practice and 7 years in specialty practice, primarily neurology.?

Kathleen于2007年畢業(yè)于賓夕法尼亞州匹茲堡的獸醫(yī)技術(shù)學(xué)院，獲得獸醫(yī)專業(yè)技術(shù)學(xué)位。2015年，她獲得了匹茲堡大學(xué)(University of Pittsburgh)的化學(xué)、生物學(xué)和心理學(xué)學(xué)士學(xué)位。她在全科醫(yī)生臨床工作了7年，在專科醫(yī)生臨床工作了7年，主要是神經(jīng)病學(xué)。

On March 26, 2019, “Sam,” a 9-year-old, 4.7-kg, intact male domestic short-haired cat, underwent dental cleaning and extractions of teeth 308, 309, 408, and 409. During the procedure, a mass was found and determined to be a bony prominence from a broken tooth. He was discharged the same day but returned on March 29 due to hiding at home. Dental radiographs showed roots that remained from teeth 308 and 309, so they were extracted. Sam was then hospitalized for medication (clindamycin at 0.27?mg/kg PO q12h) and observation and was discharged on April 5.

2019年3月26日，9歲、體重4.7公斤的未絕育雄性家養(yǎng)短毛貓“Sam”接受了牙齒清潔和拔牙手術(shù)，拔牙為308、309、408和409號牙齒。在手術(shù)過程中，發(fā)現(xiàn)了一個腫物，并確定是一顆斷裂牙齒的骨突起。它當(dāng)天出院，但由于在家里躲藏，于3月29日回到了醫(yī)院。牙科X光片顯示308號和309號牙齒的牙根還在，所以進行了牙根清除手術(shù)。隨后Sam住院用藥治療(克林霉素0.27 mg/kg PO q12h)并觀察，4月5日出院。

Presentation? 動物病況

On April 8, Sam was presented to the emergency department of our hospital for difficulty walking and a 2-week history of hiding, pawing at his face, decreased appetite, and “not being himself.” A complete blood count was within normal limits, and blood chemistry showed increased total protein (9.6 g/dL, reference range 6.5 to 8.4 g/dL), decreased albumin (2.3 g/dL, reference 2.8 to 4 g/dL), increased globulin (7.3 g/dL, reference 2 to 5 g/dL), and increased glucose (236?mg/dL, reference 70 to 160 g/dL).?

4月8日，Sam被送到我們醫(yī)院的急診科，原因是行走困難，并且有兩周的躲藏史，用爪子抓自己的臉，食欲下降，“不能正常表現(xiàn)自己應(yīng)有的行為”。全血細胞計數(shù)在正常范圍內(nèi)，血液生化顯示總蛋白升高(9.6 g/dL，參考范圍6.5至8.4 g/dL)，白蛋白降低(2.3 g/dL，參考范圍2.8至4 g/dL)，球蛋白升高(7.3 g/dL，參考2至5 g/dL)，葡萄糖升高(236 mg/dL，參考70至160 g/dL)。

At the time, the increased total protein and hypoalbuminemia were attributed to dehydration and inappetence.1,2?Hypoalbuminemia can be caused by malnutrition, liver disease, kidney disease, or sepsis.3?Elevated globulin indicates infection or inflammation.3?Hyperglycemia was correlated with the patient’s acute stress.2

當(dāng)時，總蛋白的增加和低白蛋白血癥歸因于脫水和食欲不振。1,2 低白蛋白血癥可由營養(yǎng)不良、肝臟疾病、腎臟疾病或敗血癥。3 引起球蛋白升高表明感染或炎癥。3?高血糖與病患的急性應(yīng)激相關(guān)。2

During physical examination, Sam was bright, alert, and responsive. He was ambulatory but tetraparetic and knuckling on his forelimbs. The remainder of the examination was unremarkable. Thoracic, cervical, and skull radiographs were taken. The skull radiographs indicated some bony lysis of the cranial mandible, consistent with his recent dental extractions. No other abnormalities were noted. The patient was given fluids (lactated Ringer’s solution at 2.8 mL/kg and a rate of?13 mL/hr) along with clindamycin (22.34 mg/kg?IV).

在體檢時，Sam 活潑，警覺，反應(yīng)靈敏。它可以走動，但四肢輕癱，前肢掌背貼地。檢查的其余部分無明顯異常。拍攝胸片、頸椎片和顱骨片。顱骨X光片顯示顱骨下頜骨有些骨溶解，與它最近拔牙的情況相符。沒有發(fā)現(xiàn)其他異常。給予它補充液體(乳酸林格氏液，2.8 mL/kg，速率13 mL/hr)和克林霉素(22.34 mg/kg IV)。

The next day, Sam was transferred to the neurology service, where his examination indicated spastic tetraparesis, generalized ataxia, and decreased motor function of all limbs. His postural reactions, which help determine lesion location,4?were abnormal: +0 to 1 (absent to weak) in the thoracic limbs and +1 (weak) in the pelvic limbs.?No cranial nerve deficits were noted. Spinal reflexes were normal. Palpation elicited no clear signs of spinal pain. Cranial nerve examination, used to evaluate various nerve pathways to the brain and help with lesion localization,4?revealed no deficits. Because Sam’s cranial nerve examination revealed no abnormalities and because his tetraparesis and abnormal postural reactions were more pronounced in the thoracic than in the pelvic limbs, the neuroanatomic disorder was determined to be localized to the cervical (C1 to C5) spinal cord segment.?

第二天，Sam被轉(zhuǎn)診到神經(jīng)科，檢查顯示它患有痙攣性四肢輕癱、全身性共濟失調(diào)和四肢運動功能減退。它的姿勢反應(yīng)有助于確定病變位置，其中有4項異常：前肢+0到1(無到減弱)，后肢+1(減弱)。未發(fā)現(xiàn)腦神經(jīng)缺陷。脊髓反射正常。觸診未發(fā)現(xiàn)明顯的脊柱疼痛跡象。腦神經(jīng)檢查用于評估通往大腦的各種神經(jīng)通路并幫助定位病變，4 未發(fā)現(xiàn)缺陷。由于Sam的腦神經(jīng)檢查未發(fā)現(xiàn)異常，并且由于它的四肢輕癱和異常姿勢反應(yīng)在前肢比在后肢更明顯，因此神經(jīng)解剖學(xué)上的疾病被定位于頸(C1至C5)脊髓節(jié)段。

Diagnostics, Results, and Diagnosis 診斷方式，結(jié)果和診斷

Magnetic resonance imaging (MRI) of Sam’s brain and cranial cervical region was performed by using contrast (gadolinium at 100 mg/kg IV). He was premedicated with buprenorphine (0.4 mg/kg IV), and anesthesia was induced with midazolam (0.2 mg/kg IV) and propofol (4 mg/kg IV).?

采用造影劑(釓gadolinium劑量為100 mg/kg IV)對Sam的大腦和顱頸區(qū)進行磁共振成像(MRI)檢查，麻醉前用藥為丁丙諾啡buprenorphine(0.4 mg/kg IV)，咪達唑侖midazolam(0.2 mg/kg IV)和丙泊酚propofol(4 mg/kg IV)誘導(dǎo)麻醉。

After induction, a fluid bolus (4.26 mg/kg IV) was given to remedy bradycardia (120 beats/min) and hypotension (76/57 mm Hg, mean 65 mm Hg, measured indirectly). Sam’s heart rate increased to 138?beats/min, but his blood pressure did not respond. Atropine (0.04 mg/kg IV) was then given, after which his blood pressure increased to 88/56 mm Hg (mean 68 mm Hg) and remained stable for 25?minutes. Anesthesia was maintained with isoflurane at 1.5 L/min and oxygen at 1 L/min. When heart rate and blood pressure again decreased, to 133 beats/minute and 65/44 mm Hg (mean 59 mm Hg), respectively, a second dose of atropine was given. Isoflurane was turned down to 1 L/min and 2 doses of hetastarch (hydroxyethyl starch) at 2.1 mL/kg IV were administered 5 minutes apart. Hetastarch causes an increase in plasma volume, which in turn increases and maintains appropriate blood pressure. Sam’s blood pressure increased and stayed in the mid-80s (mm Hg) for systolic and the mid-40s (mm Hg) for diastolic (approximate mean 65 mm Hg).?

誘導(dǎo)后，給予4.26 mg/kg液體團注（譯者注：可能是 mL/kg），以糾正心動過緩(120次/分)和低血壓(76/57 mm Hg，平均65 mm Hg，間接測量法)。Sam的心率增加到每分鐘138次，但它的血壓沒有反應(yīng)。給予阿托品(0.04 mg/kg IV)后，病患血壓升高至88/56 mm Hg(平均68 mm Hg)，并穩(wěn)定25分鐘。維持1.5 L/min異氟烷麻醉，1L/min供氧。當(dāng)心率和血壓再次下降至133次/分鐘和65/44mm Hg(平均59mm Hg)時，給予第二次劑量的阿托品。異氟烷降至1 L/min，并以2.1 mL/kg IV給藥2劑羥乙基淀粉，間隔5分鐘。羥乙基淀粉引起血漿容量增加，從而使血壓升高并維持在適當(dāng)水平。Sam的血壓升高，收縮壓保持在80?mmHg左右，舒張壓保持在40左右(大約平均65mmHg)。

The MRIs showed hyperintense material in both tympanic bullae, more pronounced in the right but more expansive in the left (FIGURES 1–5). The atlanto-occipital (AO) joint showed increased fluid accumulation, which was causing extradural compression of the caudal brain stem and the spinal cord at C1, tapering over the C2 vertebra. The increased fluid and the stronger peripheral contrast enhancement of the AO joint were consistent with septic arthritis. Bilateral otitis media and interna were diagnosed and deemed the most likely source of the joint infection.

MRI顯示兩個鼓泡存在（T2WI）高強度信號物質(zhì)，右側(cè)更明顯，左側(cè)更具有擴張性(圖1-5)。寰枕關(guān)節(jié)顯示積液增多，導(dǎo)致后側(cè)腦干和C1處脊髓的硬膜外壓迫，在C2椎體上方逐漸變細。寰枕關(guān)節(jié)積液增多和外周顯著增強，提示化膿性關(guān)節(jié)炎。雙側(cè)中耳炎和內(nèi)耳炎被診斷為最可能的關(guān)節(jié)感染來源。

After the MRI, ultrasonography was performed to better visualize the AO joint. The joint was deemed accessible and was aspirated, with 2 to 3 mL of translucent fluid removed for cytology, culture, and sensitivity.?

MRI后進行超聲檢查以更好地觀察寰枕關(guān)節(jié)。此關(guān)節(jié)可以夠得到并進行穿刺抽吸，取到了2 - 3ml半透明的液體進行細胞學(xué)、培養(yǎng)和藥物敏感性檢查。

After the aspiration, bilateral myringotomy was performed. An otoscope was used to visualize the eardrum. A 12-mL syringe with a 22-gauge spinal needle attached was then gently guided through the eardrum into the internal ear canal, and 4 mL of saline was flushed into each bulla and aspirated back. The aspirated fluid was placed in a culturette. With the needle remaining in place, the syringe was switched out 4 times to flush out the debris and aspirate it back. With the eardrum pierced, any remaining trapped fluid could drain into the external ear canal.5?Myringotomies are performed to obtain specimens for cytology, culture, and antibiotic sensitivity; they can also immediately relieve pain caused by pressure associated with otitis media and interna.5?

抽吸后行雙側(cè)鼓膜切開術(shù)。用耳鏡觀察鼓膜。接有22號脊髓針的12ml注射器通過鼓膜輕輕引導(dǎo)進入內(nèi)耳道，將4ml生理鹽水注入鼓泡內(nèi)并抽吸回去。將抽吸的液體放入培養(yǎng)器中。針頭留在原位，切換了4次注射器，反復(fù)沖洗掉碎片并將其抽吸回去。鼓膜穿孔后，任何殘留的液體都可能流入外耳道。5?進行鼓膜切開術(shù)以獲得細胞學(xué)、培養(yǎng)和抗生素敏感性的樣本；它們還能立即緩解由中耳炎和內(nèi)耳炎引起的壓力升高而引起的疼痛。5

Sam was extubated and recovered with heat support. Lactated Ringer’s solution was restarted at 13 mL/hr. Cefazolin was given at 30 mg/kg IV q8h. Enrofloxacin (15 mg/kg IV), dexamethasone SP (0.15 mg/kg IV), and?cefovecin?(8.5 mg/kg SQ) were each given 1 time.

（停止麻醉）拔掉Sam的氣管插管并保暖恢復(fù)。乳酸林格氏液以13mL/小時再次輸注。頭孢唑林（Cefazolin）給藥 30 mg/kg IV q8h。恩諾沙星（Enrofloxacin）(15 mg/kg IV)、地塞米松磷酸鈉（dexamethasone SP）?(0.15 mg/kg IV)、頭孢維星（cefovecin）(8.5 mg/kg SQ)各1次。

?

Sam’s vital signs returned to within normal limits, and his demeanor during the night was unremarkable. After much of the fluid in the AO joint had been aspirated, along with steroid treatment, his condition greatly improved within the next few hours. This improvement was presumed to be because the AO joint was no longer as swollen and no longer compressing the brain stem, thereby relieving his symptoms.

Sam的生命體征恢復(fù)到正常范圍內(nèi)，它在夜間的舉止也變得很平常了。在抽吸了寰枕關(guān)節(jié)內(nèi)的大部分液體后，加上類固醇治療，它的病情在接下來的幾個小時內(nèi)得到了極大的改善。這種改善被認為是因為寰枕關(guān)節(jié)不再腫脹，不再壓迫腦干，從而造成了病患的癥狀的減輕。

The cytology of the AO joint indicated that the aspirate was highly cellular, consisting of 97% neutrophils, 2% macrophages, and 1% small lymphocytes. No infectious organisms were seen and no growth occurred on culture, presumably the result of antibiotic treatment before hospitalization. The myringotomy aspirate was not sent out for culture because the treatment for the septic AO joint would also treat otitis media and interna.

寰枕關(guān)節(jié)的細胞學(xué)檢查表明，抽吸液是富含細胞的，由97%的中性粒細胞、2%的巨噬細胞和1%的小淋巴細胞組成。未見感染性微生物，培養(yǎng)未出現(xiàn)生長，可能是住院前抗生素治療的結(jié)果。由于化膿性寰枕關(guān)節(jié)的治療同時也會治療中耳炎和內(nèi)耳炎，因此沒有將鼓膜切開術(shù)的抽吸液送出進行培養(yǎng)。

Treatment and Outcome 治療和結(jié)果

By the day after surgery, Sam’s condition had improved markedly, and his medications were transitioned from intravenous to oral. He was given pradofloxacin (7.4?mg/kg PO q24h) and?gabapentin?(10.6 mg/kg PO q12h) to prevent nerve pain that may be associated with the infected AO joint.?

手術(shù)后的第二天，Sam的病情明顯好轉(zhuǎn)，它的藥物治療也從靜脈注射轉(zhuǎn)為口服。給予普拉氟沙星（pradofloxacin）(7.4 mg/kg PO q24h)和加巴噴?。╣abapentin）(10.6 mg/kg PO q12h)預(yù)防可能與寰枕關(guān)節(jié)感染相關(guān)的神經(jīng)疼痛。

Physical examination revealed a small amount of dried blood in the left ear canal and some serous ocular discharge. Neurologically, the patient was ambulatory with marginal ataxia. The rest of the examination was unremarkable. Sam was discharged home the next day. The gabapentin was continued for 1 week, pradofloxacin for 1 month, and cefovecin for 2 months (an injection every 2 weeks).

體檢發(fā)現(xiàn)左側(cè)耳道有少量干血，眼角有漿液性分泌物。神經(jīng)學(xué)方面，病患可走動，伴有邊緣性共濟失調(diào)。檢查的其余方面無明顯異常。Sam第二天出院回家了。加巴噴?。╣abapentin）治療1周，普拉氟沙星（pradofloxacin）治療1個月，頭孢維星（cefovecin）治療2個月(每2周注射一次)。

At the 6-week recheck, the client reported that Sam was doing well, eating and drinking normally, and back to “his old self.” Physical and neurologic examinations revealed no abnormalities, and no recurrence has been reported.

?6 周后復(fù)查，寵主報告說Sam一切正常，飲食正常，恢復(fù)了“本性”。體格和神經(jīng)檢查未見異常，無復(fù)發(fā)報道。

Discussion 討論

Otitis media and interna are somewhat common in cats. It is hypothesized that if left untreated, otitis externa can progress to otitis media and interna, damaging ear structures over time.5?The exact mechanism of otitis media is unknown, but it is theorized that an infection (such as a respiratory pathogen) ascends through the eustachian tube.5?It is also possible for an infection to build up in the external ear canal and rupture the eardrum, causing infection to travel from the external ear canal to the middle ear.5?If left untreated, otitis media and interna can lead to infection in nearby structures, including the brain.5?Only exceedingly rarely does otitis lead to an AO joint infection. Common clinical signs of otitis media and interna include head shaking, pain on palpation of the ear pinna or canal, and reluctance to open the mouth because of swelling within the bulla affecting the temporomandibular joint.5?Otitis media and interna can affect the sympathetic nerves that travel through the middle ear, such as the facial and trigeminal nerves. When they do, Horner’s syndrome, head tilt, or facial nerve palsy can result.5?Even after a thorough ear examination, otitis media and interna can be difficult to diagnose, especially if the eardrum is intact. A classic clinical sign is purulent mucoid exudate along the floor of the horizontal canal, but it is not necessarily diagnostic nor is radiographic assessment always conclusive.5?Otitis media and interna can be diagnosed with MRI or computed tomography.?

中耳炎和中耳炎在貓身上比較常見。據(jù)推測，如果不及時治療，外耳炎會發(fā)展為中耳炎和內(nèi)耳炎，隨著時間的推移會損害耳朵結(jié)構(gòu)。5?中耳炎的確切機制尚不清楚，但理論上認為感染(如呼吸道病原體)通過咽鼓管逆行感染。也有可能在外耳道積聚，使鼓膜破裂，導(dǎo)致感染從外耳道傳播到中耳。如果不及時治療，中耳炎和內(nèi)耳炎會導(dǎo)致附近結(jié)構(gòu)的感染，包括大腦。中耳炎導(dǎo)致寰枕關(guān)節(jié)感染的情況極為罕見。中耳炎和內(nèi)耳炎的常見臨床癥狀包括搖頭、耳廓或耳道觸診疼痛、因影響顳下頜關(guān)節(jié)的鼓泡內(nèi)腫脹而不愿張開嘴巴。中耳炎和內(nèi)耳炎可影響穿過中耳的交感神經(jīng)，如面神經(jīng)和三叉神經(jīng)。當(dāng)影響這些神經(jīng)時時，就會導(dǎo)致霍納綜合癥、頭部傾斜或面神經(jīng)麻痹。即使經(jīng)過徹底的耳部檢查，中耳炎和內(nèi)耳炎也很難診斷，特別是如果鼓膜是完好無損的時候。一個典型的臨床征象是沿水平耳道底有膿性粘液滲出，但這并不一定是診斷性的，影像學(xué)檢查也不總是有結(jié)論性的。中耳炎和內(nèi)耳炎可通過MRI或計算機斷層掃描診斷。

Sam’s infection most likely traveled from the middle ear to the AO joint via the vertebral artery, which runs anterior to the AO joint and enters the foramen magnum (FIGURE 6).5?However, other pathways could have been involved, including the carotid artery and jugular vein.4?Sam’s sympathetic nerves were not affected. His clinical signs were initially assumed to have resulted from a tooth abscess. It was not until Sam became tetraparetic that his diagnosis was investigated further. In retrospect, it was determined that his clinical signs were caused by the otitis.?The brain stem compression also contributed to Sam’s clinical signs. This type of compression can lead to tetraparesis, generalized ataxia, abnormal postural reactions, weakness, dizziness, impaired vision, neck pain, weakness in the limbs, and proprioceptive deficits.6

Sam的感染極有可能通過椎動脈從中耳傳播到寰枕關(guān)節(jié)，該椎動脈在寰枕關(guān)節(jié)前方并進入枕骨大孔(圖6) 5。然而，其他途徑也可能參與其中，包括頸動脈和頸靜脈。Sam的交感神經(jīng)沒有受到影響。它的臨床癥狀最初被認為是由牙齒膿腫引起的。直到Sam逐漸發(fā)展為四肢輕癱，它的診斷才得到進一步的調(diào)查。經(jīng)過回顧，確定它的臨床癥狀是由中耳炎引起的。腦干壓迫也導(dǎo)致了Sam的臨床癥狀。這種類型的壓迫可導(dǎo)致四肢輕癱、全身性共濟失調(diào)、異常姿勢反應(yīng)、虛弱 無力、頭暈、視力受損、頸部疼痛、四肢無力和本體感覺缺陷。6

Otitis media and interna can be hard to diagnose without access to advanced imaging such as MRI or computed tomography. Therefore, it is important to take even subtle clinical signs seriously. If an outgoing cat suddenly starts to hide in abnormal places, becomes head shy, or exhibits a darker shade of red on its ears, these signs should be cause for concern. Had Sam’s otitis externa been found and treated sooner, the infection might not have progressed. However, as with Sam, some cats do not show many clinical signs until otitis externa progresses.?

中耳炎和內(nèi)耳炎在沒有MRI或計算機斷層掃描等高階成像技術(shù)的情況下很難診斷。因此，即使是細微的臨床癥狀也要重視。如果一只外向的貓突然開始躲在不正常的地方，變得害羞，或者耳朵上出現(xiàn)更深的紅色斑塊，這些跡象應(yīng)該引起關(guān)注。如果Sam的外耳炎能早點被發(fā)現(xiàn)并治療，感染可能就不會惡化了。然而，和Sam一樣，有些貓在外耳炎漸進性發(fā)展之前沒有表現(xiàn)出很多臨床癥狀。

參考文獻 References

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2. Jain NC. Essentials of veterinary hematology. 1993 Jan 1. archive.org/details/essentialsofvete0000jain/page/n11/mode/2up?view=theater. Accessed January 2021.

3. Medline Plus. Globulin test. 2020 July 31. medlineplus.gov/lab-tests/globulin-test. Accessed January 2021.

4. Dewey CW, da Costa RC, Ducoté JM. Chapter 5: Neurodiagnostics. In:?Dewey CW, da Costa RC, eds.?Practical Guide to Canine and Feline Neurology. Hoboken, NJ: Wiley-Blackwell; 2016:61–86.?

5. Gotthelf LN. Diagnosis and treatment of otitis media in dogs and cats.?Vet Clin North Am Small Anim Pract.?2004;34(2):469–487. doi:10.1016/j.cvsm.2003.10.007

6. Rubin M. Craniocervical junction disorders. Merck Manual. merckmanuals.com/home/brain,-spinal-cord,-and-nerve-disorders/craniocervical-junction-disorders/craniocervical-junction-disorders. Accessed December 2020.

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