Clinical features and stroke etiology in 10 patients with bilateral middle cerebellar peduncle infarctions: a preliminary study / 中华神经科杂志

Objective:To characterize clinical and neuroimaging features, etiologies, and mechanisms of bilateral middle cerebellar peduncle (MCP) infarctions.Methods:Consecutive patients with bilateral MCP infarctions treated in the Beijing Tiantan Hospital, Capital Medical University between January 1, 2020 and April 30, 2022 were enrolled in this retrospective study. The demographic data, vascular risk factors, clincial manifestations and the National Institutes of Health Stroke Scale (NIHSS) scores were collected. Brain diffusion-weighted imaging was used to assess the regions of cerebral infarction, and the extracranial and intracranial segments of the vertebrobasilar artery were evaluated using magnetic resonance angiography, or computed tomography angiography. The stroke etiology and underlying mechanism were evaluated according to the Chinese Ischemic Stroke Subclassification.Results:Ten patients with bilateral MCP infarctions (8 men and 2 women) were analyzed ultimately. The onset age were 51.0-86.0 (64.8±11.4) years. NIHSS scores were 2.0-12.0 (4.9±2.9) points at admission. All patients had vascular risk factors, most of which were hypertension (10 cases) and dyslipoproteinemia (8 cases). The most common clinical manifestations were vertigo (10 cases), followed by ataxia (9 cases) and dysarthria (8 cases). Four cases were isolated bilateral MCP infarctions, while 6 patients were combined with other vertebrobasilar artery infarctions, 4 of which were combined with cerebellar hemisphere infarctions, consistent with the clinical symptoms. The etiology in all patients was large atherosclerosis (severe stenosis or occlusion of V4 segment of vertebral artery and anterior inferior cerebellar artery; 9 cases). Five patients were classified as hypoperfusion/impaired emboli clearance, while 4 patients were considered as artery-to-artery embolism, and 1 was considered as the parent artery (plaque or thrombosis) occluding penetrating artery.Conclusions:Bilateral MCP infarctions are an extremely rare cerebrovascular disease characterized by vertigo, ataxia, and dysarthria. Cerebral infarction can be isolated or often combined with cerebellar hemisphere infarction. The etiology was mostly stenosis or occlusion of V4 segment of vertebral artery and anterior inferior cerebellar artery.

Una propuesta de clasificación del complejo arteria cerebelosa anteroinferior ­ arteria subarcuata basada en el desarrollo embriológico / A proposed classification of the anteroinferior cerebellar artery - subarcuate artery complex based on embryological development

Introducción: El recorrido del "loop subarcuato" de la arteria cerebelosa anteroinferior (ACAI) presenta múltiples variaciones que condicionan además su principal eferencia, la arteria subarcuata (ASA). El espectro de variaciones de este complejo ha sido referido en la literatura de forma inconexa y desorganizada. Material y Métodos: Se propuso una clasificación sistematizada de las variantes del complejo ACAI-ASA, basada en la interacción del hueso petroso y la ACAI en el periodo embrionario. La misma fue aplicada en una serie de pacientes estudiados mediante secuencia CISS (constructive interference in steady state) de resonancia magnética para categorizar las relaciones presentes en el ángulo pontocerebeloso (APC). Resultados: Se evaluaron 84 pacientes, incluyendo 161 APC. Todos los grados propuestos fueron identificados en la serie evaluada. Las proporciones encontradas en la gradación propuesta se mantuvieron en el rango de las publicaciones aisladas. Conclusión: La clasificación propuesta para el complejo ACAI-ASA permitió distinguir y objetivar consistentemente el espectro de variaciones.

Introduction: The pathway of the anterior inferior cerebellar artery's (AICA) "subarcuate loop" can vary extensively. This variability also affects its main branch, the subarcuate artery (SAA). The spectrum of variations observed with this combination of vessels is inadequately described in the literature. Methods and Materials: A systematized classification system for AICA-SAA complex variants was proposed, based upon interactions between the petrosal bone and the AICA in embryos. This classification scheme then was applied to a series of patients assessed by magnetic resonance CISS (constructive interference in steady state) sequences, to categorize the cerebellopontine angle (CPA) relationships. Results: Eighty-four patients were evaluated, encompassing 161 CPA. All the proposed grades were identified in the evaluated series. The proportions found with the proposed gradation system were within the range of previous publications. Conclusions: The AICA-SAA complex classification system that we proposed allowed for consistently distinguishing and objectifying the spectrum of variations seen in the subarcuate loop.

Fresado de la fosa subarcuata para liberar la arteria cerebelosa anteroinferior en una cirugía de un schwannoma vestibular / Reaming the subarcuate fossa to release the anteroinferior cerebellar artery in surgery for a vestibular schwannoma

Introducción: El abordaje suboccipital retrosigmoideo es la vía principal para la resección de los schwannomas vestibulares (SV). La relación vascular más constante de los nervios del conducto auditivo interno es la arteria cerebelosa anteroinferior (ACAI); pudiendo su recorrido presentarse como un serio obstáculo para la resección completa de la lesión. Descripción del caso: Paciente varón de 38 años, con diagnóstico presuntivo de SV por resonancia magnética (Grado T3B). Se realiza cirugía por vía retrosigmoidea. Se observa a la ACAI totalmente recubierta por tejido dural y óseo, cuya liberación fue posible mediante fresado en la fosa subarcuata. Se logra una exéresis completa del tumor. El paciente evolucionó durante el estado posoperatorio sin déficit neurológico agregado. Discusión: La ACAI ha sido descripta fijada a la duramadre y/o incrustada en el hueso de la fosa subarcuata en escasas publicaciones, impidiendo la resección completa de un SV, especialmente de la porción intracanalicular. Sin embargo, su liberación supone riesgo adicional de lesión vascular. Conclusión: La lesión de la ACAI puede ser causal de alta morbilidad, por lo que el neurocirujano debe estar preparado para reconocer y resolver este tipo de situaciones.

Introduction: A retrosigmoid suboccipital approach is the route most commonly utilized to resect vestibular schwannomas (VS). However, the anterior inferior cerebellar artery (AICA) usually runs adjacent to internal auditory canal nerves, and its course may severely impede total tumor resection. Case report: A 38-year-old male patient presented with presumed grade T3B VS, diagnosed by magnetic resonance imaging (MRI). Surgery was performed using a retrosigmoid approach, during which the AICA was identified to be completely covered by dural and bone tissue. Further drilling in the subarcuate fossa was necessary to release the AICI, allowing for total gross resection of the VS. No neurological deficits were observed post-operatively. Discussion: On rare occasion, the AICA has been described fixed to the dura and/or embedded within subarcuate fossal bone, thereby preventing removal of the intra-canalicular portion of the VS and, hence, total resection. However, AICA release adds the risk of vascular injury. Conclusion: Injury to the AICA may cause high morbidity in patients with a vestibular schwannoma. Neurosurgeons must be able to recognize and deal with certain anatomical configurations that place patients at particularly-high risk.

Reconstruction of anterior inferior cerebellar artery by occipital artery through extended retrosigmoid approach / 中华显微外科杂志

Objective To explore the feasibility of occipital artery(OA) to anterior inferior cerebellar artery (AICA) through the extended retrosigmoid approach,also perform a systemic microanatomical study of OA and AICA with the exposure of extended retrosigmoid approach,find the easy way to perform the procedure.Methods From September,2016 to January,2017,5 adult cadaveric heads injected with colored latex (total 10 sides) were performed the extended retrosigmoid approach,and measured the caliber of distal occipital artery (OA),the final length of the OA harvest,the reliable landmark of the OA harvest,and the distance from the flocculonodular segment of anterior inferior cerebellar artery (AICA) to the OA,the diameter of AICA flocculonodular segment branch.Whole procedure of OA to IACA bypass also be performed.Statistical analysis was performed.Results By the extended retrosigmoid approach,AICA flocculonodular segment could be easily exposure,the average diameter was 1.2 mm,the OA branch could be harvested in average was (72.3±3.3)mm in length from the occipital sulcus,and the average distance between occipital sulcus and AICA flocculonodular segment was (47.6±l.9)mm.The bypass procedure also could be performed through the proper corridor.Conclusion The Extended retrosigmoid approach is a safe and efficient way to perform the OA-AICA bypass procedure,and the procedure is easier to be performed than other surgical approaches.

Endovascular Approach of a Proximal Anterior Inferior Cerebellar Artery Aneurysm: Case Report

Anterior inferior cerebellar artery (AICA) aneurysms are extremely rare, accounting for only 0.75% of all intracranial aneurysms. The average age of patients suffering from those aneurysms found in the literature was 44 years, with no significant difference between the sexes. These aneurysms can manifest clinically through expansive symptoms in cerebellopontine angle or through signs and symptoms of subarachnoid hemorrhage, such as nausea, vomiting, headache, nystagmus and paresis. The gold standard exam for diagnosis is cerebral angiography. The treatment of these lesions is controversial. The main difficulty of the surgical treatment of these aneurysms is the location of the AICA, which lies close to critical neurovascular structures. In this article, we describe a proximal AICA aneurysm embolization without occlusion of the parent artery, with excellent results in the postoperative period.

Os aneurismas da artéria cerebelar anterior inferior (AICA) são extremamente raros, representando apenas 0,75% de todos os aneurismas intracranianos. A idade média de acometimento encontrada na literatura é de 44 anos, não havendo diferença significativa entre os sexos. A etiologia do aneurisma da AICA é controversa, porém, acreditase haver semelhanças com aneurismas em geral. Clinicamente, esses aneurismas podem manifestar sintomas expansivos no ângulo ponto-cerebelar, ou sinais e sintomas de hemorragia subaracnóidea (HSA), como náuseas, vômitos, cefaleia, nistagmo. O exame padrão-ouro para o diagnóstico é a angiografia cerebral. A maior controvérsia dos aneurismas da AICA é o tratamento. A principal dificuldade no tratamento cirúrgico desses aneurismas é a localização da AICA, perto de estruturas neurovasculares críticas. Neste artigo, descrevemos a embolização de um aneurisma proximal da AICA sem oclusão da artéria portadora, com excelentes resultados no pósoperatório.

Recent Advances in Understanding Audiovestibular Loss of a Vascular Cause / 대한뇌졸중학회지

Acute audiovestibular loss is characterized by abrupt onset of prolonged (lasting days) vertigo and hearing loss. Acute ischemic stroke in the distribution of the anterior inferior cerebellar artery (AICA) is known to be the leading cause of acute audiovestibular loss. So far, eight subgroups of AICA territory infarction have been identified according to the patterns of audiovestibular dysfunctions, among which the most common pattern is the combined loss of auditory and vestibular functions. Unlike inner ear dysfunction of a viral cause, which can commonly present as an isolated vestibular (i.e., vestibular neuritis) or cochlear loss (i.e., sudden deafness), labyrinthine dysfunction of a vascular cause rarely results in isolated loss of vestibular or auditory function. As audiovestibular loss may precede the central symptoms or signs of an ischemic stroke in the posterior circulation, early diagnosis and proper management of audiovestiubular loss may provide a window to prevent the progression of infarction to larger areas of the posterior circulation. A clinician should consider the possibility that acute audiovestibular loss may herald impending AICA territory infarction, especially when patients have basilar artery occlusive disease close to the origin of the AICA on brain MRA. This review aims to highlight the recent advances in understanding audiovestibular loss of a vascular cause and to address its clinical significance.

Role of the Peripheral Vestibular End Organ in the Expression of c-Fos Protein in the Medial Vestibular Nucleus Following Occlusion of the Anterior Inferior Cerebellar Artery / 대한평형의학회지

BACKGROUND AND OBJECTIVES: The present study investigated the role of the peripheral vestibular end organ in vestibular symptoms and temporal changes in expression of c-Fos protein in the vestibular nuclei following anterior inferior cerebellar artery (AICA) occlusion using rats with unilateral or bilateral labyrinthectomy. MATERIALS AND METHODS: Expression of c-Fos protein in the vestibular nuclei was measured 2, 12, 24, and 48 hours after AICA occlusion. RESULTS: Unilateral AICA occlusion significantly induced expression of c-Fos protein bilaterally in the medial, inferior, superior, and lateral vestibular nuclei. Following AICA occlusion, the medial vestibular nucleus (MVN) showed the highest expression of c-Fos protein among the 4 vestibular nuclei. The expression of c-Fos protein was asymmetric between the bilateral MVN, showing higher expression in the MVN contralateral to the side of AICA occlusion compared to the ipsilateral MVN. The degree of asymmetry in c-Fos protein expression between the bilateral MVN peaked 12 hours after AICA occlusion. The expression of c-Fos protein gradually decreased 24 hours after AICA occlusion and returned to control levels 48 hours after AICA occlusion. Unilateral labyrinthectomy significantly decreased expression of c-Fos protein in the MVN ipsilateral to the side of labyrinthectomy following AICA occlusion. Moreover, bilateral labyrinthectomy significantly decreased expression of c-Fos protein in the bilateral MVN flowing AICA occlusion. CONCLUSION: These results suggest that afferent signals from the peripheral vestibular end organ are crucial to the expression of c-Fos protein in the MVN following AICA occlusion and that expression of c-Fos protein is sustained for 24 hours after AICA occlusion.

Isolated Flocculus Infarction Mimicking Acute Labyrinthitis

Acute vestibular syndrome characterized by vertigo, spontaneous nystagmus, and postural instability is caused by a unilateral injury to either peripheral or central vestibular structures. However, central vestibular syndromes, such as labyrinthine ischemia due to occlusion of anterior inferior cerebellar artery (AICA), may cause abrupt unilateral labyrinthine dysfunction that mimics peripheral vestibulopathy. Here we report an AICA infarction with isolated flocculus lesion on magnetic resonance imaging mimicking acute labyrinthitis with vertigo, unidirectional horizontal-torsional nystagmus, ipsilesional sensorineural hearing impairment, and positive head-thrust test without any typical findings of floccular lesion.

A Case of Ruptured Peripheral Aneurysm of the Anterior Inferior Cerebellar Artery Associated with an Arteriovenous Malformation : A Less Invasive Image-Guided Transcortical Approach

A 47-year-old man presented with a subarachnoid hemorrhage (SAH) and right cerebellar hematoma was referred for evaluation. Cerebral angiography revealed a distal anterior inferior cerebellar artery (AICA) aneurysm associated with an arteriovenous malformation (AVM). Successful obliteration and complete removal of the aneurysm and AVM were obtained using transcortical approach under the guidance of neuronavigation system. The association of a peripheral AICA aneurysm and a cerebellar AVM by the same artery is unique. The reported cases of conventional surgery for this disease complex are not common and their results are variable. Less invasive surgery using image-guided neuronavigation system would be helpful and feasible for a peripheral aneurysm combining an AVM of the posterior fossa in selective cases.

The Clinical Correlation between Anterior Inferior Cerebellar Artery and Sudden Sensorineural Hearing Loss / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The influence of anterior inferior cerebellar artery (AICA) loop on sudden sensorineural hearing loss (SSHL) remains controversial. The objective of this study was to evaluate the correlation between the anatomical type of AICA loop and SSHL. SUBJECTS AND METHOD: We reviewed the medical records of 69 ears from 60 patients with SSHL between January 2005 and April 2008, retrospectively. AICA loops were classified according to the Chavda classification method by magnetic resonance imaging. According to the extension depth of the loop in the internal auditory canal, it was classified as type I, II and III. The loop was classified as S (small diameter) and L (large diameter) by comparing the thickness of the loop with adjacent facial nerves. RESULTS: The predominant type of AICA loop was type I (68.1%) and type S (78.3%). There was no significant correlation between the pretreatment hearing level, extension depth and diameter. There was also no significant correlation between the rate of hearing recovery by Siegel's criteria and diameter. However, there was significant correlation between the rate of hearing recovery by Siegel's criteria and the types of the extension depth (p< 0.05). The ears with type II and III of AICA loop presented higher rates of hearing recovery by Siegel's criteria than those with type I. CONCLUSION: This study suggests that the type II and III of AICA loop may be considered a good prognostic factor in SSHL.

Two Cases of Sudden Hearing Loss With Vertigo as an Isolated Symptom of Anterior Inferior Cerebellar Artery Infarction

Isolated sudden hearing loss with vertigo is usually peripheral origin. We report two cases with anterior inferior cerebellar artery infarction (AICA) manifesting sudden hearing loss with vertigo as an isolated symptom. Patient 1 was a 64-year-old man presented with right sided sudden hearing loss and vertigo accompanying horizontal beating nystagmus to the left. He had no other neurologic symptoms. MRI showed right AICA infarction involving lateral pons and middle cerebellar peduncle. Patient 2 was a hypertensive 56-year-old man. Left sided sudden hearing loss with vertigo was as an initial manifestation. Two days later, left sided facial palsy developed and MRI showed acute infarction in left lateral pons, middle cerebellar peduncle, and cerebellum. AICA infarction can be presented the hearing loss and vertigo as an isolated symptom and mimic the syndrome of peripheral origin.

Biphasic Head-Shaking Nystagmus in a Patient with Anterior Inferior Cerebellar Artery Infarction

Head-shaking test is a sensitive screening tool for a detection of peripheral and central vestibular system disease. Biphasic head-shaking nystagmus (b-HSN) is a rather uncommon phenomenon which was a combination of the paretic nystagmus and recovery nystagmus. We report characteristics of b-HSN in a patient with anterior inferior cerebellar artery infarction, whose only complaint was recurrent vertigo.

Expression of Immediate-Early Gene Proteins by Transient Occlusion of Anterior Inferior Cerebellar Artery in Vestibular Nuclei of Sprague-Dawley Rats

BACKGROUND: Anterior cerebellar artery (AICA) occlusion results in vestibular dysfunctions because the AICA supplies the vestibular nuclei (VN) in the brain stem as well as the peripheral vestibular organs in the inner ear. The purpose of this study was to evaluate the expression of immediate-early gene products, a metabolic marker of neural excitation in neurons, by AICA occlusion in the VN of Sprague-Dawley rats. METHODS: After chloral hydrate anesthesia all animals were subjected to unilateral AICA occlusion by using a microsurgical clamp for 30 min to induce a transient ischemia. Unilateral labyrinthectomy was chemically undertaken to eliminate vestibular afferent activity. Immunohistochemical staining and image analysis for cFos, FosB, Krox-24, and JunB proteins were performed 2 hours after AICA occlusion. RESULTS: There was a high expression of cFos protein in the bilateral medial and inferior VN 2 hours after AICA occlusion. AICA occlusion induced minimal changes in cFos protein expression in the lateral and superior VN. Mild to moderate expressions of FosB and JunB protein in VN was observed 2 hours after ischemic injury of the brain stem and inner ear. On the contrary, the number of cFos and FosB immunoreactive neurons significantly decreased in the medial vestibular nucleus ipsilateral to the injured labyrinth 2 hours after AICA occlusion in the UL group. CONCLUSIONS: These results suggest that ischemic afferent activity from the peripheral vestibular apparatus is essential for the expression of immediate-early gene products in the medial and inferior VN of rats following AICA occlusion.

Sudden Deafness with Vertigo as a Sole Manifestation of Anterior Inferior Cerebellar Artery Infarction

Although sudden deafness occurs with anterior inferior cerebellar artery infarction, the deafness is usually associated with other brainstem or cerebellum sign such as crossed sensory loss, lateral gaze palsy, facial weakness, Horner syndrome or limb dysmetria. An 84-year-old woman suddenly developed right-sided tinnitus, hearing loss, vertigo, and vomiting. Audiometry and electronystagmography documented absent auditory and vestibular functions on the right side. T2-weighted and diffusion-weighted MRI showed a tiny infarct in the right lateral inferior pontine tegmentum. Anterior inferior cerebellar artery occlusion can cause sudden deafness and vertigo without brainstem or cerebellar signs.

Acute hearing symptoms as a prodrome of anterior inferior cerebellar artery infarction

OBJECTIVES: An acute auditory symptom (AAS) without any other neurological symptoms or signs suggests a lesion in the peripheral auditory system. Blood supply to the peripheral auditory system arises from the internal auditory artery, ordinarily a branch of the anterior inferior cerebellar artery (AICA), therefore a partial ischemia in the AICA distribution may manifest with an AAS and/or vertigo. The aim of this study was to investigate the clinico-radiologic features of patients who presented with an AAS as a prodromal symptom of the AICA infarction. METHODS: Sixteen consecutive cases of the AICA infarction diagnosed by brain MRI completed a standardized audiovestibular questionnaire and underwent a neurotological evaluation by an experienced neurotologist. RESULTS: Five patients (31%) had an AAS as a prodrome of the AICA infarction 1-10 days prior to onset of other brainstem and/or cerebellar symptoms. Two types of AAS were found: recurrent transient hearing loss and/or tinnitus (n=3) or a single episode of prolonged hearing loss and/or tinnitus (n=2). The episodic symptoms were brief, lasting only minutes. The tinnitus preceding infarction was identical to the tinnitus experienced at the time of infarction. At the time of the infarction, all patients developed hearing loss, tinnitus, vertigo, and an ipsilateral hemiataxia. The most common affected site was the middle cerebellar peduncle (n=5). Four of 5 patients had an incomplete hearing loss and all patients had an absence of vestibular function to caloric stimulation on affected side, respectively. CONCLUSIONS: AAS may be a warning sign of an impending pontocerebellar infarction in the distribution of the AICA. The AAS preceding an AICA infarction may result from an ischemia of the inner ear or the vestibulocochlear nerve.

Facial nerve and the surrounding vessels: an anatomic study / 医学研究生学报

Objective:To study the relationship between facial nerve and surrounding vessels. Methods:Dissect skull of cadaver 40 sides of 20 cases: open the calvaria and clean the cerebrum, then open the tentorium of cerebellum, object and measure distance between the facial nerve and the nearest vessel, follow the course of it. Results:60%(24/40) of the arteries have the comprission with the facial nerve; among the nearest vessels, 87.5%(35/40) of them are anterior inferior cerebellar artery, and 12.5% (5/40) are posterior inferior cerebellar artery; the distances between facial nerve and the nearest vessels are from zero to 5.78mm, with an average of 1.14 mm; 94.3%(33/35) of the anterior inferior cerebellar artery emitted from the lower 2/3 of the basic artery. Conclusion:The most familiar vessel next to the facill nerve is the anterior inferior cerebellar artery, and the second is the posterior inferior cerebellar artery; most of the anterior inferior cerebellar artery emitted from the basic artery, exactly, the lower 2/3 of the artery.

A Case of Vestibular and Facial Nerve Root Entry Zone Infarction in AICA Territory Presenting with Vertigo Which Mimics Labyrinthine Lesion

Vertigo mimicking labyrinthine lesions may have resulted from ischemic insult to the inner ear or the vestibular nerve and nucleus in the AICA infarction syndrome. A 56-year-old female was admitted to the emergency room with vertigo and hearing loss in right ear. On neurological examination, she had left beating jerky torsional and horizontal nystagmus with falling and past pointing to right side. Brain magnetic resonance images showed high signal intensity in anterolateral portion of inferior pons on T2- weighted images. Severe right facial palsy of peripheral type developed 24 hours after admission. Audiometry and electronystagmography documented absent auditory and vestibular function on the affected side. We argue that vertigo of the acute infarction in AICA territory can be involved the eight and seventh nerve root entry zoon and mimic labyrinthine lesions

MICROSURGICAL ANATOMY OF THE ANTERIOR INFERIOR CEREBELLAR ARTERY / 解放军医学杂志

The anatomy of the trunks and branches of anterior inferior cerebellar artery(AICA) was studied and its surgical importance especially in the operation for acoustic neuroma(AN), was discussed.15 fresh adult cadavers were perfused with ABS via internal carotid artery and vertebral artery and then dissected under operation microscope in detail. AICA was constantly present in all specimens. The incidence of labyrinthine artery(LA), recurrent perforating artery(RPA), subarcuate artery(SA),and cerebellar subarcuate artery (Cer.SA) was 100%,86.7%,80% and 16.7%, respectively. 97.1% of LA entering the internal auditory meatus (IAM) were located under the facial vestibulocochlear nerve complex, 56.7% of RPA passed between it ,and 75% of SA was located posteroinferiorly to it .60.7% of the loop of AICA was situated close to the IAM, and 53.6% of them lay between the Ⅶ and Ⅷ cranial nerves. These data may be helpful in microneurosurgical operation and radiography.

A Case of Lateral Medullary Infarction Combined with Sudden Hearing Loss / 대한뇌혈관학회지

We report a 62-year-old female with ischemic disturbance of left inner ear. The patient had a sudden onset episode of vertigo, tinnitus and hearing loss. Neurologic examination revealed incomplete Honor syndrome, left facial sensory impairment and sensorineural hearing loss. Brain MRI showed subacute infarct on medial aspect of left lateral medulla. Ischemic disturbance of inner ear have been reported only in patients with the anterior inferior cerebellar artery syndrome. Therefore, this patient who had only acute ischemic disturbance of inner ear and lateral medulla was considered to be very rare. This phenomenon may be due to variations of anterior inferior cerebellar artery anatomy.

Changes in Cochlear Blood Flow by Anterior Inferior Cerebellar Artery Occlusion in Guinea Pigs / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Cochlear blood flow is considered important as one of many causes of various inner ear diseases. Many studies have been performed to prove the decrease in cochlear blood flow as a cause of those diseases. This study was performed to determine the effects of cochlear ischemia induced by AICA occlusion on the relation of cochlear blood flow (CBF) in guinea pigs. MATERIALS AND METHODS: In 3 guinea pigs, the AICA was exposed through the basal portion of the skull with stable systemic blood pressure. The CBF of the basal area was monitored with laser Doppler flowmetry (LDF). The AICA was clamped for several minutes. With different durations, the LDF was measured under systemic blood pressure monitoring. RESULT: The vascular conductance in preocclusion state was 0.09+/-0.04 TPU (tissue perfusion unit)/mmHg. During occlusion of AICA for above 1 minute, abrupt decrease and following slow increase of CBF was observed. CONCLUSION: The autoregulation of CBF was identified, but it was incomplete even under the stable blood pressure. This study can be a good model for evalulation of hearing function during partial cochlear ischemia, but occulusion of labyrinthine artery will be a better choice for complete cochlea ischemia model.