Treatment strategies for saccular anterior inferior cerebellar artery aneurysms: a systematic review.

INTRODUCTION: The anterior inferior cerebellar artery (AICA) plays a crucial role in cerebellar blood supply, and AICA aneurysms are relatively rare, comprising less than 1-1.5% of all brain aneurysms. Understanding their clinical scenarios, management approaches, and outcomes is essential. This systematic review analyzes data from 86 studies to comprehensively explore AICA aneurysms. MATERIALS AND METHODS: The process of obtaining relevant research, which includes patients with AICA aneurysms, was carried out using the PubMed, Web of Science, and Scopus databases. This review exclusively included extensive papers written in English. The search included the MeSH phrases "Anterior inferior cerebellar artery aneurysm" and "AICA aneurysm." Microsurgical and endovascular treatments were compared using statistical analysis, exploring demographics, risk factors, treatment modalities, and clinical outcomes. RESULTS: The review includes 85 case reports and one retrospective study, totaling 140 patients. The study reveals a diverse patient profile with a slight female predominance (65%), a mean age of 50.7 years, and an 82.86% prevalence of no identified risk factors. Ruptured aneurysms accounted for 55%, with microsurgery and endovascular procedures accounting for 70.71% and 27.86%, respectively. The mortality rate was 2.86%, and no significant differences were found in rebleed, recurrence, or mortality rates between treatment groups. CONCLUSION: Microsurgical and endovascular interventions demonstrate comparable effectiveness, with microsurgery showing superiority in specific situations. Therefore, tailoring treatment is crucial to individual patient needs. Subgroup analyses highlight demographic-specific trends, guiding clinicians in managing this rare pathology.

The Anterior Inferior Cerebral Artery Variability in the Context of Neurovascular Compression Syndromes: A Narrative Review.

The anterior inferior cerebellar artery (AICA) is situated within the posterior cranial fossa and typically arises from the basilar artery, usually at the pontomedullary junction. AICA is implicated in various clinical conditions, encompassing the development of aneurysms, thrombus formation, and the manifestation of lateral pontine syndrome. Furthermore, owing to its close proximity to cranial nerves within the middle cerebellopontine angle, AICA's pulsatile compression at the root entry/exit zone of cranial nerves may give rise to specific neurovascular compression syndromes (NVCs), including hemifacial spasm (HFS) and geniculate neuralgia concurrent with HFS. In this narrative review, we undertake an examination of the influence of anatomical variations in AICA on the occurrence of NVCs. Significant methodological disparities between cadaveric and radiological studies (CTA, MRA, and DSA) were found, particularly in diagnosing AICA's absence, which was more common in radiological studies (up to 36.1%) compared to cadaver studies (less than 5%). Other observed variations included atypical origins from the vertebral artery and basilar-vertebral junction, as well as the AICA-and-PICA common trunk. Single cases of arterial triplication or fenestration have also been documented. Specifically, in relation to HFS, AICA variants that compress the facial nerve at its root entry/exit zone include parabola-shaped loops, dominant segments proximal to the REZ, and anchor-shaped bifurcations impacting the nerve's cisternal portion.

Anterior inferior cerebellar artery aneurysm with proximal parent artery stenosis: A case report.

Hemodynamic factors are associated with the progression of cerebral aneurysms. We report a 78-year-old woman with an anterior inferior cerebellar artery aneurysm and proximal stenosis of the anterior inferior cerebellar and basilar arteries. The aneurysm exhibited growth on annual follow-up imaging. Aneurysmal rupture occurred 4 years after diagnosis. Coil embolization resulted in aneurysm occlusion with parent artery preservation. Aneurysms adjacent to a more proximal region of severe stenosis in the parent vessel should be considered at high risk for growth or rupture. Such aneurysms require careful monitoring. Particular attention should be paid to posterior circulation aneurysms that occur at anatomically vulnerable sites.

A rare dissecting anterior inferior cerebellar artery aneurysm treated with flow diversion using a silk vista baby device.

BACKGROUND: Dissecting intracranial pseudoaneurysms represent a challenge for treatment both endovascularly and surgically. METHODS: We review the treatment course of a ruptured anterior inferior cerebellar artery (AICA) dissecting pseudoaneurysm in a 50-year-old patient and review the history of dissecting aneurysms and AICA aneurysms treatment. RESULTS: An aneurysm cure was achieved using flow diversion in the AICA. The recent introduction of flow diversion devices that can be deployed through 0.017" microcatheters represents a new avenue for treatment of aneurysms. CONCLUSION: To the best of our knowledge this is the first published case of flow diversion in the(?) AICA to treat a dissecting aneurysm. The introduction of Silk Vista Baby and similar future devices is likely to widen the scope of aneurysm treatment utilizing flow diversion in distal distribution with small parent arteries.

Flow Diversion for Treatment of Anterior Inferior Cerebellar Artery Aneurysms: Mechanism and Pitfalls from a Novel Management Strategy.

BACKGROUND: Anterior inferior cerebellar artery (AICA) aneurysms present a challenge for neurosurgeons and neurointerventionalists alike. METHODS: Cases of AICA aneurysms managed with endovascular flow diversion at our institute are reviewed with their angiographic outcomes. RESULTS: Both direct and indirect flow diversion provide complete aneurysm occlusion at follow-up. We propose a stratified method of approaching AICA aneurysms based on location, rupture status, and neck size. CONCLUSIONS: Careful evaluation of preoperative parameters is paramount in deciding between a surgical or a neuroendovascular approach. Low-profile stents in the future may assist in direct flow diversion of AICA trunk aneurysms. In addition, neurosurgeons need to be well versed in endovascular approaches.

Location of the AICA influences the severity but not occurrence of ISSNHL: A reappraisal using high-resolution 3 T MRI.

Objective: To investigate the potential influence of anatomical variation in the anterior inferior cerebellar artery (AICA) on the occurrence and severity of idiopathic sudden sensorineural hearing loss (ISSNHL). Methods: Ninety ISSNHL patients were enrolled. The anatomical location of the AICA was exhibited using high-resolution magnetic resonance imaging (MRI), and the various AICA types classified by previously reported Chavda and Gorrie methods were analyzed. The severity of hearing loss in the ipsilateral ear among different AICA types was compared. Results: Approximately 85.6% of subjects had unilateral ISSNHL (uISSNHL), and the others had bilateral ISSNHL (bISSNHL). In the uISSNHL group, the ratios of different AICA types were similar between the ipsilateral and contralateral ears. The ratios of the different AICA types in the bISSNHL group were similar to those in the uISSNHL group. In the uISSNHL group, pure tone audiometry (PTA) thresholds at 2 kHz, 4 kHz and 8 kHz of patients with Chavda type II AICA were higher than those of patients with Chavda type I and type III, with a significant difference at 4 kHz between type I and type II. There was a tendency of the PTA threshold in patients with Chavda type II or Gorrie type C to gradually increase from low to high frequency zones. Conclusion: When the AICA enters the IAC (Chavda type II) or crosses between the 7th and 8th cranial nerves (Gorrie type C), the severity and frequency of hearing impairment in ISSNHL but not the occurrence of ISSNHL will be affected.

Vascular Loop of the Anterior Inferior Cerebellar Artery (AICA) as a Cause of Sensorineural Hearing Loss (SNHL): A Case Report.

Sensorineural hearing loss (SNHL) is one of the most common causes of hearing loss worldwide. Although highly prevalent, many patients often present with SNHL of unknown cause. Related to SNHL is tinnitus, which often presents with SNHL and can have debilitating effects on patients. The idiopathic nature of SNHL and tinnitus often makes treatment difficult, however, a relatively new etiology has been suggested as a cause of SNHL and tinnitus -- vascular loops within the internal auditory canal (IAC). This report presents the case of a 36-year-old male with bilateral SNHL and tinnitus treated with oral steroids. The patient reported subjective improvement of hearing loss and tinnitus, and the audiogram demonstrated hearing improvement, except in higher frequencies. After initial treatment, MRI revealed a vascular loop of the anterior inferior cerebral artery (AICA) in the right IAC, in contact with the vestibulocochlear nerve. Thus, this case report seeks to present a conservative strategy for SNHL and tinnitus in the presence of a vascular loop of the AICA. As a controversial cause of SNHL and tinnitus, there is no standard of treatment for AICA loops of the IAC which are often treated surgically. This case highlights the importance of an initial conservative prior to surgical intervention. Thus, we seek to contribute to the growing body of literature by further elucidating the relationship between SNHL, tinnitus, and vascular loops and discussing potential pathophysiological mechanisms to guide optimal management strategies.

Management of a challenging dura-embedded anterior inferior cerebellar artery loop during a retrosigmoid hearing-preserving vestibular schwannoma resection: microsurgical technique and operative video. Illustrative case.

BACKGROUND: Anatomical variants of the anterior inferior cerebellar artery (AICA), such as an anomalous "AICA loop" embedded in the dura and bone of the subarcuate fossa, increase the complexity and risk of vestibular schwannoma resections. Classically, osseous penetrating AICA loops are the most challenging to mobilize, as the dura must be dissected and the surrounding petrous bone must be drilled to mobilize the AICA away from the surgical corridor and out of harm. OBSERVATIONS: The authors present a rare case of a dura-embedded, osseous-penetrating AICA loop encountered during a hearing-preserving retrosigmoid approach in which they demonstrate safe and efficient microdissection and mobilization of the AICA loop without having to drill the surrounding bone. LESSONS: Although preoperative recognition of potentially dangerous AICA loops has been challenging, thin-sliced petrous bone computed tomography scanning and high-quality magnetic resonance imaging can be useful in preoperative diagnosis. Furthermore, this report suggests that a retrosigmoid approach is superior, as it allows early intradural recognition and proximal vascular control and facilitates more versatile mobilization of AICA loops.

Anatomy of the pontine arteries and perforators of the basilar artery in humans.

Cerebral blood flow constitutes a critical area of interest for neurologists, neurosurgeons, and interventional radiologists as a social burden related to ischemic stroke, hemorrhagic stroke, and vascular dementia is expected to intensify. There is a great need to develop new and effective therapies, therefore deepening understanding of cerebrovascular anatomy, physiology, and pathology is crucial. The main aim of the study was to develop a comprehensive classification of the pontine arteries considering their typology, relations to the cranial nerves, branching schemes, and superficial pontine blood supply areas. We prepared 100 anatomical specimens of the human brainstem with the basilar artery, the pontine arteries, and the terminal perforating arteries. With the use of microsurgical microscope, we analyzed morphometry of the basilar artery, origins, courses, and branching patterns of the pontine arteries as well as distribution of the terminal perforators in relation to pontine superficial vascular areas and the cranial nerves. Additionally, we studied presence of pontine branches of the superior cerebellar artery (SCA) and anterior inferior cerebellar artery (AICA). Repetitive branching patterns, origins, and courses led us to distinguish five types of the pontine arteries: type 1-the paramedian branches, type 2-the short circumflex branches, type 3-composition of the paramedian and the short circumflex branches, type 4-long circumflex branches, and type 5-median branches penetrating the pons along the basilar sulcus. Types 1, 2, and 4 were described in the literature previously, but the classification did not include the median branches (the most prevalent branches) and frequently occurring combinations of the types 1 and 2. There were seven pontine arteries on both sides on average that presented the following general pattern: the first pontine artery below the SCA is a type 4 vessel called the posterolateral pontine artery and it is followed by a type 2 vessel-the superolateral pontine artery; the next three arteries represent the types 1, 2, and 3 and supply most of the ventral pontine surface; the sixth artery-the anterolateral pontine artery-is a short circumflex branch and the seventh artery, originating below the AICA, represents long circumflex arteries. Occlusion of each of the abovementioned vessels relates to a specific pontine vascular syndrome. As explained by the phylogenesis and ontogenesis of the central nervous system, the pontine arteries are subject to variability. The SCA and the AICA took part in the pontine blood supply in 2.5% and 12.5% of cases, respectively, therefore neurovascular interventions involving the SCA, or the AICA may lead to pontine ischemia. Contact of the pontine arteries with the cranial nerves depends on the vessel type and origin location.

Facial Spasm Caused by Compression of the Distal Portion of the Facial Nerve by the Anterior Inferior Cerebellar Artery, Resulting in Delayed Peripheral Facial Nerve Palsy: A Case Report.

Delayed onset of facial spasm following surgery for unilateral facial spasm after microvascular decompression (MVD) of the distal facial nerve is rare. We report a case of unilateral facial spasm caused by compression of the distal facial nerve successfully treated with MVD resulting in delayed peripheral facial nerve palsy. A 51-year-old male patient with a left facial spasm showed a gradual worsening of symptoms. Head imaging revealed that the left anterior inferior cerebellar artery (AICA) was in contact with the distal portion of the left facial nerve; hence, MVD was performed. The AICA was pressing on the distal facial nerve, so the AICA was transpositioned. Postoperatively, the facial spasm improved. On the eighth postoperative day, the patient showed left peripheral facial nerve palsy and was given conservative treatment. The patient was discharged home on the sixteenth postoperative day. One month after discharge, the facial palsy was in complete remission. Distal facial nerve compression may cause unilateral facial spasms. Although delayed facial nerve palsy may occur, the prognosis is good.

Anterior inferior cerebellar artery occlusion accompanied by hemorheology-documented increased blood viscosity: a case report.

Anterior inferior cerebellar artery (AICA) occlusion is a subtype of posterior circulation stroke. Confirmation of its angiomorphology and etiology is challenging because of the complex mechanisms underlying small-artery thrombogenesis. In addition to conventional factors, physicians frequently overlook hemorheological changes. In this case report, we describe right AICA occlusion in a 50-year-old man. He presented with an unsteady walk, tinnitus, dizziness, and left-sided peripheral facial palsy observed over 36 hours, accompanied by increased blood viscosity on hemorheological evaluation. Magnetic resonance imaging revealed acute infarction in the left cerebellar hemisphere and middle cerebellar peduncles. Magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) failed to detect AICA occlusion, which was later confirmed using digital subtraction angiography. Repeat routine blood examinations showed elevated erythrocyte and leukocyte counts and serum hemoglobin concentrations that persisted over many days. Hemorheological evaluation revealed increased whole blood viscosity at a low shear rate. AICA occlusion should thus be diagnosed based on its initial characteristic manifestations; notably, MRA and CTA may fail to detect arterial occlusion. The importance of hemorheological change as a factor of stroke is frequently neglected. We therefore report this case hoping to emphasize its relevance, especially in small-artery occlusion.

Case report: Bilateral sudden deafness in acute middle cerebellar peduncle infarction: central or peripheral?

Background: The middle cerebellar peduncle (MCP) is the most common site associated with hearing impairment in acute ischaemic stroke. Narrowing or occlusion of the vertebrobasilar artery due to atherosclerosis is thought to be the main pathogenesis of MCP infarction. Most previous reports of MCP infarction have not been clear whether the patient's hearing impairment is localized to the center or periphery. Case presentation: We report 44-year-old man with vertigo, tinnitus, and bilateral sudden sensorineural hearing loss (SSNHL) as the first symptoms. Pure Tone Audiogram revealed complete hearing loss in both ears. Acute bilateral MCP infarction was diagnosed by repeated brain magnetic resonance imaging (MRI). The brainstem auditory evoked potential (BAEP) and the electrocochleography were normal. The otoacoustic emissions showed binaural cochlear dysfunctions. After the antiplatelet, lipid-lowering, steroids and hyperbaric oxygen therapy, the pure-tone average (PTA) showed a clear improvement with 67 decibels (dB) on the right and 73 dB on the left at the 3-month follow-up. Conclusion: Vertebrobasilar diseases due to atherosclerosis should be routinely considered in middle-aged and elderly patients with vascular risk factors and bilateral hearing loss. Bilateral SSNHL can be a prodrome of acute MCP infarction and it can be peripheral. Brain MRI, brain magnetic resonance angiogram (MRA), brain and neck computed tomography angiography (CTA), BAEP, otoacoustic emissions, and Pure Tone Audiogram help to localize and qualify the diagnosis. Bilateral SSNHL localized to the periphery usually improves better and has a good prognosis. Early detection of hearing loss and intervention can help patients recover.

Treatment and Outcome of Anterior Inferior Cerebellar Artery (AICA) Aneurysms: Helsinki Series of 15 Consecutive Patients.

Objective Anterior inferior cerebellar artery (AICA) aneurysms are rare posterior circulation lesions that are challenging to treat. This article presents the treatment and clinical outcome of AICA aneurysms in an unselected cohort of patients. Methods A retrospective analysis of patient record files, digital subtraction angiography, and computed tomography angiography images of 15 consecutive patients harboring AICA aneurysms treated between 1968 and 2017. Results Of the 15 AICA aneurysm patients reviewed, 12 (80%) were females. Twenty percent had intracerebral hemorrhage and 40% presented with intraventricular hemorrhage. Eleven out of 15 (73%) patients presented with subarachnoid hemorrhage (SAH); 82% of SAH patients had a good-grade SAH (Hunt and Hess grade 1-3). Eleven patients (73%) were treated surgically, three (20%) were treated conservatively, and one (7%) had coil embolization. In 27% of patients, a subtemporal approach with anterior petrosectomy was performed. A retrosigmoid approach was used in the remaining 73%. In 18% of the patients, a parent vessel occlusion was necessary to occlude the aneurysm. Five out of 11 (47%) of the patients developed postoperative cranial nerve deficits. Twenty-seven percent developed shunt-dependent hydrocephalus. All patients who presented with an unruptured AICA aneurysm had good clinical outcome (modified Rankin scale [mRS] 1-2). In patients with SAH, 82% achieved good clinical outcome and 18% had poor clinical outcome (mRS 3-6) after 1 year. Conclusion Surgical treatment of AICA aneurysms has a high rate of cranial nerve deficits but most of patients have a good long-term clinical outcome.

Nervus intermedius: Microsurgical and anatomic relationships to the cerebellopontine angle neurovascular complex.

Background: The nervus intermedius (NI) comprises fibers originating from the trigeminal, superior salivary, and solitary tract nuclei, which join the facial nerve (cranial nerve [CN] VII). Neighboring structures include the vestibulocochlear nerve (CN VIII), the anterior inferior cerebellar artery (AICA), and its branches. Microsurgical procedures at the cerebellopontine angle (CPA) benefit from understanding NI anatomy and relationships, especially for the microsurgical treatment of geniculate neuralgia, where the NI is transected. This study sought to characterize common relationships between the NI rootlets, CN VII, CN VIII, and the meatal loop of AICA at the internal auditory canal (IAC). Methods: Seventeen cadaveric heads underwent retrosigmoid craniectomy. Following complete unroofing of the IAC, the NI rootlets were individually exposed to identify their origins and insertion points. The AICA and its meatal loop were traced to assess their relationship with the NI rootlets. Results: Thirty-three NIs were identified. The median number of NI rootlets was 4 per NI (interquartile range, 3-5). The rootlets mainly originated from the proximal premeatal segment of CN VIII (81 of 141, 57%) and inserted onto CN VII at the IAC fundus (89 of 141, 63%). When crossing the acoustic-facial bundle, the AICA most frequently passed between the NI and CN VIII (14 of 33, 42%). Five composite patterns of neurovascular relationships were identified regarding NI. Conclusion: Although certain anatomical trends can be identified, the NI has a variable relationship with the adjacent neurovascular complex at the IAC. Therefore, anatomical relationships should not be used as the sole method of NI identification during CPA surgery.

Vestibular paroxysmia associated with congenital vascular malformation: A case report.

Vestibular paroxysmia (VP) is an uncommon paroxysmal disease, characterized by vertigo, tinnitus, and postural unsteadiness. The main reason of VP is neurovascular cross compression, while few cases of VP accompanied with congenital vascular malformation were reported. Here, we describe a 22-year-old patient with VP caused by congenital anterior inferior cerebellar artery (AICA) malformation who completely recovered after taking oral medicine. This report shows that VP caused by congenital vascular malformation can occur in adults and that oral medication is effective.

Radiological presence of vascular loops in the cerebellopontine angle region in patients with unilateral Ménière's disease.

OBJECTIVE: The relationship between vascular compression of the vestibulocochlear nerve and audio-vestibular symptoms remains controversial. We aimed to examine the radiological features of vascular loops signs in cerebellopontine angle (CPA) and internal auditory canal (IAC) in patients with unilateral Ménière's disease (MD). METHODS: One hundred and thirty-seven patients with unilateral definite MD and 69 control subjects (138 ears) were enrolled. All subjects received magnetic resonance imaging of CPA-IAC. The configuration of vascular loops in CPA-IAC, based on the Kazawa classification system, from MD-affected, non-affected and control ears were compared. The associations between imaging findings and Ménière's stage, electrocochleogram (EcochG) and caloric test were analyzed. RESULTS: (1) Among the MD-affected ears, 6 cases (4.4%) were classified as Kazawa type IA, 27 cases (19.7%) as IB, 60 cases (43.8%) as IIA, and 44 cases (32.1%) as IIB. No significant interaural difference in the distribution of Kazawa's types was found ([Formula: see text] = 4.737, p = 0.578) in unilateral MD patients. (2) The distribution of Kazawa's types were not significantly different between the MD-affected ears and the control subjects ([Formula: see text] = 2.876, p = 0.411). (3) No relationship was found between Kazawa staging of the MD-affected ear and Ménière's stage (H = 2.679, p = 0.444), EcochG ([Formula: see text] = 0.827, p = 0.867) and caloric test ([Formula: see text] = 4.116, p = 0.248). CONCLUSIONS: In patients with unilateral MD, the configuration of vascular loops in CPA-IAC region, measured by Kazawa criteria, did not correlate with the laterality, clinical stage, the results of EcochG and caloric test, suggesting that vascular loops may be natural anatomical variations for patients with MD.

Bridge technique for hemifacial spasm with vertebral artery involvement: 2-Dimensional operative video.

Microvascular decompression for hemifacial spasm (HFS) associated with the vertebral artery (VA) is more challenging than that for small arteries. Atherosclerotic VA and tortuous VA are associated with a low success rate and high incidences of complications. Artery relocation employing a Teflon sling is helpful for small arteries. However, a different decompression technique should be considered in VA-related HFS due to the stiffness of the offending artery. With our simple decompression technique providing a secure transposition that can be performed even in the narrow cistern, a rigid Teflon bar is inserted to hold up all offending vessels between the pontine surface and the cerebellar flocculus (the bridge technique). This simple technique easily creates a free space over the root entry zone (REZ), reduces surgical manipulation compared to conventional artery relocation with a Teflon sling, and provides more secure nerve decompression than inserting Teflon pledgets on the REZ. The critical factors for successfully performing the bridge technique are using a rigid Teflon bar that can hold the rebound force of the VA and a length appropriate to generate a free space over the REZ between the pons and the cerebellar flocculus. In this video, we demonstrate our bridge technique for VA-related HFS and discuss the advantages and disadvantages of this novel approach.

Unruptured anterior Inferior cerebellar artery aneurysm following stereotactic irradiation for vestibular schwannoma: Case report and literature review.

Background: The clinical features and therapeutic measures of vestibular schwannoma (VS) radiation-related aneurysm (RRA) have not been well described. We reported the first VS RRA case admitted for acute anterior inferior cerebella artery (AICA) ischemic symptoms. Literature was reviewed to present the research fruits about VS RRAs, and some therapeutic advices were given. Materials and methods: A 54-year-old woman who had undergone GKS 10 years previously for a right VS was admitted to our hospital in 2018 because of sudden onset of severe vertigo and vomiting, accompanied with unsteady gait. During tumor resection, a dissecting aneurysm arose from the main trunk of AICA was encountered accidently within the tumor. The aneurysm was successfully treated with direct clip ligation, sparing the parent vessel. Data about this case were combined with those of other 11 radiation-related AICA aneurysm cases retrieved from the current literature. The following parameters were evaluated: Age, Sex, Diagnostic method, Location of aneurysm, Age of radiotherapy (Years)/Latency, Rupture, x-ray dosage, Type of radiotherapy, History of surgical resection of VS, Aneurysm Type, Morphology, Number, Treatment, Operative complications, Sequela, Outcome. VS RRAs mainly occurred in women (75%) with a median age of 62.5 years and were mainly located on AICA. Ruptured aneurysms accounted for 75.0% of the total cases. This paper reported the first VS case admitted with acute AICA ischemic symptoms. Cases with sacciform-like, irregular and fusiform-shaped aneurysms accounted for 50.0%, 25.0% and 25.0% of the total, respectively. After surgical treatment, 75.0% patients recovered, except for 3 patients who developed new ischemic consequence. Conclusion: Patients should be informed of the risk of RRAs after receiving radiotherapy for VS. In these patients, RRAs should be suspected when subarachnoid hemorrhage or AICA ischemic symptoms occurred. Active intervention should be conducted considering the high instability and bleeding rate of VS RRAs.

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.