Left Posterior Inferior Cerebellar Artery Research Articles

Endovascular treatment for posterior inferior cerebellar artery aneurysm with vertebral artery stenosis: The critical role of diagnosing osteophyte compression

Background: Vertebral artery (VA) stenosis can be caused by several factors, including arteriosclerosis, arterial dissection, and mechanical compression. Symptomatic vertebrobasilar insufficiency caused by VA stenosis due to mechanical compression associated with head rotation is well-known as Bow Hunter’s syndrome. However, an accurate diagnosis of asymptomatic osteophyte compression-induced nonrotational VA stenosis is difficult. We report a case of left posterior inferior cerebellar artery aneurysm with severe left VA stenosis, treated with stent-assisted coil embolization following appropriate diagnosis. Case Description: A 72-year-old female patient was found to have severe asymptomatic VA stenosis at the V2 segment (C4–5 level of the cervical spine) on cerebral angiography. Osteophyte compression-induced VA stenosis was suspected, which was confirmed by cone-beam computed tomography. The VA stenosis improved by flexing the neck and fixing the head position, following which the endovascular treatment was successfully completed. Conclusion: The site of the VA stenosis is critical in determining the etiology. Atherosclerotic VA stenosis often occurs at the origin of the artery or V4 segment, whereas bony compression-induced stenosis is more likely to occur at the V2 segment. Diagnosis and appropriate management of VA stenosis is based on determining the site.

A diagnosis that’s hard to swallow: case report of delayed onset lateral medullary syndrome presenting with only dysphagia

BackgroundLateral Medullary Syndrome (LMS) is a posterior circulation stroke (PCS) that has a broad array of manifestations but most classically presents with Horner’s syndrome, ipsilateral ataxia, and ipsilateral hyperalgesia. Although dysphagia is also common, isolated and single presentation of this alone is rare and there are only a few case reports of this in the literature. This presentation can bias a clinician’s differential diagnosis and delay diagnosis.Case presentationA previously healthy 53-year-old-male presented with a complaint of dysphagia. He had no PCS symptoms, a National Institute of Health Stroke Scale (NIHSS) of zero, and an otherwise unremarkable neurological exam. Stroke imaging including non-contrast computed tomography (NCCT) scan of his head and computed tomography angiography (CTA) scan of his head and neck revealed no acute abnormalities. He was found to be positive for Influenza A, but otherwise all other etiologies for his dysphagia were worked up, including consultation with other specialty services, without resolve. Two days later, the patient subsequently developed new right sided sensory deficits and left sided Horner’s syndrome, in which a magnetic resonance imaging (MRI) scan of his head revealed an acute infarct of the left lateral medulla with likely thrombus in the left posterior inferior cerebellar artery (PICA).ConclusionsPCS is frequently missed due to the often-vague symptoms and reassuring negative imaging. This case highlights the variability of presentations that ED physicians may encounter. Nonetheless, a high index of suspicion for PCS should be maintained even in young patients without risk factors. Lastly, dysphagia is never normal, and this case demonstrates the need to reconsider neurogenic origin when other causes have been ruled out.

Delayed spinal arachnoiditis with syringomyelia following aneurysmal subarachnoid haemorrhage: a case report with patient experience

Background and importanceSyringomyelia, or the formation of fluid-filled cysts within the spinal cord, associated with delayed spinal arachnoiditis is an uncommon complication of aneurysmal subarachnoid haemorrhage. To date, about 18 cases have been reported in medical literature, with just two reported in patients under the age of 35 years.Clinical presentationA 27-year-old female patient complained of sudden, severe headaches in the occipital region, nuchal rigidity, and drowsiness when she presented at our institution. A head computed tomography scan revealed intraventricular bleeding in the lateral and fourth ventricles with more extensive haemorrhaging in the frontal horns. A left posterior inferior cerebellar artery (PICA) aneurysm was confirmed via digital subtraction angiogram, and endovascular embolization was done. Two years later, the patient reported intense pain in the lower back along with symptoms suggestive of spinal cord compression. Spinal magnetic resonance imaging (MRI) showed spinal adhesions from C1 to L4, syringomyelia with some vasogenic oedema extending from T3 to T9 level, and a cyst in the lumbar region. Consequently, a right hemilaminectomy was performed along with microsurgical release of arachnoid adhesions and placement of a subdural drain. Radiological and symptomatic improvements were observed. Since then, the patient’s clinical condition has remained stable during the past three years of follow-up visits.ConclusionsLiterature on optimal treatment modalities and patient prognosis is scarce and debated. The time for symptom improvement depends on the level and extent of spinal cord involvement. Rehabilitation may be required for most patients, as complete symptomatic recovery may not be attainable.

Spontaneous vertebral artery stenosis, dissection and cerebellar infarction in a gentleman while playing bowling.

Background: An increased incidence of vertebral artery dissection has recently become a recognized cause of acute stroke for about 1/5 of strokes in young patients. Case Presentation: A male in his 30s presented to the emergency department with sudden onset of severe vertigo, vomiting, and dizziness while he was playing bowling. The symptoms started when he suddenly twisted his neck while throwing the ball towards pins. Initial diagnosis of central vertigo led to performing plain CT head and CT head angiogram, which demonstrated non-occlusive extradural left vertebral artery dissection. Following CT scans, an MRI head, and MRA head and neck were performed which confirmed the CT diagnosis and also showed left posterior inferior cerebellar artery territory infarcts with micro haemorrhages. The patient was started on dual antiplatelet medications which was continued for 6 months with a follow up MRI/MRA scan of head and neck. Conclusion: This appears to be a unique case where sudden twisting of the neck possibly resulted in vertebral artery dissection and cerebellar infarction. Hence, it is vital to be aware of sports related presentation resulting in sudden neck movements and tear in vertebral artery causing dissection.

Akinetic Mutism and Cognitive‐Affective Syndrome caused by unilateral PICA infarction

AbstractBackgroundAkinetic mutism (AM) is characterized by sparse volitional motor and speech activation with reasonably preserved arousal and vigilance functions. Akinetic mutism, the most severe of these disorders, is most commonly associated with bilateral hemispheric pathology, although unilateral lesions may produce this condition as well.MethodCase: Our patient is a 42‐year‐old right handed man who presented to the emergency department with an acute onset of akinetic mutism. His family described him as a calm and intelligent individual with a good cultural knowledge level and without any evident cognitive abnormality before he suddenly experienced akinetic mutism. On examination, he was alert but produced no spontaneous speech and had only rare, spontaneous movement of his arm and leg. With repeated prompting, he followed single‐step commands.ResultMagnetic resonance imaging demonstrated an infarction in the distribution of the left posterior inferior cerebellar artery. During the course of 7 days, as the patient became more interactive, he demonstrated normal language function. As he became more communicative, cognitive impairment became apparent. Neuropsychological evaluation were performed after approximately 12 days after onset because of the impossibility of test administration during the acute phase. Impaired performances were evident on executive function testing with difficulties in planning, abstract reasoning, set‐shifting and perseveration. Furthermore, attention disorders and memory dysfunction were mild observed and were probably due to the poor ability of planning and organization. Language tests revealed mild deficits in the semantic sphere with paraphasia, anomia and circumlocutory expressions. During psychometric testing, the patient presented agitated and anxious behavior with affective air hunger and episodes of crying. Brain SPECT were performed after approximately 14 days after onset. Brain SPECT demonstrated hyporperfusion in Lt. cerebellar and frontal cortex.ConclusionThe syndrome of akinetic mutism is typically the result of bilateral hemispheric injury, usually involving the anterior cingulate gyri. Other locations for lesions producing akinetic mutism include the thalami, globus pallidus, internal capsule, and frontal white matter. We describe a man with akinetic mutism and cognitive impairment due to an ischemic stroke in the distribution of the left PICA.

Bihemispheric posterior inferior cerebellar artery in a cadaver with Chiari I malformation.

Typically, patients with Chiari I malformations (CM I) do not have other intracranial anatomical variations, especially vascular derailments. Here, we report the findings of a cadaveric specimen found to have CM I and cerebellar tonsils supplied by a single posterior inferior cerebellar artery (PICA) i.e., a bihemispheric PICA. An adult male cadaver was found to have CM I. It was also noted that the left PICA descended inferiorly to the level of C1 and that there was absence of the right PICA. The territory of the right PICA was supplied by the left PICA. The tonsillar component of the left PICA gave rise to a branch that crossed to the right inferior cerebellum and herniated cerebellar tonsil. A bihemispheric PICA is very rare. To our knowledge, this is the first report of this vascular variation in combination with CM I. Such a variation should be kept in mind, especially during posterior fossa decompression for symptomatic CM I as unilateral PICA injury could have catastrophic results.

Acute airway obstruction requiring nasotracheal intubation following hypoglossal neuromonitoring: a case report

BackgroundIntraoperative neurophysiological monitoring (IONM) is utilized for both the localization of critical structures and for real time detection and prevention of intraoperative neurological injury. Use of IONM to monitor the hypoglossal nerve is performed during neurosurgical, otolaryngological, and vascular procedures to improve surgical outcomes. There is a paucity of literature describing potential complications of IONM of the hypoglossal nerve, especially with respect to airway compromise. Here we present our findings regarding a case of acute airway obstruction following hypoglossal nerve monitoring.Case PresentationA 54-year-old male was admitted for left far-lateral craniotomy and microsurgical clipping of a left posterior inferior cerebellar artery (PICA) aneurysm. Following induction and intubation but prior to the procedure start, the patient was placed in the ¾ prone position with the left side up and his neck was flexed approximately 10 degrees. He then underwent placement of subdermal needle electrodes into the facial muscles, trapezius muscles, soft palate, and tongue for IONM. The procedure lasted 523 minutes and was completed without complication. However, approximately one hour after emergence from general anesthesia, the patient experienced progressive difficulty breathing secondary to severe lingual swelling. He required emergent placement of a nasotracheal tube guided by a fiberoptic bronchoscope. He remained intubated for 3 days and was treated with dexamethasone, after which the swelling resolved, and the patient was successfully extubated.ConclusionsAcute lingual edema is a potentially life-threatening phenomenon that can lead to rapid airway compromise. Generally, causes of acute lingual swelling include hemorrhage, edema, infarction, and infection. In the case described above, we suspect traumatic injury to the tongue’s vascular supply caused a deep tissue hematoma leading to postoperative acute lingual swelling and airway obstruction. With the widespread use of IONM, it becomes essential for providers to be aware that perioperative airway compromise is a potentially life-threatening complication, especially with respect to monitoring of the hypoglossal nerve. Awake fiberoptic nasotracheal intubation can successfully be employed to establish an emergency airway in such situations.

Posterior inferior cerebellar artery originating from the posterior meningeal artery mimicking dural arteriovenous fistula.

Many variations in the origin of the posterior inferior cerebellar artery (PICA) have been reported. To our knowledge, only one case of a PICA originating from the posterior meningeal artery (PMA) has been reported. We describe a case with a PICA that was supplied retrograde from the distal segment of the PMA, mimicking a dural arteriovenous fistula on magnetic resonance angiography (MRA). A 31-year-old man was admitted to our hospital with a sudden occipital headache and nausea. MRA showed a hyperplastic left PMA, continuing to an abnormal vessel that was suspicious for venous drainage. Digital subtraction angiography revealed the left PMA originated from the extradural segment of the vertebral artery and then connected to the left PICA near the torcula. The cortical segment of the PICA flowed retrograde, which appeared as venous reflux on MRA. A second PICA originated from the extradural segment of the left vertebral artery and perfused the tonsillomedullary and televelotonsillar segment of the left PICA territory. We present an anatomical variant of the PICA mimicking a dural arteriovenous fistula. Digital subtraction angiography is useful for diagnosis of the cortical segment of the PICA flowing retrograde from the distal segment of the PMA because signal intensity in MRA of retrograde flow tends to decrease and diagnosis may be difficult. During endovascular treatment and open surgery, we should note that ischemic complications may occur due to the potential anastomosing channels between cerebral and dural arteries.

Giant dissecting aneurysm of basilar artery in a child - treated by flow reversal: A case report.

Although intracranial aneurysms are rare in the paediatric population, the proportion of those involving posterior circulation is higher than that of adults (approximately 25% vs. 8%, respectively). Moreover, posterior circulation aneurysms in kids tend to be larger in size, many of them being giant dissecting types, and treatment of them is often challenging. Treatment of giant dissecting aneurysms, especially involving the Basilar artery is difficult due to strategic location and haemodynamic factors. Use of reconstructive techniques viz. flow-diverters and braided stents is difficult in children because of the lack of standard protocol for use of antiplatelet therapy and the need for prolonged use of the same. Continuous growth of parent vessel is also suggested as a pitfall for the use of a flow diverter/ braided stent which has a fixed caliber. Carefully planned endovascular parent or feeder branch artery occlusion (FAO) is a time-tested method to achieve flow reversal or favourable flow modifications in an arterial segment harbouring dissecting aneurysm. Here, in this case report, we describe a case of a ruptured distal giant basilar artery dissecting aneurysm in a 10-year-old boy treated with flow diversion by FAO. The dominant left vertebral artery was occluded, thereby diverting flow from the right vertebral artery towards the left posterior inferior cerebellar artery and decreasing flow through the aneurysm. On 1-year follow-up, the patient was asymptomatic and on check angiography, there was complete involution of the aneurysm with increased flow through bilateral posterior communicating arteries to distal posterior circulation which proved our hypothesis correct.

Combined four neurovascular compression syndromes: the first case report and literature review

BackgroundNeurovascular compression syndromes (NVCs) are cranial nerve syndromes caused by direct contact or compression of vascular structures on the cranial nerves at the root exit/entry zone. Cases of combined NVCs are extremely rare.CaseWe reported the first case of a 41-year-old woman with combined four NVCs presenting with left hemifacial spasm followed by simultaneous left glossopharyngeal neuralgia, left type-writer tinnitus and vestibular paroxysmia due to the left posterior inferior cerebellar artery compression at the root exit/entry of the left facial, vestibulocochlear and glossopharyngeal nerves. All the symptoms resolved immediately after microvascular decompression without recurrence in a period of follow-up for one year. In addition, we presented a literature review of combined three or more NVCs.ConclusionWe discussed the hypothesis of combined three or more NVCs development, especially the central hyperactivity of the cranial nerve nuclei mechanism.

Sudden unilateral hearing loss and vertigo following isolated cerebellar hypoperfusion without infarction due to vertebral artery dissection

BackgroundThe definition of sudden sensorineural hearing loss (SSNHL) is broadly accepted as acute sensorineural hearing loss of more than 30 dB over at least three consecutive frequencies in a pure-tone audiogram (PTA). Acute audiovestibular loss is common with ischaemic stroke in the territory of the anterior inferior cerebellar artery (AICA). However, cases in which SSNHL and vertigo occur with hypoperfusion alone are very rare. We describe a patient who developed unilateral SSNHL and vertigo as initial symptoms caused by cerebellar hypoperfusion by vertebral artery (VA) dissection without the occurrence of infarction.Case presentationA 51-year-old man suddenly developed acute hearing loss (AHL) in his left ear and vertigo. On neurological examination, he had vibration-induced right-beating nystagmus and left-beating nystagmus after a head-shaking test. Additionally, he had apogeotropic nystagmus during head turns to either side. The head impulse test (HIT) was normal. PTA showed mild unilateral SSNHL in the left ear. Diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) showed territorial perfusion deficits in the left posterior inferior cerebellar artery (PICA) and anterior inferior cerebellar artery (AICA) without infarction. Two months later, the patient had no vertigo but still had hearing impairment in his left ear. A follow-up PTA documented persistent unilateral SSNHL in the left ear. Additionally, perfusion computed tomography (CT) showed that perfusion deficits remained in the left cerebellum along the PICA and AICA territories.ConclusionsOur case highlights a case of AHL and vertigo presented by isolated cerebellar hypoperfusion without infarction. It is necessary to consider the possibility of a central cause in patients with AHL and vertigo, and it is important to confirm this possibility through brain magnetic resonance imaging (MRI), including PWI, and magnetic resonance angiography (MRA).

A novel 3-Fr guiding sheath for transradial access in aneurysm embolization: Technical note.

Neurointervention via transradial access (TRA) is challenging when the radial artery is narrow. We performed aneurysm embolization via TRA using a novel 3-Fr guiding sheath (GS) (Axcelguide; Medikit, Tokyo, Japan) with an outer diameter of only 1.76 mm for patients with a radial artery of inner diameter less than 2 mm, and described the whole procedure and pitfalls as a technical note. Here, we present two patients with radial arteries less than 2 mm. One patient had a narrow neck intracranial aneurysm at the bifurcation of the left vertebral artery and posterior inferior cerebellar artery, which was embolized with the primary coiling technique. The other was a patient with a wide-necked extracranial aneurysm in the cavernous portion of the right internal carotid artery, which was embolized with the transcell technique with stent. We utilized a 3-Fr GS, distal access catheter, and a 0.0165-inch microcatheter for coil embolization. All aneurysms were completely occluded, without neurological or puncture site-related complications including subcutaneous hematoma, radial artery occlusion, and vasospasm. This report provides the first description of neurointervention using a 3-Fr GS. The 3-Fr GS contributed to successful completion of TRA aneurysm embolization without neurological or puncture site-related complications in patients with radial arteries narrower than 2 mm. The 3-Fr GS may be useful to accomplish aneurysmal embolization via TRA even in patients with a small radial artery.

Flow diversion of a dissecting PICA aneurysm

A 47-year-old female with a history of a ruptured left posterior inferior cerebellar artery (PICA) aneurysm, status post coil embolization and retreatment for recurrence, presented with evidence of a recurrent dissecting PICA aneurysm. Given that these aneurysms are considered high risk and have a greater propensity for rupture than anterior circulation aneurysms, retreatment was recommended. With the patient's strong preference for endovascular therapy, flow diversion with a Silk Vista Baby was performed. Given the low-profile design of the device, a radial artery approach and coaxial technique were used to deploy the flow diverter. The device was successfully placed, with complete obliteration of the aneurysm after 1 year. The video can be found here: https://stream.cadmore.media/r10.3171/2022.7.FOCVID2247.

Failure of Flow-Diverter Endothelization Visualized with Optic Coherent Tomography Technology

We report a case of an intracranial aneurysm of the left posterior inferior cerebellar artery, which was treated with a flow-diverting stent. One year later at follow-up, the patient presented with new symptoms due to mass effect in the posterior fossa and a 3-fold enlargement of the aneurysm. Digital subtraction angiography showed an increase in size of the aneurysm with jet flow into the sac. Optic coherent tomography was performed during the procedure, demonstrating a failure of endothelization of the stent with a focal 1-mm opening at the neck of the aneurysm, resulting in jet flow. Parent vessel sacrifice was performed by coiling of the left vertebral artery. The patient had a codominant right vertebral artery and tolerated the procedure well. Two years later, follow-up magnetic resonance angiography showed significant decrease of the size of the aneurysm and symptom regression, with a modified Rankin scale of 1 (functionally independent).

A growing aneurysm of the posterior inferior cerebellar artery complicated with cerebellar infarction: A case report.

Introduction and importanceHereby we describe an instructive patient with cerebellar infarction and a growing aneurysm at the posterior inferior cerebellar artery (PICA), which was not a true cause of infarction.Case presentationA 50-year-old female presented with dizziness and posterior neck pain at our hospital (Mitaka city, Tokyo, Japan). Diffusion weighted magnetic resonance (MR) images showed cerebellar infarction in the left PICA territory and MR angiography study showed an aneurysm at the origin of the left PICA, which grew in 2 weeks. Since we considered cerebellar infarction was caused by thrombosis from the aneurysm, trapping of the PICA and occipital artery-PICA bypass was performed to prevent recurrent cerebellar infarction and rupture of the aneurysm by neurosurgeons. During the operation, dissection was observed at the distal PICA, which was diagnosed to be the true cause of cerebellar infarction. By the follow-up for 12 months at an outpatient, there was no recurrence of cerebral infarction.Clinical discussionA specimen of the artery showing the findings of dissection was not obtained, and the pathological diagnosis could not be made. It would be controversial whether a surgical procedure presented here was the most optimal.ConclusionThis is a first reported case of growing aneurysms and cerebral infarction due to arterial dissection. Even if cerebral infarction is accompanied by growing aneurysms, arterial dissection should be included in the differential diagnoses of a cause of infarction. Posterior cervical pain can be a clue for early appropriate diagnosis in such a case.

Abstract 1122‐000052: Endovascular Management of Infectious PICA Aneurysm in the Setting of Recent Dental Work

Introduction : Infectious intracranial aneurysms (IIA) of the posterior inferior cerebellar artery (PICA) are exceedingly rare and have been infrequently reported. IIAs are typically distal and located in the anterior circulation, particularly the middle cerebral artery and its distal branches. Etiology is secondary to hematogenous spread of septic emboli from a proximal source such as infective endocarditis. Few cases have documented an association between IIA and dental disease or procedures. We describe a rare case of an infectious PICA aneurysm in the setting of recent dental work and successfully treated with endovascular intervention. Methods : An 88‐year‐old male with medical history of atrial fibrillation on anticoagulation presented with one month duration of recurrent falls and progressive generalized weakness. CT head demonstrated left cerebral hemorrhage with scattered subarachnoid hemorrhage. MRI brain noted a rounded enhancing intra‐axial lesion located at the left paramedian cerebellum measuring 7 mm in maximal dimension. Further investigation with cerebral angiography demonstrated an infectious intracranial aneurysm of the left PICA. He underwent workup with an echocardiogram that noted a mobile echo density on the aortic valve consistent with a vegetation. Blood cultures were positive for Streptococcus salivarius and viridans. Investigation revealed that he had recent dental work performed and missed taking his prophylactic amoxicillin. Infectious disease was consulted and etiology was determined to be seeding of aortic valve from recent dental procedure that ultimately led to IIA formation. Results : Patient was treated with 6‐week course of intravenous ceftriaxone and underwent glue embolization for his left PICA aneurysm. Post embolization angiogram did not reveal any evidence of contrast filling within the aneurysm. He tolerated the procedure well with no complications and was subsequently discharged to inpatient rehabilitation with a modified Rankin scale (mRS) score of 3. Conclusions : IIAs of PICA in the setting of recent dental procedures are exceptionally rare and challenging to diagnose. They may be clinically silent until rupture and are usually identified incidentally on imaging or during autopsy. Physicians should maintain vigilance for this unique entity as prompt recognition and timely intervention may prevent severe morbidity and mortality.

Clipping of Posterior Circulation Intracranial Aneurysms: Maintenance of a Necessary Skill in Low-Resource Settings

The treatment paradigm for intracranial aneurysms has evolved with technological advancements, resulting in improved patient outcomes. In particular, the management of posterior circulation aneurysms has shifted to favor endovascular therapy (EVT). However, this modality is not always accessible in low-resource settings.In our country (Trinidad and Tobago), neuroendovascular services are not readily available. We report a case of a patient with a ruptured left posterior inferior cerebellar artery (PICA) aneurysm (Fisher grade 4) who underwent a far-lateral craniotomy and clip ligation. It was done by a fellowship-trained vascular neurosurgeon in a public hospital and resulted in an excellent patient outcome. This highlights the need to maintain this surgical skill set in resource-poor countries, in spite of the increasing popularity of endovascular therapy.

VERTEBRAL ARTERY DISSECTION AND INCIDENTAL FINDING OF FIBROMUSCULAR DYSPLASIA: A CASE REPORT

TOPIC: Critical Care TYPE: Medical Student/Resident Case Reports INTRODUCTION: Fibromuscular Dysplasia (FMD) is a nonatherosclerotic, noninflammatory vascular disease. It is a rare condition that occurs more frequently in middle-aged Caucasian women. Its prevalence is not well known. We present a case of FMD in a man with stroke secondary to dissection of the vertebral artery. Increased reporting of FMD cases in recent studies raises concern about under-diagnosis of the condition. CASE PRESENTATION: A 61-year-old Caucasian male with a past medical history of hypertension presented with dysarthria, extreme disequilibrium, and left-sided headache. The patient had normal strength and sensation in all four extremities and negative cerebellar testing on physical exam. He also had a productive cough upon presentation. Computed tomography (CT) head revealed a 3 cm acute non-hemorrhagic left cerebellar infarction. Computed tomography angiography (CTA) Head and Neck showed evidence of vertebral artery dissection on the left side, including the origin of the left posterior inferior cerebellar artery (PICA). The patient had a trial of cerebral angiogram for the vertebral artery dissection, which showed incidental evidence of FMD in the femoral arteries bilaterally. The patient also had vasospasm with the angiography that resolved post-injection of five milligrams of Verapamil intraarterial, and the procedure was discontinued. He was discharged on aspirin and statin, and anticoagulation starting in two weeks. DISCUSSION: There is no clear consensus on the prevalence of FMD in the general population [1]. However, many studies have assessed the prevalence in different patient populations to be around 3%-4% [2]. The United States Registry of FMD revealed the incidence of dissection of the carotid artery in the FMD patient population to be about 75% [1]. The incidence of dissection of the vertebral artery in patients diagnosed with FMD is much lower, about 17% [1]. The most common manifestations of cervical artery dissection (CeAD) are cerebral infarction and transient ischemic attack (TIA). In FMD patients with ischemic stroke or TIA secondary to CeAD, general guidelines for thrombolysis and thrombectomy should be followed. Most recent guidelines recommend treatment with either an anticoagulant or an antiplatelet agent for at least 3–6 months [3]. Endovascular or surgical repairs are mainly reserved for patients with recurrent ischemia despite initial antithrombotic therapy. CONCLUSIONS: FMD is an intriguing vascular disorder with unclear underlying etiology, challenging manifestations, and complex clinical diagnosis. Increased reporting of FMD cases in recent literature raises concern for underdiagnosis. Furthermore, in our case, FMD was incidentally discovered during a diagnostic procedure to evaluate the vertebral artery dissection. Therefore, we recommend further screening of any patient who presents with cephalo-cervical dissection or aneurysm for underlying FMD. REFERENCE #1: Olin, J.W., Froehlich, J., Gu, X., et al. 2012, "The United States Registry for Fibromuscular Dysplasia: results in the first 447 patients", Circulation, vol. 125, no. 25, pp. 3182-3190. REFERENCE #2: Hendricks, N.J., Matsumoto, A.H., Angle, J.F., et al. 2014, "Is fibromuscular dysplasia underdiagnosed? A comparison of the prevalence of FMD seen in CORAL trial participants versus a single institution population of renal donor candidates", Vascular medicine (London, England), vol. 19, no. 5, pp. 363-367. REFERENCE #3: Powers, W.J., Rabinstein, A.A., Ackerson, et al. "2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association", Stroke, vol. 49, no. 3, pp. e46-e110. DISCLOSURES: No relevant relationships by Elizabeth Mause, source=Web Response No relevant relationships by Mohammad Selim, source=Web Response

In Reply to the Letter to the Editor Regarding “Association of Early White Blood Cell Trend with Outcomes in Aneurysmal Subarachnoid Hemorrhage”

Giant aneurysms of the intracranial vertebral artery and posterior inferior cerebellar artery are challenging to treat as they often necessitate direct sacrifice of the diseased segment, which is thought to carry high morbidity due to brainstem and cerebellar stroke. Here, we report images of twin giant aneurysms of the left posterior inferior cerebellar artery at the brainstem and cerebellopontine angle region in a young child.

Extended Retrosigmoid Craniotomy and Approach Through the Glossopharyngeal Cochlear Triangle for Clipping of a High-Riding Vertebral-Posterior Inferior Cerebellar Artery Aneurysm: 2-Dimensional Operative Video.

The far lateral transcondylar (FL) craniotomy is the standard approach for posterior inferior cerebellar artery (PICA) aneurysm exposure through microsurgical dissection in the vagoaccessory triangle (VAT).1,2 However, the extended retrosigmoid (eRS) craniotomy and dissection through the glossopharyngeal-cochlear triangle (GCT) may be more appropriate when the patient has an aneurysm arising from a high-riding vertebral artery (VA)-PICA origin.3-5 We present a case of a 41-yr-old woman with hypertension presenting with left occipital pain and left-side hearing loss and past facial spasm and pain. Computed tomography angiography and digital subtraction angiography demonstrated an unruptured 8.4×9.0×10.2 mm saccular aneurysm at the left VA-PICA junction. Surgical clipping was chosen over endovascular therapy given the relationship of the PICA origin to the aneurysm neck as well as the history of cranial neuropathy. It was noted that the VA-PICA junction and aneurysm was high-riding at the level of the internal auditory canal. An eRS craniotomy was performed with dissection through the GCT, and the aneurysm was clipped as shown in the accompanying 2-dimensional operative video. Postoperative angiography demonstrated complete occlusion of the aneurysm and patency of the left VA and PICA without stenosis, and the patient had a favorable postoperative course although her left-sided hearing remained diminished. The eRS craniotomy allowed direct exposure via the GCT for clipping of the high-riding VA-PICA junction aneurysm and decompression of the cranial nerves. The traditional FL craniotomy and exposure through the VAT would likely have resulted in a less desirable inferior trajectory. The patient gave informed consent for the operation depicted in the video. Animation at 2:43 in video is used with permission from Barrow Neurological Institute, Phoenix, Arizona.