Left Posterior Cerebral Artery Research Articles

High Doses of Caffeine-Induced Cerebral Infarction Leading to Partial Locked-In Syndrome in a Young Adult: A Novel Association?

This is a case of a 30-year-old male with no prior medical conditions presented to the emergency department for presumed seizures after ingesting 900 mg of caffeine via pre-workout drinks and pills. Patient was described as having nearly 15 minutes of generalized seizure activity observed by emergency medical service, requiring midazolam. A head computerized tomography (CT) demonstrated a possible thrombus, and further, CT angiography and CT perfusion confirmed a basilar artery occlusion. He was treated with tissue plasminogen activator (tPA) and underwent thrombectomy achieving TICI grade 3 in the left posterior cerebral artery and TICI grade 2b in the superior cerebellar artery. Unfortunately, the patient experienced a hemorrhagic conversion leading to an incomplete locked-in syndrome. This case report suggests a novel association between energy drinks and caffeine supplements as potential etiologies for rapid onset on cerebrovascular incidents.

A Case of Moyamoya Disease in Morning Glory Syndrome

Purpose: We report a diagnosis of Moyamoya disease based on brain magnetic resonance imaging (MRI) and brain magnetic resonance angiography (MRA) performed in a child diagnosed with morning glory syndrome.Case summary: A 6-year-old boy visited the hospital with a chief complaint of exodeviation of his left eye that started at 1 year of age. The corrected visual acuity was 20/30 in the right eye and 20/400 in the left. The Krimsky test showed exotropia of 35 prism diopters (PD) for near vision and 30 PD for distance. Fundus photography showed an enlarged optic disc with funnel-shaped excavation in the left eye. With a diagnosis of morning glory syndrome accompanied by exotropia, the patient underwent brain MRI and brain MRA. The patient had no neurological symptoms such as headache and muscle weakness. Moyamoya disease was diagnosed, as brain MRI and MRA showed tiny tortuous vessels forming collateral vessels from the lenticulostriatal arteries, left posterior cerebral artery, and left middle meningeal artery, which originated from the external carotid artery.Conclusions: Moyamoya disease can occur in children with morning glory disease. Brain MRI and MRA can help to diagnose Moyamoya disease. Caution is needed because transient ischemic attack, cerebral infarction, and cerebral hemorrhage may occur in patients with Moyamoya disease.

Image-based hemodynamic simulations for intracranial aneurysms: the impact of complex vasculature

PurposeHemodynamics play an important role in the assessment of intracranial aneurysm (IA) development and rupture risk. The purpose of this study was to examine the impact of complex vasculatures onto the intra-vessel and intra-aneurysmal blood flow.MethodsComplex segmentation of a subject-specific, 60-outlet and 3-inlet circle of Willis model captured with 7T magnetic resonance imaging was performed. This model was trimmed to a 10-outlet model version. Two patient-specific IAs were added onto both models yielding two pathological versions, and image-based blood flow simulations of the four resulting cases were carried out. To capture the differences between complex and trimmed model, time-averaged and centerline velocities were compared. The assessment of intra-saccular blood flow within the IAs involved the evaluation of wall shear stresses (WSS) at the IA wall and neck inflow rates (NIR).ResultsLower flow values are observed in the majority of the complex model. However, at specific locations (left middle cerebral artery 0.5 m/s, left posterior cerebral artery 0.25 m/s), higher flow rates were visible when compared to the trimmed counterpart. Furthermore, at the centerlines the total velocity values reveal differences up to 0.15 m/s. In the IAs, the reduction in the neck inflow rate and WSS in the complex model was observed for the first IA (IA-A δNIRmean =  − 0.07ml/s, PCA.l δWSSmean =  − 0.05 Pa). The second IA featured an increase in the neck inflow rate and WSS (IA-B δNIRmean = 0.04 ml/s, PCA.l δWSSmean = 0.07 Pa).ConclusionBoth the magnitude and shape of the flow distribution vary depending on the model’s complexity. The magnitude is primarily influenced by the global vessel model, while the shape is determined by the local structure. Furthermore, intra-aneurysmal flow strongly depends on the location in the vessel tree, emphasizing the need for complex model geometries for realistic hemodynamic assessment and rupture risk analysis.

Persistent intracranial hyper-inflammation in ruptured cerebral aneurysm after COVID-19: case report and review of the literature

BackgroundThe systemic manifestations of coronavirus disease 2019 (COVID-19) include hyperinflammatory reactions in various organs. Recent studies showed evidence for the frequent involvement of central nervous system in affected patients; however, little is known about clinical features of cerebrovascular diseases in childhood-onset COVID-19.Case presentationA 10-year-old boy recovered from SARS-CoV-2 infection without complication. On 14 days after infection, he presented with loss of consciousness. A head computed tomography detected a ruptured cerebral aneurysm at the left posterior cerebral artery accompanying subarachnoid hemorrhage (SAH). Immediate surgical intervention did not rescue the patient, resulting in the demise 7 days after admission. Serological and genetic tests excluded the diagnosis of vasculitis and connective tissue disorders. Retrospective analysis showed markedly higher levels of interleukin (IL)-1β, IL-6 and IL-8 in the cerebrospinal fluid than the serum sample concurrently obtained. A review of literature indicated that adult patients with COVID-19 have a risk for the later development of SAH during the convalescent phase of COVID-19.ConclusionsSAH is a severe complication of COVID-19 in children and adults who have asymptomatic cerebrovascular aneurysms. The markedly high levels of cytokines detected in the cerebrospinal fluid suggested that intracranial hyperinflammatory condition might be one of the possible mechanisms involved in the rupture of a preexisting cerebrovascular aneurysms.

A data-driven computational methodology towards a pre-hospital Acute Ischaemic Stroke screening tool using haemodynamics waveforms

Background and ObjectiveAcute Ischaemic Stroke (AIS), a significant global health concern, results from occlusions in cerebral arteries, causing irreversible brain damage. Different type of treatments exist depending on the size and location of the occlusion. Challenges persist in achieving faster diagnosis and treatment, which needs to happen in the first hours after the onset of symptoms to maximize the chances of patient recovery. The current diagnostic pipeline, i.e. “drip and ship”, involves diagnostic via advanced imaging tools, only available in large clinical facilities, which poses important delays. This study investigates the feasibility of developing a machine learning model to diagnose and locate occluding blood clots from velocity waveforms, which can be easily be obtained with portable devices such as Doppler Ultrasound. The goal is to explore this approach as a cost-effective and time-efficient alternative to advanced imaging techniques typically available only in large hospitals. MethodsSimulated haemodynamic data is used to conduct blood flow simulations representing healthy and different AIS scenarios using a population-based database. A Machine Learning classification model is trained to solve the inverse problem, this is, detect and locate a potentially occluding thrombus from measured waveforms. The classification process involves two steps. First, the region where the thrombus is located is classified into nine groups, including healthy, left or right large vessel occlusion, left or right anterior cerebral artery, and left or right posterior cerebral artery. In a second step, the bifurcation generation of the thrombus location is classified as small, medium, or large vessel occlusion. ResultsThe proposed methodology is evaluated for data without noise, achieving a true prediction rate exceeding 95% for both classification steps mentioned above. The inclusion of up to 20% noise reduces the true prediction rate to 80% for region detection and 70% for bifurcation generation detection. ConclusionsThis study demonstrates the potential effectiveness and efficiency of using haemodynamic data and machine learning to detect and locate occluding thrombi in AIS patients. Although the geometric and topological data used in this study are idealized, the results suggest that this approach could be applicable in real-world situations with appropriate adjustments. Source code is available in https://github.com/ahmetsenemse/Acute-Ischaemic-Stroke-screening-tool-.

A rare anatomical variation of the circle of Willis in a patient with an ischemic stroke

Purpose 
 The cerebral arterial circuit provides collateral circulation to the brain and protects the brain from ischemia, by sustaining tissue perfusion in case of reduced or impaired blood flow through its branches. Although many random anatomical variations in the circle of Willis (CoW) are of minor importance, some increase the risk of ischemic events, aneurysm, and atherosclerosis, and play an important role in endovascular and surgical treatment planning.  
 Case presentation 
 We report a rare arterial variation of the CoW diagnosed by computed tomography angiography in a patient with ischemic stroke. We found aplasia of the A1 segment of the left anterior cerebral artery and ipsilateral hypoplasia of the P1 segment of the left posterior cerebral artery.  
 Conclusion 
 For neurosurgeons, neurologists, and neuroradiologists, detailed knowledge of the numerous anatomical variations in the arterial supply to the brain is crucial to make a correct diagnosis and choose the appropriate treatment. The type of CoW variation influences stroke severity and outcome, with an incomplete CoW related to more severe conditions (higher National Institutes of Health Stroke Scale scores, more severe neurological deficits, and worse neurological outcomes) and poor prognosis. 

Cerebral blood flow and white matter alterations in adults with phenylketonuria

BackgroundPhenylketonuria (PKU) represents a congenital metabolic defect that disrupts the process of converting phenylalanine (Phe) into tyrosine. Earlier investigations have revealed diminished cognitive performance and changes in brain structure and function (including the presence of white matter lesions) among individuals affected by PKU. However, there exists limited understanding regarding cerebral blood flow (CBF) and its potential associations with cognition, white matter lesions, and metabolic parameters in patients with PKU, which we therefore aimed to investigate in this study. MethodArterial spin labeling perfusion MRI was performed to measure CBF in 30 adults with early-treated classical PKU (median age 35.5 years) and 59 healthy controls (median age 30.0 years). For all participants, brain Phe levels were measured with 1H spectroscopy, and white matter lesions were rated by two neuroradiologists on T2 weighted images. White matter integrity was examined with diffusion tensor imaging (DTI). For patients only, concurrent plasma Phe levels were assessed after an overnight fasting period. Furthermore, past Phe levels were collected to estimate historical metabolic control. On the day of the MRI, each participant underwent a cognitive assessment measuring IQ and performance in executive functions, attention, and processing speed. ResultsNo significant group difference was observed in global CBF between patients and controls (F (1, 87) = 3.81, p = 0.054). Investigating CBF on the level of cerebral arterial territories, reduced CBF was observed in the left middle and posterior cerebral artery (MCA and PCA), with the most prominent reduction of CBF in the anterior subdivision of the MCA (F (1, 87) = 6.15, p = 0.015, surviving FDR correction). White matter lesions in patients were associated with cerebral blood flow reduction in the affected structure. Particularly, patients with lesions in the occipital lobe showed significant CBF reductions in the left PCA (U = 352, p = 0.013, surviving FDR correction). Additionally, axial diffusivity measured with DTI was positively associated with CBF in the ACA and PCA (surviving FDR correction). Cerebral blood flow did not correlate with cognitive performance or metabolic parameters. ConclusionThe relationship between cerebral blood flow and white matter indicates a complex interplay between vascular health and white matter alterations in patients with PKU. It highlights the importance of considering a multifactorial model when investigating the impact of PKU on the brain.

Abstract 18886: Rare but Fatal: Thrombus Formation and Cerebral Infarction Following Atrial Fibrillation Ablation

Introduction: Atrial fibrillation (AF) ablation has become increasingly common as a first line treatment for young, healthy patients and recurrent AF. While the procedures are effective and safe with a mortality rate of <0.1%, it can be associated with fatal complications. Case Presentation: A 74-year-old male with a history of AF status post epicardial ablation, ascending and thoracic aortic aneurysm, hypertension, dilated cardiomyopathy, sick sinus syndrome and alcohol use presented with left hemiparesis and left sided facial droop. He had undergone radiofrequency ablation about 3 weeks prior. Initial evaluation for stroke with computed tomography (CT) of head and CT angiography (CTA) of head/neck was negative. He was intubated for airway protection. Upon insertion of the nasogastric tube, it had dark blood concerning for an upper gastrointestinal bleed. The hospital course was complicated by sinus bradycardia and severe hypotension requiring dopamine and norepinephrine infusions. Repeat CTA head/neck demonstrated new evolving infarcts in the left middle cerebral artery (MCA), left posterior cerebral artery and right MCA territories. During an esophagogastroduodenoscopy to rule out atrioesophageal fistula, patient had a vasovagal episode which resolved with epinephrine. Subsequent transesophageal echocardiogram (TEE) demonstrated an echogenic long protruding thrombus extending across the iatrogenic atrial septal defect from the right atrium to the posterior wall of the left atrium, attached near the ostium of the right lower pulmonary vein. Repeat CT head multiple new areas concerning for developing infarctions and pneumocephalus. Given his overall grim prognosis, the patient was transitioned to comfort care. Conclusions: As ablative procedures for management of AF become more prevalent, it is imperative to maintain a high clinical suspicion for rare but fatal complications which require prompt diagnosis and early aggressive management.

Abstract 104: Fetal Posterior Cerebral Artery (PCA) Occlusion from Occluded Cavernous ICA Stent

Introduction Posterior Cerebral Artery (PCA) is a medium vessel occlusion (MVO) which is 5‐10% of all acute ischemic events. Safety and efficacy of mechanical thrombectomy in posterior circulation MVO is unclear compared to medical treatment only (1). There is concern that fragility of distal, smaller vessels may have an increased risk of procedural complications (e.g., arterial dissection and or perforations). More people are getting flow divertors over the years and rate of flow diverter of ICA occlusion is 0.05%‐0.08% (2). Here we present a case of embolic fetal PCA stroke with ICA stent occlusion. Methods We report a case of fetal origin posterior cerebral artery occlusion from ICA with literature search of Pubmed. Results 77 years old female with left cavernous‐ICA stent presented from a rehab facility with complaints of word finding difficulty, confusion, right hemiparesis, right sided neglect, and visual disturbance. In the emergency department (ED), her NIHSS was 28. ED presentation was 2.5 hrs after the last known well (LKW). Of note, patient had a with left cavernous‐ICA stent placement a month before the presentation and was noncompliant to antiplatelets. CT head was negative for intracranial bleeding and ASPECT score was 7. CT angiography head and neck was obtained, showing new complete interval occlusion of the intracranial extradural left ICA with reconstitution of distal branches through anterior communicating artery. Patient received IV thrombolytics, intubated for airway protection and was transferred to a comprehensive stroke center for possible mechanical thrombectomy. Time of the arrival was approximately 6 hours after the LKW, reexamination was hindered by the sedation and intubation but was concerning for possible PCA occlusion rather than ICA occlusion. As the localization of ischemic area was unclear, CT perfusion (CTP) was obtained. CTP showed 27 ml penumbra without core infarct in left PCA territory. As fetal origin of left PCA from ICA is occluded, without ability to access through occluded stent, noted risk of left ICA complications with attempts to recanalize stent for noted PCA hypoperfusion outweigh the benefits. With the exam improvement post thrombolytics administration and small penumbra, mechanical thrombectomy was not indicated. Conclusion In acute large vessel occlusion, utility of CT perfusion (CTP) usually recommended after 6 hours from last well known. In this case, patient presented within the 6 hours but the reexamination post thrombolytics was not localizing to suggest large vessel occlusion (LVO) and the territory at risk was unclear. We described a left intracranial ICA flow diversion occlusion without anterior circulation ischemia and left PCA ischemia demonstrated. In this case, CTP was employed to differentiate the territory at risk for triage to appropriate intervention, to differentiate the LVO vs MVO.

Abstract 089: A Case of Complicated Dissection: Vertebral Artery Sacrifice for Recurrent Stroke Prevention

Introduction Posterior circulation strokes account for 20% of ischemic strokes (1). Optimal management for posterior circulation strokes has been studied less than for anterior circulation strokes (2). Endovascular parent vessel sacrifice is an established technique used to treat vascular pathologies. There is limited evidence for parent artery sacrifice for recurrent strokes and there is no current guideline for standard of care. Methods '‐ Results 51‐year‐old gentleman with history of tobacco use presented with left homonymous hemianopsia, onset 1.5 hours prior to arrival. CT brain showed no bleed and patient received IV tissue‐plasminogen activator (tPA). CT angiography (CTA) demonstrated occlusion of the right posterior cerebral artery (PCA) and dissection of the left vertebral artery (V2 segment) with distal reconstitution. He underwent emergent thrombectomy for right P2 thrombus with complete reperfusion TICI 3 (Thrombolysis in Cerebral Infarction Score). Less than 24 hours later, he developed a right homonymous hemianopsia, and was found to have a new occlusion of the left P1 segment of the left PCA. Emergent thrombectomy was performed with complete reperfusion (TICI3). MRI brain demonstrated bilateral PCA territory infarcts. Within 12 hours of the second thrombectomy, his neurological exam deteriorated, and interval imaging revealed a basilar trunk thrombus, for which he underwent a successful endovascular thrombectomy complete reperfusion (TICI3). His antiplatelet regimen was optimized with Aspirin. Heparin was considered as treatment but was not provided because of the hemorrhagic conversion of his ischemic strokes. Given the persistent recurrence of thromboemboli in the posterior circulation despite being on optimal medical management, and evidence of hemorrhagic conversion, a decision was made to perform endovascular coil embolization of the left vertebral artery V2 segment at the site of dissection. Angiographic imaging demonstrated antegrade blood flow through the dissection as the source of recurrent embolic strokes. Six Stryker Target coils were deployed spanning the region of dissection within the left V2 segment via a right radial access with the guide catheter in the right vertebral artery. Post coil embolization angiographic runs demonstrated complete occlusion of the left vertebral V2 segment at the region of dissection which was confirmed via a left vertebral injection from a left femoral arterial access. There was preservation of ascending cervical collaterals beyond the dissection with patency of the contralateral vertebral artery supplying the intracranial circulation. Following embolization, repeat imaging showed no new infarcts and no new or worsening hemorrhage. He was continued on Aspirin monotherapy. It is notable that though his neurological exam deteriorated during each recurrent thromboembolic event, his neurologic exam at the time of discharge significantly improved with NIHSS of 3. He is currently being followed at our neuroscience institute. Conclusion Cervical arterial dissections pose increased risk for ischemic strokes (3). Vertebral artery dissection accounts for approximately 2%, of which, 10‐25% occur in middle‐aged and younger patients (4). This is a case of a young patient that exemplifies a successful role for vertebral artery sacrifice with coil embolization to prevent recurrent thromboembolic posterior circulation strokes. However controlled studies are needed for safety and efficacy of these interventions.

Memory, Executive, and Intellectual Functions in Adults with Moyamoya Disease

Cognitive function can decline in adults with moyamoya disease (MMD). Memory, which is an essential but complex and multifaceted function, underpins executive and intellectual functions. However, the relationship between memory and executive or intellectual functions in adults with MMD has not been well studied. The relationship between memory and cerebral blood flow has also not been elucidated. This study investigated correlations between memory, executive function, and intellectual function, and associations between cerebral blood flow and memory in adults with MMD. Memory, executive function, and intellectual function were assessed using the Wechsler Memory Scale-Revised (WMS-R), Frontal Assessment Battery (FAB), and Wechsler Adult Intelligence Scale (WAIS) third or fourth edition, respectively, in 31 adults with MMD. Cerebral blood flow was measured with iodine 123I-iodoamphetamine single-photon emission computed tomography. WMS-R scores correlated significantly with total FAB and WAIS scores before and after revascularization. Cerebral blood flow in the left posterior cerebral artery territory correlated positively with WMS-R and WAIS scores pre- and postoperatively. Postoperative cerebrovascular reserves of the right cerebellum, pons, and vermis were positively associated with visual memory, and postoperative cerebrovascular reserve of the pons was also associated with general memory. Memory function correlates with executive and intellectual functions in adults with MMD. The FAB, which requires about 10min to administer, might be useful to screen for memory dysfunction. Memory might be vulnerable to hypoperfusion in the posterior cerebral artery territory among adults with MMD. Postoperative cerebrovascular reserve might help predict memory dysfunction in adults with MMD.

How I do it? Preoperative Microsoft HoloLens 2 planning-assisted surgical clipping of a fetal posterior cerebral artery aneurysm.

The treatment of intracranial aneurysms has predominantly shifted towards endovascular strategies, but complex cases still necessitate microsurgery. Preoperative stimulation can be beneficial for inexperienced young neurosurgeons in preparing for safe microsurgery. A 72-year-old female with a left irregular fetal posterior cerebral artery (PCA) aneurysm underwent clipping repair. Microsoft HoloLens 2, utilizing mixed reality technology, was employed for preoperative stimulation and anatomical study. During the operation, we successfully identified the planned relationship between the aneurysm and the fetal PCA. The patient was cured without any complications. We hope that this report will highlight the significance of Microsoft HoloLens 2 in microsurgical planning and education.

Heritability of cerebral blood flow in adolescent and young adult twins: an arterial spin labeling perfusion imaging study.

Blood perfusion is a fundamental physiological property of all organs and is closely linked to brain metabolism. Genetic factors were reported to have important influences on cerebral blood flow. However, the profile of genetic contributions to cerebral blood flow in adolescents or young adults was underexplored. In this study, we recruited a sample of 65 pairs of same-sex adolescent or young adult twins undergoing resting arterial spin labeling imaging to conduct heritability analyses. Our findings indicate that genetic factors modestly affect cerebral blood flow in adolescents or young adults in the territories of left anterior cerebral artery and right posterior cerebral artery, with the primary contribution being to the frontal regions, cingulate gyrus, and striatum, suggesting a profile of genetic contributions to specific brain regions. Notably, the regions in the left hemisphere demonstrate the highest heritability in most regions examined. These results expand our knowledge of the genetic basis of cerebral blood flow in the developing brain and emphasize the importance of regional analysis in understanding the heritability of cerebral blood flow. Such insights may contribute to our understanding of the underlying genetic mechanism of brain functions and altered cerebral blood flow observed in youths with brain disorders.

Microneurosurgical treatment of a small perimesencephalic pure pial arterial malformation: an under-recognized etiology of angiographically occult subarachnoid hemorrhage. Illustrative case.

Pial arterial malformations (PAMs) are rare vascular lesions consisting of dilated tortuous arteries without venous drainage. Current PAM understanding is limited by the lesion's rarity, limited anatomopathological studies, and frequent misclassifications. A 23-year-old male experienced two spontaneous subarachnoid hemorrhages (SAHs) over 6 months with initially unremarkable diagnostic cerebral angiograms. Magnetic resonance imaging (MRI) and angiography after the second SAH revealed a small perimesencephalic ovoid lesion within the left crural cistern, between the left superior and posterior cerebral arteries, appearing to be an exophytic cavernoma, a thrombosed aneurysm, or a hemorrhagic tumor. Microsurgical resection was achieved with a pterional craniotomy and anterior clinoidectomy. The resected lesion was characteristic of a pure PAM arising from superior cerebellar arterial branches. Small pure PAMs can be deceitfully dynamic lesions causing episodes of hemorrhage, complete thrombosis (angiographically occult), recanalization, and rehemorrhage. Small thrombosed vascular malformations or aneurysms should be included in differential diagnoses of angiographically occult SAH. MRI can be diagnostic, but the true angioarchitecture can only be elucidated with microneurosurgery. The only definitive cure is removal. The microneurosurgical strategy should account for worst-case scenarios, provide adequate skull base exposures, and include bypass revascularization options when thrombosed aneurysms are encountered.

Unilateral rete mirabile in multiple intracranial arteries with ipsilateral agenesis of the internal carotid artery: a case report

BackgroundRete mirabile of the cerebral artery is a rare anomaly, with most previous cases occurring in the middle cerebral artery or internal carotid artery. Here, we present the first report of unilateral rete mirabile in multiple intracranial arteries with ipsilateral internal carotid artery agenesis.Case presentationA 64-year-old Japanese woman was brought to the emergency department of our hospital in a deep coma. Computed tomography of the head showed severe intraventricular hemorrhage with subarachnoid hemorrhage. Computed tomography angiography showed not only congenital left internal carotid artery agenesis, but also rete mirabile of the left posterior communicating artery, the left posterior cerebral artery, and the left anterior cerebral artery. This unilateral vessel anomaly complex may have contributed to the formation of a peripheral aneurysm arising from a perforating branch of the pericallosal artery, which ruptured. The patient underwent urgent bilateral external ventricular drainage, but deteriorated and was declared brain dead.ConclusionsWe report the first case of unilateral rete mirabile in multiple intracranial arteries. Because the cerebral arteries in patients with rete mirabile may be vulnerable, close attention should be paid to the development of cerebral aneurysms.

CORTICAL BLINDNESS DUE TO BILATERAL STROKES – A CASE REPORT OF ANTON SYNDROME

Background: Blindness (anopia) is a functional loss of vision, which could be due either to ophthalmological or neurological conditions. Blindness may be congenital or acquired. The main causes of blindness in adults are cataracts, uncorrected ametropia (myopia, astigmatism), glaucoma, macular dystrophy, cortical ischemic strokes, etc. In less than 10% of the patients, the reason for cortical blindness is bilateral occipital strokes, one of them hemorrhagic. Case Description: In the current case report, we present a 75-year-old patient with complaints of headache and visual loss. The patient has a history of a left PCA (posterior cerebral artery) distal ischemic stroke. The CT scan reveals a hypodense cerebral lesion in the left medial occipital cortex and subcortex (lingual gyri and cuneus) and a hyperdense cerebral lesion in the right medial occipital cortex and subcortex (lingual gyri and cuneus). The neurological examination shows only bilateral visual loss without motor deficits. The patient has visual anosognosia and confabulation in the setting of obvious visual loss and cortical blindness(Anton-Babinski syndrome, also known as ABS or Anton syndrome). However, performing cerebellar tests (dysdiadochokinesis, finger-to-nose test, heel-to-shin test, cerebellar ataxia) was not done because of the visual loss. After being consulted by a neurologist and neurosurgeon with the preliminary diagnosis of brain hemorrhage, the patient was admitted to the Neurology Clinic of UMHAT D-r "Georgi Stranski", Pleven, Bulgaria. Conclusion: Occipital infarction must be considered in all cases with sudden onset of isolated visual loss. Early diagnosis and treatment of stroke reduce mortality and morbidity. The prognosis depends on the extension of the visual cortex damage.

Internal Carotid Artery Agenesis: A Rare Incidental Finding

Internal carotid artery agenesis is a very rare anomaly, occurring during the early stages of embryonic development. We report the clinical presentation and imaging findings both on CT and MRI of the incidental finding of a left internal carotid agenesis in a 40 year old female. Magnetic resonance angiography was the most valuable diagnostic tool for the positive diagnosis, showing the absence of the left internal carotid artery, with left circulation arising from the right anterior cerebral artery and left posterior cerebral artery. Unenhanced computed tomography was used to differentiate between internal carotid agenesis and hypoplasia. Imaging should also look for associated malformations such as aneurysms as well as ischemic and hemorrhagic complications.

Posterior Reversible Encephalopathy Syndrome (PRES), Hypoxic Injury and Stroke: A Sequelae of Bath Salt Inhalation? (P2-5.012)

<h3>Objective:</h3> To describe a case of bath salt inhalation causing PRES, hypoxic injury, and acute stroke. <h3>Background:</h3> Bath salts contain 3,4-methylenedioxypyrovalerone, a substance similar to cocaine and amphetamines, and can lead to vasospasm by inhibiting dopamine and norepinephrine reuptake. PRES and stroke can be caused by hypertension, but its coexistence in a patient with bath salt inhalation has been not described. <h3>Design/Methods:</h3> This is a case report of a 48-year-old female patient with a history of heroin abuse was found unresponsive. On arrival, was noted to have a systolic blood pressure over 200s and was seizing. On exam, she had expressive and receptive aphasia. Initial labs including a urine toxicology screen were unremarkable. CTA was concerning for vasospasm vs vasculitis. MRI Brain revealed multiple infarcts in bilateral hemisphere with extensive involvement of left posterior cerebral artery and T2 hyperintensities in the bilateral cerebellum and pons. Moreover, T2 FLAIR hyperintensities were noted in bilateral frontal and parietal white matter indicative of PRES. There was also injury to bilateral thalami and watershed vascular distributions suggestive of hypoxic insult. Extensive workup including TEE and LP failed to show an embolic source or vasculitis. <h3>Results:</h3> On further history, mother reported that patient routinely inhales bath salts. PRES findings were improved on repeat MRI 5 days later, but ischemia persisted. Her BP was hard to manage as stroke requires permissive hypertension and PRES requires BP control. She remained aphasic. <h3>Conclusions:</h3> Bath salt inhalation is shown to be associated with ischemic colitis and myocardial infarction, but no instances of stroke or PRES have been reported. The pathophysiological mechanisms between PRES and stroke differ, but may be secondary to vasospasm in the setting of bath salt inhalation. <b>Disclosure:</b> Dr. Mufti has nothing to disclose. Dr. Shi has nothing to disclose. Dr. Mufti has nothing to disclose. Dr. Hasan has nothing to disclose.

Fenestrated P1 segment of posterior cerebral artery, partly duplicated posterior communicating artery.

Anatomic variations at the junction of primitive internal carotid and basilar arteries are exceedingly rare. We aimed at reporting such rare variants involving the posterior communicating artery (PComA) and the P1 segment of posterior cerebral artery (PCA). The circle of Willis was dissected in an adult cadaver after removal of the cranial vault and cerebral hemispheres. The basilar end was rotated axially to the right. The P1 segment of the right PCA was fenestrated and occupied the interpeduncular fossa. The right PComA passed over the oculomotor nerve to join the anterior arm of the P1 fenestration. On the opposite side, the PComA coursed supero-medially to the oculomotor nerve and it had a partly duplicated posterior end, with two arms, medial, larger, and lateral, thinner, inserting successively into the left PCA. Extremely rare anatomic variations of the circle of Willis should not be ignored when endovascular or microneurosurgical specific approaches are intended.

Extremely long posterior cerebral artery P1 segment.

Excluding aplasia and hypoplasia of the P1 segment of the posterior cerebral artery (PCA), anatomical variations in the PCA are rare. To our best knowledge, there are few reports of an extremely long P1 segment of the PCA. Herein, we report a rare case of an extremely long P1 segment of the PCA, which was diagnosed by 1.5-T magnetic resonance angiography (MRA). A 96-year-old woman was transferred by ambulance to our hospital with impaired consciousness. Her symptom improved, and magnetic resonance imaging showed no significant findings. MRA revealed an extremely long P1 segment of the left PCA. The length of the P1 segment of the left PCA was 27.3mm. The left posterior communicating artery (PCoA) was 20.9mm, which is not considered long. The left anterior choroidal artery branched from the internal carotid artery distal to the PCoA branching position. Basilar artery fenestration was also incidentally identified. Careful imaging assessment was important for identifying the extremely long P1 segment of the PCA in the present case. This rare anatomical variation can also be confirmed by 1.5-T MRA.