Posterior Circulation Territory Research Articles

Basilar Artery Tortuosity Increases the Risk of Persistent Dizziness and Unsteadiness After Posterior Circulation Infarction.

Basilar artery (BA) tortuosity is closely associated with posterior circulation infarction (PCI) and dizziness/unsteadiness. This study aims to determine the relationship between BA tortuosity and the outcome of dizziness and unsteadiness in PCI patients. This study prospectively recruited PCI patients presenting with dizziness and unsteadiness. BA tortuosity was diagnosed based on Smoker's criteria. The BA tortuosity index (BATI) was measured from magnetic resonance angiography (MRA) images. Posterior circulation was divided into proximal (medulla oblongata and posterior inferior cerebellar), middle, and distal territories. Symptoms, risk of falls, and quality of life were followed up in 3 months after stroke. Logistic regression was used to identify possible factors associated with the persistence of dizziness and unsteadiness. Among 182 PCI patients presenting with dizziness and unsteadiness, 97 (53.3%) had BA tortuosity, including 19 (10.4%) with moderate-to-severe BA tortuosity. At the 3-month follow-up, 58 (31.9%) patients continued to experience dizziness and unsteadiness, with significantly decreased quality of life and a high risk of falls. Binary logistic regression analysis identified moderate-to-severe BA tortuosity (OR, 4.474; 95% CI, 1.591-12.579; p = 0.004) and lesions involving the proximal posterior circulation territory (OR, 2.146; 95% CI, 1.097-4.199; p = 0.026) as risk factors for persistent dizziness and unsteadiness after PCI, while thrombolysis (OR, 0.280; 95% CI, 0.079-0.992; p = 0.049) as a protective factor. BATI (OR, 1.072; 95% CI, 1.028-1.119; p = 0.001) was also independently associated with dizziness and unsteadiness after PCI. Prominent BA tortuosity increases the risk of persistent dizziness and unsteadiness after PCI, leading to a high risk of falls and decreased quality of life. This warrants more attention in clinical practice.

Radiographic predictors of neurologic outcomes in patients with basilar artery occlusion: A single-center experience.

Randomized controlled trials indicate functional and mortality benefits in endovascular therapy for basilar artery occlusion (BAO). However, these studies only include patients who meet specific prognostic scores. This study investigates radiographic predictors of posterior circulation territory infarcts that may predict neurologic outcome at 90-day post-intervention. This is a retrospective cohort study of a prospectively maintained thrombectomy database of all patients who underwent mechanical thrombectomy for BAO. Baseline demographics, comorbidities, baseline functional status (mRS), and severity of presenting neurologic deficits (NIHSS) were collected. Pc-ASPECTS, posterior circulation collateral score (PCCS), and basilar artery on computed tomography angiography (BATMAN) measured radiographic characteristics. Core infarct territory was identified. Primary outcomes were good neurologic outcome (mRS 0-3) and poor neurologic outcome (mRS 4-6) at 90-day post-thrombectomy. 90-day mortality was a secondary outcome. About 21.5% of patients achieved a good neurologic outcome. About 32.3% of patients were deceased at 90 days. Receiver operating characteristic analysis shows PCCS collateral scores (AUC = 0.74, SE = 0.03, CI = 0.62-0.74) and BATMAN (AUC = 0.72, SE = 0.04, CI = 0.35-0.49) have potential to differentiate between those with good neurologic outcome from those with poor neurologic outcome. Although there was no statistically significant difference in AUC between the three curves, pc-ASPECTS score trended toward being weaker predictor of neurologic outcome (AUC = 0.49, SE = 0.04, CI = 0.35-0.49). There were significant associations between 90-day poor neurologic outcome and established infarcts within the pons (p = 0.01), left cerebellum (p = 0.01), and left occipital lobe (p = 0.03) on pre-thrombectomy CT. Low BATMAN and PCCS collateral scores can be predictors of poor neurologic outcomes at 90-day post-thrombectomy for BAO while pc-ASPECTS score may be a weaker predictor of outcome.

Territory-Related Functional Connectivity Changes Associated with Verbal Memory Decline in Patients with Unilateral Asymptomatic Internal Carotid Stenosis.

Verbal memory decline is a common complaint of patients with severe asymptomatic stenosis of the internal carotid artery (aICS). Previous publications explored the associations between verbal memory decline and altered functional connectivity (FC) after aICS. Patients with severe aICS may show reduced perfusion in the ipsilateral territory and redistribution of cerebral blood flow to compensate for the deficient regions, including expansion of the posterior and contralateral ICA territories via the circle of Willis. However, aICS-related FC changes in anterior and posterior territories and the impact of the sides of stenosis were less explored. This study aims to investigate the altered FC in anterior and posterior circulation territories of patients with left or right unilateral aICS and its association with verbal memory decline. We enrolled 15 healthy controls (HCs), 22 patients with left aICS (aICSL), and 33 patients with right aICS (aICSR) to receive fMRI, Mini-Mental State Examination (MMSE), the Digit Span Test (DST), and the 12-item Chinese version of Verbal Learning Tests. We selected brain regions associated with verbal memory within anterior and posterior circulation territories. Territory-related FC alterations and verbal memory decline were identified by comparing the aICSL and aICSR groups with HC groups (P < .05, corrected for multiple comparisons), respectively. Furthermore, the association between altered FC and verbal memory decline was tested with the Pearson correlation analysis. Compared with HCs, patients with aICSL or aICSR had significant impairment in delayed recall of verbal memory. Decline in delayed recall of verbal memory was significantly associated with altered FC between the right cerebellum and right middle temporal pole in the posterior circulation territory (r = 0.40, P = .03) in the aICSR group and was significantly associated with altered FC between the right superior medial frontal gyrus and left lingual gyrus in the anterior circulation territory (r = 0.56, P = .01) in the aICSL group. Patients with aICSL and aICSR showed different patterns of FC alterations in both anterior and posterior circulation territories, which suggests that the side of aICS influences the compensatory mechanism for decline in delayed recall of verbal memory.

Percutaneous transluminal angioplasty for persistent primitive hypoglossal artery stenosis: illustrative case.

We report a case of symptomatic, progressive stenosis of a persistent primitive hypoglossal artery (PPHA), which was successfully treated with percutaneous transluminal angioplasty (PTA) of the origin of the PPHA. The PPHA is a type of carotid-basilar anastomosis with an incidence of 0.02% to 0.10%. It originates from the internal carotid artery (ICA), passes through the hypoglossal canal, and merges with the basilar artery. In many cases, the ipsilateral vertebral artery is hypoplastic; therefore, PPHA stenosis causes cerebral infarction in the posterior circulation territory, as in this case. The patient's right PPHA had severe and progressive stenosis; therefore, he experienced cerebral infarction despite medical treatment. Therefore, PTA for the stenosis was performed, which ceased the recurrence of cerebral infarction and dizziness by improving blood flow in the posterior circulation. Several reports have described ICA stenosis accompanied by PPHA or PPHA stenosis in patients receiving endovascular treatments. Almost all cases were nonprogressive, and the treatment procedure was stenting. However, in our case, the PPHA stenosis was progressive, and we performed PTA because the patient experienced resistance to antiplatelet drugs and had poor collateral flow.

Do monosymptomatic stroke patients with dizziness present a vestibular syndrome without nystagmus? An underestimated entity.

Vestibular symptoms are common in emergency department (ED) patients and have various causes, including stroke. Accurate identification of stroke in patients with vestibular symptoms is crucial for timely management. We conducted a prospective cross-sectional study from 2015 to 2019 to determine stroke prevalence and associated symptoms in ED patients with vestibular symptoms, aiming to improve diagnosis and outcomes. As part of the DETECT project, we screened 1647 ED patients with acute vestibular symptoms. Following a retrospective analysis of 961 head and neck magnetic resonance imaging (MRI) scans, we included 122 confirmed stroke cases and assessed them for vestibular signs and symptoms. Stroke prevalence in dizzy patients was 13% (122/961 MRI scans). Most patients (95%) presented with acute vestibular symptoms with or without nystagmus, whereas 5% had episodic vestibular syndrome (EVS). Nystagmus was present in 50% of stroke patients. Eighty percent had a purely posterior circulation stroke, and nystagmus was absent in 46% of these patients. Seven patients (6%) had lesions in both the anterior and posterior circulation. Vertigo was experienced by 52% regardless of territory. A stroke was identified in 13% of ED patients presenting with acute vestibular symptoms. In 5%, it was EVS. Most strokes were in the posterior circulation territory; vertigo occurred with similar frequency in anterior and posterior circulation stroke, and absence of nystagmus was common in both.

An Efficient Approach to Mapping the Distribution of Renal Cell Carcinoma (RCC) Brain Metastases (BrM) (P10-13.003)

<h3>Objective:</h3> To assess the distribution of RCC BrM in clinical context. <h3>Background:</h3> RCC frequently presents with hemorrhagic BrMs. BrM distribution patterns and their associations with lab/clinical parameters are poorly understood. <h3>Design/Methods:</h3> We performed a retrospective analysis including RCC patients who underwent BrM resection at our institution. We reviewed gadolinium-enhanced MRI brain and CT head at the time of BrM diagnosis and assessed the presence of hemosiderin (MRI) or hemorrhage (CT) in the BrM. BrMs were marked in their corresponding anatomic location in a brain template. Public brain atlases (Faria and Liu 10.25790/bml0cm.109; Vachet, SCR_002606) were used for distribution analysis. Serum markers were correlated with imaging. <h3>Results:</h3> A total of 67 BM were analyzed from 46 patients (age 63±10years/35M), 23 synchronous BM, 9 patients had two, 6 had 3 concurrent BrMs. 97% of the lesions were spheric in shape. Mean 1D and 2D (RANO) tumor dimensions were 2.0±1.1cm and 4.7±4.9cm², respectively and correlated with neutrophil count at BrM diagnosis (r=0.3, p=0.01). Multilobar edema was seen in 36% of BrM. 82% of BrMs contained hemosiderin and 80% were hemorrhagic. Most BrMs were in the frontal (45%), parietal (21%) and occipital (18%) lobes. Posterior cerebral artery distribution contained 34% of BrM despite it supplying only 16% of brain volume. Higher platelet counts were associated with BrMs in the posterior circulation territories (p=0.05). BrM hemosiderin was associated with larger tumors (p=0.04), lower platelet counts (p=0.01) and higher hemoglobin (p=0.08). Renal vein thrombosis (RVT) at primary diagnosis was associated both BrM hemosiderin (p=0.05) and hemorrhage (p=0.03). CNS progression-free survival was shorter in those who had RVT (p=0.04), or had BrM hemosiderin (p=0.04). <h3>Conclusions:</h3> The presented mapping method offers an objective and efficient way to assess lesion distribution that reveals clinically relevant patterns. BrM hemosiderin deposits are linked to lower platelet counts and may provide prognostic information. Further analyses are underway. <b>Disclosure:</b> The institution of Dr. Kamson has received research support from Maryland Cigarette Restitution Fund. Mr. Feinaj has nothing to disclose. Dr. Elias has nothing to disclose. Mr. Yerrapragada has nothing to disclose. Dr. Bettegowda has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Bionaut Labs. Dr. Bettegowda has received personal compensation in the range of $10,000-$49,999 for serving as an Expert Witness for Rodey, Dickason, Sloan, Akin &amp; Robb, P.A.. Dr. Bettegowda has stock in OrisDx. The institution of Dr. Bettegowda has received research support from NIH. Dr. Bettegowda has received intellectual property interests from a discovery or technology relating to health care. Mr. Singla has nothing to disclose. Yasser Ged has nothing to disclose.

Recanalized paramedian thalamoperforators after intraarterial tirofiban treatment in a patient with bilateral fetal-type PCAs (P8-5.028)

<h3>Objective:</h3> NA <h3>Background:</h3> There are increasing evidence that support the treatment effect of intraarterial tirofiban during endovascular thrombectomy in acute ischemic stroke. Here, we report a patient with bilateral fetal-type PCAs, whose paramedian perforating thalamic-mesencephalic arteries were recanalized after intraarterial tirofiban treatment during thrombectomy. <h3>Design/Methods:</h3> NA <h3>Results:</h3> A 78-year-old woman presented to the emergency room with acute onset of drowsy mentality, gaze palsy and quadriplegia (NIHSS 9). She had a history of hypertension and diabetes. Brain CT scan revealed no definite early ischemic damage and CTA showed steno-occlusion at the left distal VA and bilateral fetal type PCAs. Brain perfusion CT showed perfusion delay in posterior circulation territory. Under local anesthesia, an 6F Envoy^® catheter (Codman) was placed in the left distal VA of distal V2 segment. The angiography revealed the distal VA occlusion (V4 segment) (Fig. 1A). Suction thrombectomy was performed twice using 5F Sofia^® catheter (Microvention), and no clot was extracted (Fig. 1B). Recanalization of left distal VA with underlying severe ICAS at the occlusion site (Fig. 1C). Delayed angiogram showed subtle re-occlusion tendency of left distal VA, 0.5mg of intraarterial tirofiban was injected. Successful recanalization (mTICI 2C) with further recanalized paramedian perforating thalamic-mesencephalic arteries on distal BA after SCA branches was achieved (Fig. 1D). Follow-up brain MRI showed acute infarction at the posterior circulation territory including bilateral thalami. MRA showed patent left distal VA with underlying severe ICAS, and vessel wall MRI showed eccentric wall thickening without contrast enhancement or plaque hemorrhage. The patient recovered well at 1 week (NIHSS 0). <h3>Conclusions:</h3> In a patient with bilateral fetal type PCAs, distal BA could end after SCA branches and this site should be evaluated cautiously, because thalamoperforators could originate. Intraarterial tirofiban could be helpful to recanalize perforating arteries during thrombectomy. <b>Disclosure:</b> Dr. Baik has nothing to disclose.

Mapping distribution of brain metastases in renal cell carcinoma (RCC) and association with clinical features.

727 Background: Brain metastases (BM) are frequently observed in metastatic RCC (mRCC) with a tendency to present with hemorrhagic BM. Distribution patterns of BM in RCC and associations with clinical outcomes are not well understood. Here we present a detailed distribution analysis in a surgically resected BM RCC cohort with a focus on clinically relevant associations. Methods: A retrospective analysis was performed on patients (pts) with mRCC who underwent craniotomy for BM at our institution. We reviewed gadolinium-enhanced MRI brain and CT head (if available) at the time of BM diagnosis. We assessed the presence of hemosiderin on MRI or hemorrhage on CT in the BM lesion and marked each at their corresponding anatomic location. Public brain atlases were used for distribution analysis. Overall survival (OS) from the date of BM diagnosis and CNS progression free survival (CNS-PFS) from the date of craniotomy were calculated. Results: A total of 67 BM were analyzed from 46 pts. 23 with synchronous BM, 9 with two and 6 with 3 concurrent BM. Most patients were male (n=35, 76%) with a median age at diagnosis of 63 years. Primary histology was clear cell in 42 pts (91%) and 10 pts (22%) had renal vein thrombosis (RVT) at primary diagnosis. IMDC scores at time of BM diagnosis were favorable in 20%, intermediate in 60% and poor in 20%. Hemosiderin (MRI) or hemorrhage (CT) was seen in 82% and 80% of BM, respectively. 55% of lesions were left sided, 45% frontal, 21% parietal, 18% occipital, 7% temporal and 6% cerebellar. Posterior circulation and posterior cerebral artery territories contained 42% and 34% of BM despite supplying only 30% and 16% of the brain volume, respectively. Patients with solitary BM had higher Karnofsky performance status (p=0.006) and lower disease burden (p=0.004) than those with multiple BM. Shorter CNS-PFS was seen in association with hemosiderin on MRI (log-rank p=0.04) and RVT in primary specimen (log-rank p=0.002). IMDC risk scores (log-rank p&lt;0.001) predicted OS. On multivariable OS analysis, BM lateralized to the right (HR 2.6, p=0.06), hemosiderin in BM (HR 6.5, p=0.02) and IMDC risk groups (intermediate HR 2.9, poor risk HR 25.6, p&lt;0.04) were independent prognostic factors for shorter OS. Conclusions: The above-presented lesion mapping method shows clinically relevant findings in RCC BM. Tumoral hemosiderin deposits appear a potential parameter to predict outcomes in RCC BM which deserve further study and validation.

Massive microbleeds in posterior circulation territory in an immunocompromised patient with sepsis

Massive microbleeds in posterior circulation territory in an immunocompromised patient with sepsis

Vertebrobasilar dolichoectasia in patients with cerebrovascular ischemic stroke: does it have a role in cerebral microbleeds?

Abstract Background Vertebrobasilar dolichoectasia (VBD) may account for cerebral microbleeds (CMBs) in ischemic cerebrovascular stroke. Objectives To examine whether VBD is associated with the involvement of CMBs in any region and, if so, whether it is associated with CMBs among ischemic stroke patients located in posterior circulation territory. For patients with VBD, we also studied ischemic stroke subtypes, and checked whether dolichoectasia was linked to vascular risk factors. Methods Two hundred ischemic stroke patients in whom detailed clinical data and brain MRI sequences were obtained, and stroke subtyping with TOAST classification (Trial of ORG 10172 in Acute Stroke Treatment) was performed. Results The mean age of patients was (65.22 ± 12.88), male patients were more frequent (67.5%); dyslipidemia was the most frequent risk factor (55%). Cardio-embolic stroke subtype was the most frequent (37%) and (71.5%) of patients had no history of previous use of antithrombotic drugs. Ectasia was found in 28 (14%), dolichosis was found in 50 (25%) and vertebrobasilar dolichoectasia was found in 19 (9.5%) of patients. Cerebral microbleeds were detected in 114 (57%) patients. Mild degree CMBs was the most prevalent among patients 69 (61%) and were located predominantly in both anterior and posterior territories 41 (36%). CMBs were significantly more frequent in hypertensive and older patients. Conclusions In patients with VBD, severe degree CMBs were more common and were located as a vascular territory supplied by vessels originating from dolichoectatic parent vessels in the posterior region.

Clinical Profile of Posterior Circulation Stroke: A Prospective Study at Dhaka Medical College Hospital

Studies regarding clinical characteristics of stroke involving the posterior circulation territory of the brain in Bangladesh are rare although large number of patients were found in hospital admission and with a high morbidity and mortality. Study for better understanding of the clinical features, risk factors and aetiologies of posterior circulation stroke (PCS) may be very helpful for early diagnosis, treatment, and also for setting primary and secondary prevention strategies. The objective of the study was to identify clinical features and short-term outcome of PCS. Adult patients admitted in Dhaka Medical College Hospital with clinical features consistent with posterior circulation stroke involving brain stem or, cerebellum or thalamus or occipital area and confirmed by computer tomography (CT) scan of brain were the the cases as respondents. Few cases were needed MRI of brain to confirm diagnosis. This was a hospital based prospective observational study with descriptive and analytical component. Sample was selected from the study population by purposive type of non-probability sampling technique. Sample size was 30. A semi-structured questionnaire was prepared containing patients’ profile as well as stroke patients’ reporting form which included all the essential information regarding clinical profile of PCS as well as short term outcome. Analysis was done using Statistical Package for the Social Sciences (SPSS) software. Thirty consecutive cases of strokes involving posterior circulation territory were included in the study according to inclusion and exclusion criteria. Male female ratio was 1.7:1. Most of the patients in both sexes were affected after the age of 50 years. Hemorrhagic PCS was significantly higher than ischaemic PCS. Among hemorrhagic PCS common symptoms were decreased level of consciousness and motor disturbances. Most common clinical sign in ischemic PCS is impaired consciousness which was present in 55.6% of the total ischemic PCS cases. Whereas this sign was present in all the cases of hemorrhagic PCS (100%). Like presenting symptoms, most of the clinical signs were also more common in hemorrhagic PCS. But few clinical signs were more common in ischemic strokes, such as cranial nerve involvement and nystagmus. Commonest predisposing factors were tobacco abuse, hypertension and dyslipidemia. Mortality was higher in hemorrhagic PCS than ischemic PCS within 7 days of follow up.&#x0D; Bangladesh Med J. 2021 Sept; 50(3): 20-25

Evaluation of the association between the internal carotid artery and vertebral artery tortuosity and acute ischemic stroke using tortuosity index.

To determine the association between the tortuosity of the internal carotid artery and vertebral artery and the occurrence of acute ischemic stroke based on a new quantitative method. This retrospective case-control study was conducted on 63 patients diagnosed with acute ischemic stroke in the case group and 52 patients in the control group. All the participants underwent neck Computed Tomography Angiography. The images were retrospectively reviewed and the tortuosity index was measured for internal carotid and vertebral artery. Then, a multivariable binary logistic regression model adjusted for the potential confounders was performed to assess the independent effect of internal carotid/vertebral artery tortuosity on acute ischemic stroke. Analysis of the logistic regression model revealed a significant effect of the internal carotid artery tortuosity index on anterior territory infarction (odds ratio = 1.04, p = 0.01) as well as a significant effect of the vertebral artery tortuosity index on posterior territory infarction (odds ratio = 1.14, p < 0.001). The optimal cut-off points for the internal carotid and vertebral artery tortuosity were 16.91 and 22.96, respectively. This study showed that tortuosity of extracranial portions of the internal carotid and vertebral artery could be an independent imaging predictor of acute ischemic stroke in anterior and posterior circulation territories, respectively.

Topography and etiologies of cerebellar infarcts presenting as isolated acute vestibular syndrome

To investigate the topography and etiologies of acute cerebellar infarcts (ACIs) that presented as isolated acute vestibular syndromes (AVSs). ACI was ascertained on magnetic resonance diffusion-weighted imaging combined with apparent diffusion coefficient sequence and was categorized into the simple (territory and small infarct) and the complicated (concomitant infarcts in territories of posterior circulation besides cerebellum). Infarct topography and etiologies were compared between ACI patients with isolated AVS and non-isolated AVS (general and/or local neurological symptoms and/or signs with or without AVS). We enrolled 129 ACI patients, and 53 patients (53/129, 41.1%) had isolated AVS. In isolated AVS, the infarct lesions could be territory infarcts, small infarcts involving cortical, subcortical, and areas directly related to vestibular structures, and the primary etiologies were of large artery atherosclerosis and small vessel disease. Compared with the patients with non-isolated AVS, those with isolated AVS had more prevalence of small vessel disease (OR 6.30, 2.16-18.39; p = 0.001) and more probability of small infarcts (OR 6.04, 95%CI 2.31-15.76; p < 0.0001). In isolated AVS patients, the small infarct located more frequently in cerebellar hemispheres than the areas directly related to vestibular structures (27/35 vs 8/35), and the territory infarct located more frequently in the area supplied by posterior inferior cerebellar artery than the other areas (9/13 vs 4/13). Our study found that ACI could be presented as isolated AVS, which occurred more frequently in patients with small hemisphere infarct or infarct in the territory supplied by posterior inferior cerebellar artery.

Significance of Low Signal in Intracranial Vertebral Artery Wall Observed on Susceptibility-Weighted Angiography

Purpose: We aimed to investigate the clinical significance of the low signal in the intracranial vertebral artery wall observed on susceptibility-weighted angiography. Materials and Methods: We retrospectively reviewed susceptibility-weighted angiographies from 200 consecutive patients with acute ischemic stroke in the posterior circulation territory. The presence of eccentric or concentric low signals in the vertebral artery wall was examined and evaluated. The etiology of the low signal was also investigated as much as possible by referring to computed tomography and T1-weighted imaging (T1WI). We also compared its frequency in each stroke subtype. Results: A low signal was observed in 128/200 patients (64%). The low signals (58%) corresponded to vessel wall calcification in 74 of 128 patients and to vessel wall thickening showing intermediate to low (n = 8) or high (n = 16) signals on T1WI in 24 (19%) patients. The low signal did not have vessel wall thickening or calcification in 1 patient, and the cause of the low signal could not be verified in 29 patients. According to stroke subtypes, a low signal was observed in 14/14 (100%) vertebral artery dissections, all of which corresponded to intramural hematoma. A low signal was observed in 51/65 (78%) atherothromboses, which were significantly more frequent than cardioembolism (34/66; 52%) and small-artery disease (18/39; 46%) (p < 0.01). In atherothrombosis, calcification was the most common cause of low signal (n = 32; 63%). Conclusion: Low signals on susceptibility-weighted angiography were frequently observed in vertebral artery dissection and atherothrombosis, reflecting intramural hematoma in all of the former and predominantly calcification in the latter.

Comparison of symptomatic vertebrobasilar plaques between patients with and without Diabetes Mellitus using computed tomographic angiography and vessel wall magnetic resonance imaging.

ObjectivesDiabetes mellitus is significantly associated with posterior circulation ischemic stroke. We aimed to compare the characteristics of vertebrobasilar plaques in symptomatic patients with and without diabetes using high-resolution vessel wall magnetic resonance imaging and computed tomographic angiography.MethodsFrom April 2017 to May 2021, cases from patients with transient ischemic attack or stroke in the posterior circulation territory who underwent high-resolution vessel wall magnetic resonance imaging and computed tomographic angiography were reviewed. Characteristics of culprit vertebrobasilar plaques were compared between patients with and without diabetes. Multivariate regression analysis was performed to assess the correlation between culprit plaque characteristics and diabetes.ResultsA total of 148 patients were included and 75 patients were diagnosed with diabetes mellitus. Patients with diabetes had more intraplaque hemorrhage, calcification, spotty calcification presence, and higher calcification volume (all p < 0.05) compared with those without diabetes. Multivariate analysis demonstrated differences in the presence of intraplaque hemorrhage (p = 0.045) and number of spotty calcifications (p = 0.047) were statistically significant after adjusting for baseline characteristics.ConclusionsSymptomatic patients with diabetes have a higher incidence of intraplaque hemorrhage and larger calcification burden than those without diabetes, indicating the association of diabetes with more advanced plaque features in the posterior circulation.

Opalski syndrome: A rare presentation of Wallenberg syndrome

Lateral Medullary Syndrome (LMS) is a well studied vascular syndrome of the posterior circulation territory. This syndrome is localised with its typical presentation including vertigo, nystagmus, hoarseness, dysphagia, ipsilateral cerebellar signs and Horner’s syndrome with classical crossed sensory deficits, specifically loss of pain and temperature sensation affecting trunk and extremities contralateral to the infarct along with ipsilateral facial numbness. We present a case of Opalski syndrome which is a rare variant of Wallenberg syndrome, where lateral medullary syndrome is associated with ipsilateral hemiparesis and positive Babinski sign. This case report showcases one of the varied presentation of ipsilateral weakness in Lateral Medullary Syndrome or Wallenberg syndrome.

Occlusion of the Anterior Cerebral Artery Mimicking a Cerebral Aneurysm: Clinical Presentation and Literature Review

Intracranial aneurysms may be misdiagnosed with other vascular lesions such as vascular loops, infundibulum, or the stump of an occluded artery (very rare and reported compromising only the middle cerebral artery and the posterior circulation territory). Our aim was to describe a unique case of occlusion of an anterior cerebral artery mimicking a cerebral aneurysm in a probable moyamoya disease patient, and to highlight its clinical presentation, diagnosis, and management, and to perform an extensive literature review. A 67-year-old man suffering from recurrent dizziness for 3 months. Previous medical history was unremarkable. Brain magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) demonstrated occlusion of the right middle cerebral artery (MCA) associated with a "probable moyamoya disease" and an aneurysm-like shadow protruding lesion at the anterior communicating artery (AcomA). Perfusion images showed ischemia along the right temporo-occipital lobe. Due to MCA occlusion with perfusion deficits and unspecific symptoms, we offered a right side encephalo-duro-myo-synangiosis (EDMS) and clipping of the AcomA aneurysm in one session. Intraoperatively, there was no evidence of the AcomA aneurysm; instead, this finding corresponded to the stump of the occluded right anterior cerebral artery (A1 segment). This segment appeared to be of yellowish color due to atherosclerosis and lacked blood flow. The patient underwent as previously planned a right side EDMS and the perioperative course was uneventful without the presence of additional ischemic attacks. Arterial branch occlusions can sometimes present atypical angiographic characteristics that can mimic a saccular intracranial aneurysm. It is relevant to consider this radiographic differential diagnosis, especially when aneurysm treatment is planned.

An anatomical investigation of the proximal vertebral arteries (V1, V2) in a select South African population

IntroductionThe most common type of vascular complication during cervical spine surgery is the vertebral artery (VA) injury. The presence of anatomical variation in the artery's morphology has been a significant factor for arterial injury during surgery. Therefore, physicians planning interventions in the craniospinal region need to be aware of the extents of variations. In addition to vascular injury, anatomical variations can predispose to some pathologies in the posterior circulation territory. To provide useful data to interventional radiologists, anatomists, and surgeons, we evaluated the anatomical features of the V1 and V2 segments of the VA in a South African population.Materials and methodsThe study is an observational, retrospective chart review of 554 consecutive South African patients (Black, Indian and White) who had undergone computed tomography angiography (CTA) from January 2009 to September 2019.ResultsThe VA exhibited morphological variation in its course. We report the incidence of variant origin of the left VA, all from the aortic arch. Variation in the level of entry into the transverse foramen ranged between C7 and C3. A left dominant pattern was observed; we also report on hypoplasia of the VA. In addition, we report incidence of VA tortuosity at V1, V2 to be 76.6% and 32.1%, respectively.ConclusionsThe baseline data established in this study regarding the diameter, variant origin, and level of entry into the transverse foramen will assist neurosurgeons and interventional radiologists in interpreting, diagnosing, and planning and executing various vascular procedures and treatment of pathology in the vicinity of the VA.

Abstract P568: Incidence and Progression of Posterior Circulation Involvement in Moyamoya Disease

Introduction: The incidence and natural history of posterior circulation moyamoya disease (PCMMD) is not well-characterized. Methods: Consecutive patients with moyamoya disease prospectively treated at our institution from 2015-2018 were reviewed. Results: 262 consecutive patients with moyamoya disease undergoing 370 revascularization procedures were enrolled. Concurrent PCMMD was identified in 68 (26%) patients – all of which were confined to the anterior circulation. There were no differences in age, sex, race, or rates of diabetes, hypertension, smoking, or symptoms upon presentation between patients with or without PCMMD. Patients with PCMMD were more likely to present with bilateral disease (p&lt;0.001), higher Suzuki grade (p=0.001), more extensive collateral angiopathy (p&lt;0.001), and pial-pial collaterals from the PCA territory (p=0.03). Patients with PCMMD were more likely to suffer from ischemic peri-operative complications in both the anterior (p=0.03) and posterior (p&lt;0.001) circulation territories after anterior circulation revascularization. No differences were observed for hemorrhagic complications (p=1.0). Over a mean follow-up of 1.91±1.5 years, 19 (7.3%) developed new or progressive PCMMD. Patients with PCMMD progression had an Asian predilection and were less likely to present with sentinel symptoms such as headaches (p=0.05 and 0.01 respectively). Patients with bilateral disease (p=0.02), higher Suzuki (p&lt;0.001) and collateral angiopathy grades (p=0.002), and more extensive external carotid artery supply (p=0.03) were also more likely to experience PCMMD progression. There was no association between PCMMD progression and delayed neurological events or functional outcomes, but patients with concurrent PCMMD upon presentation were associated with poor functional outcome (mRS &gt;2) at last follow-up (p=0.02). Conclusions: Posterior circulation disease involvement often presents in the later stages of moyamoya and is associated with higher rates of ischemic peri-operative complications and poor functional outcomes likely due to reduced collateral flow. Progression of PCMMD is not uncommon. Future studies are needed to assess the impact of PCMMD progression on long-term outcomes.

Endovascular Treatment in the Subclavian Steal Syndrome: Series of 29 Patients

AbstractSubclavian steal syndrome is a group of symptoms resulting from retrograde flow in the vertebral artery, “stealing” blood from the posterior intracranial circulation and other territories, caused by stenosis or occlusion of the subclavian artery proximal to the origin of the same vertebral artery, or even of the brachiocephalic trunk. Most of the time, it is an incidental finding in patients with other conditions or cerebrovascular risk factors. We report a series of 29 patients with an angiographic diagnosis, in which 7 received treatment (all endovascular), all with symptoms directly related to this condition. Advanced age, systemic arterial hypertension, diabetes mellitus, smoking and stroke were comorbidities frequently related. Six patients improved completely after the procedure and one remained with vertigo.