Hyperdense Basilar Artery Sign Research Articles

The Role of Hyperdense Basilar Artery Sign in Predicting Outcome of Acute Basilar Artery Occlusion within Twelve Hours of Onset

The correlation between hyperdense basilar artery sign (HDBAS) and outcome after acute basilar artery occlusion (ABAO) is debated. Our objective was to determine the usefulness of HDBAS in predicting the outcomes of patients with ABAO after endovascular treatment (EVT), intravenous thrombolysis (IVT), and best medical treatment (BMT). The study's participants were selected from the ATTENTION trial. The study's primary outcome was a 90-day modified Rankin Scale (mRS) score, and the secondary outcome was the recanalization rate, any intracranial hemorrhage, and 90-day mortality. The study comprised 276 participants, with cohorts for EVT (N=188), IVT (N=82), and BMT (N=88). In EVT cohort, the HDBAS was not associated with 90-day mRS (adjusted OR, 0.87; 95% CI, 0.51-1.48; P=0.6029), the recanalization after 24 hours of onset (adjusted OR, 0.76; 95% CI, 0.30-3.61; P=0.9422), and 90-day mortality (adjusted OR, 0.77; 95% CI, 0.41-1.46; P=0.4238). In IVT cohort, the HDBAS was not associated with 90-day mRS (adjusted OR, 0.69; 95% CI, 0.31-1.56; P=0.3742), the recanalization after 24 hours of onset (adjusted OR, 2.24; 95% CI, 0.47-10.78; P=0.3132), and 90-day mortality (adjusted OR, 0.64; 95% CI, 0.26-1.57; P=0.3264). Similarly, in BMT cohort, the HDBAS was not associated with 90-day mRS (adjusted OR, 1.11; 95% CI, 0.47-2.63; P=0.8152), the recanalization after 24 hours of onset (adjusted OR, 1.27; 95% CI, 0.40-4.02; P=0.6874), and 90-day mortality (adjusted OR, 1.17; 95% CI, 0.46-2.96; P=0.748). The HDBAS may not be a reliable predictor of outcomes for patients with ABAO, regardless of whether they received EVT, IVT, or BMT.

Multi-territorial posterior circulation ischemic stroke after cocaine intoxication.

A 35-year-old man presented to the emergency department with altered mental status and bilateral tonicclonic seizures. Due to a progressive decrease in consciousness, he was intubated for airway protection. The patient’s relatives reported that he had used cocaine, leading to an initial suspicion of acute cocaine intoxication. However, a head CT scan without contrast revealed a hyperdense basilar artery sign without other signs of infarction (figure 1).

Hyperdense Artery Sign and Clinical Outcomes After Endovascular Treatment in Acute Basilar Artery Occlusion

BackgroundThis study aimed to investigate the association between the hyperdense basilar artery sign (HBAS) on non-enhanced computed tomography (CT) and clinical outcomes in patients with acute basilar artery occlusion (BAO) who underwent endovascular treatment (EVT).MethodsEligible patients who underwent EVT due to acute BAO between January 2014 and May 2019 were divided into two groups based on HBAS. HBAS was assessed by two neuroradiologists using five grades on nonenhanced CT. The primary outcome was a favorable functional outcome (defined as a modified Rankin Scale [mRS] of 0–3) at 90 days. Secondary outcomes included successful recanalization and mortality within 90 days.ResultsAmong 829 patients with BAO as assessed with CT angiography, magnetic resonance angiography, or digital subtraction angiography, 643 patients were treated with EVT. Of these, 51.32% (330/643) had HBAS. Patients with HBAS were older and had more severe neurological deficits and a higher frequency of atrial fibrillation than those without HBAS. There was no significant difference in favorable outcome (adjusted odds ratio [aOR]: 1.354, 95% confidence interval [CI]: 0.906–2.024; p = 0.14), successful recanalization (aOR: 0.926, 95% CI: 0.616-−1.393; p = 0.71), and mortality (aOR: 1.193, 95% CI: 0.839–1.695; p = 0.33) between patients with or without HBAS. Subgroup analysis showed that the HBAS predicted a favorable outcome in patients aged <60 years (aOR: 2.574, 95% CI: 1.234–5.368; p = 0.01) and patients with vertebral artery-V4 segment occlusion (aOR: 3.738, 95% CI: 1.212–11.530; p = 0.02). In patients with HBAS, the baseline National Institutes of Health Stroke Scale (NIHSS) score, posterior circulation–Acute Stroke Prognosis Early Computed Tomography Score (pc-ASPECTS), and stent retriever were associated with successful recanalization.ConclusionsOur study did not find a significant association between HBAS and favorable outcomes and successful recanalization in patients with BAO who underwent EVT. Moreover, large prospective studies are warranted to further investigate this relationship.

A big white dot after CPR

IntroductionPatients may remain comatose after the resumption of spontaneous circulation with cardiopulmonary resuscitation. A primary neurologic event may precede a cardiac standstill.Case reportWe present a 33-year-old patient with successful resuscitation for pulseless electrical activity and a “normal computed tomography (CT) scan.” Further scrutiny showed a hyperdense basilar artery sign (‘big white dot’) that led to a CT angiogram confirming an embolus to the proximal basilar artery. His examination showed fixed and dilated midsize (mesencephalic) pupils and extensor posturing. Endovascular retrieval of the clot was successful, but there was a devastating ischemic injury to the brainstem.ConclusionThis case reminds us to consider neurologic causes of cardiac arrest.

Diagnostic and prognostic computed tomography imaging markers in basilar artery occlusion (Review).

Acute ischemic stroke treatment has been revolutionized by the addition of mechanical and aspiration thrombectomy. Randomized controlled trials have proven beyond doubt, the substantial clinical impact of endovascular interventions in anterior circulation territory strokes. Unfortunately, patients with vertebrobasilar ischemic stroke could not be included in these early trials due to inherent clinical, radiological, and prognostic particularities of posterior circulation ischemia; thus, indications for the treatment of posterior fossa strokes and basilar artery occlusion (BAO) are mainly based on retrospective studies and registries. BAO carries high morbidity and mortality, despite the new improvements in endovascular therapy. Identifying patients who will likely benefit from invasive treatment and have a good clinical outcome resides in discovering clinical, biological, or imaging markers, that have prognostic implications. Such imaging markers have been described, especially in the last decade. Hyperdense Basilar Artery Sign (HDBA), Posterior Circulations-Alberta Stroke Program Early CT Score (pc-ASPECTS), Pons-Midbrain Index (PMI), Posterior Circulation Collateral Score (pc-CS), Posterior Circulation CT Angiography Score (pc-CTA), and Basilar Artery on CT Prognostic Score (BATMAN), are computed tomography (CT) markers with properties that can aid the diagnosis of BAO and can independently predict clinical outcome. This paper aims to present a comprehensive review of these imaging signs to have a thorough understanding of their diagnostic and prognostic attributes.

Assessment of Vessel Density on Non-Contrast Computed Tomography to Detect Basilar Artery Occlusion.

IntroductionBasilar artery occlusion (BAO) may be clinically occult due to variable and non-specific symptomatology. We evaluated the qualitative and quantitative determination of a hyperdense basilar artery (HDBA) on non-contrast computed tomography (NCCT) brain for the diagnosis of BAO.MethodsWe conducted a case control study of patients with confirmed acute BAO vs a control group of suspected acute stroke patients without BAO. Two EM attending physicians, one third-year EM resident, and one medical student performed qualitative and quantitative assessments for the presence of a HDBA on axial NCCT images. Our primary outcome measures were sensitivity and specificity for BAO. Our secondary outcomes were inter-rater and intra-rater reliability of the qualitative and quantitative assessments.ResultsWe included 60 BAO and 65 control patients in our analysis. Qualitative assessment of the hyperdense basilar artery sign was poorly sensitive (54%–72%) and specific (55%–89%). Quantitative measurement improved the specificity of hyperdense basilar artery assessment for diagnosing BAO, with a threshold of 61.0–63.8 Hounsfield units demonstrating relatively high specificity of 85%–94%. There was moderate inter-rater agreement for the qualitative assessment of HDBA (Fleiss’ kappa statistic 0.508, 95% confidence interval: 0.435–0.581). Agreement improved for quantitative assessments, but still fell in the moderate range (Shrout-Fleiss intraclass correlation coefficient: 0.635). Intra-rater reliability for the quantitative assessments of the two attending physician reviewers demonstrated substantial consistency.ConclusionOur results highlight the importance of carefully examining basilar artery density when interpreting the NCCT of patients with altered consciousness or other signs and symptoms concerning for an acute basilar artery occlusion. If the Hounsfield unit density of the basilar artery exceeds 61 Hounsfield units, BAO should be highly suspected.

The hyperdense basilar artery sign: a case of locked-in syndrome.

BackgroundLocked-in syndrome, although a notoriously famous clinical entity, the rarity of the condition coupled with the variability of clinical features on acute presentation represents a potential diagnostic pitfall for the emergency physician.CaseA previously healthy 25-year-old female was brought to our Emergency Department after being found unresponsive. On examination, she was conscious and alert with a Glasgow Coma Score of 9; on neurological examination, the patient was quadriplegic and unable to speak but was able to move her eyes and blink. Non-contrast brain computed tomography (CT) revealed a hyperdense basilar artery, and CT cerebral angiography confirmed basilar artery thrombosis.ConclusionThis case highlights the need for a high index of suspicion to make a diagnosis of locked-in syndrome in the Emergency Department, especially in young patients with no apparent risk factors for an ischemic stroke. The hyperdense basilar artery sign is one of the earliest signs on non-contrast CT imaging and may be the only clue to guide further management in a patient with basilar artery occlusion.

Sensitivity of Hyperdense Basilar Artery Sign on Non-Enhanced Computed Tomography.

PurposeThe hyperdense basilar artery sign (HBAS) is an indicator of vessel occlusion on non contrast-enhanced computer tomography (NECT) in acute stroke patients. Since basilar artery occlusion (BAO) is associated with a high mortality and morbidity, its early detection is of great clinical value. We sought to analyze the influence of density measurement as well as a normalized ratio of Hounsfield unit/hematocrit (HU/Hct) ratio on the detection of BAO on NECT in patients with suspected BAO.Materials and Methods102 patients with clinically suspected BAO were examined with NECT followed immediately by Multidetector computed tomography Angiography. Two observers independently analyzed the images regarding the presence or absence of HBAS on NECT and performed HU measurements in the basilar artery. Receiver operating characteristic curve analysis was performed to determine the optimal density threshold for BAO using attenuation measurements or HU/Hct ratio.ResultsSensitivity of visual detection of the HBAS on NECT was relatively low 81% (95%-CI, 54–95%) while specificity was high 91% (95%-CI, 82–96%). The highest sensitivity was achieved by the combination of visual assessment and additional quantitative attenuation measurements applying a cut-off value of 46.5 HU with 94% sensitivity and 81% specificity for BAO. A HU/Hct ratio >1.32 revealed sensitivity of 88% (95%-CI, 60–98%) and specificity of 84% (95%-CI, 74–90%).ConclusionIn patients with clinically suspected acute BAO the combination of visual assessment and additional attenuation measurement with a cut-off value of 46.5 HU is a reliable approach with high sensitivity in the detection of BAO on NECT.

Abstract T P43: Hyperdense Basilar Artery (HDBA) Sign: Its Association With Clinical Signs, Symptoms And Outcome Of Posterior Circulation Ischemic Stroke

Background and purpose: Posterior circulation ischemic stroke is a clinical syndrome associated with ischemia related to stenosis, in situ thrombosis, or embolic occlusion of the posterior circulation arteries - the vertebral arteries, basilar, posterior cerebral arteries, and their branches. In order to reach the definite diagnosis, different imaging methods can be used, such as CT (computed tomography) and MRI (magnetic resonance imaging), or by conventional angiography. Hyperdense Basilar artery (HDBA) is a radiologic sign seen on unenhanced computed tomography scan suggestive of an early ischemic stroke. In a hospital facility that lacks advancement in neuroimaging, evaluating HDBA sign on unenhanced cranial CT scan can help clinicians in the diagnosis of posterior circulation ischemic stroke. Methods: A total of 67 subjects were included in the study. Medical records and neuroimaging of patients with a final diagnosis of posterior circulation ischemic stroke were retrieved. The radiologist who read the Cranial CT Scan was blinded as to the clinical signs, symptoms, and outcome of our subjects. All neuroimaging were reviewed as to location of the posterior circulation infarction, and for presence or absence of HDBA sign. Results: There were higher proportions with cerebellar signs and quadriplegia among those with positive HDBA sign, and a higher proportion with ocular signs among those with negative HDBA sign. However, we found no significant statistical difference (P=0.185). Location of infarction (P=0.363), baseline NIHSS (p=0.307), MRS on discharge (P=0.938), and timing of neuroimaging (P=0.227) were also not statistically significant. A positive HDBA sign had low sensitivity (54%), specificity (43%) and positive predictive value (16%). However, it had a high negative predictive value which means that among those found without an HDBA sign, 83% are likely to survive. Conclusion: There is no significant association between HDBA sign and clinical findings among patients with a posterior circulation ischemic stroke. Among those found with a positive HDBA sign, there is high likelihood for the presence of infarction and for those with a negative HDBA sign, a higher likelihood for survival.

Hyperdense Basilar Artery Sign: An Indicator of Basilar Artery Thrombosis

Posterior circulation is a vital area of brain blood supply and stroke in this territory could be fatal or result in severe disability. Many patients have preceding symptoms (vertigo or head ache) 2 weeks before [1]. Although brain CT scan is a rapid standard method to detect infarction after the first presentations, because of bony structures and artifacts, it is less sensitive for the posterior fossa and brain stem parenchyma. As brain MRI or brain vessels imaging (CTA, MRA) are not easily available tools for patients’ evaluation, fine informative changes on brain CT scan contributes to physicians’ early and more effective intervention. Hyperdense basilar artery sign is a sign of basilar artery thrombosis or embolism that predicts basilar territory infarction [2]. Here, we describe a 70 year-old lady who was referred to the hospital with sudden impaired level of consciousness. One day before, she had developed the right upper limb weakness and slurred speech and in the previous week she had new onset of headache and vertigo. Past medical history was consistent with ischemic heart disease and previous ischemic stroke 2 years ago. Brain CT showed hyper-dense signal change in the basilar artery indicative of basilar artery thrombosis and pons infarction (Figure 1a and 1b). Impaired blood supply of the basilar artery causes devastating results and by the time the stroke develops, it is too late to approach appropriately. Non- enhanced brain CT scan is a very useful tool for early evaluation of patients with acute infarction; however, in the brain stem area and for basilar artery territory, it has some limitations because of bony artifacts in the skull base and most of the time further modalities are needed to document brain stem ischemia. So rapid and correct diagnosis just based on non-enhanced CT scan is sometimes a challenge especially for inexperienced physician.

Hyperdense basilar artery sign—a reliable sign of basilar artery occlusion

We aimed to investigate the value of the hyperdense basilar artery (HBA) sign and of basilar artery (BA) attenuation measurements as predictors of basilar artery occlusion (BAO) on nonenhanced cranial CT (NECT). Forty-one consecutive patients with proven BAO in CT angiography, who had undergone NECT for initial evaluation (30 males, 11 females) were retrospectively included. Another 41 age-matched patients without BAO were included as a control group. The NECT scans of both groups were assessed by three independent blinded readers (staff, fellow, and resident) in a randomized reading order using a standardized semiquantitative questionnaire. Visual BA hyperdensity, including the presence of HBA sign (hyperdensity scores of 4 and 5/5), was assessed, quantitative BA attenuation was measured in a region of interest (ROI), and diagnosis of BAO was made before and after ROI measurements. For statistical analysis, multivariate mixed effects models, likelihood ratio tests, and receiver operating characteristics techniques were applied. HBA sign had a relatively low sensitivity (60.98-65.85%), specificity (70.73-90.24%), and accuracy (65.85-75.61%) for the presence/absence of BAO on NECT. Optimal cut-off points were 40-42 HU (sensitivity, 68.29-78.05%; specificity, 75.61-82.93%; accuracy, 74.39-80.49%). In basilar artery occlusion, quantitative measurement of BA attenuation can slightly improve the diagnostic predictiveness of NECT. However, even with optimal cut-off values, the sensitivity is too low to serve as the sole diagnostic decision-making tool.

Hyperdense basilar artery sign diagnoses acute posterior circulation stroke and predicts short-term outcome

It is well established that the hyperdense middle cerebral artery sign is a specific marker for early ischemia in anterior circulation. However, little is known about the hyperdense basilar artery sign (HDBA) in posterior circulation. Our aim was to determine whether the HDBA sign has utility in early diagnosis of acute posterior circulation stroke and prediction of short-term outcome. Three-blinded readers examined unenhanced computed tomography scans for the HDBA sign, and materials were classified into two groups according to this sign. Vascular risk factors, admission and discharge National Institute of Health Stroke Scale (NIHSS) scores, short-term outcome, and radiological findings between the two groups were compared. One hundred and twenty-six cases of acute posterior circulation stroke (PCS) were included in the study. No statistically significant differences were found in risk factors of ischemic stroke, except atrial fibrillation (P=0.025). Admission and discharge NIHSS scores for the positive HDBA group were significantly higher than scores for the negative HDBA group (P=0.001, 0.002, respectively). The infarction territory for the positive HDBA group was mainly multi-region in nature (51.6%, P<0.001), while the negative HDBA group showed mainly middle territory infarction. Significant independent predictors of short-term outcome included the HDBA sign (P<0.001) and admission NIHSS scores (P<0.001). Approximately half of the HDBA patients showed multi-region infarction and a serious neurological symptom. Based on our results, this sign might not only be helpful in early diagnosis of acute PCS but also be able to correlate with a poor short-term outcome.

Hyperdense Basilar Artery Sign on Unenhanced CT Predicts Thrombus and Outcome in Acute Posterior Circulation Stroke

In acute stroke patients, the presence of a hyperdense middle cerebral artery sign on unenhanced CT is a specific but insensitive indicator of acute thrombosis. Our purpose was to determine whether the hyperdense basilar artery (HDBA) sign has utility in detecting thrombosis and predicting outcome in patients presenting with signs and symptoms of posterior circulation stroke. Unenhanced CT scans obtained within 24 hours of symptom onset in 95 patients with suspected posterior circulation stroke were reviewed. Three neuroimagers blinded to clinical outcome and results of the concurrent CT angiography (which served as the reference standard) rated presence of HDBA sign on a 5-point scale for level of certainty (1=definitely absent; 5=definitely present). Receiver operating characteristic curve analysis was performed. Short-term outcome was measured by discharge National Institute of Health Stroke Scale (NIHSS) scores; long-term outcome was measured by 6-month modified Rankin score (dichotomized, poor outcome defined as modified Rankin score >2). The following variables were correlated with short-term and long-term outcome by univariate analysis: HDBA sign, age, sex, time from stroke onset to imaging, admission NIHSS, history of stroke/TIA, atrial fibrillation, coronary artery disease, hypertension, diabetes, hypercholesterolemia, tobacco use, and thrombolysis. Variables showing correlation with P<0.1 were included in multiple regression analysis. Using a level of certainty cutoff score of >/=4 (probable, definite), HDBA sign had 71% sensitivity, 98% specificity, 94% accuracy, 83% positive predictive value, and 95% negative predictive value for basilar artery occlusion. In univariate analysis, factors significantly correlated with discharge NIHSS were: admission NIHSS (P<0.0001; r=0.77), HDBA sign (P=0.01), and diabetes (P=0.02). Factors showing significant correlation or association with poor long-term outcome were age (P=0.02), admission NIHSS (P=0.007), HDBA sign (P=0.02), and history of stroke or TIA (P=0.007). The odds ratio of HDBA sign for predicting poor long-term outcome was 5.3 (95% CI, 1.1-33.3). In multiple regression analysis, the only independent predictors of discharge NIHSS were admission NIHSS (P<0.0001) and HDBA sign (P=0.004). Significant independent predictors of poor long-term outcome were age (P=0.02), admission NIHSS (P=0.008), history of stroke/TIA (P=0.03), and HDBA sign (P=0.05). In patients presenting with a high pretest probability of posterior circulation stroke based on clinical symptoms, the presence of the HDBA sign on unenhanced CT is a strong predictor of basilar artery thrombosis, and both short- and long-term outcome.

Locked-in or Comatose? Clinical Dilemma in Acute Pontine Infarct

A 50-year-old man presented after acute onset of dysarthria and tetraparesis, rapidly progressing to unresponsiveness. Neurologic examination revealed spontaneous ocular bobbing, pinpoint pupils with normal light response (top), extensor posturing, and bilateral Babinski signs. Loud noises, such as the clapping of hands, elicited a nonreproducible startle response evidenced by spontaneous eye opening. However, there were no eye movements on command. Computed tomography of the brain and magnetic resonance imaging showed evidence of an acute basilar artery thrombosis, also known as a hyperdense basilar artery sign (red arrow) and acute pontine infarction (middle). Electroencephalography showed presence of an α coma (bottom). Electroencephalography was helpful in determining the patient’s level of consciousness. Patients with locked-in syndrome have similar findings on neuroimaging studies, but awareness and eye movements are preserved and become the only means for communication. Electroencephalographic findings of an α coma indicate that the patient had impaired awareness and therefore did not have lockedin syndrome. α Coma after brainstem infarction was first described by Westmoreland et al1 in 1975. Normally, when patients’ eyes are closed, electroencephalography shows α activity in the posterior parts of the brain. In pathologic conditions, α activity emerges over all areas of the brain and remains whether eyes are open or closed. In this patient, coma resulted from a pontine infarction, which destroyed the ascending reticular activating system. Immediate and accurate assessment of consciousness in patients with acute pontine infarct is a very important task for clinicians.

The Hyperdense Posterior Cerebral Artery

In the anterior circulation, the hyperdense middle cerebral artery sign (HMCAS) is a well established marker for early ischemia. Similarly, the hyperdense basilar artery sign may be a diagnostic clue for basilar artery thrombosis. Other hyperdense artery signs have not yet been described. The purpose of this study was to define the hyperdense posterior cerebral artery sign (HPCAS) and determine its incidence, diagnostic value, and reliability as a marker for ischemia in the territory of the posterior cerebral artery (PCA). CCTs of 69 patients with proven acute ischemia in the PCA territory were compared by three independent and blinded readers to the CCTs of 86 age-matched patients without PCA infarction. Using follow-up imaging, the correlation of the HPCAS with infarct size, thalamic infarction and bleeding were investigated. A HPCAS was found in 37.7% of all patients with PCA-infarction, typically within the ambient cistern with a specificity of 95.4%. The thalamus was affected significantly more often (p = 0.03), and the size of the infarct was significantly more often large than medium or small (p = 0.02) when a HPCAS was present. Hemorrhagic transformation tended to occur more often when the HPCAS was present. HPCAS was detected in more than one third of all patients with PCA ischemia, suiting the incidence of the HMCA. Based on our results, this sign may not only be helpful in the early diagnosis of PCA infarction but might also act as a prognostic marker in acute PCA territory ischemic stroke.

The Hyperdense Posterior Cerebral Artery Sign

In the anterior circulation, the hyperdense middle cerebral artery (MCA) sign is a well-established marker for early ischemia. Similarly, the hyperdense basilar artery sign or the MCA "dot" sign may be a diagnostic clue for basilar artery or distal MCA branch thrombosis. The purpose of this study was to define the hyperdense posterior cerebral artery (PCA) sign and determine its incidence, diagnostic value, and reliability as a marker for ischemia in the territory of the PCA. Cranial computed tomographies (CCTs) of 48 patients with proven acute ischemia (<12 hours) in the PCA territory were compared by 3 independent and blinded readers to the CCTs of 86 age-matched patients without PCA infarction. Using follow-up imaging, the correlation of the hyperdense PCA (HPCA) with infarct size, thalamic infarction, and bleeding were investigated. An HPCA was found in 35.4% of all patients with PCA infarction, typically within the ambient cistern, with a specificity of 95.4%. The thalamus was affected significantly more often (P=0.009) and the size of the infarct was significantly more often large than medium (P=0.018) or small (P<0.001) when an HPCA was present. Hemorrhagic transformation tended to occur more often when the HPCA was present. An HPCA was detected in more than one third of all patients with PCA ischemia, suiting the incidence of the hyperdense MCA. Based on our results, this sign may not only be helpful in the early diagnosis of PCA infarction but might also act as a prognostic marker in acute PCA territory ischemic stroke.

Clinical and radiological predictors of recanalisation and outcome of 40 patients with acute basilar artery occlusion treated with intra-arterial thrombolysis

Objective: To define predictors of recanalisation and clinical outcome of patients with acute basilar artery occlusions treated with local intra-arterial thrombolysis (IAT). Methods: Vascular risk factors, severity of the neurological...