Citations

Abstract Neurological instability during the first days following ischemic stroke reflects the potential to salvage brain tissue at risk for infarct growth, hemorrhagic transformation, or malignant edema. However, current clinical care provides intermittent assessments on the order of at least an hour apart potentially missing the early detection of neurological deterioration. Optical imaging offers a continuous, portable alternative to the current combination of physical exams and radiological imaging. However, optical imaging technology has heretofore lacked the crucial combination of portability, resolution, and coverage required for assessing distributed brain function. Here, we present a portable high-density diffuse optical tomography (HD-DOT) system that overcomes these limitations to assess neurological disruption at the bedside. We imaged patients within 72 hours after ischemic stroke onset and demonstrate that HD-DOT is sensitive to both the presence of stoke (Cohen’s d = 1.5, p = 1.2 × 10− 3) as well as the degree of neurological disruption measured by NIH Stroke Scale (R2 = 0.69, p = 4.7 × 10− 4).

ObjectivesSilent cerebral artery vasospasm in aneurysmal subarachnoid hemorrhage causes serious complications such as cerebral ischemia and death. A transcranial Doppler (TCD) ultrasound system is a noninvasive device that can effectively detect cerebral artery vasospasm as soon as it sets in, even before and in the absence of clinical deterioration. Continuous or even daily TCD monitoring is challenging because of the operator expertise and certification required in the form of a trained sonographer and interpretive experience required in the form of an additionally trained and certified physician to perform these studies. This barrier exists because of a lack of automation for detection (without human intervention) of cerebral artery vasospasm using TCD ultrasound. To overcome this barrier, we present an algorithm that automates detection of cerebral artery vasospasm.MethodsWe extracted features such as the energy, energy entropy, zero‐crossing rate, spectral centroid, spectral speed, spectral entropy, spectral flux, spectral roll‐off, harmonic ratio, chroma, and Mel frequency cepstral coefficients for signal classification. Then we applied principal component analysis to reduce the data dimensionality.ResultsAll of the chosen features were used for training a decision‐tree classifier. The algorithm had high accuracy for cerebral artery vasospasm detection, with overall sensitivity of 87.5% and specificity of 89.74%.ConclusionsThe algorithm has the potential for development into a continuous cerebral artery vasospasm monitor.

Introduction: Takayasu arteritis is a large-vessel vasculitis that may cause oculo-cerebral ischemia. We report a patient with visual loss as initial manifestation, and discuss transcranial Doppler (TCD) findings before and after surgical revascularization. Case Description: A 19-year-old female developed episodes of transient positional right vision loss, progressing to permanent right vision loss and bright light-induced left amaurosis. Examination demonstrated subclavian bruits, palpable epigastrium aortic pulsation, faint radial pulses, right retinal pallor, arteriolar narrowing, and bilateral boxcarring. Head and neck computed tomography angiogram demonstrated left subclavian origin and right common carotid artery occlusion, and severe innominate and left common carotid artery stenosis. TCD demonstrated right ophthalmic artery flow reversal and nonpulsatile waveforms with dampened spectra in the right anterior circulation. Corticosteroids, methotrexate, infliximab, and dual-antiplatelet therapy were initiated. Eleven weeks later, the patient underwent ascending aortic aneurysm repair and bilateral carotid artery bypass with an aortic graft. Pathology was consistent with chronic active Takayasu arteritis. Two weeks postoperatively, left eye visual symptoms resolved; right visual loss persisted. Postoperative TCD showed marked improvement in cerebral perfusion. Conclusions: Retinal ischemia in young women should prompt emergent inflammatory and systemic vascular evaluation. In our subject, prolonged right retinal ischemia had dismal prognosis despite carotid-aortic revascularization, whereas left retinal boxcarring reversed. Surgical revascularization is recommended for severely symptomatic oculo-cerebrovascular disease, once inflammation is better controlled with immunosuppressive therapy. TCD documented the presence and monitored the subsequent resolution of blood flow changes causing retinal and brain hypoxia.

Introduction: Despite the recognized linkage between retinal microvascular abnormalities and cerebrovascular ischemic diseases (CVD), the retinal findings’ standardization and the degree of association remain unclear. We aimed to investigate the quantitative association between various retinal microvascular signs and CVD. Hypothesis: retinal microvascular abnormalities best predictive of CVD could be identified by synthesizing estimates of CVD risk from population-based studies. Methods: We followed MOOSE guidelines and systematically searched 6 databases through September 2016 for studies evaluating the association between retinal microvascular abnormalities and white matter hyperintense lesions (WMHI), lacunar infarcts (LI), and cerebral infarctions (CI). Adjusted and unadjusted odds ratios (ORs) and confidence intervals were pooled into the analyses using the DerSimonian and Laird random effects model. Study quality and dissemination biases were assessed and integrated. Results: Thirty-four prospective studies encompassing 84,144 patients were eligible for meta-analysis. After adjustment for vascular risk factors, focal arteriolar narrowing was associated with WMHI (OR, 1.24 [1.01-1.79]), LI (OR, 1.77 [1.14-2.74]), and CI (OR, 1.75 [1.14-2.69]). Venular dilation was significantly associated with LI (OR, 1.46 [1.10-1.93]), whereas retinal hemorrhage was associated with WMHI (OR, 2.23 [1.34-3.70]). Arteriovenous nicking was associated with WMHI (OR, 1.51 [1.22-1.88]) and LI (OR, 1.70 [1.05-2.76]). Any retinopathy exhibited significant association with WMHI, LI, and CI. Heterogeneity was significant ( I 2 >50%) for all syntheses except retinal hemorrhages and WMHI, retinopathy and CI ( I 2 =0.0%) and respectively LI ( I 2 =45.80%). Conclusions: Retinal hemorrhages were most highly associated with WMHI. Focal arteriolar narrowing and retinopathy were associated with WMHI, LI, and CI. Our findings may assist in the development of a noninvasive retinal microvascular tool for routine use in CVD research and clinical practice.

Background: Control of systolic blood pressure (SBP) after primary intracerebral hemorrhage improves outcomes. Factors determining the number of blood pressure medications (BPM) required for goal SBP<160 mm Hg at discharge are unknown. We hypothesized that higher admission-SBPs require a greater number of BPM for goal discharge-SBP<160 mm Hg, and investigated factors influencing this goal. Materials and Methods: We conducted a retrospective review of 288 patients who presented with primary intracerebral hemorrhage. Admission-SBP was obtained. Primary outcome was the number of BPM at discharge. Comparison was made between patients presenting with and without a history of hypertension, and patients discharged on <3 and ≥3 BPM. Results: Patients with hypertension history had a higher median admission-SBP compared with those without (180 vs. 157 mm Hg, P=0.0001). In total, 133 of 288 (46.2%) patients were discharged on <3 BPM; 155/288 (53.8%) were discharged on ≥3 BPM. Hypertension history (P<0.0001) and admission-SBP (P<0.0001) predicted the number of BPM at discharge. In patients without hypertension history, every 10 mm Hg increase in SBP resulted in an absolute increase of 0.5 BPM at discharge (P=0.0011), whereas in those with hypertension, the absolute increase was 1.3 BPM (P=0.0012). In comparison with patients discharged on <3 BPM, patients discharged on ≥3 BPM were more likely to have a higher median admission-SBP, be younger in age, belong to the African-American race, have a history of diabetes, have higher median admission–National Institutes of Health Stroke Scale and modified Rankin Scale of 4 to 5 at discharge. Conclusions: An understanding of the factors influencing BPM at discharge may help clinicians better optimize blood pressure control both before and after discharge.

Introduction: Major surgery in the past 14 days is a relative contraindication to treatment of acute stroke with intravenous (IV) alteplase. The 2016 American Heart Association/American Stroke Association scientific statement discussing inclusion and exclusion criteria for alteplase in acute stroke allows for provider judgment citing a lack of evidence to support surgery as an absolute contraindication. Case Report: A 59-year-old woman presented with acute left hemiparesis, dysarthria, and acute respiratory failure. National Institutes of Health Stroke Scale was 17. Two days prior she underwent abdominoplasty and liposuction. Computed tomography angiogram of the head demonstrated acute occlusion of right M2, and computed tomography angiogram of the chest was positive for bilateral pulmonary emboli. After urgent consultation with the plastic surgery and neurosurgery teams, the patient was treated with IV alteplase followed by cerebral mechanical thrombectomy. This was complicated by surgical-site hemorrhage in the abdomen requiring operative intervention. Abdominal hemorrhage was controlled and the patient showed remarkable neurological recovery, later being discharged with no residual neurological deficits. Conclusions: Interdisciplinary collaboration can successfully inform the decision to treat acute ischemic stroke with IV alteplase in the setting of recent major surgery.

Background and Purpose— Meta-analyses of extant genome-wide data illustrate the need to focus on subtypes of ischemic stroke for gene discovery. The National Institute of Neurological Disorders and Stroke SiGN (Stroke Genetics Network) contributes substantially to meta-analyses that focus on specific subtypes of stroke. Methods— The National Institute of Neurological Disorders and Stroke SiGN includes ischemic stroke cases from 24 genetic research centers: 13 from the United States and 11 from Europe. Investigators harmonize ischemic stroke phenotyping using the Web-based causative classification of stroke system, with data entered by trained and certified adjudicators at participating genetic research centers. Through the Center for Inherited Diseases Research, the Network plans to genotype 10 296 carefully phenotyped stroke cases using genome-wide single nucleotide polymorphism arrays and adds to these another 4253 previously genotyped cases, for a total of 14 549 cases. To maximize power for subtype analyses, the study allocates genotyping resources almost exclusively to cases. Publicly available studies provide most of the control genotypes. Center for Inherited Diseases Research–generated genotypes and corresponding phenotypes will be shared with the scientific community through the US National Center for Biotechnology Information database of Genotypes and Phenotypes, and brain MRI studies will be centrally archived. Conclusions— The Stroke Genetics Network, with its emphasis on careful and standardized phenotyping of ischemic stroke and stroke subtypes, provides an unprecedented opportunity to uncover genetic determinants of ischemic stroke.