Developing Systems of Care for Stroke in Resource-limited Settings.

Although stroke prevention and treatment strategies have significantly advanced in recent years, implementation of these care elements in resource-limited settings can be challenging, since the burden of stroke is higher and access to stroke care is lower. Barriers to stroke care in resource-limited settings include insufficient prevention, reduced awareness of stroke symptoms, limited prehospital care and lack of triage systems, limited access to comprehensive stroke centers, inadequate personnel education, lack of staff and resources, as well as limited access to neuroimaging, thrombolytics, mechanical thrombectomy, neurosurgical care, and rehabilitation. Here, we suggest strategies to improve stroke care in these settings, including public health campaigns, protocols for prehospital notification, organized flow to specialized stroke centers, development of dedicated stroke units, and utilization of telemedicine and telerehabilitation. We also highlight the role of international organizations and governments in reducing the global burden of stroke.

Multimodal monitoring intracranial pressure by invasive and noninvasive means.

Although the placement of an intraventricular catheter remains the gold standard method for the diagnosis of intracranial hypertension (ICH), the technique has several limitations including but not limited to its invasiveness. Current noninvasive methods, however, still lack robust evidence to support their clinical use. We aimed to estimate, as an exploratory hypothesis generating analysis, the discriminative power of four noninvasive methods to diagnose ICH. We prospectively collected data from adult intensive care unit (ICU) patients with subarachnoid hemorrhage (SAH), intraparenchymal hemorrhage (IPH), and ischemic stroke (IS) in whom invasive intracranial pressure (ICP) monitoring had been placed. Measures were simultaneously collected from the following noninvasive methods: optic nerve sheath diameter (ONSD), pulsatility index (PI) using transcranial Doppler (TCD), a 5-point visual scale designed for brain Computed Tomography (CT), and two parameters (time-to-peak [TTP] and P2/P1 ratio) of a noninvasive ICP wave morphology monitor (Brain4Care[B4c]). ICH was defined as a sustained ICP > 20 mmHg for at least 5 min. We studied 18 patients (SAH = 14; ICH = 3; IS = 1) on 60 occasions with a mean age of 52 ± 14.3 years. All methods were recorded simultaneously, except for the CT, which was performed within 24 h of the other methods. The median ICP was 13 [9.8-16.2] mmHg, and intracranial hypertension was present on 18 occasions (30%). Median values from the noninvasive techniques were ONSD 4.9 [4.40-5.41] mm, PI 1.22 [1.04-1.43], CT scale 3 points [IQR: 3.0], P2/P1 ratio 1.16 [1.09-1.23], and TTP 0.215 [0.193-0.237]. There was a significant statistical correlation between all the noninvasive techniques and invasive ICP (ONSD, r = 0.29; PI, r = 0.62; CT, r = 0.21; P2/P1 ratio, r = 0.35; TTP, r = 0.35, p < 0.001 for all comparisons). The area under the curve (AUC) to estimate intracranial hypertension was 0.69 [CIs = 0.62-0.78] for the ONSD, 0.75 [95% CIs 0.69-0.83] for the PI, 0.64 [95%Cis 0.59-069] for CT, 0.79 [95% CIs 0.72-0.93] for P2/P1 ratio, and 0.69 [95% CIs 0.60-0.74] for TTP. When the various techniques were combined, an AUC of 0.86 [0.76-0.93]) was obtained. The best pair of methods was the TCD and B4cth an AUC of 0.80 (0.72-0.88). Noninvasive technique measurements correlate with ICP and have an acceptable discrimination ability in diagnosing ICH. The multimodal combination of PI (TCD) and wave morphology monitor may improve the ability of the noninvasive methods to diagnose ICH. The observed variability in non-invasive ICP estimations underscores the need for comprehensive investigations to elucidate the optimal method-application alignment across distinct clinical scenarios.

Vasoconstriction and long-term headache in reversible cerebral vasoconstriction syndrome.

BACKGROUND: Angiographic vasoconstriction in reversible cerebral vasoconstriction syndrome (RCVS) is often undetectable at symptom onset and the diagnosis relies on clinical presentation. Although thunderclap headache is a hallmark feature of RCVS, the incidence and predictors of long-term headaches (LTH) are incompletely understood. Our study aims were twofold: to examine the sensitivity and specificity of a recently developed score (RCVS2) for vasoconstriction detection in a real-world clinical context and describe the incidence and predictors of LTH beyond the acute phase of RCVS. METHODS: Retrospective analysis of consecutive patients with clinical diagnosis of RCVS in a tertiary hospital between 2017 and 2021. We examined associations between demographic factors, comorbidities, medications, imaging characteristics, and LTH (defined as at least one episode present at greater than 6-months follow-up necessitating medication). We separately examined the association between RCVS2 score and angiographic vasoconstriction and computed its sensitivity, specificity, and negative and positive predictive value based on established cutoffs (certain ≥ 5, negative ≤ 2). RESULTS: We included 55 patients, 50.5 (± 13.7) years; 41 (75%) female. 25 (49%) patients had LTH; only prior history of headache was significantly associated with LTH [OR 4.3, 95% CI (1.1-16.2), p = 0.03]. We found a significant association between RCVS2 score and angiographic vasoconstriction [OR 1.49, 95% CI (1.18-1.88), p = 0.001]; sensitivity, specificity, and positive and negative predictive value were 64%, 94%, 95% and 58% respectively. CONCLUSIONS: Approximately 50% of RCVS patients experienced LTH; only prior headache history was associated with its incidence. The RCVS2 score had a significant association with high specificity and positive predictive value for angiographic vasoconstriction in our cohort, validating its utility in improving the accuracy of diagnosis in the clinical setting.

Waveform Morphology as a Surrogate for ICP Monitoring: A Comparison Between an Invasive and a Noninvasive Method.

BACKGROUND: Although the placement of an intraventricular catheter remains the gold standard technique for measuring intracranial pressure (ICP), the method has several limitations. Therefore, noninvasive alternatives to ICP (ICPni) measurement are of great interest. The main objective of this study was to compare the correlation and agreement of wave morphology between ICP (standard intraventricular ICP monitoring) and a new ICPni monitor in patients admitted with stroke. The second objective was to estimate the discrimination of the noninvasive method to detect intracranial hypertension. METHODS: We prospectively collected data of adults admitted to an intensive care unit with subarachnoid hemorrhage, intracerebral hemorrhage, or ischemic stroke in whom an invasive ICP monitor was placed. Measurements were simultaneously collected from two parameters [time-to-peak (TTP) and the ratio regarding the second and first peak of the ICP wave (P2/P1 ratio)] of ICP and ICPni wave morphology monitors (Brain4care). Intracranial hypertension was defined as an invasively measured sustained ICP > 20 mm Hg for at least 5 min. RESULTS: We studied 18 patients (subarachnoid hemorrhage = 14; intracerebral hemorrhage = 3; ischemic stroke = 1) on 60 occasions with a median age of 52 ± 14.3 years. A total of 197,400 waves (2495 min) from both ICP (standard ICP monitoring) and the ICPni monitor were sliced into 1-min-long segments, and we determined TTP and the P2/P1 ratio from the mean pulse. The median invasively measured ICP was 13 (9.8-16.2) mm Hg, and intracranial hypertension was present on 18 occasions (30%). The correlation and agreement between invasive and noninvasive methods for wave morphology were strong for the P2/P1 ratio and moderate for TTP using categoric (κ agreement 88.1% and 71.3%, respectively) and continuous (intraclass correlation coefficient 0.831 and 0.584, respectively) measures. There was a moderate but significant correlation with the mean ICP value (P2/P1 ratio r = 0.427; TTP r = 0.353; p < 0.001 for all) between noninvasive and invasive techniques. The areas under the curve to estimate intracranial hypertension were 0.786 [95% confidence interval (CI) 0.72-0.93] for the P2/P1 ratio and 0.694 (95% CI 0.60-0.74) for TTP. CONCLUSIONS: The new ICPni wave morphology monitor showed a good agreement with the standard invasive method and an acceptable discriminatory power to detect intracranial hypertension. Clinical trial registration Trial registration: NCT05121155.

Cerebral Microembolism in Intracerebral Hemorrhage: A Prospective Case-Control Study.

BACKGROUND: Small and remote acute ischemic lesions may occur in up to one-third of patients with spontaneous intracerebral hemorrhage (ICH). Possible mechanisms include cerebral embolism, small vessel disease, blood pressure variability and others. The embolic mechanism has not been adequately studied. Using transcranial Doppler (TCD), we assessed the incidence of spontaneous microembolic signals (MESs) in patients with acute ICH. METHODS: Twenty acute ICH patients were prospectively evaluated within 48 h of hospital admission. Clinical and imaging data were collected. Continuous TCD monitoring was performed in both middle cerebral arteries for a one-hour period on days 1, 3 and 7 of hospital admission. Monitoring was performed in the emergency room, ICU or ward, according to patient location. We compared the frequency and risk factors for MES in patients with ICH and in 20 age- and gender-matched controls without history of ischemic or hemorrhagic stroke. RESULTS: The mean age was 57.5 ± 14.1 years, and 60% were male. MESs were detected in 7 patients with ICH and in one control patient without ICH (35% vs 5%, p = 0.048). The frequency of MES on day 1 was 15% (3 of 20 patients), on day 3, 26% (5 of 19 patients) and on day 7, 37.5% (3 of 8 patients). Among patients with ICH, those with MES had a tendency to higher frequencies of dyslipidemia (83% vs 33%, p = 0.13) and lobar location of hemorrhages (71% vs 30%, p = 0.15). Two out of 6 patients with ICH who also underwent MRI had remote DWI lesions, of whom one showed MES on TCD. CONCLUSION: Micro-embolic signals occur in over one-third of patients with ICH. Further research is needed to identify the sources of cerebral microembolism and their relationship with small acute infarcts in ICH.

Intracerebral hemorrhage: update and future directions.

Intracerebral hemorrhage (ICH), defined as bleeding into the brain parenchyma, is a significant public health issue. Although it accounts for only 10 to 15% of strokes, it is associated with the highest morbidity and mortality rates. Despite advances in the field of stroke and neurocritical care, the principles of acute management have fundamentally remained the same over many years. The main treatment strategies include aggressive blood pressure control, early hemostasis, reversal of coagulopathies, clot evacuation through open surgical or minimally invasive surgical techniques, and the management of raised intracranial pressure.

Subdural Hematoma: Predictors of Outcome and a Score to Guide Surgical Decision-Making.

OBJECTIVE: There is little evidence to guide patient selection for subdural hemorrhage (SDH) evacuation. This study was designed to assess the benefit of surgical evacuation of SDH, identify predictors of functional outcome, and create a bedside score to guide the clinical management of SDH. METHODS: A cohort of 331 patients presenting to a single center from 2010 to 2014 with a principal diagnosis of subdural hemorrhage was identified. Clinical and radiographic information were extracted from the medical record. Outcomes of interest were (1) the occurrence of surgical evacuation of SDH, and (2) an unfavorable 90-day functional status represented by a modified Rankin score (mRS) ≥ 3. Propensity score matching and adjustment techniques were employed to assess the benefit of surgery accounting for confounding by indication. Multivariable logistic regression models predicting follow-up functional outcome were generated and bootstrapped separately among those with acute SDH and those with either subacute or chronic SDH. Clinical scores were created using model coefficients. RESULTS: In this cohort [65% male, mean age 67 years], 47% underwent surgery. Age, focal neurologic deficit, SDH thickness > 10 mm, midline shift > 5mm, and SDH acuity predicted undergoing surgery. Propensity score matching analysis demonstrated that operated patients overall were less likely to have unfavorable 90-day mRS outcome (OR 0.35, 95% C.I. 0.15-0.82). Among patients with acute SDH, age, female sex, pre-admission mRS, focal neurologic deficit, and neuropsychiatric symptoms predicted 90-day functional outcome (c-statistic 0.89, optimism-corrected c-statistic 0.87) and were incorporated into an acute SDH score (range 1-10). Patients with SDH score > 4 were significantly more likely to have an unfavorable outcome if treated medically versus surgically; there was no difference in 90-day functional status by treatment strategy among patients with SDH score ≤ 4. No difference in outcome was seen by surgical status across the spectrum of chronic SDH scores. CONCLUSIONS: Surgical evacuation of subdural hematomas overall is associated with favorable outcome. Patient selection for evacuation is enhanced by the application of the acute SDH score. Future studies are necessary to validate the SDH score in an external cohort.

Intracerebral hemorrhage: update and future directions / Hemorragia intracerebral: atualização e direções futuras

ABSTRACT Intracerebral hemorrhage (ICH), defined as bleeding into the brain parenchyma, is a significant public health issue. Although it accounts for only 10 to 15% of strokes, it is associated with the highest morbidity and mortality rates. Despite advances in the field of stroke and neurocritical care, the principles of acute management have fundamentally remained the same over many years. The main treatment strategies include aggressive blood pressure control, early hemostasis, reversal of coagulopathies, clot evacuation through open surgical or minimally invasive surgical techniques, and the management of raised intracranial pressure.

RESUMO A hemorragia cerebral é definida como um sangramento no parênquima cerebral e representa um importante problema de saúde pública. Ela corresponde a 10 a 15% das causas de AVC e está associada a altas taxas de morbimortalidade. Apesar dos avanços no campo do AVC e dos cuidados neurocríticos, os princípios do manejo agudo permaneceram fundamentalmente os mesmos por muitos anos. As principais estratégias de tratamento incluem controle agressivo da pressão arterial, hemostasia precoce, reversão de coagulopatias, evacuação do coágulo por meio de técnicas cirúrgicas abertas ou cirúrgicas minimamente invasivas e gerenciamento da pressão intracraniana elevada.

Testing the applicability of dendrochemistry using X-ray fluorescence to trace environmental contamination at a glassworks site.

The potential of dendrochemistry as a tool for tracing anthropogenic contamination at a glassworks site in southeastern Sweden was investigated through a multidisciplinary approach combining continuous high-resolution time series of tree rings and sediment profiles. Tree cores from Scots pine (Pinus sylvestris), Norway spruce (Picea abies) and European aspen (Populus tremula) were analysed for their elemental composition using an energy dispersive X-ray fluorescence (ED-XRF) technique. Sediment cores were sampled along a transect extending from the pollution point source to unpolluted areas and analysed using core-scanning-XRF (CS-XRF). High contaminant concentrations in the soil were found for As (≈2000 ppm), Pb (>5000 ppm), Ba (≈1000 ppm) and Cd (≈150 ppm). The concentrations decreased with depth and distance from the pollution source. The dendrochemical analyses revealed alterations in the Barium, Chlorine and Manganese profiles, allowing the identification of seven potential asynchronous releases from the glassworks. Our results suggest that differences in the response of tree species to elemental uptake together with soil chemical properties dictate the success of dendrochemistry as an environmental monitoring tool.

Premature vascular disease in young adult stroke: a pathology-based case series.

INTRODUCTION: The prevalence of modifiable vascular risk factors is increasing in young adults and may contribute to the growing frequency of stroke in this population. The neuropathology and end-organ damage profile of young adult stroke patients with clinically advanced atherosclerosis or arteriosclerosis has not been studied. METHODS: This retrospective study included patients aged 18-60 years admitted to our hospital from 1995 to 2017 with recurrent ischemic or hemorrhagic strokes, fatal stroke, or stroke associated with advanced small vessel disease (SVD) on brain MRI, who had no evidence for structural, genetic, inflammatory, or infectious etiology for stroke, and had adequate pathological materials available for analysis. The presence of atherosclerosis, arteriolosclerosis, left ventricular hypertrophy, and nephrosclerosis was evaluated. RESULTS: Twelve patients (mean age 47 ± 9 years, range 31-57 years, 67% male) met inclusion criteria. Four had fatal intracerebral hemorrhage (ICH), three had recurrent non-fatal ICH, one had ICH with advanced SVD on MRI, and four had recurrent ischemic strokes including two with transient ischemic attacks. Pathological studies showed moderate/severe atherosclerosis in 64% and moderate/severe arteriolosclerosis in 42% of patients. Pathological data to evaluate end-organ damage were available for nine patients; eight showed left ventricular hypertrophy and all showed nephrosclerosis. CONCLUSION: Young adult stroke patients with recurrent stroke, fatal stroke, or SVD on imaging have advanced atherosclerosis and arteriolosclerosis-related pathological changes in multiple organ systems. Aggressive control of atherosclerosis risk factors is warranted even in young individuals.

Reduced Ischemic Lesion Growth with Heparin in Acute Ischemic Stroke.

OBJECTIVE: The role of heparin in acute ischemic stroke is controversial. We investigated the effect of heparin on ischemic lesion growth. METHODS: Data were analyzed on nonthrombolyzed ischemic stroke patients in whom diffusion-weighted imaging (DWI)/perfusion-weighted imaging (PWI) MRI was performed less than 12 hours of last known well and showed a PWI-DWI lesion mismatch, and who underwent follow-up neuroimaging at least 4 days after admission. Lesion growth was assessed by (1) absolute lesion growth and (2) percentage mismatch lost (PML). Univariate and multivariate regression analysis, and propensity score matching, were used to determine the effects of heparin on ischemic lesion growth. RESULTS: Of the 113 patients meeting study criteria, 59 received heparin within 24 hours. Heparin use was associated with ∼5-fold reductions in PML (3.5% versus 19.2%, P = .002) and absolute lesion growth (4.7 versus 20.5 mL, P = .009). In multivariate regression models, heparin independently predicted reduced PML (P = .04) and absolute lesion growth (P = .04) in the entire cohort, and in multiple subgroups (patients with and without proximal artery occlusion; DWI volume greater than 5 mL; cardio-embolic mechanism; DEFUSE-3 target mismatch). In propensity score matching analysis where patients were matched by admission NIHSS, DWI volume and proximal artery occlusion, heparin remained an independent predictor of PML (P = .048) and tended to predict absolute lesion growth (P = .06). Heparin treatment did not predict functional outcome at discharge or 90 days. CONCLUSION: Early heparin treatment in acute ischemic stroke patients with PWI-DWI mismatch attenuates ischemic lesion growth. Clinical trials with careful patient selection are warranted to investigate the potential ischemic protective effects of heparin.

RCVS2 score and diagnostic approach for reversible cerebral vasoconstriction syndrome.

OBJECTIVE: To develop a method to distinguish reversible cerebral vasoconstriction syndrome (RCVS) from other large/medium-vessel intracranial arteriopathies. METHODS: We identified consecutive patients from our institutional databases admitted in 2013-2017 with newly diagnosed RCVS (n = 30) or non-RCVS arteriopathy (n = 80). Admission clinical and imaging features were compared. Multivariate logistic regression modeling was used to develop a discriminatory score. Score validity was tested in a separate cohort of patients with RCVS and its closest mimic, primary angiitis of the CNS (PACNS). In addition, key variables were used to develop a bedside approach to distinguish RCVS from non-RCVS arteriopathies. RESULTS: The RCVS group had significantly more women, vasoconstrictive triggers, thunderclap headaches, normal brain imaging results, and better outcomes. Beta coefficients from the multivariate regression model yielding the best c-statistic (0.989) were used to develop the RCVS2 score (range -2 to +10; recurrent/single thunderclap headache; carotid artery involvement; vasoconstrictive trigger; sex; subarachnoid hemorrhage). Score ≥5 had 99% specificity and 90% sensitivity for diagnosing RCVS, and score ≤2 had 100% specificity and 85% sensitivity for excluding RCVS. Scores 3-4 had 86% specificity and 10% sensitivity for diagnosing RCVS. The score showed similar performance to distinguish RCVS from PACNS in the validation cohort. A clinical approach based on recurrent thunderclap headaches, trigger and normal brain scans, or convexity subarachnoid hemorrhage correctly diagnosed 25 of 37 patients with RCVS2 scores 3-4 across the derivation and validation cohorts. CONCLUSION: RCVS can be accurately distinguished from other intracranial arteriopathies upon admission, using widely available clinical and imaging features. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that the RCVS2 score accurately distinguishes patients with RCVS from those with other intracranial arteriopathies.

Post-stroke Recrudescence from Infection: an Immunologic Mechanism?

Post-stroke recrudescence (PSR) usually occurs in the setting of infection, hypotension, hyponatremia, insomnia or stress, and benzodiazepine use. Animal studies have suggested an infection-related immunologic mechanism for PSR. This retrospective study was designed to assess whether infection-triggered PSR is related to a prior infection during the index stroke. We identified 95 patients admitted to Massachusetts General Hospital from 2000 to 2015 with post-stroke recrudescence who had adequate medical record information concerning the index stroke. The frequency of infections, as well as other triggers such as hypotension, hyponatremia, insomnia/stress, and benzodiazepine use, was compared between the index stroke and the PSR episode. Independent predictors of infection-related PSR were identified using a logistic regression model. The mean age was 66 ± 17 years (53% female); 29 (31%) had infections during the index stroke as compared to 40 (42%) during the PSR episode. The frequency of PSR triggered by infection was higher in patients with infections during the index stroke (65% vs 32%, p = 0.003). The same relationship occurred with benzodiazepine-triggered PSR (41% vs 12%, p = 0.008). The frequencies of other triggers such as hypotension, hyponatremia and insomnia/stress were not significantly different between the index stroke and the PSR episode. In a logistic regression model, infection during the index stroke was an independent predictor of infection-triggered PSR (odds ratio 4.85, 95% C.I. 1.7, 13.7). The association between infection during index stroke and infection-triggered PSR supports the immunologic mechanism postulated in animal models.

Isolated Upper Limb Weakness From Ischemic Stroke: Mechanisms and Outcome.

OBJECTIVE: To characterize isolated upper extremity (UE) weakness from stroke. METHODS: In our Get with the Guidelines-Stroke dataset (n = 7643), 87 patients (1.14%) had isolated UE weakness and underwent thorough stroke evaluation with diffusion-weighted magnetic resonance imaging and good-quality arterial imaging. We analyzed clinical-imaging features, etiology, management, and outcome. Since isolated UE weakness is typically associated with contralateral hand-knob area infarcts, patients were classified into Group-A (motor strip infarct) or Group-B (non-motor strip infarct). RESULTS: The mean age was 68 years; 66% were male, 72% had hypertension, 22% diabetes, 53% hyperlipidemia, and 16% were smokers. In Group-A (n = 71), 18 patients had single and 53 had multiple infarcts involving the contralateral motor strip. In Group-B (n = 16), 6 patients had contralateral subcortical white matter infarcts, 9 had bihemispheric infarcts and 1 had a brainstem infarct. Compared to Group-B, patients in Group-A more often had carotid artery stenosis or irregular plaque (84.5% versus 50%, P = .006) and large-artery atherosclerosis mechanism (46% versus 19%, P = .05), and less often cardioembolic mechanism (13% versus 44%, P = .008). Among 36 patients with large-artery mechanism, 27 had less than 70% stenosis including 19 with plaque ulceration/thrombus. Recurrent strokes occurred in 10 patients (11.5%), including 5 with mild-moderate carotid stenosis and plaque ulceration/thrombosis, over 1515 days follow-up. CONCLUSION: Stroke mechanism in acute isolated UE weakness is variable. Contralateral motor-strip infarcts are associated with carotid stenosis, often with plaque ulceration ("vulnerable carotid plaque"), and infarcts in other locations with cardioembolism. Recurrent stroke risk is high especially with mild-moderate carotid artery stenosis and plaque ulceration/thrombus.

Traumatic spinal cord injury: current concepts and treatment update.

Spinal cord injury (SCI) affects 1.3 million North Americans, with more than half occurring after trauma. In Brazil, few studies have evaluated the epidemiology of SCI with an estimated incidence of 16 to 26 per million per year. The final extent of the spinal cord damage results from primary and secondary mechanisms that start at the moment of the injury and go on for days, and even weeks, after the event. There is convincing evidence that hypotension contributes to secondary injury after acute SCI. Surgical decompression aims at relieving mechanical pressure on the microvascular circulation, therefore reducing hypoxia and ischemia. The role of methylprednisolone as a therapeutic option is still a matter of debate, however most guidelines do not recommend its regular use. Neuroprotective therapies aiming to reduce further injury have been studied and many others are underway. Neuroregenerative therapies are being extensively investigated, with cell based therapy being very promising.