Abstract T MP12: Predictors Of Angiographic Collaterals In Patients Undergoing Intra-arterial Therapy For Acute Ischemic Stroke

Introduction: Greater degree of collaterals to ischemic brain tissue from large vessel occlusion has been correlated to multiple endpoints including improved outcomes, improved recanalization and smaller infarct volume. The predictors of collateral circulation are poorly understood with inconsistencies in previous studies.

Methods: Retrospective study from 1/07-12/12 of AIS patients who underwent IAT for ICA/M1 occlusions with TICI 0/1 flow was conducted. Baseline characteristics and treatment times were collected. Collaterals were graded using the angiographic ASITN collateral-flow grading system. Collateral were grouped into "good collaterals” (GC) for grades 3 and 4, and "poor collaterals" (PC) for grades 0, 1 and 2.

Results: ASITN grading was available in 180 patients including 32 (18%) with GC and 148 (82%) with PC. Baseline demographics of all patients and each group are outlined in Table 1, with significant differences in baseline CT ASPECTS score and IV tPA administration. Multivariable logistic regression analysis demonstrated that female sex, CT ASPECTS and time to first angiographic run were the only independent predictors of GC.

Conclusions: We have confirmed previous reports that GC is associated with small infarct volume, which corresponds to higher CT ASPECTS score. Odds of GC were 5.7 times in females compared to males, which is inconsistent with previous literature. Previously demonstrated association of hypertension, high admission blood pressure and high NIHSS with lesser collaterals was not seen in our study. Since collaterals affect outcomes in acute ischemic stroke, further studies of predictors of good collaterals are needed.

Abstract W P10: Lower Intraprocedural Mean Arterial Pressure Predicts Good Outcome and Lower Mortality in Patients Undergoing Endovascular Therapy for Acute Ischemic Stroke

Introduction: Several factors influence the outcome of patients who undergo intra-arterial therapy (IAT) for acute ischemic stroke (AIS). The influence of intra-procedural hemodynamics on functional outcome and mortality has not been studied. There is no data to guide intraprocedural blood pressure (BP) management and it is unknown whether systolic, diastolic, or mean arterial pressure (MAP) is important for determining outcomes.

Methods: Retrospective study of patents that underwent IAT for anterior circulation AIS between 1/08- 12/12 was conducted. Detailed intra-procedural hemodynamics, demographics, NIH stroke scale score, IV tPA use, thrombus location, recanalization grade, intracranial hemorrhage were collected. Outcomes measured were in-hospital mortality and 30-day good outcome defined as modified Rankin Scale score of 0-2. Successful recanalization was defined as TICI 2b-3 and ICH was classified into parenchymal hematoma (PH1+2) and hemorrhagic infarction (HI 1+ 2).

Results: The cohort in the analysis consisted of 190 patients (56% females, mean age 67 + 15 years). Thirty-six (19%) patients died in-hospital, and 25 (17%) achieved an mRS 0-2. Intra-procedural maximum systolic BP (SBP) and maximum MAP were significantly lower in the good outcome group (Table 1). In multivariable logistic regression analysis, maximum MAP was an independent predictor of good outcomes along with baseline CT ASPECTS score, and successful recanalization. Maximum MAP was also an independent predictor of mortality along with age and presence of PH 1+2 ICH.

Conclusions: Maximum intraprocedural MAP was an independent predictor of good outcome and mortality in in patients undergoing IAT for AIS. This results may have implications for intraprocedural BP management.

The effects of acrylamide polyelectrolytes on aquatic organisms: relating toxicity to chain architecture

Understanding the inherent toxicity of water-soluble synthetic polyelectrolytes is critical for adequate risk management as well as enhancing product design when biological activity is a key performance index (e.g. for application in biofouling bivalves' control). The toxicity of two cationic acrylamide copolymers with different chain branching degree was evaluated. Standard ecotoxicity tests were conducted with microalgae and daphnids. The susceptibility of Corbicula fluminea, as a biofouling bivalve, was also evaluated. The effect of polyelectrolyte on the test media viscosity and the polymer chain size distributions under the experimental conditions were also examined. The susceptibility of the microalgae to both polymers was similar. As the complexity and size of the test organisms increased, differences in toxicity due to different chain architecture were noticeable. The more branched polymer was significantly less toxic to both daphnids and the bivalves, which could be linked to the distinctive features of its bimodal size chain distribution. This architecture resulted in both more compact globular molecules and the formation of aggregates, which reduce the polymer interaction with the biological surfaces. The results of this study promote the incorporation of environmental considerations in polyelectrolyte development and contribute to the design of improved solutions for controlling biofouling bivalves.

A low cost, safe, disposable, rapid and self-sustainable paper-based platform for diagnostic testing: lab-on-paper

There is a strong interest in the use of biopolymers in the electronic and biomedical industries, mainly towards low-cost applications. The possibility of developing entirely new kinds of products based on cellulose is of current interest, in order to enhance and to add new functionalities to conventional paper-based products. We present our results towards the development of paper-based microfluidics for molecular diagnostic testing. Paper properties were evaluated and compared to nitrocellulose, the most commonly used material in lateral flow and other rapid tests. Focusing on the use of paper as a substrate for microfluidic applications, through an eco-friendly wax-printing technology, we present three main and distinct colorimetric approaches: (i) enzymatic reactions (glucose detection); (ii) immunoassays (antibodies anti-Leishmania detection); (iii) nucleic acid sequence identification (Mycobacterium tuberculosis complex detection). Colorimetric glucose quantification was achieved through enzymatic reactions performed within specific zones of the paper-based device. The colouration achieved increased with growing glucose concentration and was highly homogeneous, covering all the surface of the paper reaction zones in a 3D sensor format. These devices showed a major advantage when compared to the 2D lateral flow glucose sensors, where some carryover of the coloured products usually occurs. The detection of anti-Leishmania antibodies in canine sera was conceptually achieved using a paper-based 96-well enzyme-linked immunosorbent assay format. However, optimization is still needed for this test, regarding the efficiency of the immobilization of antigens on the cellulose fibres. The detection of Mycobacterium tuberculosis nucleic acids integrated with a non-cross-linking gold nanoprobe detection scheme was also achieved in a wax-printed 384-well paper-based microplate, by the hybridization with a species-specific probe. The obtained results with the above-mentioned proof-of-concept sensors are thus promising towards the future development of simple and cost-effective paper-based diagnostic devices.

Abstract W P12: Intra-procedural Hemodynamics in General Anesthesia versus Monitored Anesthesia Care During Endovascular Therapy for Acute Anterior Circulation Ischemic Stroke

Background: Recent studies have identified general anesthesia (GA) as a predictor of poor outcome compared to non-intubated sedation techniques during intra-arterial therapy (IAT) for acute ischemic stroke (AIS). Factors contributing to this difference are not well understood.

Objective: Identify factors associated with poor outcome in patients receiving GA vs Monitored Anesthesia Care (MAC). We speculated that peri-procedural blood pressure (BP) may be influenced by anesthesia and could plausibly contribute to differences in outcome.

Methods: 190 patients who underwent IAT for anterior circulation AIS from 1/2008 to 12/2012 were included. Patients <18 years of age and posterior circulation AIS were excluded. Demographics, NIHSS, IV tPA use, use of GA/MAC, thrombus location, recanalization grade, post-procedure intracranial hemorrhage (ICH), and 30-day outcomes were collected. Intra-procedural hemodynamics including maximum/minimum heart rate and systolic/diastolic/mean BP were collected. Primary outcomes were in-hospital mortality and good outcome (mRS 0-2) at 30 days. Secondary outcomes were successful recanalization (TICI 2b-3) and ICH (PH1+2) based on ECASS definitions.

Results: There were 91 and 99 patients in the GA and MAC groups respectively. Baseline characteristics including NIHSS scores were similar between both groups. The GA group had more ICA terminus occlusions (39.1% vs 18.2%, p = 0.043). There was significantly higher mortality (25.8% vs 13.3%, p = 0.040) and a trend towards poorer outcome (14.9% vs 22.8% with mRS 0-2, p = 0.239) in the GA group. Successful recanalization was higher in the GA group (57.1% vs 47.5%, p = 0.182), but the rate of PH1+2 ICH was significantly higher in the GA group (26.3% vs 10.1%, p = 0.003). There were no significant differences in intra-procedural hemodynamics, prior to or after recanalization. GA was an independent predictor of mortality and PH1+2 ICH.

Conclusions: Patients placed under GA prior to IAT appear to have a higher probability of mortality and a trend towards poorer outcome. Outcome differences do not seem to be related to hemodynamic factors. There were significantly higher number of ICHs in the GA group and this could potentially be the factor driving the difference between outcomes.

Human adipose-derived mesenchymal stromal cells injected systemically into GRMD dogs without immunosuppression are able to reach the host muscle and express human dystrophin

Duchenne muscular dystrophy (DMD), a lethal X-linked disorder, is the most common and severe form of muscular dystrophies, affecting 1 in 3,500 male births. Mutations in the DMD gene lead to the absence of muscle dystrophin and a progressive degeneration of skeletal muscle. The possibility to treat DMD through cell therapy has been widely investigated. We have previously shown that human adipose-derived stromal cells (hASCs) injected systemically in SJL mice are able to reach and engraft in the host muscle, express human muscle proteins, and ameliorate the functional performance of injected animals without any immunosuppression. However, before starting clinical trials in humans many questions still need to be addressed in preclinical studies, in particular in larger animal models, when available. The best animal model to address these questions is the golden retriever muscular dystrophy (GRMD) dog that reproduces the full spectrum of human DMD. Affected animals carry a mutation that predicts a premature termination codon in exon 8 and a peptide that is 5% the size of normal dystrophin. These dogs present clinical signs within the first weeks and most of them do not survive beyond age two. Here we show the results of local and intravenous injections of hASCs into GRMD dogs, without immunosuppression. We observed that hASCs injected systemically into the dog cephalic vein are able to reach, engraft, and express human dystrophin in the host GRMD dystrophic muscle up to 6 months after transplantation. Most importantly, we demonstrated that injecting a huge quantity of human mesenchymal cells in a large-animal model, without immunosuppression, is a safe procedure, which may have important applications for future therapy in patients with different forms of muscular dystrophies.

Abstract WP20: Procedure Time and Degree of Collateral Flow Determines Outcome in Acute Endovascular Stroke Therapy

BACKGROUND AND PURPOSE: Treatment options for acute ischemic stroke remain limited. There is a clear time dependant nature to this condition, though more evidence is accumulating that degree of collateral flow is a powerful modulator of the effect of time in acute ischemic stroke. In addition, longer procedural times have been associated with worse outcome. We sought to study the relationship between procedure times, collateral flow, recanalization, and clinical outcomes.

MATERIALS AND METHODS: A retrospective review of prospectively collected database of 152 patients with anterior circulation strokes treated with endovascular stroke therapy within 8 hours of symptom onset from August 2006 to December 2011. General demographics, clinical features, imaging findings, and outcomes were collected. Univariate and multivariate analysis was performed using JMP statistical analysis software.

RESULTS: 152 patients [71 (46.7%) male, mean age: 68±15 years;] were included in the analysis. Complete or partial revascularization occurred in 121 (81%) patients. Collateral circulation was assessed on CTA with 7 (0.6%) having no significant collateral flow, 22 (20.7%) having low collateral flow (50% of affected territory), and 28 (26.4%) having full collateral flow. Overall, there was no significant difference in the baseline clinical and radiographic features between the groups. Analysis of procedural times showed significantly reduced chance of good outcome with procedure times >90 minutes. This effect was more pronounced based on collaterals; in those with good collaterals, good outcome (mRS ≤3) was significantly higher in procedures < 90 minutes (56% vs. 24%; p=0.02); in those with poor collaterals, no good outcomes were seen after 90 minutes of procedure time (39% vs. 0%; p=0.02).

CONCLUSION: Procedure time and the degree of collateralization play a significant role in determining outcome in patients who undergo endovascular therapy in acute ischemic stroke, with significantly worse outcomes seen in patients with procedure times >90 minutes, particularly in those with poor collaterals. Treating physicians should keep these factors in mind during the treatment of acute stroke patients.

Determinants of effective cooling during endovascular hypothermia

BACKGROUND

Therapeutic hypothermia is a promising neuroprotective therapy with multiple mechanisms of action. We demonstrated the feasibility of thrombolysis combined with endovascular hypothermia, but not all patients achieved effective cooling. We sought to identify the factors that determined effective cooling.

METHODS

In 26 patients who underwent endovascular hypothermia, we computed four measures of effective cooling: time to reach target; Area-Under-the-Curve (AUC) 34 ratio; AUC-34; and AUC-35. By multivariate regression, we examined the effects of age, weight, starting temperature, body mass index, body surface area (BSA), gender, shivering, and total meperidine dose on the four outcome measures.

RESULTS

In univariate analyses, all four outcome measures were significantly influenced by BSA (p < 0.01 in all univariate analyses). Time to reach target temperature was quicker in older patients (p < 0.01). Shivering and meperidine dose were highly intercorrelated (r = 0.6, p < 0.01) and both marginally influenced all four outcome measures. In multivariate analysis, AUC ratio and time to reach target temperature were significantly influenced by BSA (p < 0.01) and meperidine (p < 0.05); AUC-34 was influenced only by BSA (p < 0.01). The AUC-35 was influenced by BSA (p < 0.01), shivering, and total meperidine dose (p < 0.05).

CONCLUSIONS

The most important determinant of effective cooling during endovascular hypothermia is BSA; larger patients are more difficult to cool and maintain in therapeutic range. Older patients cool more quickly. Shivering was well controlled by the combination of meperidine, buspirone, and surface counter-warming and only minimally influenced cooling effectiveness. Future trials of therapeutic hypothermia may include added measures to cool larger patients more effectively.

Impact of a neurointensivist on outcomes in critically ill stroke patients

BACKGROUND

Current guidelines for management of critically ill stroke patients suggest that treatment in a neurocritical care unit (NCCU) and/or by a neurointensivist (NI) may be beneficial, but the contribution of each to outcome is unknown. The relative impact of a NCCU versus NI on short- and long-term outcomes in patients with acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), and aneurysmal subarachnoid hemorrhage (SAH) was assessed.

METHODS

2,096 stroke patients admitted to a NCCU or nonneuro ICU at a tertiary stroke center were analyzed before the appointment of a NI, during the NI's tenure, and after the NI departed and was not replaced. Data included admission ICU type, availability of a NI, age, NIHSS, ICH score, and 3 and 12 month outcome.

RESULTS

For AIS, compared to the time interval with a NI, departure of the NI predicted a worse rate of return to pre-stroke function at 3 months. For ICH, NCCU treatment predicted shorter ICU and hospital LOS but had no effect on short- or long-term outcomes. No effect of a NI was seen. For SAH, availability of an NI (but not an NCCU) predicted improved outcomes but longer ICU LOS. Disposition and in-hospital mortality improved when a NI was present, but continued improvement did not occur after the NI's departure.

CONCLUSION

Presence of an NI was associated with improved clinical outcomes. This effect was more evident in patients with SAH. Patients with ICH tend to have poor outcomes regardless of the presence of a NCCU or a NI.

Primary cutaneous actinomycosis caused by Actinomyces meyeri as first manifestation of HIV infection

Primary cutaneous actinomycosis is very uncommon. We report a patient with cutaneous actinomycosis with multiple lesions without any detectable extra-cutaneous lesions. In our patient the actinomycosis was the presenting manifestation of HIV infection.

Safety and tolerability of deferoxamine mesylate in patients with acute intracerebral hemorrhage

BACKGROUND AND PURPOSE

Treatment with the iron chelator, deferoxamine mesylate (DFO), improves neurological recovery in animal models of intracerebral hemorrhage (ICH). We aimed to evaluate the feasibility, safety, and tolerability of varying dose-tiers of DFO in patients with spontaneous ICH, and to determine the maximum tolerated dose to be adopted in future efficacy studies.

METHODS

This was a multicenter, phase-I, dose-finding study using the Continual Reassessment Method. DFO was administered by intravenous infusion for 3 consecutive days, starting within 18 hours of ICH onset. Subjects underwent repeated clinical assessments through 90 days, and computed tomography neuroimaging pre- and post-drug-administration.

RESULTS

Twenty subjects were enrolled onto 5 dose tiers, starting with 7 mg/kg per day and ending with 62 mg/kg per day as the maximum tolerated dose. Median age was 68 years (range, 50-90); 60% were men; and median Glasgow Coma Scale and National Institutes of Health Stroke Scale scores on admission were 15 (5-15) and 9 (0-39), respectively. ICH location was lobar in 40%, deep in 50%, and brain stem in 10%; intraventricular hemorrhage was present in 15%. DFO was discontinued because of adverse events in 2 subjects (10%). Six subjects (30%) experienced 12 serious adverse events, none of which were drug-related. DFO infusions were associated with mild blood-pressure-lowering effects. Fifty percent of patients had modified Rankin scale scores ≤2, and 39% had modified Rankin scale scores of 4 to 6 on day 90; 15% died.

CONCLUSIONS

Consecutive daily infusions of DFO after ICH are feasible, well-tolerated, and not associated with excessive serious adverse events or mortality. Our findings lay the groundwork for future studies to evaluate the efficacy of DFO in ICH.

Occupational and environmental risk factors of adult primary brain cancers: a systematic review

The incidence of brain neoplasm has been progressively increasing in recent years in the industrialized countries. One of the reasons for this increased incidence could be better access to health care and improved diagnosis in the industrialized countries. It also appears that Caucasians have a higher incidence than blacks or Hispanics or Asians. A number of risk factors have been identified and described including the genetic, ethnic and age-based factors. Certain occupational and environmental factors are also believed to influence the risk of primary adult brain tumors. Potential occupational and environmental factors include exposure to diagnostic and therapeutic radiations, electromagnetic radiation from cellular phones and other wireless devices, infectious agents, air pollution and residence near landfills and high-voltage power lines and jobs as firefighters, farmers, physician, chemists and jobs in industries such as petrochemical, power generation, synthetic rubber manufacturing, agricultural chemicals manufacturing. The purpose of this systematic review is to examine occupational and environmental risk factors of brain neoplasm. A range of occupational and environmental exposures are evaluated for significance of their relationship with adult primary brain tumors. On the basis of this review we suggest a concurrent evaluation of multiple risk factors both within and beyond occupational and environmental domains. The concurrent approach needs to consider better exposure assessment techniques, lifetime occupational exposures, genotypic and phenotypic characteristics and lifestyle and dietary habits. This approach needs to be interdisciplinary with contributions from neurologists, oncologists, epidemiologists and molecular biologists. Conclusive evidence that has eluded multitude of studies with single focus and single exposure needs to multifaceted and multidisciplinary.

Control of solid-state lasers using an intra-cavity MEMS micromirror

High reflectivity, electrothermal and electrostatic MEMS (Micro-Electro-Mechanical Systems) micromirrors were used as a control element within a Nd-doped laser cavity. Stable continuous-wave oscillation of a 3-mirror Nd:YLF laser at a maximum output power of 200 mW was limited by thermally-induced surface deformation of the micromirror. An electrostatic micromirror was used to induce Q-switching, resulting in pulse durations of 220 ns - 2 μs over a repetition frequency range of 6 kHz - 40 kHz.

Feline Leishmania infection in a canine leishmaniasis endemic region, Portugal

Canine leishmaniasis (CanL) caused by Leishmania infantum is a serious zoonotic public health and veterinary problem in the Mediterranean basin. Leishmania infection in domestic cats (Felis catus domesticus) has been reported in several countries where this zoonosis is endemic, such as Portugal, Spain, Italy, France, Greece, Israel, Palestine and Brazil. The aim of this study was to contribute to the knowledge of the role played by cats in Leishmania epidemiology, in an endemic focus of zoonotic leishmaniasis, the Lisbon metropolitan area, Portugal. L. infantum DNA was detected in peripheral blood of 28 out of 138 cats (20.3%). The result of PCR in blood of cats was not closely associated with the level of specific circulating antibodies in their sera. Positive serology was observed only in one cat out of 76. In the same geographic region and time period the indirect immunofluorescent test revealed 20.4% (31/152) of dogs with antibodies and PCR detected Leismania DNA on 34.9% (53/152) animals. Despite the fact that specific antibodies have been validated for diagnosis of CanL, their detection does not seem to be sensitive enough to predict Leishmania infection in cats. On the other hand, the presence of parasite DNA in cat's peripheral blood during the transmission season and out of the season suggests that these animals living in endemic areas are frequently exposed or infected with the parasite. Although dogs have been universally regarded as the major domestic/peridomestic reservoir hosts, the present data allow us to hypothesize that cats can act as an alternative reservoir host of L. infantum, rather than an accidental host. However, in order to evaluate the existence of a transmission cycle with cats sustaining and spreading zoonotic leishmaniasis is necessary to prove that these animals can transmit the parasite to the vector in nature.

Toxicological assessment of coated versus uncoated rubber granulates obtained from used tires for use in sport facilities

Reuse of tire crumb in sport facilities is currently a very cost-effective waste management measure. Considering that incorporation of the waste materials in artificial turf would be facilitated if the rubber materials were already colored green, coatings were specifically developed for this purpose. This paper presents an experimental toxicological and environmental assessment aimed at comparing the obtained emissions to the environment in terms of polycyclic aromatic hydrocarbons (PAHs), heavy metals, and ecotoxicity for coated and noncoated rubber granulates. This study is a comprehensive evaluation of the major potential critical factors related with the release of all of these classes of pollutants because previous studies were not systematically performed. It was concluded that between the two types of coatings tested, one is particularly effective in reducing emissions to the environment, simultaneously meeting the requirements of adherence and color stability.

Oral exposure of male and female mice to formulations of organophosphorous pesticides: congenital malformations

Birth outcome was studied in pre-partum litters of mice exposed to oral doses of organophosphorous pesticides at low and high concentrations before mating. Exposed and unexposed pregnant dams were delivered by Caesarean section 1 day before partum, the fetuses were collected, counted and weighed, and the numbers of resorptions were recorded. Live litter sizes were non-significantly higher in all the exposed groups compared with the control group. The numbers of resorptions were significantly higher in all the exposed groups than in the comparison groups. The incidence of intra-uterine growth retardation was significantly higher in all the exposed groups than in the comparison groups. The incidences of congenital malformations were significantly higher in the exposed groups than in one or more of the comparison groups for the defects of the ears, eyes, jaws, brain, and tongue in all the exposed groups. Low set microtia, cataract or open eyelids, microcephaly or anencephaly, maxillary or mandibular hypoplasia, and protruding tongue were observed in all groups, but the numbers were significantly higher in the exposed groups compared with one or more of the comparison groups. Curled or missing tail and intra-auricular septal or intra-ventricular septal defects were observed in higher numbers in the groups in which both the males and the females were exposed than in the comparison groups. Male:female sex ratios were significantly higher in the groups in which males only and females only were exposed.

Diagnosis of hyperlipidemia and treatment with a statin in the outpatient stroke clinic

The aim of this study was to assess a stroke clinic's performance in the diagnosis of hyperlipidemia and more specifically to evaluate the effectiveness of statins in patients with cerebrovascular disease not enrolled in a research study. The records of 370 consecutive patients seen at a stroke clinic over a 4-year period were reviewed, and information regarding neurologic diagnosis, lipid profile, and use and type of cholesterol-lowering medication was abstracted. Hyperlipidemia was defined as a total cholesterol level equal to or more than 200 mg/dL. Forty-eight patients meeting specific criteria were further analyzed to monitor the effects of statins. Cholesterol testing was obtained in 324 patients (88%) and 178 (55%) were hyperlipidemic, but only 86 (48%) patients received treatment. The mean cholesterol level of the 48 patients dropped from 246.2 mg/dL to 197.1 mg/dL (P < .0001) after the initiation of statin therapy, and significant reductions were present in subgroups with pretreatment levels of 200 to 249 mg/dL and 250 to 299 mg/dL. Of the 21 patients with repeated cholesterol testing more than 6 months after the first posttreatment test, only 11 (52%) maintained a level below 200 mg/dL. Effective control of hyperlipidemia can be achieved in patients with cerebrovascular disease, but not all are adequately tested or treated. Improved physician awareness and more effective health care delivery systems are needed.

Magnetic resonance imaging in the evaluation of intracranial hemorrhage

Magnetic resonance imaging is emerging as a valuable tool for the urgent evaluation of patients with acute stroke. This review focuses on the applications of magnetic resonance imaging in the diagnosis and management of intracranial hemorrhage. The biophysical properties of blood in the neuroaxis and the magnetic resonance imaging evolution of intracranial bleeding are reviewed. The potential applications of magnetic resonance imaging in the evaluation and therapy of specific types of intracranial hemorrhage are discussed. Emphasis is made on the superiority of magnetic resonance imaging in detecting intracranial hemorrhage and ischemic stroke. Although there is some hesitation to perform magnetic resonance imaging to evaluate acute intracranial hemorrhage, there is strong evidence that magnetic resonance imaging is not inferior to computerized tomography in this clinical setting. In the era of acute stroke intervention, magnetic resonance imaging offers significant advantages over computed tomography.

Stroke in the tropics

Similar to northern developed countries, cerebrovascular disease is a leading cause of morbidity and mortality in tropical countries. The epidemiology of stroke in the tropics is different from one tropical region to another and from the tropics to northern latitudes. In tropical regions, stroke is due to the conventional mechanisms encountered in other latitudes, as well as unusual causative mechanisms unique to the tropics. In tropical regions, infectious causes of stroke and nonatherosclerotic mechanisms are more common than in nontropical areas. Our current knowledge of stroke in the tropics is limited by the financial restrictions existing in such regions limiting health care delivery and epidemiological research.