Climate Change and Stroke: A Topical Narrative Review.

The impacts of accumulating atmospheric greenhouse gases on the earth's climate are now well established. As a result, there have been increases in ambient temperatures and resultant higher frequency and duration of temperature extremes and other extreme weather events, which have been linked to a wide range of adverse health outcomes. This topical narrative review provides a summary of published evidence on the links between climate change and stroke. There is consistent evidence of associations between stroke incidence and mortality and increasing ambient temperature and air pollution. Associations have also been shown for changes in barometric pressure, wildfires, and desert dust and sandstorms, but current evidence is limited. Flooding and other extreme weather events appear to primarily cause service disruption, but more direct links to stroke may emerge. Synergies between dietary changes that reduce stroke risk and may also reduce carbon footprint are being explored. We also discuss the impact on vulnerable populations, proposed pathophysiologic mechanisms, mitigation strategies, and current research priorities. In conclusion, climate change increasingly impacts the stroke community, warranting elevated attention.

Antiplatelet Use in Ischemic Stroke.

OBJECTIVE: A literature review of antiplatelet agents for primary and secondary stroke prevention, including mechanism of action, cost, and reasons for lack of benefit. DATA SOURCES: Articles were gathered from MEDLINE, Cochrane Reviews, and PubMed databases (1980-2021). Abstracts from scientific meetings were considered. Search terms included ischemic stroke, aspirin, clopidogrel, dipyridamole, ticagrelor, cilostazol, prasugrel, glycoprotein IIb/IIIa inhibitors. STUDY SELECTION AND DATA EXTRACTION: English-language original and review articles were evaluated. Guidelines from multiple countries were reviewed. Articles were evaluated independently by 2 authors. DATA SYNTHESIS: An abundance of evidence supports aspirin and clopidogrel use for secondary stroke prevention. In the acute phase (first 21 days postinitial stroke), these medications have higher efficacy for preventing further stroke when combined, but long-term combination therapy is associated with higher hemorrhage rates. Antiplatelet treatment failure is influenced by poor adherence and genetic polymorphisms. Antiplatelet agents such as cilostazol may provide extra benefit over clopidogrel and aspirin, in certain racial groups, but further research in more diverse ethnic populations is needed. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: This review presents the data available on the use of different antiplatelet agents poststroke. Dual therapy, recurrence after initiation of secondary preventative therapy, and areas for future research are discussed. CONCLUSIONS: Although good evidence exists for the use of certain antiplatelet agents postischemic stroke, there are considerable opportunities for future research to investigate personalized therapies. These include screening patients for platelet polymorphisms that confer antiplatelet resistance and for randomized trials including more racially diverse populations.

Predictors of ischemic versus hemorrhagic strokes in hypertensive patients.

OBJECTIVE: To identify the factors that predispose to ischemic versus hemorrhagic stroke in hypertensive patients. DESIGN: Cohort study. PLACE AND DURATION OF STUDY: The study was conducted at the Aga Khan University Hospital (AKUH), Karachi, from August 1999 to May 2001. MATERIALS AND METHODS: All the hypertensive patients, who were registered in AKUH acute stroke outcome data base, over a period of 22 months, were identified and from this cohort the patients with first ever stroke were selected. The data regarding demographics, stroke type (ischemic vs. hemorrhagic), pre-existing medical problems, laboratory and radiological investigations was recorded and analyzed. RESULTS: Five hundred and nineteen patients with either ischemic stroke or parenchymal hemorrhage were registered over a period of 22 months. Three hundred and forty-eight patients (67%) had hypertension and of these, 250 had first ever stroke at the time of admission. Presence of diabetes mellitus (OR: 3.76; CI:1.67-8.46) and ischemic heart disease (OR: 6.97; CI:1.57-30.98) were found to be independent predictors of ischemic strokes. CONCLUSION: Presence of diabetes mellitus and ischemic heart disease predict ischemic stroke in a patient with hypertension.

MR imaging in toxoplasmosis encephalitis after bone marrow transplantation: paucity of enhancement despite fulminant disease.

We present a patient who underwent bone marrow transplantation (BMT) after developing chronic myelocytic leukemia. Four months after BMT, he became comatose and died. MR imaging revealed multifocal brain lesions that were progressive but produced no edema. Postcontrast studies revealed that most of the lesions were nonenhancing. There was only discrete, irregular leptomeningeal enhancement with possible minimal enhancement of the cortex and subcortical white matter. Autopsy showed overwhelming toxoplasmosis encephalitis. This case illustrates that toxoplasmosis lesions may lack obvious contrast enhancement in the brain of the immunocompromised patients, despite severe involvement. Recognition of this unusual MR imaging manifestation of toxoplasmosis should lead to earlier diagnosis and treatment.