Stroke is more than a hemiparesis: the pre‐hospital detection of stroke

The first step to improving outcomes for women with stroke is to identify them

Pre‐hospital identification of people with stroke potentially eligible for reperfusion therapy is a crucial step in the chain of stroke survival. In most pre‐hospital services, the selection criteria are based on symptoms related to large vessel occlusions, such as the face/arm/speech (FAST) criteria. In a population‐based cohort study linking hospital and ambulance data, Wang and colleagues report that women under 70years of age with stroke are more likely than men to be assessed by paramedics as having non‐stroke conditions, and are consequently less likely to receive specific stroke‐related care from emergency medical services.1

Differences in symptom presentation by men and women with myocardial infarction and other cardiologic conditions are recognised, but differences in stroke symptom presentation have not been as well characterised. In the report by Wang and colleagues in this issue of the MJA, women subsequently diagnosed in hospital with stroke were more likely than men to be assessed by paramedics as having anxiety, nausea, headache, or being unconscious, rather than stroke.1 Two recent meta‐analyses similarly found that women with stroke exhibit non‐focal symptoms more often than men, including generalised weakness, change in mental status, confusion, headache, and loss of consciousness.2,3

Although stroke symptoms are directly referable to the brain areas affected, there are several potential explanations for differences in the symptoms presented by men and women. First, women and men may have different stroke lesion patterns.4 Second, in countries where more women than men live alone (because of greater longevity), less information from family and relatives about women may be available to emergency medical service workers.5 However, in the study by Wang and colleagues, younger women (under 70years of age) with stroke were more frequently evaluated by emergency services personnel as having non‐stroke conditions than men, whereas differences between older men and women were not statistically significant.1

Most emergency medical services use FAST to identify stroke in pre‐hospital assessments. FAST is a crude criteria set, and does not capture the more general, non‐focal symptoms more often seen in women. As many as one‐third of patients with acute stroke not identified by emergency medical services present with non‐FAST symptoms,6 which can lead to a delay in initiating reperfusion treatment and consequently to poorer outcomes.

Better tools for pre‐hospital stroke assessment are therefore needed to identify stroke in men and women alike. Most stroke research is concerned with identifying patients with large vessel occlusions (which typically cause FAST symptoms) so that they can be triaged to the appropriate level of care.7 Pre‐hospital identification of stroke should not focus on large vessel occlusions alone, but also heed the many other symptoms that can be presented. This will require better knowledge among pre‐hospital workers of stroke, including recognising differences between men and women in symptom presentation, pre‐hospital stroke assessment tools that capture symptoms beyond FAST, and better communication between pre‐ and in‐hospital services.

As some ambulance personnel, because of geographic location and other demographic factors, only occasionally encounter patients with suspected stroke, identifying stroke symptoms without appropriate tools can be challenging. Enhancing the competence of ambulance personnel in acute stroke assessment, including in the recognition of atypical stroke symptoms, could reduce the number of misclassified patients. Providing ambulance workers with better tools to identify suspected stroke could also increase the number of strokes detected before arrival at hospital, in both women and men.

The National Institute of Health Stroke Scale (NIHSS) has been successfully introduced in pre‐hospital settings in Switzerland and in Norway.8,9 As the NIHSS is the preferred stroke scale in hospitals in these countries, its pre‐hospital use provides a common language for pre‐ and in‐hospital stroke care providers. As well as directly improving the assessment of patients with suspected stroke by capturing more atypical symptoms, improved communication with in‐hospital services could enhance patient care.8

Given the sex differences in pre‐hospital assessments of people later diagnosed with stroke and the care provided by emergency medical services described by Wang and colleagues,1 differences in stroke symptom presentation warrant further study. In order to improve outcomes for women with stroke, we first need to identify them.