Cochrane Stroke Group: Twenty Years of Evidence-Based Stroke Medicine

Evolution of Evidence-Based Medicine in Stroke

The introduction and evolution of evidence-based stroke medicine has realized major advances in our knowledge about stroke, methods of medical research, and patient outcomes that continue to complement traditional individual patient care. It is humbling to recall the state of knowledge and scientific endeavour of our forebears who were unaware of what we know now and yet pursued the highest standards for evaluating and delivering effective stroke care. The science of stroke medicine has evolved from pathophysiological theory to empirical testing. Progress has been steady, despite inevitable disappointments and cul-de-sacs, and has occasionally been punctuated by sensational breakthroughs, such as the advent of reperfusion therapies guided by imaging.

Acute stroke chameleons in a university hospital: Risk factors, circumstances, and outcomes

OBJECTIVE

To identify risk factors, circumstances, and outcomes for individuals with acute ischemic stroke (AIS) chameleons (AIS-C) arriving in the emergency department of a university hospital.

METHODS

We retrospectively reviewed all patients with AIS from the prospectively constructed Acute Stroke Registry and Analysis of Lausanne during 8.25 years. AIS-C were defined as a failure to suspect stroke or as incorrect exclusion of stroke diagnosis. They were compared with patients diagnosed correctly at the time of admission.

RESULTS

Forty-seven of 2,200 AIS were missed (2.1%). These AIS-C were either very mild or very severe strokes. Multivariate analysis showed a younger age in patients with AIS-C (odds ratio [OR] per year 0.98, p < 0.01), less prestroke statin treatment (OR 0.29, p = 0.04), and lower diastolic admission blood pressure (OR 0.98 p = 0.04). They showed less eye deviation (OR 0.21, p = 0.04) and more cerebellar strokes (OR 3.78, p < 0.01). AIS-C were misdiagnosed as other neurologic (42.6% of cases) or nonneurologic (17.0%) disease, as unexplained decreased level of consciousness (21.3%), and as concomitantly present disease (19.1%). At 12 months, patients with AIS-C had less favorable outcomes (adjusted OR 0.21, p < 0.01) and higher mortality (adjusted OR 4.37, p < 0.01).

CONCLUSIONS

AIS are missed in patients with younger age with a lower cerebrovascular risk profile and may be masked by other acute conditions. Patients with chameleons present more often with milder strokes or coma, fewer focal signs and cerebellar strokes, and have higher disability and mortality rates at 12 months. These findings may be used to raise awareness in emergency departments to recognize and treat such patients appropriately.