A stroke is a serious medical condition that requires emergency care.

Use the letters in FAST to spot a stroke:

F = Face Drooping – Does one side of the face droop or is it numb? Ask the person to smile. Is the person's smile uneven?

A = Arm Weakness – Is one arm weak or numb? Ask the person to raise both arms. Does one arm drift downward?

S = Speech Difficulty – Is speech slurred?

T = Time to call for help – Stroke is an emergency. Every minute counts.

There are two types of stroke ischaemic stroke (most cases), and haemorrhagic stroke. Hypertension and aneurysms are examples of conditions that can cause a haemorrhagic stroke.

Patients with stroke mimics (SM), conditions with stroke-like symptoms, may risk harm if treated with intravenous thrombolysis (IVT). Keselman et al (2019) compared safety and outcomes following IVT between patients with acute ischaemic stroke and mimicking conditions. Outcomes were parenchymal haematoma (PH) after treatment, symptomatic intracerebral haemorrhage (SICH) per Safe Implementation of Thrombolysis in Stroke Monitoring Study (SITS-MOST), Second European Co-operative Stroke Study (ECASS II) and National Institutes of Neurological Disorders and Stroke Study (NINDS) criteria, death and modified Rankin Scale score (mRS) at three months. Of 10 436 patients, 4% showed SMs. The most common types were functional (30%), migraine (17%) and seizure (14%). Patients with mimics had fewer cerebrovascular risk factors and lower median National Institutes of Health Stroke Scale score. Among mimic’s vs stroke patients, PH was seen in 1% vs 5%, SICH NINDS in 0.5% vs 3.9%, SICH ECASS II in 0.2% vs 2% and SICH SITSMOST in 0% vs 0.5% (P = 0.28). This large observational study indicated that PH and SICH following IVT in patients with SM are uncommon.²

In the randomised, placebo-controlled European Cooperative Acute Stroke Study III (ECASS III), the authors assessed whether the time window for initiation of alteplase could be safely increased from the standard three hours after the onset of stroke symptoms to up to 4.5 hours. Patients treated with alteplase had a significantly better outcome at day 90 than did controls for the primary endpoint. Bluhmki et al’s double-blind, multicentre study results support the use of alteplase up to 4.5 hours after the onset of stroke symptoms across a broad range of subgroups of patients who meet the requirements of the European product label but miss the approved treatment window of 0-3 hours.

Very severe stroke defined as NIH Stroke Scale (NIHSS) scores above 25 points. Here, the European Medicines Agency licence for alteplase contraindicates treatment, stating: “Patients with very severe stroke are at higher risk for intracerebral haemorrhage (ICH) and death and should not be treated.” Formulated in 2003, this was not based on high-grade evidence, as several trials at the time had Increasing stroke severity is associated with higher risk of SICH. During the development of the SITS Risk Score, a predictive instrument for thrombolysis-related SICH, the authors found indications that the risk may plateau at high NIHSS levels. They hypothesised that there may not be a significant increase in ICH risk following thrombolysis in very severe stroke defined as NIHSS scores >25.

Mazya et al (2015) showed no excess risk of cerebral haemorrhage in patients with NIHSS score >25 compared to score 15-25, suggesting that the European contraindication to IV tissue plasminogen activator treatment at NIHSS levels >25 may be unwarranted. Increased mortality and lower rates of functional independence in patients with NIHSS score >25 is explained by higher stroke severity, impaired consciousness on presentation due to posterior circulation ischaemia, and longer treatment delays.

References available on request.