Acute ischaemic stroke symptoms and mimics

Acute ischaemic stroke symptoms and mimics

Acute ischaemic stroke patients require time-critical reperfusion treatments, so rapid identification of stroke symptoms and a quick reaction time are critical to initiate prompt intervention.

The FAST test is popular for identifying acute stroke symptoms where FAST stands for Face drooping, Arm weakness, Speech difficulty, Time to call emergency.1,2

When looking for stroke signs, asymmetry is important. Using the FAST test:

FACE: Facial weakness due to acute stroke will cause one side of the face to droop and often, the patient’s smile is uneven or lopsided, or they may be drooling from one side of the mouth.

ARM: When asked to raise both arms, a stroke should be suspected if only one arm is mobile, or one arm is weaker, numb or drifting downward.

SPEECH: Slurred or incoherent speech and/or the inability to understand or repeat simple sentences are often a sign of stroke.

TIME: If any of the above signs are present and sudden in onset, the emergency services must be called immediately and informed that the patient may have had an acute stroke. Time is of the essence here and the patient needs to be transported to stroke facilities as quickly as possible.


FAST test to identify acute stroke symptoms

FAST test to identify acute stroke symptoms


In addition to FAST, there may be additional stroke symptoms that can occur such as:3

  • Weakness or numbness in the face and extremities (arm, leg, face; especially on one side)
  • Confusion or trouble understanding other people
  • Problems in vision with one or both eyes
  • Sudden severe headache
  • Difficulty in coordination (walking, etc.)
  • Dizziness
  • Loss of balance
  • Difficulty in swallowing

An additional set of symptoms such as vertigo, nausea and vomiting may occur when a patient suffers from “posterior circulation stroke” that occurs in the back part of the brain. When stroke symptoms subside after a few minutes, it could be a sign of transient ischaemic attack (TIA). Even though not as severe as a stroke, TIA should not be ignored. It is viewed as a warning sign after which the risk of stroke is significantly higher.

Depending on the hemispheres of the brain where stroke occurs, symptoms can be characterised as shown in the figure below.4


Stroke symptoms based on the location of the stroke

Stoke symptoms based on the location of the stroke

Furthermore, haemorrhagic stroke can be subdivided into intraparenchymal and subarachnoid haemorrhagic stroke, which are often associated respectively with the symptoms shown in the figure below.


Intracerebral haemorrhagic stroke

Intracerebral haemorrhagic stroke



There are several conditions that mimic stroke leading to misdiagnosis, and physicians need to be aware of these. The most common stroke mimics are:5

  • Brain tumours (gliomas, meningiomas, and adenomas)
  • Toxic or metabolic disorders (hypoglycaemia, hypercalcaemia, hyponatraemia, uraemia, hepatic encephalopathy, hyperthyroidism, thyroid storm, alcohol intoxication, drug overuse)
  • Infectious disorders (meningoencephalitis, sepsis, cerebral infections)
  • Psychological disorders and migraines
  • Demyelization disorders
  • Transient global amnesia
  • Seizure or post seizure (Todd’s paralysis)
  • Epidural haematoma
  • Neuropathies (Bell’s Palsy)
  • Hypertensive encephalopathy


Especially in the paediatric population the incidence of stroke mimics is relatively high, with complicated migraine, seizures disorders, Bell’s Palsy and conversion disorders being the most common diagnosis.6 Therefore, clinical identification of stroke and accurate differentiation from mimics is crucial to ensure a proper treatment of these patients.


Stroke assessment tests

Emergency physicians or paramedics with training for acute stroke assessment demonstrate a higher sensitivity to stroke than those without. Pre-hospital acute stroke assessment training has also been shown to increase the accuracy of acute stroke identification. Field assessment of acute stroke look at several criteria that help identify the patient’s condition.7

Several tests are performed to confirm acute stroke. The most time critical of these is imaging – either computerised tomography (CT scan) or magnetic resonance imaging (MRI) – to identify whether the acute stroke is ischaemic or haemorrhagic and to rule out haemorrhagic stroke in the case of an ischaemic stroke if thrombolysis is being considered. Angiograms and further contrast imaging studies can help to identify and locate blocked and damaged arteries, as well as ruling out stroke mimics.

  1. American Stroke Association | A Division of the American Heart Association. Available at: Accessed February 7, 2019.
  2. Kobayashi A., et al. European Academy of Neurology and European Stroke Organization consensus statement and practical guidance for pre-hospital management of stroke. Eur J Neurol 2018;25:425–433.
  3. Powers WJ., et al. 2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke 2018;49:e46–e110.
  4. Summers D., et al. Comprehensive overview of nursing and interdisciplinary care of the acute ischemic stroke patient: a scientific statement from the American Heart Association. Stroke 2009;40:2911–2944.
  5. Hosseininezhad M., et al. Stroke mimics in patients with clinical signs of stroke. Casp J Intern Med 2017;8:213–216.
  6. Mackay MT., et al. Differentiating Childhood Stroke From Mimics in the Emergency Department. Stroke J Cereb Circ 2016;47:2476–2481.
  7. American Heart Association. Stroke training for EMS professionals.