medtigo Journal of Emergency Medicine

|Literature Review

| Volume 2, Issue 3

Stroke – Screening Tools and Mimics

  • 1

Author Affiliations

medtigo J Emerg Med. |
Date - Received: May 13, 2025,
Accepted: May 16, 2025,
Published: Jul 03, 2025.

https://doi.org/10.63096/medtigo3092232

Abstract

Background: Prehospital clinicians should have available screening tools to diagnose patients with signs and symptoms of a stroke against possible mimics.
Aim: This study aims to review the current stroke screening tools available, taking into consideration the stroke locations and the stroke mimics.
Methodology: A literature search was undertaken aiming to identify the different types of stroke screening tools from papers previously published and to compare their factors. A literature search aiming to identify stroke mimics was also undertaken.
Results: There were 8 stroke locations, 14 signs and symptoms, 42 stroke screening tools, and 40 stroke mimics identified. Posterior National Institutes of Health Stroke Scale (P-NIHSS) was identified as the stroke screening tool more capable of assessing stroke signs and symptoms. Glasgow coma scale (GCS) and head impulse, nystagmus, test of skew (HiNTS) were identified as the stroke screening tools less capable of assessing stroke signs and symptoms. Nevertheless, the effectiveness of the stroke screening tools depends on the experience and training of the prehospital clinician and the depth of the assessment.
Conclusion: Stroke mimics have the potential to mislead prehospital clinicians, no matter what the stroke screening tool is in use. Adequate patient assessment and history taking are paramount to deliver the appropriate treatment and to transport the patient to the most appropriate hospital facility able to deliver definitive care.

Keywords

Stroke, Screening tools, Mimics, Cerebral thrombosis, Magnetic resonance imaging.

Introduction

Working as a prehospital clinician involves providing care to patients having a stroke. A stroke is a permanent disruption in the blood supply to a part of the brain, resulting in signs and symptoms that last 24 hours or longer.[1,2] Such disruption can be ischemic (85%), caused by a cerebral thrombosis or embolism, or haemorrhagic (15%), caused by a burst blood vessel. According to the Stroke Association, a stroke is the 4th leading cause of death in the United Kingdom (UK).[3] Time is brain. If a stroke is ischemic, the patient may be a candidate to receive recombinant tissue plasminogen activator (rTPA) such as alteplase or tenecteplase between 4.5 and 9 hours from the symptom onset.[4]

Aiming to comply with this timeframe, it is becoming common practice in Europe, North America, Asia, and Australia to deploy computed tomography (CT) equipped ambulances for early diagnosis of ischemic stroke and administration of rTPA on the scene.[5] Nevertheless, if it is a large vessel occlusion (30%), the addition of mechanical thrombectomy is considered more efficient than the rTPA alone.[6] The patient may be a candidate to a mechanical thrombectomy if the pre-stroke modified rankin scale (mRS) is less than 2; if NIHSS is equal or above 6; if the Alberta stroke program early CT score (ASPECTS) is equal or above 6; if the procedure starts within 6 hours of symptom onset; if it is the causative occlusion of the internal carotid artery or the proximal middle cerebral artery; and if the age of the patient is above 18 years old.[7] The patient may be excluded from receiving rTPA or mechanical thrombectomy if it is a haemorrhagic stroke or a large infarct core with minimal penumbra, if the patient has a coagulopathy, or has an elevated blood pressure that cannot be corrected.[7]

For the emergency medical services (EMS) who do not have available CT-equipped ambulances, the prehospital clinicians transport their stroke patients to the nearest healthcare facility capable of administering rTPA. There are also stroke mimics that can confuse prehospital clinicians while assessing the patient.  Differentiating a mimic from a stroke can be crucial to prevent delays in accessing definitive treatment. Approximately 30% of patients presenting with a stroke mimic tend to be misdiagnosed even after being admitted to a hyperacute stroke unit. Therefore, prehospital clinicians should have available reliable stroke screening tools to quickly diagnose patients in the field.[8] This study aims to review the current stroke screening tools available, taking into consideration the affected brain areas and the stroke mimics.

Methodology

A literature search was undertaken aiming to identify the different types of stroke screening tools from papers previously published and to compare their factors. A literature search aiming to identify stroke mimics was also undertaken.

Results

Affected brain areas
The following affected brain areas were identified:

Frontal lobe: It presents signs and symptoms such as impulsiveness, disinhibition, and apathy. Affecting problem solving and decision making, and aphasia if the inferior frontal gyrus is affected.[8]

Parietal Lobe: It presents different signs and symptoms depending on the affected hemisphere. If the right-sided parietal lobe is affected, the patient may present signs and symptoms such as left-sided paralysis or paresthesia, left inferior quadrantanopia, spatial disorientation, left agnosia, left-sided neglect, and inappropriate behaviours. If the left-sided parietal lobe is affected, the patient may present signs and symptoms such as right-sided paralysis or paresthesia, right inferior quadrantanopia, dyscalculia, dysgraphia, dyslexia, impaired ability to learn new information, and change of behaviour.[9]

Temporal lobe: It presents different signs and symptoms depending on the affected hemisphere and which hemisphere is dominant. The patient may present aphasia (expressive, receptive, or both), unilateral neglect, long-term memory impairment, prosopagnosia, aphasia, impairment of visual perception, hearing impairment, and change of behaviour.[9]

Occipital lobe: It presents signs and symptoms such as impairment of deep perception and distance, colour blindness, blindness, hemianopsia, central vision defect, visual hallucinations, prosopagnosia, headache, dizziness, seizures, change of mental status, aphasia, hemiparesis and hemiplegia, and agraphia.[10]

Brain stem: It presents signs and symptoms such as altered level of consciousness, hyperthermia, hemiparesis, hemiplegia, tetraplegia, ataxia, dysphagia, dysarthria, vertigo, alteration of hearing, and gaze deviation.[11]

Cerebellum: It presents signs and symptoms such as headache, altered mental status, vomiting, drowsiness, ataxia, unilateral hearing loss, facial paralysis, slurred speech, and horizontal ipsilateral nystagmus.[11]

Thalamic lesions: They present signs and symptoms such as altered level of consciousness, disorientation, personality changes, aphasia, acalculia, memory impairment, apraxia, hemiparesis, and ataxia.[12]

Basal ganglia: It presents signs and symptoms such as hemiplegia, hemianopsia, and aphasia.

Internal capsule: It presents signs and symptoms such as seizures, aphasia, agnosia, dysgraphia, apraxia, alexia, and amnesia if lacunar, or hemiparesis, ataxia, and dysarthria if motor.

Stroke screening tools
The following stroke screening tools were identified:

3Item Stroke Scale (3ISS); Adam’s Scale of Posterior Stroke (ASPOS); Balance, Eyes, Face, Arm, Speech, Time (BE-FAST); Canadian Neurological Stroke Scale (CNSS); Cincinnati/Naloxone National Institutes of Health Stroke Scale (C/N NIHSS); Cincinnati Prehospital Stroke Scale (CPSS); Cincinnati Prehospital Stroke Severity Score (CP-SSS); Conveniently-Grasped Field Assessment Stroke Triage (CG-FAST); Emergency Triage Stroke Scale (ETSS); European Stroke Scale (ESS); Face, Arm, Speech, Time (FAST); Face, Arm, Speech Test – Vision, Aphasia and Neglect (FAST-VAN); Face, Arms, Stability, Talking, Eyes, React (FASTER); Field Assessment Stroke Triage for Emergency Destination (FAST-ED); Field cut, Aphasia, Neglect, Gaze preference, Dense hemiparesis (FANG-D); Gaze, Face, Arm, Speech and Time (G-FAST); Give Me 5 For Stroke: Walk, Talk, Reach, See, Feel; GCS; HiNTS; Israeli Vertebrobasilar Stroke Scale (IVBSS); Kurashiki Prehospital Stroke Scale (KPSS); Los Angeles Motor Scale (LAMS); Los Angeles Prehospital Stroke Scale (LAPSS); Lower extremity strength, Eyes/visual fields, Gaze deviation, Speech difficulty (LEGS); Medic Prehospital Assessment for Code Stroke (MedPACS); Melbourne Ambulance Stroke Scale (MASS); Miami Emergency Neurologic Deficit (MEND); Modified G-FAST (mG-FAST); Modified National Institutes of Health Stroke Scale (mNIHSS); Modified Prehospital Acute Stroke Severity Scale (mPASS); NIHSS; Ontario Prehospital Stroke Screening Tool (OPSST); Polish version of NIHSS (PL-NIHSS); Posterior NIHSS (P-NIHSS); Prehospital Acute Stroke Severity Scale (PASSS); PreHospital Ambulance Stroke Test (PreHAST); Rapid Arterial occlusion Evaluation (RACE); Recognition of stroke in the emergency room (ROSIER); Short NIHSS 4 (sNIHSS-4) and sNIHSS-5; Scandinavian stroke scale (SSS); and Vision, Aphasia and Neglect (VAN).[10-19]

Mimics
The following mimics were identified:

Acute disseminated encephalomyelitis (ADEM): It is also referred to as a post-infectious encephalomyelitis, an autoimmune disease characterized by demyelination in the brain and spinal cord secondary to an inflammation. With a progression within days, it can present signs and symptoms such as altered mental status, paraparesis, tetraparesis, dysarthria, ataxia, aphasia, colour blindness, and blindness. The diagnosis includes magnetic resonance imaging (MRI), and the treatment involves a high dose of glucocorticoids.[20]

Acute vestibular neuritis (AVN): It is a result of an inflammation of the vestibular portion of the cranial nerve VIII, corresponding to 4% of the most common stroke mimics, and it can present signs and symptoms such as vertigo, nystagmus, and ataxia. The diagnosis includes an MRI, and the treatment involves symptomatic therapy.[21,22]

Alcohol overdose: It presents signs and symptoms such as diplopia, nystagmus, dysarthria, dysphagia, ataxia, and altered level of consciousness. The diagnosis includes a Blood alcohol concentration (BAC) test, and the treatment involves supportive therapy.[23]

Amyotrophic lateral sclerosis (ALS): It is also known as Lou Gehrig’s disease or as Motor Neuron Disease, is progressive, and can present signs and symptoms such as arm and leg weakness, dysphagia, and dysarthria. The diagnosis includes a magnetic resonance imaging (MRI), and there is no treatment for ALS.[24]

Arnold-Chiari malformation (ACM): It is a group of deformities of the posterior fossa and hindbrain. It can present signs and symptoms such as dizziness, arm and leg weakness, ataxia, nystagmus, strabismus, and diplopia. ACM is usually of slow progression, but symptoms can be sudden. The diagnosis includes an MRI, and the treatment involves surgery.[25]

Autonomic dysreflexia: It is a condition secondary to a spinal cord injury above T6. It can present signs and symptoms such as headache, diplopia, miosis, dizziness, aphasia, and confusion. The diagnosis includes patient assessment and history taking, and the treatment involves moving the patient upright, bladder drainage, and administration of Nitroglycerine 2%.[26,27]

Bell’s palsy: It is a nerve dysfunction secondary to trauma or inflammation of the cranial nerve VII. It can present signs and symptoms such as upper and lower facial paralysis, distinguishing from a stroke, which normally presents only with lower facial paralysis, and the treatment is based on corticosteroids.[28]

Botulism: It is caused by a neurotoxin produced by Clostridium botulinum, and can present signs and symptoms such as symmetric descending flaccid paralysis, facial palsy, diplopia, dysphagia, and dysarthria. The diagnosis includes laboratory diagnostics, and the treatment is supportive.[29]

Brain tumour: It corresponds to 7% of the most common stroke mimics. Depending on its location, brain tumours can present progressive signs and symptoms such as headache, altered mental status, ataxia, dysarthria, behavioural changes, memory problems, hemiparesis, hemiplegia, hemianopsia, and blindness. The diagnosis includes CT and/or MRI, and the treatment involves radiotherapy, chemotherapy, and surgery.[30]

Carbon monoxide (CO) toxicity: CO binds to haemoglobin forming Carboxyhemoglobin (COHb) with 220% greater affinity to haemoglobin than oxygen and presents signs and symptoms such as headache, dizziness, and altered level of consciousness. Pulse oximetry (SpO2) measurements consistently overestimate the fractional arterial oxygen saturation. Pulse Co-Oximetry (SpCO) measurement is a reliable method to identify COHB and is available in most of the new prehospital monitors. Levels >10%, SpCO supports the diagnosis of CO toxicity, and the treatment involves the administration of oxygen, from 100% to hyperbaric.[31]

Central pontine myelolysis (CPM): It is also known as Osmotic Demyelination Syndrome, and is a neurologic condition caused by the rapid correction of hyponatremia in cases such as severe burns, liver transplantation, anorexia, hyperemesis, and hyperglycaemia. It can present signs and symptoms such as dysarthria, dysphagia, and quadriplegia. The diagnosis includes patient assessment, history taking, and arterial/venous blood gas measurement, which are already available in some EMS. The treatment is mainly supportive.[32]

Conversion disorder, schizophrenia, and bipolar disorders: They correspond to 75% of stroke mimics. It is a psychiatric disorder that can present symptoms such as altered level of consciousness, paralysis, gait disorder, sensory loss, and visual disturbances with forced eye closure. “Drift without pronator” can be used to confirm the diagnosis.[33]

Creutzfeldt-Jakob disease (CJD): It is also known as bovine spongiform encephalopathy or mad cow disease, is a progressive neurodegenerative disorder. It presents signs and symptoms such as aphasia, impaired concentration, memory, and judgment; nystagmus; ataxia; extensor plantar response. The diagnosis includes an MRI, and there is no treatment for CJD.[34]

Dementia: It corresponds to 3% of the stroke mimics, is a syndrome caused by several diseases such as Alzheimer’s disease, vascular dementia, Lewy body dementia, frontotemporal dementia, and mixed dementia. Being progressive, dementia can present as memory loss, communication and language impairment, agnosia, and impaired executive functions. The diagnosis includes patient assessment, history taking, CT, and/or MRI. There is currently no cure for dementia, and the treatment involves supportive therapy.[35]

Dialysis disequilibrium syndrome (DDS): It is a neurologic manifestation seen during or following dialysis due to fluid shifts, presenting signs and symptoms such as headache, nausea, diplopia, restlessness, confusion, coma, and seizures. MRI could be helpful to support the diagnosis, and haemodialysis could be part of the treatment.[36]

Encephalitis and meningitis: It is an inflammation of the brain and/or meninges resulting in altered level of consciousness, headache, fever, stiff neck (Paediatric Child Health, 1998), diplopia, and vision loss. The diagnosis encompasses patient assessment (including Brudzinski and Kerning’s sign), lumbar puncture, and antibiotics that should start at the prehospital setting.[37,38]

Gerstmann syndrome: It is also known as Angular Gyrus lesion, a lesion of the dominant inferior parietal lobule, a neurological disorder that causes impairment in performing calculations, finger agnosia, agraphia, aphasia, and left-right disorientation. It can be a consequence of neuron necrosis in ischemic stroke, necrotizing granulomatous inflammation of small and medium-sized subarachnoid vessels, dilated perivascular spaces with multiple cystic lesions, human immunodeficiency virus (HIV) correlated encephalopathy, Lupus, and Alzheimer’s. The diagnosis includes an MRI. There is currently no cure for Gerstmann syndrome, and the treatment involves supportive therapy.[39]

Guillain-Barre syndrome: It is a progressive autoimmune disease that causes the destruction of the peripheral nervous system. With a progression of days, it can present signs and symptoms such as bilateral paralysis, facial paralysis, and dysphagia. The diagnosis includes patient assessment, history taking, and MRI, and the treatment includes plasmapheresis and immunoglobulin therapy.[40]

Heatstroke: It occurs after exposure to extreme environmental conditions. It can present signs and symptoms such as hyperthermia, cognitive dysfunction, altered level of consciousness, ataxia, and dysarthria. The diagnosis includes patient assessment, history taking, measurement of the core temperature, and the treatment includes passive cooling and application of cold packs to the cheeks, palms, and soles.[41]

Hepatic encephalopathy: It is normally associated with liver disease, presents signs and symptoms such as lethargy, asterixis, disarthria, confusion, and jaundice. The diagnosis includes liver function tests, and the treatment includes lactulose.[42]

Horner’s syndrome: It is associated with a disruption in the sympathetic nerve and causes a partial ptosis, miosis, and facial anhidrosis. The diagnosis includes an MRI, and the treatment includes surgery.[43]

Huntington’s disease: It is a progressive condition causing cognitive and behavioural disturbances, dysphagia, dysarthria, ataxia, and memory lapses. The diagnosis includes an MRI, and there is no cure for Gerstmann Syndrome.[43]

Hyperglycaemia: It occurs normally with Type 2 Diabetic patients with Hyperosmolar Hyperglycemic State (HHS) but also can occur with Type 1 diabetic patients with diabetic ketoacidosis (DKA). It presents with signs and symptoms of altered level of consciousness, aphasia, hemiparesis, and conjugate gaze paresis. The diagnosis includes patient assessment, and the treatment includes insulin and fluids.[44]

Hyperthyroidism and thyroid storm: It presents with signs and symptoms of dysarthria, dysphagia, diplopia, high temperature, agitation, confusion, and altered level of consciousness. The diagnosis includes blood tests such as hormones T-4, T-3, and thyroid-stimulating hormone (TSH), and the treatment includes antithyroid drugs, radioactive iodine, and thyroidectomy.[45]

Hypoglycaemia: It is defined as a low capillary blood glucose, can be classified as level 1 with a glucose <70mg/dL (3.9mmol/L) and ≥54mg/dL (3.0mmol/L); and level 2 with a glucose <54mg/dL (3,0mmol/L) leading to signs and symptoms such as behavioural changes, confusion, loss of consciousness, seizures, hemiplegia and aphasia. The diagnosis includes the Whipple’s triad: recognition of signs and symptoms, blood glucose measurement, and the administration of glucose.[46]

Hypokalaemia: It is defined as a potassium level below 3mmol/L, which is normally due to cardiac disease, renal failure, malnutrition, and dehydration, and presents with signs and symptoms such as facial and extremities paralysis. Although it is possible to measure potassium in the prehospital field if adequate equipment is available, it is also possible to see changes in T wave morphology and U wave on the electrocardiogram (ECG). The treatment includes the administration of potassium chloride, 40 40mmol, given every 3 to 4 hours.[47]

Hyponatraemia: It leads to hyponatraemic encephalopathy, defined as a sodium level below 135mmol/L due to dehydration, congestive heart failure, and renal and liver diseases. It presents with signs and symptoms such as acute confusion. Although it is possible to measure sodium in the prehospital field if adequate equipment is available, caution should be taken while correcting the sodium levels due to the risk of CPM. The current recommendation is 8-12mEq/L/24 hours.[48]

Hypoxia: It causes signs and symptoms such as headache, confusion, and altered level of consciousness with SpO2 <90%. The treatment includes the administration of oxygen.[49]

Malignant hyperthermia: It is caused by exposure to haloalkane anaesthetic gases or depolarizing muscle relaxant succinylcholine. It presents signs and symptoms such as hypoxia, headache, confusion, altered level of consciousness, high temperature, skeletal muscle rigidity, and altered mental status. Treatment includes dantrolene.[50]

Medication overdose: Such as clozapine, or intoxications with products such as ethylene glycol, cause dysarthria, ataxia, nystagmus, and altered level of consciousness. History taking is paramount to correlate signs and symptoms to the presentation of the patient and to administer the correct antagonist if available.[51]

Migraine: It corresponds to 9% of stroke mimics and about 18% of all improper thrombolytic treatments. It presents signs and symptoms such as hemiplegic migraine, depression, cognitive decline, vertigo, diplopia, dysarthria, impaired hearing, ataxia, confusion, and occasional loss of consciousness. The diagnosis includes patient assessment and history taken, and the treatment involves a combination of medication for prevention and immediate relief during the acute phase.[52,53]

Multiple sclerosis (MS): It is a chronic autoimmune disease characterized by inflammation, demyelination, gliosis, and neuronal loss. Being progressive, MS presents with signs and symptoms such as cognitive impairment, diplopia, hemiplegia, and facial palsy. The diagnosis includes patient assessment, history taken, and MRI. There is currently no cure for MS, and the treatment involves supportive therapy.[54]

Myasthenia gravis: It is an autoimmune disorder affecting the neuromuscular junction of the skeletal muscles. Being progressive, it presents with signs and symptoms such as dysphagia and dysarthria, facial palsy, and diplopia. The diagnosis includes patient assessment, history taken, and blood tests such as acetylcholine and anti-MuSK antibodies. There is currently no cure for Myasthenia Gravis, and the treatment involves supportive therapy.[55]

Narcolepsy: It is a disorder characterised by excessive daytime sleepiness. Being progressive, it presents with signs and symptoms such as sleep paralysis and hypnagogic hallucinations. The diagnosis includes patient assessment and history taken. There is currently no cure for Narcolepsy, and the treatment involves supportive therapy.[56]

Neuroleptic malignant syndrome (NMS): It is associated with the use of dopamine-receptor antagonist medications such as antipsychotics, presents with signs and symptoms such as altered level of consciousness, high temperature, and muscle rigidity. The diagnosis includes patient assessment, history taken, and the treatment includes the cessation of the offending medication.[57]

Peripheral neuropathy: It is corresponding to 4% of the most common stroke mimics, is frequently found in patients with Type 1 and Type 2 diabetes, but also with chronic excessive alcohol consumption, low level of vitamin B12, as a side effect of cancer treatment, myelin inflammation, meralgia paresthetica, and multifocal motor neuropathy. It presents with signs and symptoms such as an isolated motor deficit in a leg or arm without a sensory impairment, ataxia, and dysarthria. The diagnosis includes patient assessment, history taken, MRI, and the treatment may include immunoglobulin and/or plasmapheresis if appropriate.[58]

Posterior reversible encephalopathy syndrome (PRES): It occurs as a consequence of hypertension, renal failure (uremic encephalopathy), liver failure (Wernicke’s encephalopathy caused by thiamine deficiency), sepsis (corresponding to 12% of the most common stroke mimics), organ transplantation, eclampsia and pre-eclampsia, malignancy, electrolytic imbalance, hypercholesterolemia, autoimmune disorders, toxins, cytotoxic and immunosuppressive medication, among other medication. PRES signs and symptoms manifest over several hours or days, such as altered level of consciousness, seizures, headaches, diplopia, blindness, abnormal colour vision, visual hallucinations, nystagmus, aphasia, and hemiparesis. The diagnosis includes patient assessment, history taken, and MRI, and the treatment includes the management of the underlying aetiology.[59]

Progressive supranuclear palsy (PSP): It is an uncommon and progressive neurologic disorder that is frequently misdiagnosed as Parkinson’s disease due to the presence of tremors that can affect movement, gait, balance, speech, swallowing, vision, eye movements, mood, behaviour, cognition, and the alien limb phenomenon. The diagnosis includes an MRI, and the treatment involves supportive therapy. [60]

Traumatic brain injury (TBI): It causes signs and symptoms such as headache, confusion, dizziness, diplopia, tinnitus, behaviour change, memory impairment, blindness, dysarthria, seizures, anisocoria, paresthesia, and altered level of consciousness. The diagnosis includes patient assessment, history taken, head CT, and MRI, and the treatment depends on its severity.[61]

Todd’s palsy: It is associated with weakness or paralysis after 13% of all seizures and 20% of stroke mimics, and can originate from previous ischemic or haemorrhagic strokes. It can present with signs and symptoms such as motor paresis, dysarthria, diplopia, and altered level of consciousness. The diagnosis includes patient assessment and history taken, and there is no treatment for Todd’s Palsy. Signs and symptoms can last from 30 minutes to 36 hours.[62]

Discussion

Based on the data obtained, a matrix was created identifying eight affected brain areas, signs and symptoms of a stroke grouped in 14 signs and symptoms, 42 stroke screening tools, and 40 stroke mimics.

Level of consciousness & behaviour: Aim to assess the level of consciousness of the patient in terms of orientation in space, time, and person. Three questions should be asked: “What is your name?”, “What month are we in?”, and “Where are we right now?”. Aphasic and stuporous patients, patients having seizures, intubated patients, patients with facial trauma, patients with dysarthria, and non-English speaking patients won’t be able to comply.

Aphasia, dysarthria & dyslexia: Aim to assess the receptive and expressive speech. Three questions should be asked to assess receptive language: “Can you close/open your eyes?”, “Does a stone sink in water?”, and “Can you point to the ceiling/sky?” Two questions should be asked to assess expressive language while showing three objects: “What is this?” and “What is this for?” An order to assess dysarthria/dyslexia, one order should be given: “Please, repeat after me: You can’t teach an old dog new tricks”.

Facial droop, numbness, and palsy: Aim to assess the face through the cranial nerve VII (Facial). Four questions should be given: “Can you smile, showing your teeth?”, “Can you puff out your cheeks?” and “Can you raise your eyebrows?” Upper droop, numb & palsy. Aim to assess the strength/sensibility of the upper limbs. Pronator drift test should be performed for 20 seconds with the patient’s eyes closed and the palms facing up. Patients with upper limb amputations or previous neuropathic problems will not be able to comply.

Lower droop, numb & palsy: Aim to assess the strength/sensibility of the lower limbs. In supine position, raise the leg of the patient (one at a time) 30 degrees and ask the patient to hold it for 5 seconds. The Babinski test was also considered. Patients with lumbosacral nerve root irritation, such as lumbar disc herniation, will not be able to comply.[63]

Gait: Aim to identify the presence of ataxia/dizziness/vertigo. Stance and posture, gait, tandem walk, and Romberg’s test are some of the assessments that could be done.

Eye movement: Aim to assess the movement of the eyes through the cranial nerves III (Oculomotor), IV (Trochlear), and VI (Abducens). Holding a pen or finger in front of the patient, ask them to follow it without moving the head. The movement should be in an H-

shaped pattern. Abnormal findings include gaze deviation/ophthalmoplegia and nystagmus. Patients with strabismus will not be able to comply.

Vision: Aim to assess the vision acuity, visual fields, pupillary light reflexes, and the accommodation reflex through the cranial nerve II (Optic). Abnormal findings include anisocoria, fixed miosis or mydiasis, vision loss, diplopia, hemianopia, and quadrantanopia.

Unilateral extinction, inattention, neglect, denial & agnosia. Aim to assess the ability to perceive stimuli towards the affected side.[63] Two questions should be asked: “Whose arm is this?” (while lifting the affected arm), and “Can you lift both arms and clap?”.

Cough & dysphagia: Aim to assess the ability to cough and swallow through the cranial nerves IX (Glossopharyngeal) and X (Vagus). Asking the patient to open their mouth and say “Aah!”, confirm if the palate elevates symmetrically, if the uvula is midline, and if the gag reflex is present.

Tongue deviation: Aim to assess the tongue through the cranial nerve XII (Hypoglossal). Asking the patient to protrude the tongue, confirm if the tongue is aligned without atrophy, fasciculation, or deviation.[64,65]

Headache: Aim to assess the presence of a headache. According to Aghangar et al.[66] There is no association between a new-onset headache and a stroke. Nevertheless, headaches are present in 6-44% of the ischemic stroke population. A sudden, severe thunderclap headache is associated with a subarachnoid haemorrhage. Only Give me 5 For Stroke is the only screening tool that considers headache.

Horner’s syndrome: Aim to assess the presence of Horner’s Syndrome in order to rule out a stroke. Miosis can be identified in Vision, but only P-NIHSS assesses ptosis and anhidrosis.

Hyperthermia: Aim to assess the presence of hyperthermia. Despite being essential for the evaluation of temperature, which is mandatory to be assessed in a prehospital setting, no stroke screening tools assess temperature.[66]

P-NIHSS was identified as the stroke screening tool more capable of assessing stroke signs and symptoms. GCS and HiNTS were identified as the stroke screening tools less capable of assessing stroke signs and symptoms. Nevertheless, the effectiveness of the stroke screening tools depends on the experience and training of the prehospital clinician and the depth of the assessment. Difficulties in accurately identifying the location of a stroke based only on signs and symptoms were also noticed. As an example, aphasia will cause a communication problem affecting the evaluation of the level of consciousness, description of vision, and assessment of neglect.[67]

Stroke mimics have the potential to mislead prehospital clinicians, no matter the stroke screening tool used. Some exams were excluded. An example is the Rinne and Weber tests to assess cranial nerve VIII, expecting to detect nystagmus while assessing “eye movement.” Adequate patient assessment and history taking are paramount to deliver the appropriate treatment and to transport the patient to the most appropriate hospital facility able to deliver definitive care. Therefore, neuroimaging such as head CT and specific blood tests play an essential role in ruling out stroke mimics, distinguishing between ischemic and haemorrhagic stroke, and identifying its location.[67]

Conclusion

There were identified 8 affected brain areas, 14 signs and symptoms, 42 stroke screening tools, and 40 stroke mimics were identified. P-NIHSS was identified as the stroke screening tool more capable of assessing stroke signs and symptoms, and GCS and HiNTS were identified as the stroke screening tools less capable of assessing stroke signs and symptoms. Nevertheless, the effectiveness of the stroke screening tools depends on the experience and training of the prehospital clinician and the depth of the assessment. Stroke mimics have the potential to mislead prehospital clinicians, no matter what the stroke screening tool is in use. Adequate patient assessment and history taking are paramount to deliver the appropriate treatment and to transport the patient to the most appropriate hospital facility able to deliver definitive care.

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Author Information

Alfredo Manuel da Silva Leal
Independent Researcher
College of Remote and Offshore Medicine, Portugal
Email: a.leal@corom.edu.mt

Acknowledgments

Not applicable

Funding

No funding bodies/grants supported this research or contributed to the salary of the author.

Author Information

Alfredo Manuel da Silva Leal
Independent Researcher
College of Remote and Offshore Medicine, Portugal
Email: a.leal@corom.edu.mt

Author Contribution

The author contributed to the conceptualization, investigation, and data curation by acquiring and critically reviewing the selected articles and was involved in the writing – original draft preparation and writing – review & editing to refine the manuscript.

Ethical Approval

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Conflict of Interest Statement

I, Alfredo Manuel da Silva Leal, declare that I have no conflict of interest relating to this article. I have no personal, financial, or other relationships that could influence my work or decisions in this matter.

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DOI

https://doi.org/10.63096/medtigo3092232

Cite this Article

Leal AMS. Stroke – Screening Tools and Mimics. medtigo J Emerg Med. 2025;2(3):e3092232. doi:10.63096/medtigo3092232 Crossref

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