Introduction[edit | edit source]
’ Time is Brain’ i.e we should not waste any time at all in assessment.
Acute Stroke is a medical emergency. Stroke is a major cause of death and disability, and patient outcomes depend on how quickly the blood flow can be restored to the damaged area of the brain. The assessment of a stroke patient involves stabilizing the Airway, Breathing, and Circulation (ABC). This is followed by a rapid, concise, history and exam (eg NIHSS see below) which is administered simultaneously as the patient gets IV access, telemetry, and lab tests were drawn. The patient should then get a stat non-contrasted head CT or a combination of Head CT, CT Angiography, and perfusion imaging.
Pre-hospital and Acute Stroke scales are standardized assessment tools are used to identify Stroke and clear a path to reperfusion.
Treatment options for stroke include thrombolytic medications that aim to dissolve the clot, and interventional endovascular procedures (similar to a cardiac catheterization) to remove it. Successful stroke care requires early recognition, transporting the patient to a designated stroke centre, and early activation of a stroke team at the hospital. In 2018, a significant paradigm shift happened in stroke care. DAWN trial showed significant benefits of Endovascular thrombectomy in patients with large vessel occlusion in the arteries of the proximal anterior circulation. This trial extended the stroke window up to 24 hours in selected patients using perfusion imaging. Due to this more patients can be treated even up to 24 hours post-event.
In addition to their importance for assessing the impact of therapeutic interventions in clinical trials, stroke scales are useful in the routine clinical setting as aids to improve diagnostic accuracy, help determine the appropriateness of specific treatments, monitor a patient's neurologic deficits through the continuum of care, and predict and gauge outcomes. Not only are different types of scales needed for these different purposes, but no single scale is suitable for capturing all of the effects of stroke.
Diagnostic Accuracy of clinical tools for assessment of acute Stroke[edit | edit source]
A wide range of clinical assessment tools for selecting subjects with acute stroke has been developed in recent years. Assessment of both cortical and motor function using RACE, FAST-ED and NIHSS showed the best diagnostic accuracy values for selecting subjects with large vessel occlusion.
- There were limited data on clinical tools that can be used to differentiate between acute ischaemia and haemorrhage.
- Diagnostic accuracy appeared to be modest for distinguishing between acute stroke and stroke mimics.
- Further prehospital research is required to improve the diagnostic utility of clinical assessments with the possible application of a two-step clinical assessment or involvement of simple brain imaging, such as transcranial ultrasonography.
Pre Hospital Scales[edit | edit source]
Emergency Medical Services (EMS) provide the first medical contact for up to 70% of all stroke patients, and are therefore in a unique position to reduce delays in presentation and treatment. Reliable identification of stroke patients in the field could decrease delays by permitting paramedics to notify receiving hospitals of the imminent arrival of a stroke case ensuring rapid mobilization of stroke teams and early access to required scanning on hospital arrival. Pre-Hospital assessment and determination of stroke severity is a new concept, with the best scale yet to be determined. The Cincinnati and Los Angeles scales have been validated in hospital trials, but studies are mixed when applied by EMS . The RACE Scale has had some positive results when tested among paramedics in Spain with more studies underway, currently it is being adopted by many EMS Systems in the United States.
Cincinnati Pre-Hospital Stroke Scale
Easy to Conduct - 3 Items < 1 Min
Derived from NIHSS
Unable to measure
Posterior Circulation Strokes
Does not assess Stroke Severity
Face Arms Speech Test
Easy to Use
Can be used by Medical and Non-Medical
|Does not assess Stroke Severity|
Los Angeles Prehospital Stroke Screen
Takes < 3 mins to perform
More Sensitive / Specific than CPSS
Nine Items to Assess
Does not assess Stroke Severity
Los Angeles Motor Scale
Derived from NIHSS
Assess Stroke Severity
Can Identify Large Vessel Occlusion
|Takes more time to complete|
Rapid Arterial oCclusion Evaluation
Assess Stroke Severity
Can Identify Large Vessel Occlusion
|Takes more time to complete|
Miami Emergency Neurological Deficit
Combines Cincinnati Scale with components of NIHSS
Takes < 3 mins to perform
|No Published Studies|
Cincinnati Pre-Hospital Stroke Scale (CPSS)[edit | edit source]
Developed in 1997 at the University of Cincinnati Medical Center for pre-hospital use the Cincinnati Pre-Hospital Stroke Scale (CPSS) was derived from the National Institutes of Health Stroke Scale. The CPSS is used to diagnose a potential stroke in a pre-hospital setting through testing the following three signs . If any one of these tests shows abnormal findings, the patient may be having a stroke and should be transported to a hospital as soon as possible. Patients with 1 of these 3 findings as a new event have a 72% probability of an ischemic stroke, while if all 3 findings are present the probability of an acute stroke is greater than 85% .
FAST (Face, Arm, Speech Test)[edit | edit source]
FAST was developed in the UK in 1998 by a group of stroke physicians, ambulance personnel, and emergency room physician and was designed to be an integral part of a training package for ambulance staff. The FAST was derived following a review of existing stroke identification instruments including the Cincinnati Prehospital Stroke Scale (CPSS) and the Los Angeles Prehospital Stroke Screen (LAPSS). FAST was created to expedite the administration of intravenous tissue plasminogen activator to patients within 3 hours of acute stroke symptom onset. During the development of the FAST Scale, emphasis was placed on producing a simple test that would complement existing assessments used by UK paramedics, such as the Glasgow Coma Scale. FAST contains 3 key elements from the CPSS ((Facial Weakness, Arm Weakness, and Speech Disturbance) but avoids the need to repeat a sentence as a measure of speech, instead of using assessment of language ability by the paramedic during a normal conversation with the patient. The 3 assessments contained within the FAST were incorporated into the standard ambulance report form used for recording all ambulance contacts within the UK.
The FAST Test is now used in many countries as a Campaign for to help the public achieve a better understanding of the warning signs of stroke, ensuring that individuals get the medical assistance they need quicker.
Los Angeles Prehospital Stroke Screen (LAPSS)[edit | edit source]
The Los Angeles Prehospital Stroke Screen (LAPSS) is a long and widely used validated screening tool for early identification of stroke by Emergency Medical Technicians / Paramedics. The LAPSS showed a Sensitivity of 91%, Specificity of 97% with a Positive Predictive Value of 86% and Negative Predictive Value of 97% following a Prospective Study In Field Validation Study with 19 UCLA Paramedic Crews, who following a 60-min Training Session . If Items 1 - 6 below are all Yes's or Items 5 - 7 Unknown then LAPSS Screening Criteria is met. Note: the patient may still be experiencing a Stroke even if LAPSS Criteria are not met.
Los Angeles Motor Scale (LAMS)[edit | edit source]
The Los Angeles Motor Scale (LAMS) is a brief 3-item stroke severity assessment measure designed for prehospital and Emergency Department use, derived from the Los Angeles Prehospital Stroke Screen which quantitatively characterizes stroke severity in the field, and predicts functional outcomes with accuracy nearly comparable to that of the full NIHSS. The Los Angeles Motor Scale (LAMS) was constructed by assigning point values to LAPSS items of Facial Weakness (0,1), Arm Strength (0,1,2) and Grip (0,1,2) to yield a total 0–5 Scale . A motor score derived from the LAMS rapidly quantifies stroke severity in the field and predicts functional outcomes with accuracy comparable to that of the full NIHSS and the NIHSS . A score ≥ 4 is highly predicted of large artery occlusion. Compared with other instruments proposed for prehospital stroke severity assessment the LAMS has advantages of greater simplicity, more rapid administration, and of being immediately derivable from a validated stroke recognition instrument, rather than requiring separate examinations for stroke diagnosis and stroke severity assessment .
Performing the LAMS is a good strategy to identify stroke patients in the field, assess their severity, and determine the likelihood that they are candidates for endovascular therapies. Where those with a LAMS score of ≥4, a pre-arrival notification could accelerate endovascular interventions by permitting early mobilization of the endovascular team and readying of the angiographic suite.
Rapid Arterial oCclusion Evaluation (RACE)[edit | edit source]
The Rapid Arterial Occlusion Evaluation (RACE) Scale is the most recent scale developed and was designed based on the National Institutes of Health Stroke Scale (NIHSS) to accurately assess stroke severity and identify patients with acute stroke with large artery occlusion at prehospital setting by medical emergency technicians who may be candidates to be treated with endovascular techniques in a comprehensive stroke centre . The RACE Scale takes slightly more time to perform than the CPSS and the LAPSS with the goal of the scale to more accurately identify Stroke Severity and localise the area affected .
The RACE scale is a simplification of the NIHSS scale using those items with a higher ability to predict the presence of large vessel occlusion. It evaluates 5 items: Facial Palsy, Brachial Paresis, Crural Paresis, Oculocephalic Deviation and Aphasia/Agnosia, with a total score of 0-9. Based on the RACE Scale a Stroke is likely with a score above 1 and an Emergent Large Vessel Occlusion is likely if the cumulative score is > 4 with a sensitivity of 85% and specificity of 69%.
Miami Emergency Neurological Deficit (MEND)[edit | edit source]
The Miami Emergency Neurologic Deficit (MEND) is an easy-to-learn, easy-to-use checklist that provides key information which incorporates the three components of the Cincinnati Prehospital Stroke Scale (CPSS) as well as additional components from the NIH Stroke Scale (NIHSS). The MEND was devised to facilitate communication between healthcare providers throughout the continuum of care for stroke patients as it can be used to obtain a baseline exam in the prehospital setting and then for initial evaluation and subsequent exams in the emergency department or ICU. It is more thorough than the CPSS but takes less than 3 minutes to perform and requires no additional tools. in the prehospital setting is that the CPSS be performed on scene and the MEND exam is performed en route, to minimize transport delays.
ABCD / ABCD2[edit | edit source]
The ABCD / ABCD2 can be used to predict the risk of stroke during the first seven days after having a Transient Ischemic Attack (TIA). Researchers found there to be over 30% risk of stroke in TIA patients with an 'ABCD score' of six, as compared to no strokes in those with a low ABCD score. Can be used in routine clinical practice to identify high-risk individuals who require emergency investigation and treatment.
The ABCD2 score was created by merging two previously validated clinical decision rules - the ABCD and the California scores. The ABCD score was created to estimate the 7-day risk of stroke following a TIA, while the California score predicted the 90-day risk. The ABCD2 score is a validated, seven-point, risk-stratification tool to identify patients at high risk of stroke following a TIA. Patients with scores ≥4 are at considerably higher risk of stroke in the 2 days following a TIA, and may potentially require urgent intervention as inpatients.
Acute Hospital Scales[edit | edit source]
The main role is to measure deficits and stroke severity, which predicts patient discharge disposition. It provides a Standardized Neurological Exam, that can be utilised to monitor Neurological Status and can also be used to match patients to allow for comparison in clinical trials.
National Institutes of Health Stroke Scale (NIHSS)[edit | edit source]
The National Institutes of Health Stroke Scale (NHISS), considered the Gold Standard Acute Stroke Assessment, is a systematic assessment tool that provides a quantitative measure of stroke-related neurologic deficit. The NIHSS was originally designed as a research tool to measure baseline data on patients in acute stroke clinical trials. Now, the scale is also widely used as a clinical assessment tool to evaluate the acuity of stroke patients, determine appropriate treatment, and predict patient outcomes.
The NIHSS can be used as a clinical stroke assessment tool to evaluate and document neurological status in acute stroke patients. The stroke scale is valid for predicting lesion size and can serve as a measure of stroke severity. The NIHSS is a predictor of both short and long term outcomes of stroke patients. Additionally, the stroke scale serves as a data collection tool for planning patient care and provides a common language for information exchanges among healthcare providers.
The scale is designed to be a simple, valid, and reliable tool that can be administered at the bedside consistently by physicians, nurses or therapists. Read more about the NIHSS.
Stroke severity may be stratified based on NIHSS Scores as follows:
[edit | edit source]
The National Institutes of Health Stroke Scale (NIHSS) is the first choice among stroke scales. The Scandinavian Stroke Scale (SSS) is an alternative stroke scale, that is to apply in clinics, frequently used in Scandinavian countries and has recently also been validated in the Portuguese language . Inter-rater reliability of the items varies from excellent for conscious level, orientation and gait, to moderate for facial palsy . Neurological recovery, as measured by the SSS change score during the first week after onset of stroke, was shown to be an independent predictor of good functional outcome. The advantage of the SSS is its simplicity, which makes it easy to perform repeated measures in the very acute phase after stroke. In a 2016 prospective study including patients with acute stroke, the SSS was as good as the NIHSS in identifying patients who had died or were dependent at 3-month follow-up.
According to Askim et al (2016) although the measurement properties of the NIHSS and the SSS are equal in their ability to identify outcomes, the superiority of the SSS lies with its simplicity and ease of use in the clinic. An example is a difference in measuring motor function between the two scales. While in the NIHSS patients are asked to keep their limb against gravity for 10 s, which means that you need a watch, in the SSS patients must keep their limb against manual resistance to get a full score. This advantage of the SSS is of particular importance when repeated measures of selected items are used to detect early neurological deterioration .
Canadian Neurological Scale (CNS) - 1986[edit | edit source]
One of the first scales developed to assess stroke patients, the Canadian Neurological Scale (CNS) developed in 1986 as a simple tool to be used in the evaluation and monitoring of the neurological status of patients with stroke in the acute phase and is a validated score to assess stroke severity . Lower scores indicate greater stroke severity. The CNS evaluates 10 clinical domains, including mentation (level of consciousness, orientation and speech) and motor function (face, arm and leg). Previous studies showed good to excellent inter-rater agreement . The CNS is brief, valid and reliable, and can be administered in approximately five minutesbut should not be used for the unconscious/stuporous patient.The CNS can also be reliably converted to the NIHSS using a simple conversion formula: NIHSS = 23 - 2 x CNS. This finding may have a practical impact by permitting reliable comparisons with NIHSS-based evaluations and simplifying the routine assessment of acute-stroke patients in more diverse settings . The CNS can be accessed here.
Stroke severity may be stratified based on CNS Scores as follows:
European Stroke Scale (ESS) - 1994[edit | edit source]
The European Stroke Scale (ESS), which consists of 14 items selected for their specificity and their prognostic value, was designed specifically for clinical stroke trials in patients with middle cerebral artery stroke . This scale can be used as an instrument for matching of treatment groups as well as for evaluation of the patient's level of impairment. The scale consists of 14 items selected based on their specificity and their prognostic value. The 14 items are level of consciousness, comprehension, speech, visual field, gaze, facial movement, maintenance of arm position, arm raising, wrist extension, finger strength, maintenance of leg position, leg flexing, foot dorsiflexion, and gait. Because gait is part of the standard clinical neurological evaluation and can be considered as a mixture of different prognostic levels of impairments (i.e, proximal and distal motor function of the leg, postural control), this item was included in the scale. This scale is heavily weighted toward motor function.
The scale is reliable, sensitive, and easy to use and has prognostic value for the outcome. Its concurrent validity was tested in terms of correlation with other neurological scales and with a motor, functional, and handicap scale. The ESS can be used to assess a patient who has recently had a stroke involving the distribution of a middle cerebral artery. This can be used to measure therapeutic efficacy and to match patients for comparison.
Functional and Outcome Assessment Scales[edit | edit source]
Pre-hospital and Acute Scales focus more on impairments such as hemiparesis, consciousness, gaze deviation, muscle tone, reflex abnormalities, and intellectual function which in the acute phase is important to assist with diagnosis and prognosis. During the rehabilitation phase and more chronic chronic phase of stroke, these types of measurement tend to be less important as the focus turns more to performance in functional tasks. For a patient, the most important aspect of his disease is not the specific level of impairment e.g. grade of hemiparesis but more on their ability to perform daily activities and to fulfil social roles. As highlighted by Harrison et al (2013) as stroke is an exemplar disabling long-term condition, measures of function are well suited as outcome assessment. Functional assessment scales are utilised to give a numerical value to abstract concepts such as “disability,” they can be used to objectively quantify deficits and track change over time. This can be particularly useful in a rehabilitation setting.
The following Physiopedia Page outlines a selection of outcome measures that provides the best available information on how outcome measures might be classified and selected for use, based upon their measurement qualities Stroke Outcome Measures Overview.
Here are some of the more common Functional and Outcome Assessment Scales currently used in Stroke Treatment and Management:
Outcome Assessment Scales[edit | edit source]
Summary[edit | edit source]
There are many scoring systems to screen for an acute ischemic stroke in the field. EMS groups most commonly use Face Arm Speech Test (FAST), Cincinnati Prehospital Stroke Scale (CPSS), or Los Angeles Prehospital Stroke Screen (LAPSS). Many of the more commonly used stroke scales are not designed to identify posterior circulation strokes .
The most common scale used in the hospital setting is the NIHSS. For prehospital assessment, the shortened version was developed, including assessment of gaze, visual field, motor function of the right and left leg, language, level of consciousness, facial paresis, and dysarthria. It attempts to predict stroke severity but is more complicated than some of the other stroke scales. With its complexity, it can evaluate strokes outside of the middle cerebral artery distribution.
Current Prehospital Treatment Recommendation
Level A Recommendation
The World Health Organization’s International Classification of Functioning, Disability and Health (WHO-ICF) gives a conceptual framework that can aid the classification of the Stroke Assessment Scales to decide on the appropriate measure for specific functional assessment. The ICF as a framework to approach patient care that shifts the conceptual emphasis away from negative connotations such as disability and places focus on the positive abilities of the individual at the patient level rather than the systems level. The ICF framework is a classiﬁcation of the health components of functioning and disability and focuses on 3 perspectives: body, individual, and societal. These 3 perspectives underscore the importance of the interplay and inﬂuence of both internal and external factors to each individual’s condition of health. Many assessment tools, spanning various functional domains, are available to clinicians and researchers working with stroke survivors.
References[edit | edit source]