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Cincinnati Prehospital Stroke Severity Scale (CP-SSS)

Calculators  Neurology
Cincinnati Prehospital Stroke Severity Scale (CPSSS) is used to identify patients with severe stroke and large vessel occlusion (LVO).
Conjugate gaze deviation
No 0
Yes 2
Ask about age and current month to patient
Both correct 0
One correct 1
Neither correct 1
Ask to close eyes and open/close hand to the patient
Follows both commands 0
Follows one command 0
Follows neither command 0
Inform the patient to hold arm (either or both) up for 10 seconds
Can do 0
Cannot do 1


Measured Factor
Measured Factor Disease
  • Acute ischemic stroke
Measured Factor Detail
The Cincinnati prehospital stroke severity scale is composed of 3 items: 2 points if the patient has a deviation of the gaze, 1 point if the patient is not able to give the date and answer to a simple order such as closing the eyes or clenching the fist and 1 point if the patient presents a hemiplegia. The CPSSS score ranges from 0 to 4, highest value indicating the worst score. It will be considered positive if it is equal to 2 or more.
Body System
Measured Factor High Impact
  • Large vessal occlusion
  • Acute ischemic stroke

Result Interpretation

Ranges Ranges
  • Critical High: 2
  • Normal: 0
  • Normal Adult Male: 0
  • Normal Adult Female: 0
  • Normal Geriatric Male: 0
  • Normal Geriatric Female: 0
Result High Conditions
  • Acute ischemic stroke
  • Large vessal occlusion
Test Limitations
The CPSSS is likely to be less sensitive to subarachnoid hemorrhage in which patients presentations are often non-focal, unless the patient presents in coma. The test was a retrospective analysis of two existing ischemic stroke trial cohorts; therefore prospective evaluation by Emergency medical services (EMS) providers is required. There is variability of the NIH stroke scale (NIHSS) during the first few hours of acute ischemic stroke onset and it is possible the stroke severity at the time of EMS examination will change by the time a treatment decision for ischemic stroke is made by medical providers. Next, isolated M2 lesions were not included in the CPSSS’s LVO prediction analysis; however, only a minority of isolated M2 occlusions (2-8% of patients) was included in recent positive endovascular trials.
References: 1


Study Validation 1
The Cincinnati Prehospital Stroke Severity Scale (CPSSS) has been recently developed to predict large-vessel occlusions (LVOs) in patients with acute ischemic stroke (AIS). In its derivation study, which consisted of patients enrolled in thrombolysis and endovascular therapy trials, the CPSSS had excellent discriminatory performance.The present study is aimed to externally validate the CPSSS in an independent cohort using institution's prospective stroke registry. The primary outcome was presence of LVO and the secondary outcome was a National Institutes of Health Stroke Scale (NIHSS) score of 15 or higher. Harrell's c-statistic was calculated to determine the CPSSS score's discriminatory performance. Using the previously defined cut-point of 2 or higher (range 0-4)  the test properties of the CPSSS for predicting study outcomes were evaluated. The results of the study indicate that CPSSS can identify stroke patients with NIHSS≥15 and LVO. However a  prospective prehospital validation is warranted.
References: 2
Study Additional 1
This study aims to develop a simple scale to identify patients with prehospital stroke with large vessel occlusion (LVO), without losing sensitivity for other stroke types. The Emergency Medical Stroke Assessment (EMSA) was derived from the National Institutes of Health Stroke Scale (NIHSS) items and validated for prediction of LVO in a separate cohort. The study compared the EMSA with the 3-item stroke scale (3I-SS), Cincinnati Prehospital Stroke Severity Scale (C-STAT), Rapid Arterial Occlusion Evaluation (RACE) scale, and Field Assessment Stroke Triage for Emergency Destination (FAST-ED) for prediction of LVO and stroke. The study concluded that EMSA has superior abilities to identify LVO versus 3I-SS and stroke versus 3I-SS and C-STAT. The EMSA has similar ability to triage patients with stroke compared with the FAST-ED and RACE, but is simpler to perform and interpret.
References: 3
Study Additional 2
This study describes the feasibility and effectiveness of prehospital implementation of a previously retrospectively derived and validated Cincinnati Stroke Triage Assessment Tool (C-STAT) to identify subjects with severe stroke (NIHSS ≥15) among all prehospital patients with clinical suspicion of stroke/TIA. It also evaluated the tool's ability to identify subjects with NIHSS ≥10, large vessel occlusion (LVO), or needing services available only at a  comprehensive stroke centers (CSC). Cincinnati Fire Department providers performed standard stroke screening ("face, arm, speech, time;" FAST) and C-STAT as part of their assessment of suspected stroke/TIA patients. Outcomes for patients brought to the region's only CSC or assessed by the regional stroke team were determined through structured chart review by a stroke team nurse. C-STAT test characteristics for each outcome were calculated with 95% confidence intervals. The study concluded that C-STAT is comparable to other published tools in test characteristics and may inform appropriate CSC triage beyond LVO ascertainment alone.
References: 4
Study Additional 3
The aim of te study was to  assess the utility of the Cincinnati Prehospital Stroke Scale (CPSS) and Recognition of Stroke in the Emergency Room (ROSIER) tools in children presenting to the emergency department (ED) with brain attack symptoms. The ROSIER and CPSS tools were retrospectively applied to 101 children with stroke, presenting from 2003 to 2010, and prospectively to 279 children with mimics, presenting from 2009 to 2010. Positive CPSS was defined as ≥1 positive sign (face/asymmetrical arm weakness, speech disturbance). Positive ROSIER was defined as a score of ≥1. Accuracy and interrater agreement between the tools and patients' true status were assessed for combined stroke types and arterial stroke (AIS) and hemorrhagic stroke (HS) subtypes vs mimics. The study concluded that adult stroke recognition tools perform poorly in children and require modification to be useful for pediatric stroke identification.
References: 5


Brian S. Katz
MD, 2010
vascular neurologist, OhioHealth Riverside Methodist Hospital in Columbus, Ohio
Research Interests: He has authored or co-authored several studies in stroke neurology


  1. Katz BS, McMullan JT, Sucharew H, Adeoye O, Broderick JP. Design and validation of a prehospital scale to predict stroke severity: Cincinnati Prehospital Stroke Severity Scale. Stroke. 2015 Jun;46(6):1508-12.
  2. Kummer BR, Gialdini G, Sevush JL, Kamel H, Patsalides A, Navi BB. External Validation of the Cincinnati Prehospital Stroke Severity Scale. J Stroke Cerebrovasc Dis. 2016 May;25(5):1270-1274.
  3. Gropen TI, Boehme A, Martin-Schild S, Albright K, Samai A, Pishanidar S, et al. Derivation and Validation of the Emergency Medical Stroke Assessment and Comparison of Large Vessel Occlusion Scales. J Stroke Cerebrovasc Dis. 2018 Mar;27(3):806-815.
  4. McMullan JT, Katz B, Broderick J, Schmit P, Sucharew H, Adeoye O. Prospective Prehospital Evaluation of the Cincinnati Stroke Triage Assessment Tool. Prehosp Emerg Care. 2017 Jul-Aug;21(4):481-488.
  5. Mackay MT, Churilov L, Donnan GA, Babl FE, Monagle P. Performance of bedside stroke recognition tools in discriminating childhood stroke from mimics. Neurology. 2016 Jun 7;86(23):2154-61.

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