Cincinnati Prehospital Stroke Scale

The assessment method explained

The CPSS is a neurological examination that can help diagnose a potential stroke in a pre-hospital setting. It was derived at the University of Cincinnati Medical Center from the National Institutes of Health Stroke Scale.

Before the patient can reach ER or during ER, three areas of nerve function are evaluated, each being described with the normal and abnormal reaction (binomial reporting):

■ The first assessment checks for facial palsy. The patient is asked to smile and the medical professional assesses the degree of symmetry in the facial movement or any unilateral disparity. The test is considered normal if the patient manages to smile and show teeth and if the movement is equal in both sides. If there is a drift to one side, the test is deemed abnormal/positive for stroke.

■ The second assessment checks whether the patient can hold their arms symmetrically in front of them, for 10 seconds, while keeping their eyes closed. If there is a drift to one side from the starting position, the test is deemed positive.

■ The third assessment checks for any speech abnormalities by asking the patient to repeat a simple sentence such as “you can't teach an old dog new tricks”. If the patient repeats the sentence correctly, the test is negative. If the patient is unable repeat the words correctly, intelligibly or in case there is no verbal response, the test is abnormal/positive for stroke.

CPSS Interpretation

If either of the three criteria in the Cincinnati prehospital stroke scale is present, then a stroke episode is likely to be diagnosed.

Patients with 1 of the 3 criteria have a 72% probability of an ischemic stroke. When all three criteria are present, the probability of stroke being present increases to 85%.

The main limitation of the study is the fact that it does not offer any information on the severity of symptoms and only focuses on presence or absence of stroke.

About the study

The CPSS was created by Kothari et al. in 1997, following a study on:

■ 74 patients treated in a thrombolytic stroke trial;

■ 225 consecutive non-stroke patients evaluated during 4 random 12-hour ER shifts.

Patients have been evaluated with the NIH stroke scale. Items of the scale have been modified and recoded to a binomial (normal or abnormal) scale.

Three items were identified in all patients with stroke: facial palsy, motor arm, and dysarthria. The new scale showed a sensitivity of 100% and a specificity of 88%.

The CPSS can be used with high sensitivity and specificity for identifying patients with stroke at the earliest stage before admission to hospital.

Stroke and TIA symptoms

A stroke episode occurs when there is an interruption to the blood flow to an area in the brain. This is a serious medical emergency and can result in permanent brain damage or death. There are two types of stroke:

■ Ischemic stroke – In 80% of strokes, blood flow to the brain is impaired by blood clotting or plaque deposits (fatty deposits and cholesterol);

■ Hemorrhagic stroke – In 20% of strokes, a blood vessel in the brain ruptures and bleeding damages brain cells. This is caused by high blood pressure and brain aneurysms.

A transient ischemic attack has similar symptoms to a stroke but only lasts from a few minutes to a few hours. The symptoms disappear after the event. In stroke, the symptoms do not always disappear and the patient is left different degrees of damage to the nervous function that require long term recovery.

Transient attacks warn that there is a brain blood supply impairment and are one of the main risk factors for a subsequent stroke attack.

It is important to recognize the main symptoms of stroke as this is a condition in which rapid intervention can mean the difference between life and death. Stroke symptoms include:

■ Complete paralysis of one side of the body;

■ Sudden blurring or loss of vision;

■ Dizziness;

■ Confusion;

■ Balance and coordination impairment;

■ Difficulty interacting with others;

■ Headache of high intensity;

■ Loss of consciousness.

Original source

Kothari R, Hall K, Brott T, Broderick J. Early stroke recognition: developing an out-of-hospital NIH Stroke Scale. Acad Emerg Med. 1997; 4(10):986-90.

Other references

1. Kothari RU, Pancioli A, Liu T, Brott T, Broderick J. Cincinnati Prehospital Stroke Scale: reproducibility and validity. Ann Emerg Med. 1999; 33(4):373-8.

2. 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; 46(6):1508-12.

3. Hurwitz AS, Brice JH, Overby BA, Evenson KR. Directed use of the Cincinnati Prehospital Stroke Scale by laypersons. Prehosp Emerg Care. 2005; 9(3):292-6.