The Prehospital Stroke Scale (PSS) is a patient assessment tool to identify signs and symptoms of stroke (asymmetric facial weakness, upper extremity weakness, and/or any abnormalities of speech or language), as well as the time elapsed from onset of patient symptoms to arrival of EMS on-scene.

Stroke Symptoms:

Facial Droop (The patient shows teeth or smiles).
Normal: Both sides of face move equally.
Abnormal: Right side of face does not move as well as the left.
Abnormal: Left side of face does not move as well as the right.

Arm Drift (The patient closes their eyes and extends both arms straight out for 10 seconds).
Normal: Both arms move the same, or both arms do not move at all.
Abnormal: Right arm either does not move, or drifts down compared to the left.
Abnormal: Left arm either does not move, or drifts down compared to the right.

Speech (The patient repeats “The sky is blue in New York City today.” Or other sentence).
Normal: The patient says the correct words with no slurring of words.
Abnormal: The patient slurs words, says the wrong words, or is unable to speak.

Time Elapsed (from onset of symptoms)
All providers are required to ask the patient, and/or bystanders/family members the following question(s):
A. To bystanders/ family members: “What time was ________ (the patient) last seen (in his/her usual state of health) before he/she became weak, paralyzed or unable to speak clearly?”
B. To patients: “When was the last time you remember being in your usual state of health – in other words, before you first noticed that you had become weak, paralyzed or unable to speak clearly?”
Also:
Onset
Progression
Preceding Symptoms(Headache)
Seizures
AMS
Paralysis
Pupils