The MEND Stroke Assessment for Prehospital Care

If you’ve been in and out of a few continuing education classes over the past four years, you’ve almost assuredly heard reference to the MEND neurological exam. Perhaps it was gone over in detail or maybe it was mentioned as a passing reference. Of course…now you’ve forgotten exactly what the MEND exam was, or perhaps, if you do remember…you don’t really remember. In any case, I’m betting this might be a good time to review the MEND exam.

Let’s take a closer look at what the MEND exam is and what it can do for you as a prehospital provider.

MEND is an acronym for the Miami Emergency Neurologic Deficit Exam. (Yes…quite a mouthful of words.) The MEND exam is used to gauge both the probability and the severity of a stroke in patients with new-onset of neurological deficits. It’s a more detailed assessment than its more-well-known cousin, the Cincinnati Prehospital Stroke Scale (CPSS), and it takes more time to perform. (Though it encompasses several of the same assessments.)

We should start by saying that the MEND exam has a specific use and purpose in the prehospital setting. It may fit into your clinical practice well or it may have little or no purpose in your prehospital system. Having said that…any prehospital provider can benefit from learning the MEND exam. All of these assessments can be tucked away in your assessment toolbox for use when you’re trying to determine if your patient could be having a stroke-type event.

We’ll start with a look at all the assessments that make up a MEND exam, then we can talk about how and when you might perform this type of exam and then let’s touch briefly on how gathering this information might help the patients progression through the healthcare system. Let’s get started.

There are 12 tests that make up the MEND exam. You can use any of them in your patient evaluation or you can complete them all and hand off a complete MEND exam to the receiving facility. For each of the exams, you’ll make the outcome either normal (for this patient), unable to complete or abnormal. The exams are divided into three categories. They are mental status (four tests), cranial nerves (three tests), and limb function (five tests). If you have completed a CPSS exam on scene, you will only have nine more tests to complete for a full MEND exam.

Mental Status Checks

1) Level of Consciousness: Stimulate the patient and record their highest level of response based on the AVPU scale. Anything less than awake and alert is considered abnormal.

2) Speech (CPSS): Have the patient repeat the phrase, “You can’t teach an old dog new tricks.” Listen for slurring, inability to pronounce the words or inability to remember all the words and repeat them correctly. If the patient is unable to attempt the phrase (completely aphagic) or not verbally responsive, mark the exam as unable to complete (not abnormal).

3) Question / Response: Ask a question and see if the patient can respond appropriately and in context. Questions like, “How are you feeling today?” or “What’s your name?” are completely appropriate and may seem less offensive to your oriented patient than, “Where are you right now?”

4) Respond to a Command: Ask the patient to open and close their eyes. This is not a motor test; it’s a cognitive function test. If the patient attempts to open and close their eyes, they are marked as normal. (Regardless of motor function or gaze abnormalities.) If the patient is unable to understand or attempt to follow your commands they are marked as abnormal. All of these tests assume compliance on the part of the patient as a prerequisite.

Cranial Nerve Assessments

5) Facial Droop (CPSS): Ask the patient to smile and look for unilateral asymmetry in the facial muscles. This is the classic “facial droop” sign. Any new onset facial asymmetry is marked as abnormal.

6) Visual Fields: Sit in front of the patient with your face looking directly at the patients face and your eyes on the same level. Ask the patient to stare at your nose. Now hold your fingers up half way between your patients face and yours (about 18 inches away from both you and the patient) at the level just above your eyebrows. Your fingers should be well within your field of view when you look at the patients nose. Ask the patient to tell you when they see your fingers wiggle.  Wiggle your fingers on one hand at a time. Now bring your fingers down to chin level and repeat.  If the patient is unable to see your fingers move, record the test as abnormal and note which visual field is absent.

7) Horizontal Gaze: Ask the patient to hold their head still. Hold up your pointer finger and ask the patient to follow your finger with their eyes only. If the patient moves their head you can place a finger from your opposite hand on their chin as a reminder. Both eyes should track evenly to the outer limit of the normal ocular range. The presence of nystagmus does not affect a normal score (though it should be noted). If either or both eyes are unable to track completely in one direction or another, make the test as abnormal.

Limb Function (Motor, Sensory and Coordination)

Note that in all limb function tests, symmetry is far more important that strength or weakness. If a patient has limb tremors or bilateral weakness, the exam is still recorded as normal (for the patient). Only asymmetrical limb weakness is recorded as abnormal.

8) Motor – Arm Drift / Pronator Drift (CPSS): Ask the patient to hold out their arms with their palms facing downward. (I call it Mummy style.) Ask the patient to close their eyes and keep both hands up and still. Look for a downward drift of one arm but not the other. Inability to hold either hand up is marked as unable to complete. Downward drift of both hands is normal. Downward or outward drift of one hand is abnormal.

9) Motor – Leg Drift: Ask the patient to raise one leg several inches off the bed and hold it for five seconds. This is more accurate than having the patient kick up or push up against your hand. If the patient exhibits weakness equally in both legs or no weakness, the test is normal. If the patient shows asymmetrical weakness, the test is abnormal.

10) Sensory – Arms and Legs: Ask the patient to close their eyes and uncross their hands and feet. Have them sit or lay comfortably. Ask them to report when they feel you touch their limbs. Touch the backs of the forearms and hands and the shins and tops of both feet. Any inability to feel your touch in any limb is recorded as abnormal. Make a note of which limb experienced the decreased sensation. (Note: Some MEND tools separate this assessment into two individual assessments for the arms and legs. Some keep them together as one.)

11) Coordination – Arms, Finger-to-Nose: Hold your pointer finger vertically about 18 inches in front of the patients face. Ask the patient to take their pointer finger and touch your finger and then their nose several times. A physical demonstration is often helpful. Repeat this on both sides. Look for an inability to find the tip of your finger or the tip of their nose with one hand but not the other. Bilateral tremors or coordination deficits are marked as normal. If the patient doesn’t understand, they are marked as unable to complete. Unilateral coordination deficit is marked as abnormal.

12) Coordination – Legs, Heal-to-Shin: Ask the patient to take the heal of one foot and run in down the opposite shin from the knee to the foot. Lifting the patients foot and demonstrating the move for them first is often helpful. Repeat this on both sides. Look for an inability to track along the opposite shin with one foot but not the other. Bilateral tremors or coordination deficits are marked as normal. If the patient doesn’t understand, they are marked as unable to complete. Unilateral incoordiantion is marked as abnormal.

Don’t forget to ask.

There are also three more critical questions that you should strive to answer while assessing any new-onset stroke patient. As the prehospital provider, you may be the only clinician who can accurately answer these questions based on eye-witness reports at the scene of the emergency.

  • When was the patient last known to be normal (Absent any symptoms).
  • Did the patient have a seizure or experience a head injury at the onset of symptoms?
  • Is the patient taking any type of blood thinner?

When would you do a full MEND exam?

This isn’t an on-scene exam. When you are simply evaluating and trying to determine if your patient is having a stroke, the Cincinnati Prehospital Stroke Scale is perfectly adequate. A certain percentage of strokes will not be picked up by the CPSS and may be identified by a full MEND exam.  Most systems that are using MEND in the field routinely are advising crews to complete the exam enroute to the hospital.

Don’t delay transport of a stroke patient for the purpose of completing a MEND exam. If the patient is still in the window of time for fibrinolytic therapy or interventional radiology, time is of the essence. Transport to an appropriate receiving facility and do the full MEND enroute is time permits. Also know that some elements of the exam can be done during your introduction and while moving the patient (i.e. Asking the patients name and response to command.)

There is benefit to completing a full MEND exam, especially if the receiving hospital is prepared to use the information on your arrival. As previously stated, MEND will identify some strokes that may not be caught using the CPSS alone.

It’s a good idea to complete a full MEND exam if a patient with reported neurological symptoms decides that they wish to refuse care. Beyond that, the more detailed MEND exam can help clinician’s pinpoint specific stroke syndromes. It establishes a baseline of brain function for later comparison and it tells us far more about the severity of the stroke than the CPSS alone.

But nobody else in my system uses this…

It’s always difficult to feel like you are the first person to start a new trend. It’s easier to lead than to follow. But there’s no harm in doing a full MEND exam on your patient. (As long as you’ve covered your clinical bases first.) EMS needs leaders. I’d encourage you to print out a MEND exam checklist and give it a try. When you get to the hospital, copy it off and give it to the staff for inclusion in the patients chart.

Having a baseline prehospital MEND exam can be great for neurologists farther down the patient-care continuum. Try it out and see what type of reaction you get from your receiving hospital. Then come back here and let us know.

Comments

  1. Any reason for palms down when testing pronator drift? I always understood supinated to be a more sensitive test.

  2. This comment is for Brandon,

    The NIH stroke scale that the MEND scale is modeled after doesn’t test for pronation. I think the confusion here is that pronator drift has been used interchangably with arm drift when there is actually a very important distinction. Pronation is the act of the patient’s palms rotating from supine to prone not the arm drifting down. Arm drift as tested by the NIH stroke scale requires a patient’s fingers to be fully extended as curling of fingers prior to the full ten seconds is considered a subtle form of drift. So as far as supinate being a more sensitive test, in regards to the NIH this would not be the case as it would be much easier for the patient to hold their fingers straight with their palms supine.

    Now whether the fingers curling matters for the MEND exam I don’t know. A big difference between the two scales is that the NIH scores each component on severity (0 up to 4 on some components) whereas the MEND is pass or fail. It should also be noted that the NIH tests each limb individually with the patient’s eyes open whereas the MEND evaluates both arms simualtaneously with eyes closed. Why they changed this for the MEND I’m not sure because reproducibilty of results is why the NIH criteria has such strict guidlines for how it’s supposed to be performed (that not everyone pay’s attention to unfortunately :( ).

    It could be that in condensing the NIH to a prehospital format, having the patient rely on proprioception (eyes closed) would hopefully increase it’s sensitivity especially if the criteria is pass or fail. And testing both limbs simultaneously would save some time (negligible amount in my opinion).

    Regardless, the MEND exam is far superior to the Cincinnati and I’m with the author in encouraging EMS providers to not be afraid to be first :)

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  4. Nor cal has been stressing B.E.F.A.S.T
    Balance of the person standing
    Eyes= are they able to identify the object/how many do they see

    Facial droop= same as the past

    Arm drift=same as the past

    Speech= Same as the past

    Time= time sensitive transport

  5. While I greatly appreciate the value of the MEND scale; my system uses it by protocol, why aren’t we using the actual NIHSS enroute?

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