Date Published

March 21, 2024

Updated For

ALS PCS Version ALS PCS Version 5.2


Recently brought a pt in to hospital that was negative for facial droop, slurred speech, arm drift and has equal grips. His complaint was on dizziness but he also was being treated for a uti. Nursing staff tested his arm drift again and had him close his eyes which threw him off. Is that the proper way to assess for arm drift to have a pt close their eyes while doing it? Thank you for your help


The answer is more complicated than you’d think.

The short answer is that there are different types of “drift” you can assess for on your neurologic physical exam and each is slightly different.

For testing arm motor strength via the National Institute of Health Stroke Scale (NIHSS), the standardized test for acute stroke testing, you are allowed to have your eyes open and you assess with palms downward facing.

However, if assessing for pronator drift (assessing for a subtle non-specific upper motor neuron lesion as part of your general neurologic physical exam) you assess with palms facing UP and eyes closed. With the eyes closed you remove the patient’s corrective response thus making the test more accurate. In the presence of an upper motor neuron lesion, the supinator muscles in the upper limb are weaker than the pronator muscles, and as a result, the arm can drift downward and the palm turns toward the floor.



CVA, Physical Exam, Pronator Drift, Stroke Bypass

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