For healthcare professionals
Los Angeles Motor Scale (LAMS)
The Los Angeles Motor Scale is a short prehospital stroke severity score. It adds three motor findings, facial strength (0 to 1), arm strength (0 to 2) and grip strength (0 to 2), for a total of 0 to 5. A score of 4 or more is used to flag a possible large vessel occlusion (LVO). This calculator is written for clinicians and EMS. It is not a self-check and not a diagnosis.
Score the three items
Items and points as printed in Arthur and colleagues (Arthur 2023). The short test notes are our own. Nothing you enter leaves this page.
What you will see
The LAMS total from 0 to 5 and whether it reaches the published cut-off of 4 for a possible large vessel occlusion.
Educational only, not medical advice. A score supports, and does not replace, clinical judgment and local stroke triage protocols.
Source
Llanes JN et al., Prehosp Emerg Care 2004 (the original scale) and Nazliel B et al., Stroke 2008 (large arterial occlusion), both cited only. Items and points as printed in Arthur KC et al., J Clin Med 2023, and the cut-off of 4 as printed in Behnke S et al., Neurol Res Pract 2021, both open access (CC BY 4.0).
Validated in
Developed for prehospital use in the US (Llanes 2004). In the open studies cited here: 1,123 patients with suspected stroke triaged by EMS across the state of Saarland, Germany (Behnke 2021), and adults with a large vessel occlusion at a US stroke center (Arthur 2023).
Limits
A triage aid for clinicians and EMS, not a diagnosis. It tests only face, arm and grip, so it does not capture deficits of speech, vision, gaze or balance. At a cut-off of 4 it missed about one in three occlusions. It does not tell a stroke from a bleed or a stroke mimic. Vessel imaging decides.
How the scale is scored
The LAMS score ranges from 0 to 5. Facial strength scores 0 or 1, arm strength 0, 1 or 2, and grip strength 0, 1 or 2 (Arthur 2023). Llanes and colleagues described the scale in 2004 as a measure of stroke severity in the field (Llanes 2004), and Nazliel and colleagues studied it for finding patients with a large arterial occlusion (Nazliel 2008).
| Item | 0 | 1 | 2 |
|---|---|---|---|
| Facial strength | Normal | Droop | Not scored |
| Arm strength | Normal | Drifts down | Falls rapidly |
| Grip strength | Normal | Weak | No grip |
| Total | 0 to 5. A score of 4 or more is the cut-off for a possible LVO. | ||
Item names, points and level wording follow the Methods of Arthur and colleagues (Arthur 2023), who grouped patients as LAMS 0 to 3 versus 4 to 5.
The cut-off of 4
In a statewide triage protocol in Saarland, Germany, a LAMS cut-off score of 4 was used to decide whether to take a patient to a comprehensive stroke center (Behnke 2021). At 4 or more, the LAMS detected large vessel occlusion with a sensitivity of 67.5% and a specificity of 83.5%, and the authors found the cut-off of 4 appropriate across the cut-offs they compared (Behnke 2021). So about one in three occlusions scored under 4, and some patients scoring 4 or more had no occlusion. Local protocols, time from onset and imaging guide the final decision.
Citation check
The item wording, points and cut-off on this page were checked against the full text of the two open access papers above in Europe PMC, where both carry a Creative Commons Attribution 4.0 (CC BY 4.0) license. The original papers by Llanes (2004) and Nazliel (2008) are cited, not quoted.
Related stroke tools
For the three-sign face, arm and speech screen used before hospital, see the Cincinnati Prehospital Stroke Scale. For a five-item score from 0 to 9 that also checks the leg, gaze and aphasia or agnosia, see the RACE scale. For a five-item score that adds eye deviation and denial or neglect, with a cut-off of 4, see FAST-ED. To score the full neurological deficit on arrival, use the NIH Stroke Scale (NIHSS) calculator. To grade disability after a stroke, see the modified Rankin Scale. Other bedside scores are listed under For healthcare professionals. For a yes or no screen that needs arm weakness plus visual disturbance, aphasia or neglect, see the VAN stroke screen.
Sources
- Arthur KC, Huang S, Gudenkauf JC, Mohseni A, Wang R, Aslan A, Nabi M, Hoseinyazdi M, Johnson B, Patel N, Urrutia VC, Yedavalli V. Assessing the Relationship between LAMS and CT Perfusion Parameters in Acute Ischemic Stroke Secondary to Large Vessel Occlusion. J Clin Med. 2023;12(10):3374. doi:10.3390/jcm12103374. PMID 37240480. Open access (CC BY 4.0). Methods: LAMS items, points and total 0 to 5. pmc.ncbi.nlm.nih.gov/articles/PMC10219214/
- Behnke S, Schlechtriemen T, Binder A, et al. Effects of state-wide implementation of the Los Angeles Motor Scale for triage of stroke patients in clinical practice. Neurol Res Pract. 2021;3:31. doi:10.1186/s42466-021-00128-x. PMID 34059132. Open access (CC BY 4.0). Methods (cut-off score of 4) and Table 3: at 4 or more, sensitivity 67.5%, specificity 83.5% for LVO. pmc.ncbi.nlm.nih.gov/articles/PMC8167958/
- Llanes JN, Kidwell CS, Starkman S, Leary MC, Eckstein M, Saver JL. The Los Angeles Motor Scale (LAMS): a new measure to characterize stroke severity in the field. Prehosp Emerg Care. 2004;8(1):46-50. doi:10.1080/312703002806. PMID 14691787. Original scale (cited, not quoted). doi.org/10.1080/312703002806
- Nazliel B, Starkman S, Liebeskind DS, et al. A brief prehospital stroke severity scale identifies ischemic stroke patients harboring persisting large arterial occlusions. Stroke. 2008;39(8):2264-2267. doi:10.1161/STROKEAHA.107.508127. PMID 18556587. LAMS and large arterial occlusion (cited, not quoted). doi.org/10.1161/STROKEAHA.107.508127
- Centers for Disease Control and Prevention. Signs and Symptoms of Stroke. www.cdc.gov/stroke/signs-symptoms/index.html
- National Institute of Neurological Disorders and Stroke (NIH). Transient Ischemic Attack (TIA). www.ninds.nih.gov/health-information/disorders/transient-ischemic-attack
Written and maintained by the uncovermyrisk.com editorial team. We do not have a medical reviewer; every claim links to its primary source above. Last reviewed: 2026-11-04. Spotted an error? See About.