LAMS (Los Angeles Motor Scale) Calculator

LAMS (Los Angeles Motor Scale) Calculator for Neurology. A total >=4 raises concern for large arterial occlusion, as investigated in the primary study: https://pubmed.ncbi.nlm.nih.gov/18556587/ . Vascular imaging and specialist evaluation, not the score, establish occlusion.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

Add face 0-1, arm 0-2 and grip 0-2, maximum 5. This is the original unilateral motor scale: https://pubmed.ncbi.nlm.nih.gov/14691787/ . Weights are confirmed in the AHA table: https://cpr.heart.org/en/-/media/3F66CFCE07324829B49D82662665CAA0.pdf

When to use this calculator

Support acute stroke motor-severity communication and local triage. Keep the affected side consistent; do not add left and right scores into this version.

Inputs used

  • Suspected acute stroke with assessable motor findings
  • Facial droop: absent or present
  • Arm: sustained, drifting or falling rapidly
  • Grip: normal, weak or absent

Clinical interpretation

A total >=4 raises concern for large arterial occlusion, as investigated in the primary study: https://pubmed.ncbi.nlm.nih.gov/18556587/ . Vascular imaging and specialist evaluation, not the score, establish occlusion.

Worked example

Facial droop 1, an arm that falls rapidly 2, and weak grip 1 give LAMS 4. Normal grip would lower the same example to 3.

Limitations and safety notes

Nonmotor, posterior-circulation and mild-deficit strokes may have low totals. Pre-existing weakness and stroke mimics confound scoring. No transport destination or reperfusion eligibility is automatically assigned.

Frequently asked questions

Is the maximum 5 or 10?

This route implements the unilateral 0-5 version. Bilateral adaptations are separate and must not be mixed with this threshold.

References

  • Llanes et al. Original LAMS motor severity study, 2004: https://pubmed.ncbi.nlm.nih.gov/14691787/
  • Nazliel et al. LAMS and large arterial occlusion, 2008: https://pubmed.ncbi.nlm.nih.gov/18556587/
  • AHA LAMS criteria table; unilateral 0-5 version: https://cpr.heart.org/en/-/media/3F66CFCE07324829B49D82662665CAA0.pdf

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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