Los Angeles Motor Scale (LAMS)
Stratifies stroke severity in the field.
When to Use
Use in a prehospital (i.e., by EMS providers) or triage setting for patients with stroke symptoms.
- The LAMS is a validated 3-item prehospital scoring tool derived from the motor exam components of the Los Angeles Prehospital Stroke Screen (LAPSS). It was designed to rapidly quantify stroke severity in the prehospital setting.
- LAMS ≥4 has a sensitivity of 81% and specificity of 89% for predicting large vessel occlusion (LVO).
- Although other scores such as the NIH Stroke Scale (NIHSS), Cincinnati Prehospital Stroke Scale (CPSS), Rapid Arterial oCclusion Evaluation (RACE) Scale, and the full Los Angeles Prehospital Stroke Screen (LAPSS) are more comprehensive, the LAMS is a much simpler assessment tool that takes only 20-30 seconds to complete, making it well-suited for prehospital or triage settings.
- Correlates strongly with the full NIHSS (gold standard) and predicts long-term functional outcomes following stroke events.
- Rapid access to time-sensitive interventions such as thrombolysis and endovascular therapy (EVT) for eligible patients is directly linked with improved long-term neurological outcomes for stroke patients.
- Early recognition of severe strokes (LAMS ≥4) by prehospital providers in the field shortens time to definitive diagnosis and treatment.
- Simple, reproducible, and rapid way to identify severe strokes in the prehospital setting.