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Los Angeles Motor Scale (LAMS)

The Los Angeles Motor Scale (LAMS) is a predictive tool which can quantify the severity of stroke in filed.
Facial drooping
Absent 0
Present 1
Arm drift
Absent 0
Drifts down 1
Falls rapidly 2
Grip strength
Normal 0
Weak grip 1
No grip 2


Measured Factor
Large vessel occlusion (LVO)
Measured Factor Disease
  • Stroke
Measured Factor Detail
LAMS is effecient tool for predicting the severity of stroke in patients with cerberal ischemia or intracerebral hemorrhage. LAMS shows the stroke severity in terms of LVO which directly corelates to stroke occurence.
Body System
Measured Factor Low Impact
  • A score of 0 indicates less chances of LVO with minor or moderate stroke severity.
Measured Factor High Impact
  • A maximum score of 5 indicates increased chances of LVO to occur with more severity of stroke. It requires acute treament and patient needs to shift immediately to stroke centre having endovascular capabilities.

Result Interpretation

Ranges Ranges
  • Critical High: ≥4
Result High Conditions
  • LVO may occur with increased chances of stroke
Test Limitations
Easy to learn structure of this scores can make influence of the setting or the examiners
References: 2, 3


Study Validation 1
This retrospectively study aimed to determine the performance of Los Angeles Motor Scale (LAMS) that rapidly characterizes pretreatment stroke severity. LAMS score was assigned to the patients from scale 0-5. Outcome parameters evaluated were facial weakness, arm strength, and grip. Comparison of LAMS score were done with entry National Institutes of Health Stroke Scale (NIHSS) and the five-item shortened NIHSS (sNIHSS) scores. Results showed that scores correlated closely with entry NIHSS scores (r=0.75) and also to sNIHSS score. Study concluded that LAMS was effective tool in predicting stroke severity and functional measures with accuracy compared to other available score.
References: 1
Study Validation 2
The purpose of this study was to validate the Los Angeles Motor Scale (LAMS) for predicting stroke severity for prehospital and emergency department use. A total 119 patients with mean age of 67 were involved in the study. LAMS and NIHSS were scored in under-12-hour acute anterior circulation ischemic stroke patients. C- statistics and likelihood ratios were used to calculate predictive value for vascular occlusion of stroke severity ratings. LAMES score from 0-5 were assigned according to the severity. LAMS scores showed sensitivity 0.81, specificity 0.89, and overall accuracy 0.85. This study concluded that LAMS tool is good and effective in predicting the presence of large artery anterior occlusion which aid in identifying the stroke patients for direct transport to stroke centers
References: 4
Study Validation 3
A prospective, multicentre study was conducted on 1632 actute cerebrovascular disease patients to validate the performance of Los Angeles Motor Scale (LAMS) for prehospital use. LAMS scores were stable in 40.5%, improved in 37.6%, and worsened in 21.9%.. Predictive accuracy (adjusted C statistics) for nondisabled 3-month outcome was as follows: prehospital LAMS, 0.76 (95% confidence interval 0.74-0.78); Early postarrival (EPA) LAMS, 0.85 (95% confidence interval 0.83-0.87); and EPA National Institutes of Health Stroke Scale (NIHS), 0.87 (95% confidence interval 0.85-0.88) and EPA National Institutes of Health Stroke Scale (NIHSS) 0.87 (95% confidence interval 0.85-0.88). After comparison of LAMS score with other models showed that LAMS provides overall better predictive validity and is excellent diagnostic criteria in determining the stock severity.
References: 5
Study Additional 1
The aim of the study was to validate the LAMS for large vessel occlusion (LVO) and Comprehensive Stroke Centers (CSCs) recognition. 94 patients with acute cerebral ischemia (ACI) and CSC-appropriate patients were involved in the study. LAMS administered postarrival was compared concurrently with 6 other scales. The LAMS administered by paramedics in the hospital performed moderately well in identifying LVO among patients with ACI (C statistic, 0.79; accuracy, 0.72) and CSC-appropriate among all suspected stroke transports (C statistic, 0.80; accuracy, 0.72).This study concluded that LAMS is effective and important tool in identifiying LVO and CSC-appropriate patients with good accuracy
References: 6
Study Additional 2
The objective of this study was to check the association of prehsopital Los Angeles Motor Score (LAMS) with mechanical thrombectomy in patients (median age, 68) with acute ischemic stroke. 157 patients were involved in the study and were assigned LAMS score based on following observations: facial droop, arm drift, and grip strength for a total of 0 to 5 points. Patients with LAMS of 5 (P= 0.0193 were significantly more likely to received mechanical thrombectomy and tPA (P=0.0002). Study concluded that LAMS score of 5 is strong predictor of stroke patients that are suspected to have mechanical thrombectomy
References: 7


  1. 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.
  2. Purrucker JC, Hametner C, Engelbrecht A, Bruckner T, Popp E, Poli S. "Comparison of stroke recognition and stroke severity scores for stroke detection in a single cohort." J Neurol Neurosurg Psychiatry (2014): jnnp-2014
  3. Kim JT, Chung PW, Starkman S, Sanossian N, Stratton SJ, Eckstein M, et al. Field Validation of the Los Angeles Motor Scale as a Tool for Paramedic Assessment of Stroke Severity. Stroke. 2017;48(2):298-306
  4. Nazliel B, Starkman S, Liebeskind DS, Ovbiagele B, Kim D, Sanossian N, et al. A brief prehospital stroke severity scale identifies ischemic stroke patients harboring persisting large arterial occlusions. Stroke. 2008;39(8):2264-7.
  5. Kim JT, Chung PW, Starkman S, Sanossian N, Stratton SJ, Eckstein M, et al. Field Validation of the Los Angeles Motor Scale as a Tool for Paramedic Assessment of Stroke Severity. Stroke. 2017;48(2):298-306.
  6. Noorian AR, Sanossian N, Shkirkova K, Liebeskind DS, Eckstein M, Stratton SJ, et al. Los Angeles Motor Scale to Identify Large Vessel Occlusion: Prehospital Validation and Comparison With Other Screens. Stroke. 2018;49(3):565-572.
  7. L Ganti, P Banerjee, Higher Score on Preospital Los Angeles Motor Scale Predicts Likelihood of Mechanical Thrombectomy After Acute Ischemic Stroke 2018;90(15):472

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