The Awaji recommendations for the use of electrodiagnostic studies in the diagnosis of amyotrophic lateral sclerosis (ALS) were proposed to enable earlier diagnosis of ALS to be achieved to meet an acknowledged need to obviate diagnostic delay.
Awaji Criteria for the Diagnosis of Amyotrophic Lateral Sclerosis
Principles of the Awaji-Shima
- Evidence of LMN loss (reduced interferential pattern on full contraction and increased firing rate)
- Evidence of reinnervation (motor units of large amplitude and longer duration)
- Fibrillation and sharp waves or fasciculation potentials (fibrillation and sharp waves are required in weak limb muscles)
No. of Muscles Affected by Region:
- Cervical and lumbar-sacral region: a minimum of 2 muscles innervated by different roots and nerves
- Bulbar and thoracic region: a minimum of 1 muscle
Diagnostic Classification: Awaji-Shima Consensus
- Clinically definite ALS is defined by clinical or electrophysiological evidence by the presence of LMN as well as UMN signs in the bulbar region and at least 2 spinal regions or the presence of LMN and UMN signs in 3 spinal regions.
- Clinically probable ALS is defined on clinical or electrophysiological evidence by LMN and UMN signs in at least 2 regions with some UMN signs necessarily rostral to the LMN signs. The revised El Escorial Criteria have an additional category “Probable ALS–Laboratory Supported,” which is defined when clinical signs of UMN and LMN dysfunction are found in only 1 region but electrophysiological signs of LMN loss are observed in ≥2 regions.
- Clinically possible ALS is defined when clinical or electrophysiological signs of UMN and LMN dysfunction are found in only 1 region or UMN signs are found alone in ≥2 regions or LMN signs are found rostral to UMN signs.
Abbreviations: ALS, amyotrophic lateral sclerosis; LMN, lower motor neuron; UMN, upper motor neuron.
References:
- Ido BJF, Kacem I, Ouedraogo M, Nasri A, Mrabet S, Gargouri A, Ben Djebara M, Kabore BJ, Gouider R. Sensitivity of Awaji Criteria and Revised El Escorial Criteria in the Diagnosis of Amyotrophic Lateral Sclerosis (ALS) at First Visit in a Tunisian Cohort. Neurol Res Int. 2021 Jan 22;2021:8841281. [Medline]
- Johnsen B, Pugdahl K, Fuglsang-Frederiksen A, Kollewe K, Paracka L, Dengler R, Camdessanché JP, Nix W, Liguori R, Schofield I, Maderna L, Czell D, Neuwirth C, Weber M, Drory VE, Abraham A, Swash M, de Carvalho M. Diagnostic criteria for amyotrophic lateral sclerosis: A multicentre study of inter-rater variation and sensitivity. Clin Neurophysiol. 2019 Feb;130(2):307-314. [Medline]
- Costa J, Swash M, de Carvalho M. Awaji criteria for the diagnosis of amyotrophic lateral sclerosis:a systematic review. Arch Neurol. 2012 Nov;69(11):1410-6. [Medline]
Created Aug 02, 2021.
