The Awaji criteria, recently introduced to increase diagnosis sensitivity in 
amyotrophic lateral sclerosis (ALS), equate the diagnostic significance of 
neurogenic electrophysiological changes to clinical signs of lower motor neuron 
dysfunction. They also increase the electrophysiological significance of 
fasciculation potentials (FPs). The aim of our study was to analyse whether the 
new parameters improve diagnostic sensitivity in ALS patients primarily 
diagnosed with the El Escorial criteria. Medical and electrophysiological 
records of 135 consecutive patients with ALS and 25 patients with progressive 
muscular atrophy (PMA) who underwent electrophysiological examination of at 
least three anatomical regions were analysed retrospectively. Results showed 
that implementation of the Awaji criteria increased the level of ALS diagnosis 
sensitivity in 5.9% of cases - 1.5% due to the new role of FPs potentials and 
4.4% because of equalization of clinical and EMG findings. In 4% of patients the 
ALS diagnosis was, however, changed from laboratory-supported probable ALS to 
possible ALS. In conclusion, our study confirms that Awaji modifications are 
able to improve the diagnostic certainty in a few ALS cases. Although the new 
approach to FPs markedly increases the number of involved muscles, it only 
slightly raises the number of involved regions.