Are we really closer to improving the diagnostic sensitivity in ALS patients with Awaji criteria?

Abstract

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.

Optimizing muscle selection for electromyography in amyotrophic lateral sclerosis

“…Several studies have been performed to examine the superiority of the AwC over the rEEC . A prospective study of 200 cases found that the AwC upgraded ALS diagnostic categories by 1 step in 25.7% of cases .…”

“…22,23 Several studies have been performed to examine the superiority of the AwC over the rEEC. 7,[24][25][26][27] A prospective study of 200 cases found that the AwC upgraded ALS diagnostic categories by 1 step in 25.7% of cases. 25 Gawel and colleagues observed that, although the inclusion of fasciculation potentials as a sign of active denervation markedly increased the number of involved muscles, it did little to improve overall sensitivity for identification of an EDX-positive segment.…”

“…25 Gawel and colleagues observed that, although the inclusion of fasciculation potentials as a sign of active denervation markedly increased the number of involved muscles, it did little to improve overall sensitivity for identification of an EDX-positive segment. 26 Higashihara et al observed that the AwC actually downgraded some patients who have UMN signs in 1 body region from the subgroup of clinically probable laboratory supported to the clinically possible ALS category. 7 Whether fasciculation potentials are comparable to fibrillation potentials and positive sharp waves as a useful EDX marker in ALS remains debatable.…”

Comment on: The Awaji criteria are not always superior to the previous criteria: A meta‐analysis

“…They included 2 recent, less positive studies and did not include the strongly positive study of Okita et al The study by Higashihara et al was not included in our meta‐analysis, because it was not published at the time our manuscript was accepted. There are other important issues in the various papers analyzed that they may have overlooked.…”

“…Moreover, looking at the Jang and Bae Table 2, it is apparent that other studies in which cranial‐innervated muscles were investigated “…when indicated…” or “…in very few patients…” were included. It is relevant that in another study they included, only 3 muscles were investigated in some patients, but from 4 different regions (Table 2). These differences in methodology are important and do not comply with the recommendations of the original description of the Awaji algorithm for electrophysiological assessment for diagnosis of ALS …”