Comparison of diagnostic criteria in patients with amyotrophic lateral sclerosis: The contribution of electromyographic findings

Abstract

Diagnosis of amyotrophic lateral sclerosis (ALS) is based on combination of clinical signs and electrophysiological correlates of pathological process which takes place in general. New electrophysiological criteria Awaji-Shima (AS) additionally qualify the complex fasciculations and neurogenically modified potentials of motor units as signs of active lesions of peripheral motor neuron, contrary to previously valid revised El Escorial criteria (rEE). The objective of this research was to determine the clinical significance and advantages of using the AS criteria in patients with ALS. Methods. Thirty patients (59.2 ± 10.9 years, 57% of them with spinal form of the disease) with clinically suspected ALS were monitored from the time of diagnosis until reaching the category of definitive diagnosis or death. The clinical evaluation and electromyographic (EMG) examinations were carried out at 3-month intervals. Results. By applying the AS criteria, the category of probable or definite diagnosis was achieved in all patients with ALS, except in one (96.6%), as contrary to the rEE (33.3%), after 6 months of the follow-up period. The subclinical affection in more than two body regions has been defined through detection of denervation potentials (80% of the patients by using the AS, or 67% by the rEE criteria). The complex fasciculations were registered particularly often in small muscles of the feet (37- 40%). Conclusion. Application of the AS criteria improve the achievment of category of probable or definite diagnosis of ALS by 2.7 months earlier compared to the rEE. This outcome is particularly affected by a higher frequency of positive EMG findings, when the AS criteria were employed. Early determination of diagnosis provides the better perspective and more frequent participation of the ALS patients in pharmacotherapy studies intended to establish new therapeutic options.

Dijagnoza amiotrofične lateralne skleroze (LS) zasniva se na kombinaciji kliničkih znakova i elektrofizioloških korelata patološkog procesa koji se odvija u osnovi. Novi elektrofiziološki kriterijumi, Awaji-Shima (AS), dodatno kvalifikuju kompleksne fascikulacije i neurogeno izmenjene potencijale motornih jedinica kao znakove aktivnih lezija perifernog motornog neurona, nasuprot ranije važećim revidiranim El Escorial kriterijumima (rEE). Cilj ovog istraživanja bio je da se utvrdi klinički značaj i prednosti primene AS kriterijuma, kod obolelih od ALS. Metode. 30 bolesnika (59,2 ± 10,9 godina, od kojih 57% sa spinalnom formom bolesti) sa klinički suspektnom ALS, praćeno je od vremena postavljanja dijagnoze do postizanja kategorije definitivne dijagnoze ili smrtnog ishoda. Kod bolesnika su obavljane klinička evaluacija i elektromiografski (EMG) pregledi u tromesečnim intervalima. Rezultati. Primjenom AS kriterijuma, nakon 6 meseci praćenja, kategorija verovatne ili pouzdane dijagnoze postignuta je kod svih bolesnika sa ALS, izuzev jednog (96,6%), nasuprot rEE kriterijuma (33.3%). EMG nalazi bili su pozitivni u ≥ 2 telesna regiona kod 80% bolesnika primenom AS, odnosno 67% primenom rEE. Kompleksne fascikulacije zabeležene su posebno učestalo u malim mišićima stopala (37-40%). Zaključak. Primenom AS kriterijuma kategorija vjerovatne ili pouzdane dijagnoze ALS postiže se za 2,7 meseca ranije, u poređenju sa rEE, na šta posebno utiče veća učestalost pozitivnih EMG nalaza. Ranije utvrđivanje dijagnoze donosi perspektivu veće zastupljenosti obolelih u farmakoterapijskim studijama sa novim terapeutskim agensima.