The electromyographic diagnosis of amyotrophic lateral sclerosis: Does the evidence support the El Escorial criteria?

Abstract

The aim of this retrospective cohort study was to examine the accuracy of the El Escorial electromyographic criteria for the diagnosis of amyotrophic lateral sclerosis (ALS). Based on a consecutive series of 73 patients with suspected ALS, the sensitivity of electromyography (EMG) ranged from 0.2 in the cranial segment to 0.74 in the thoracic segment. Specificity was highest (0.92-1.0) in the cranial and thoracic segments. Using receiver operating characteristic (ROC) curve analysis to examine the effect of varying the number of abnormal segments required for the diagnosis, we found an overall accuracy of 0.90 and 0.87 if one or two abnormal segments, respectively, were required. The best combination of sensitivity and specificity was achieved by requiring EMG changes in two segments with abnormalities in a single muscle in the cranial and thoracic segments, but abnormalities in two muscles in the cervical and lumbosacral regions. These findings lend support to the EMG criteria proposed at El Escorial.

CSF neurofilament protein analysis in the differential diagnosis of ALS

“…Interestingly, there is a clear lack of formal and rigorous diagnostic studies that address the value (accuracy) of EMG in the diagnosis of ALS, although this investigation is part of the clinical criteria for ALS. In a retrospective study with 35 patients with ALS and 38 with an ALS-mimic this problem was only recently addressed and a maximal ROC AUC of 0.87-0.90 was reported [9]. In the light of these findings future research is warranted that should encompass a prospective analysis in which CSF analysis of NF proteins is used in combination with electrophysiological studies (and possible other clinical biomarkers) in order to study the diagnostic accuracy of a combination of biomarkers.…”

The Criteria for Diagnosing Amyotrophic Lateral Sclerosis May Be Unsuitable for Clinical Use

“…Utility of the revised El Escorial Criteria is immense for clinical research, pharmacological trials and exchange information among research centers. In addition, the El Escorial clinical criteria for the diagnosis of ALS are considered very reliable, with virtually absent risk of false-positive diagnosis [18,19]. However, this study indicates that the clinical presentation and course of some ALS patients have not adhered to the criteria in the point of view of neurological clinicians who actually treat these patients.…”

Prediction of prognosis of ALS: Importance of active denervation findings of the cervical-upper limb area and trunk area

“…In needle EMG of the trunk area, muscles of the thoracic spinal cord are tested, including the paraspinal muscles and abdominal rectus muscle (23,24). Degeneration of motor neurons may spread contiguously throughout the threedimensional anatomy of connected and neighboring neurons in ALS (25,26), and this may explain upper limb dysfunction resulting from proximal progression of denervation of the trunk area and walking disability due to distal progression.…”