Variation in the neurophysiological examination of amyotrophic lateral sclerosis in Europe

Our objective was to analyse how patients with amyotrophic lateral sclerosis (ALS) are examined neurophysiologically at different European centres in order to identify possible areas with variation or disagreement in the neurophysiological examination of ALS. Ninety-three prospectively collected examinations from six out of seven neurophysiologists in the European ESTEEM project were analysed. All examinations were peer reviewed with an electromyographic consensus diagnosis of motor neuron disease and the diagnosis of ALS confirmed by clinical follow-up. The examinations were analysed for differences among the physicians in EMG techniques and number and distribution of examined and abnormal muscles and nerve segments. Considerable variation was found among the physicians regarding the average numbers of performed and abnormal EMG and nerve conduction studies per patient, the EMG techniques used, and the topographical distribution of the examined muscles. The existence of two different examination approaches, one with quantitative EMG analyses and relatively few muscles studied, and one with more muscles studied using qualitative methods was clearly confirmed in the present study. The large variation among the physicians indicates that different criteria were used, or that criteria were used inconsistently.