Medical technology assessment. Electrodiagnosis in motor neuron diseases and amyotrophic lateral sclerosis.

In motor neuron diseases/amyotrophic lateral sclerosis (MND-ALS), electrodiagnostic techniques are essential in supporting the diagnosis and excluding other conditions that clinically resemble MND-ALS. Electrodiagnostic techniques can also monitor disease progression and provide prognostic information. Electromyography has an important role in the diagnosis of MND-ALS, but some drawbacks should be borne in mind. Although internationally accepted electrophysiological criteria have been defined to support MND-ALS diagnosis, differences in different laboratories can raise unexpected difficulties in application of diagnosis criteria. Much work needs to be done to increase standardisation of the electrodiagnosis of MND-ALS in order to improve quality. Differential diagnosis with motor axonal neuropathies may be particularly difficult. EMG is an essential tool for the early diagnosis of MND-ALS, which increases potential benefit of therapeutic interventions. A wide discussion among neurophysiologists from different schools could create a sound consensus on early diagnosis of MND-ALS.