Current status on electrodiagnostic standards and guidelines in neuromuscular disorders.

The aim of this review is to present the status of electrodiagnostic standards and guidelines in neuromuscular disorders. Electrodiagnostic guidelines are developed on the background of medical technology assessment, wherefore a short presentation of medical technology assessment is given covering: (1) Evidence-based medicine, i.e. "to do the right thing", describing practice parameters and the STARD initiative which introduces evidence-based medicine in electrodiagnostic medicine, (2) Continuous quality improvement, i.e. "to do the thing right", describing variation among laboratories in methods and interpretation of tests, and the need for medical audit and implementation of electrodiagnostic guidelines, (3) Outcome studies, i.e. "is it worthwhile to do the right thing right?". In electrodiagnostic medicine there are very few outcome studies. Standards and guidelines described in the literature for different neuromuscular disorders are presented, often as figures or tables. These cover guidelines developed in detail for CIDP by expert consensus multicentre groups by AAN, INCAT, EFNS/PNS and for other inflammatory demyelinating neuropathies are described, as well as guidelines differentiating between demyelinating pathophysiology and axonal loss by motor and sensory nerve conduction studies. Furthermore, electrodiagnostic guidelines for ALS as detailed in the El Escorial, the modified El Escorial and the recent supplementary Awaji criteria are described and presented in a comprehensive table. Only few electrodiagnostic guidelines are published for nerve entrapment, cervical radiculopathy and neuromuscular transmission failure whereas none are known for myopathy. If no electrodiagnostic criteria for a given disorder exist, criteria for the electrodiagnostic examination are described if present. It is concluded that future research is needed in order to develop more electrodiagnostic guidelines in neuromuscular disorders by international expert consensus groups. Such research should use an evidence-based medicine approach and medical technology assessment and include continuous quality development and outcome studies.