Introduction: In the intensive care unit (ICU) patients sometimes develop diffuse neuromuscular deficit resulting in flaccid tetraparesia with a more or less severe prognosis.
State of the art: ICU-acquired neuromuscular disorders have various possible origins, including necrotic or catabolic myopathies and sensori-motor axonal neuropathies. Electrophysiological testing determines these pathophysiological mechanisms better than clinical examination. The technique of direct muscle stimulation has been proposed, in addition to conventional electroneuromyographic methods, to improve the reliability of electrodiagnosis in ICU, but has been rarely studied. Using this technique, we recently showed that a majority of ICU-acquired pareses are of myopathic origin.
Perspectives: The technique of direct muscle stimulation could be fruitfully associated with usual electroneuromyographic methods to differentiate myopathic from neuropathic involvement at the origin of any severe weakness in ICU.
Conclusion: The contribution of myopathic processes in ICU-acquired paresis is probably underestimated. Direct muscle stimulation enables better understanding of the mechanisms underlying acquired motor deficit in ICU patients. However, it remains to be determined whether this refinement could have a significant impact on prognosis and treatment.