[Critical illness polyneuropathy].
Critical illness polyneuropathy (CIP) is a recently identified entity for which reliable data is unavailable and of which the prevalence is unknown. Although the percentage of patients suffering CIP is low, more cases, including subclinical ones, are likely to be detected through the use of electroneurography. Any aged patient may be affected by CIP. It usually occurs a long stay in the intensive care unit (ICU) and is generally associated with sepsis, severe trauma and so-called multiple organ failure. The main clinical sign is distal weakness in the lower extremeties, although finding one or more of the following signs is not uncommon: quadriparesis, quadriplegia, difficult weaning, loss of osteo-tendon reflexes and muscle atrophy. The pathophysiology of CIP is unknown, although such mechanisms as cell dehydration, increased proteolysis and the activation of certain cytokins have been suggested. Before diagnosing CIP, other neuromuscle diseases and several recently described toxic myopathies must be ruled out. Electroneuromyographic study of axonal lesions may be of great utility, whereas analyses have low specificity. Histologic examination, when possible, allows axonal lesions (but never demyelinization) to be observed along with the non specific changes of myopathy. Although no specific treatment is available, the long-term prognosis is good if the underlying disease that gave rise to ICU admission is controlled, and if rehabilitation therapy is started early.