Acute weakness syndromes in the critically ill patient.

Over the past three decades there has been increasing interest in acute weakness syndromes in critically ill mechanically ventilated patients. Many of these patients require rehabilitation, and some understanding of potential etiologies and functional outcomes for these syndromes is useful to rehabilitation practitioners. A clearer understanding of these syndromes has evolved over time, as has the terminology to describe these conditions. This article will review commonly encountered causes of acute weakness in critically ill patients, including disorders of the peripheral nerves, the neuromuscular junction, and muscle.