Sepsis and multiple organ failure (critical illness, systemic inflammatory response syndrome) develop in the majority of patients receiving mechanical ventilation for ≥ 1 week in major medical and surgical ICUs, and the majority are nervous system complications of septic encephalopathy,1–2 critical illness polyneuropathy (CIP),3and critical illness myopathy (CIM).4 These complications appear as stupor or coma, difficulty weaning from mechanical ventilation, and limb weakness. As intensivists struggle to overcome the complex problems of sepsis and multiple organ failure, these nervous system complications are either overlooked or misdiagnosed. Stupor is attributed to sedation, weaning difficulties to diaphragmatic fatigue, and limb weakness to catabolic myopathy. With successful weaning, the patient is discharged to a general ward, where the patient experiences impaired cognition; difficulty dressing, eating, and rising from the bed or toilet seat; difficulty standing and walking; shortness of breath; and fatigue. A prolonged stay in a rehabilitation center may be necessary. Unless further investigated, the nature of these symptoms remains unexplained and a puzzle to the patient, family, and caregivers.