Table 1

Clinical, electrophysiological, and histological features of intensive care unit-acquired weakness (ICUAW)

Investigation

CIP

CIM

CINM

Physical examination

Distal muscle weakness

Proximal muscle weakness

Proximal and distal muscle weakness

Distal sensory deficit

Normal sensory testing

Distal sensory deficit

Normal or depressed deep tendon reflexes

Normal or depressed deep tendon reflexes

Depressed deep tendon reflexes

Electrophysiology studies

Decreased CMAP and decreased SNAP

Decreased CMAP and normal SNAP

Decreased CMAP and SNAP

Normal MUAP

Decreased MUAP

Decreased MUAP

Normal or near-normal conduction velocity

EMG shows short duration, low amplitude activity

EMG shows short duration, low-amplitude activity

Histology

Axonal degeneration of distal motor and sensory nerves

Thick filament (myosin) loss, type II fiber (fast twitch) atrophy, necrosis

Axonal degeneration and evidence of loss in myosin, type II fiber atrophy, and necrosis

CIM = critical illness myopathy; CINM = critical illness neuromyopathy; CIP = critical illness polyneuropathy; CMAP = compound muscle action potential; EMG = electromyography; MUAP = muscle unit action potential; SNAP= sensory nerve action potential.

Lee and Fan BMC Medicine 2012 10:115   doi:10.1186/1741-7015-10-115