Table 4.

Causes of acute flaccid paralysis

Acute neuropathy •Guillain–Barré syndrome •Other acute neuropathies (see Table 2) Acute myopathy (no sensory loss, reflexes often preserved) •e.g. hypokalaemic periodic paralysis Acute neuromuscular junction disorders (tend to cause paralysis descending from the cranial nerves rather than ascending from the lower limbs) •Myasthenic crisis •Botulism Acute myelopathy (an acute, severe cord lesion can be associated with ‘spinal shock’ – flaccidity and areflexia for days before conventional upper motor neurone signs develop – hence MRI of the cervical spine is sometimes justified in the investigation of early Guillain–Barré syndrome, before cranial nerve features have appeared, to exclude cord pathology)