Table 1.

Diagnostic criteria of GBS; acute inflammatory demyelinating polyneuropathy and acute motor axonal neuropathy [1].

Features required for diagnosis of GBS

Progressive weakness in legs and arms (sometimes initially only in legs)

Areflexia (or decreased tendon reflexes) in weak limbs

Acute inflammatory demyelinating polyneuropathy (AIDP)
Additional symptoms	Nerve conduction study findings
Progressive phase lasts days to 4 weeks	Features of demyelination (only assessable if distal CMAP amplitude is > 10% LLN)
Relative symmetry of symptoms	Prolonged distal motor latency
Mild sensory symptoms or signs	Decreased motor nerve conduction velocity
Cranial nerve involvement, especially bilateral weakness of facial muscles	Increased F‐wave latency, conduction blocks and temporal dispersion
Autonomic dysfunction
Pain (often)

Acute motor axonal neuropathy (AMAN)
Additional symptoms	Nerve conduction study findings
Progressive phase lasts days to 4 weeks	No features of demyelination (or, one demyelinating feature in one nerve if distal CMAP amplitude is < 10% LLN)
Relative symmetry of symptoms	Distal CMAP amplitude is < 80% LLN in at least two nerves
No sensory symptoms or signs	Transient motor nerve conduction block may be present (possibly caused by antiganglioside antibodies)
Cranial nerve involvement (rarely)	No features of demyelination (or, one demyelinating feature in one nerve if distal CMAP amplitude is < 10% LLN)
Autonomic dysfunction	—
Pain (sometimes)	—