Acute Inflammatory Demyelinating Polyneuropathy
Acute Motor Axonal Neuropathy (AMAN)
- Comprise about 5-10% of GBS presentations in America; commonly seen in Asia associated with C. jejuni infection
- Causes axonal damage rather than demyelination of nerves seen in AIDP
- May have a more rapid presentation than AIDP resulting in prolonged paralysis and respiratory failure
- Has selective involvement of motor nerves; sensory nerves are not involved
- Reflexes can be spared in some patients with AMAN
- Associated with GM1, GD1a, GalNac-GD1a, and GD1b
Acute Motor Sensory Axonal Neuropathy (AMSAN)
- Similar to AMAN but represents a more severe form of AMAN in which both motor and sensory nerves
- Causes axonal damage rather than demyelination of nerves seen in AIDP
- Associated with GM1, GD1a, GalNac-GD1a, and GD1b
GQ1B Syndromes
Miller Fisher Syndrome (MFS)
- Occurs in approximately 5-10% of GBS cases in the US and Europe; 20% in Asia
- Characterized by triad of ophthalmoplegia, ataxia, areflexia; some patients will have some limb weakness +/- fixed and dilated pupils while others may have an incomplete presentation triad
- Likely secondary to demyelination rather than axonal damage
- Antibodies against GQ1b (a ganglioside component of nerve) are present in 85 to 90 percent of patients with MFS
Bickerstaff Brainstem Encephalitis