What is Guillain Barre Syndrome (GBS) with Anti-Muscle Specific Tyrosine Kinase (AMSA) type in an adult patient with a recent minor infection?

Clarification: "AMSA" is Not a Recognized GBS Subtype

There is no recognized Guillain-Barré syndrome subtype called "AMSA type" in the medical literature or current clinical guidelines. You may be confusing terminology or referring to one of the established GBS variants 1.

Established GBS Subtypes and Variants

The recognized electrophysiological subtypes of GBS include 1, 2:

Primary Electrophysiological Subtypes:

• AIDP (Acute Inflammatory Demyelinating Polyneuropathy): Most common in Europe and North America (70% of cases), characterized by demyelination of peripheral nerves 2, 3
• AMAN (Acute Motor Axonal Neuropathy): More common in Asia (30-70% of cases), involves motor axon damage without sensory involvement 1, 2
• AMSAN (Acute Motor and Sensory Axonal Neuropathy): Severe variant with both motor and sensory axonal damage 1, 2

Clinical Variants:

• Miller Fisher Syndrome (MFS): Characterized by ophthalmoplegia, ataxia, and areflexia (5-25% of cases) 4, 5
• Pure motor variant: Motor weakness without sensory signs (5-70% of cases) 1, 4
• Pharyngeal-cervical-brachial weakness: Weakness limited to upper limbs and cranial nerves 1
• Paraparetic variant: Weakness limited to lower limbs 1
• Bilateral facial palsy with paresthesias: Isolated cranial nerve involvement 1, 4

Possible Confusion with Other Terms

You may be thinking of:

• AMAN (Acute Motor Axonal Neuropathy) - not "AMSA" 1, 2
• AMSAN (Acute Motor and Sensory Axonal Neuropathy) 1
• Anti-MuSK (Muscle-Specific Kinase) antibodies - these are associated with myasthenia gravis, not GBS, which is a completely different neuromuscular disorder 1

Key Diagnostic Approach

If evaluating a patient with suspected GBS after recent infection 6:

Immediate assessment priorities 4:

• Respiratory function (vital capacity, negative inspiratory force using "20/30/40 rule")
• Autonomic stability (continuous cardiac monitoring, blood pressure)
• Functional disability using GBS disability scale

Diagnostic workup 4:

• CSF examination showing albumino-cytological dissociation (elevated protein, normal cell count)
• Electrodiagnostic studies to classify demyelinating vs. axonal pattern
• Look for "sural sparing pattern" (normal sural nerve with abnormal median/ulnar responses)

Treatment for patients unable to walk unaided within 2-4 weeks 4:

• IVIg 0.4 g/kg/day for 5 consecutive days (first-line, easier to administer) 1, 7
• Plasma exchange 200-250 ml/kg over 4-5 sessions (equally effective alternative) 1, 7

Please clarify what specific condition or antibody you are asking about, as "AMSA type" does not correspond to any established GBS classification.