From the Guidelines
The recommended workup for Acute Motor and Sensory Axonal Neuropathy (AMSAN), a severe variant of Guillain-Barré Syndrome (GBS), includes cerebrospinal fluid (CSF) analysis, nerve conduction studies, and serological testing, as outlined in the 2019 Nature Reviews Neurology study 1.
Key Components of Workup
- CSF analysis typically shows albuminocytologic dissociation (elevated protein with normal cell count) 1
- Nerve conduction studies reveal reduced compound muscle action potentials and sensory nerve action potentials, indicating axonal damage 1
- Serological tests should check for recent infections like Campylobacter jejuni, cytomegalovirus, Epstein-Barr virus, and Zika virus 1
Treatment
- Treatment consists of intravenous immunoglobulin (IVIG) at 0.4 g/kg/day for 5 days or plasma exchange (PLEX) with 5 exchanges over 2 weeks, as recommended in the 2019 Nature Reviews Neurology study 1
- These should be initiated within 2 weeks of symptom onset
Supportive Care
- Supportive care is crucial, including respiratory monitoring (with forced vital capacity measurements), cardiac monitoring, deep vein thrombosis prophylaxis, pain management, and early rehabilitation 1
- AMSAN has a worse prognosis than demyelinating forms of GBS, with slower and often incomplete recovery, making prompt diagnosis and aggressive treatment essential to improve outcomes 1
From the Research
Recommended Workup for AMSAN GBS
The recommended workup for Acute Motor and Sensory Axonal Neuropathy (AMSAN), a subtype of Guillain-Barré Syndrome (GBS), involves a combination of clinical assessment, electrophysiological studies, and laboratory tests.
- Clinical assessment: Patients with AMSAN typically present with acute onset of distal weakness, loss of deep tendon reflexes, and sensory symptoms 2.
- Electrophysiological studies: These studies show mildly reduced nerve conduction velocities combined with a marked reduction of muscle action and sensory nerve action potentials 2.
- Laboratory tests: These may include blood tests to detect the presence of autoantibodies and other markers of inflammation.
Treatment Options
Treatment options for AMSAN GBS include:
- Plasma exchange (PE): This involves removing plasma from the blood to reduce the levels of autoantibodies and other inflammatory mediators 3, 4, 5, 6.
- Intravenous immunoglobulin (IVIG): This involves administering IVIG to neutralize autoantibodies and reduce inflammation 3, 4, 5.
- Corticosteroids: These may be used to reduce inflammation and suppress the immune system 2.
- Pain management: This is an important aspect of treatment, as patients with AMSAN GBS often experience severe pain 2.
Comparison of Treatment Options
Studies have compared the effectiveness of PE and IVIG in treating GBS, with some showing that PE may have a more significant curative effect 4, while others have found that IVIG may be more effective in improving outcomes 3.
- A study published in 2023 found that IVIG was more effective than PE in improving outcomes at 1 and 3 months, although there was no significant difference in outcome at 1 year 3.
- A study published in 2015 found that PE was more effective than IVIG in improving nerve function and reducing symptoms 4.
- A Cochrane review published in 2017 found that PE significantly increased the proportion of patients who recovered the ability to walk with assistance and improved disability grades after 4 weeks 6.