[Impairment of peripheral nerve excitability]

Area of Science:

• Neuroscience
• Immunology
• Channelopathies

Context:

• Peripheral nerve disorders often involve functional abnormalities, particularly changes in axon excitability.
• Conditions like Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), and Isaacs' syndrome are characterized by specific ion channel dysfunctions.

Purpose:

• To review the functional abnormalities of axon excitability in peripheral nerve disorders.
• To discuss the role of autoantibodies in targeting ion channels and causing conduction block and other neurological symptoms.
• To highlight the utility of the threshold electrotonus method for evaluating axonal excitability in vivo.

Summary:

• Changes in axon excitability, particularly involving voltage-gated sodium channels (VGSC) and voltage-gated potassium channels (VGKC), are implicated in peripheral neuropathies.
• Autoantibodies against VGSC and VGKC are associated with conditions like GBS, CIDP, and Isaacs' syndrome, potentially causing conduction block, myokymia, and neuromyotonia.
• The threshold electrotonus method is a valuable tool for assessing axonal excitability, aiding in the diagnosis and understanding of these axonal channelopathies.

Impact:

• This review expands the understanding of axonal channelopathies, linking specific ion channel targets to clinical neurological presentations.
• It emphasizes the diagnostic potential of assessing ion channel function and autoantibody presence in peripheral nerve disorders.
• The findings suggest that further research into axonal ion channel involvement will refine diagnostic and therapeutic strategies for neurological conditions.