myelination

What is Guillain-Barré Syndrome

The peripheral nervous system is comprised of all the nerves outside of the brain and spinal cord. The nerve stem, known as the axon is covered by an insulating layer of myelin. The myelin sheath doesn’t cover the entire axon, and there are gaps in the myelin known as the Nodes of Ranvier.

A nerve impulse in a healthy nerve can travel at speeds close to 120 meters per second. This speed is achieved because the nerve impulse bounces from one Node of Ranvier to the next, since the axon inbetween these nodes is insulated by myelin.

In demyelination disorders this speed is severely compromised. For example in Multiple Sclerosis which also an autoimmune demyelination disorder but affecting the central nervous system, this speed of conduction can be as low as 8 meters per second.  Guillian-Barré Syndrome affects the peripheral nervous system and is known to completely block nerve conduction and where conduction continues it is generally below 20 meters per second.

Guillain-Barré : Quick Facts

  • GBS is normally preceded by a viral or bacterial infection.
  • Most common preceding illness is diarhea caused by “Campylobacter Jejuni” infection, which is generally found in under cooked poultry.
  • There has been a high instance of GBS among people recovering from ZIKA virus in South America.
  • There is no cure for GBS, treatment includes :
    (1) Plasmaphersis which removes the harmful antibodies from blood, and
    (2) Immunoglobulins which block the antibodies causing demyelination.
  • Hospital treatment is required in all GBS cases.

Guillain-Barré : Symptoms

  • The first symptoms are tingling in fingers and toes.
  • This is followed by progressing muscle weakness in arms and legs.
  • Eventually mobility is restricted and moving limbs becomes impossible.
  • There will also be difficulty moving eyes, face, talking, chewing and swallowing.
  • Severe lower back pain.
  • Loss of bladder control.
  • When the rapidly progressing paralysis reaches the diaphragm intubation and mechanical ventilation is required to prevent death.
  • The most serious cases of GBS can result in fatal respiratory failure within 24hrs of the first tingling sensation.