• Question: If one of our nerves are broken/stop working, are we gonna be paralyzed?

    Asked by anon-221051 on 28 Jun 2019.
    • Photo: Marianne King

      Marianne King answered on 28 Jun 2019:

      It depends what nerve it is! If we sever the spinal cord then this can lead to paralysis, depending on how high up it was severed dictates where we would be paralysed from. Unfortunately our spinal cords don’t heal because we end up with something called a glial scar. This is where lots of glial cells flood the site of injury and pretty much prevent our nerves from connecting to one another again. If we sever nerves in the peripheral nervous system though these can heal, sometimes completely.

    • Photo: Nina Rzechorzek

      Nina Rzechorzek answered on 30 Jun 2019: last edited 30 Jun 2019 1:19 pm

      Great question – not necessarily. This depends on which nerve it is, what part of the nerve is damaged, and how severely it is damaged. By definition a ‘nerve’ is part of the peripheral nervous system (PNS) which has much greater capacity to repair than the central nervous system (CNS; including brain and spinal cord which contain neurons but no nerves).
      Mild damage to some small sensory nerves may just give you some abnormal sensation (‘dysaesthesia’) such as burning, tingling, prickling, or aching. It is the more severe damage to peripheral motor nerves (the ones that allow for muscle contraction) that can cause paralysis. Paralysis can also result from damage only to the CNS, since this part of the nervous system ultimately controls what the PNS does. That is why a fractured vertebral column (‘spine’) or brain trauma (such as happens in stroke) can lead to paralysis. Paralysis (‘plegia’) is ultimately the loss of the ability to move some or all of the body. This website gives an overview of paralysis:
      This video gives a really lovely overview of the CNS and PNS, and the types of nerve injury (by definition in the PNS) based on Seddon’s classification system:

      There is also ‘Sunderland’s Classification’ and this video provides a nice comparison between the two systems:

      If there is capacity for repair, then rehabilitation (physiotherapy) is key to guiding regeneration/repair of nerves – in essence ‘teaching them how to work again’ through use and experience. This effectively mimics the process that happened during neurodevelopment.