What Are Nerve Injuries?

Nerve injuries result from pressure, stretching or cutting, often following trauma. These injuries result in an interruption of signals to and from the brain, causing a loss of feeling and cessation of muscles working properly. This often results in pain, burning, tingling or loss of sensation.

Types of Nerve Injuries

There are a range of classifications of nerve injuries, the primary three types affect the peripheral nervous system, a network of sensory and motor nerves that connect the spinal cord and brain. The various types of nerve injuries include: 

  • Neurapraxia: Neuropraxia is the mildest form of traumatic peripheral nerve injury. It is characterized by focal segmental demyelination at the site of injury without disruption of axon continuity and its surrounding connective tissues. This condition results in blockage of nerve conduction and transient weakness or paresthesia.
  • Axonotmesis: This type of injury to the nerves in which the axons and their protective sheath, known as myelin, are damaged. 
  • Neurotmesis: This type of injury results in a complete cutting of a peripheral nerve resulting in complete sensory and motor deficits to the skin and muscles supplied by the injured nerve.

Causes of Nerve Injuries

The most common causes of injury to the nerve network result from an accident or medical conditions, like carpal tunnel syndrome, Guillain-Barré syndrome, diabetes and autoimmune diseases.

Types of damage that can result in injuries include:

  • Laceration
  • Electrical injury
  • Severe bruising
  • Drug injection injury
  • Stretching

Risk Factors for Nerve Injuries

As the most common causes of nerve damage are diabetes and accidents, lifestyle plays a major part in avoiding the risks of nerve injury. Early diagnosis and treatment are important to avoid complications and permanent, long-term damage.

Screening for & Preventing Nerve Injuries

Various types of screening methods can be used to look closer at nerve injuries to determine severity. The various types of methods include:

  • Magnetic resonance imaging scan (MRI) to get detailed images of the damaged area
  • Ultrasound, which uses sound waves to get images of nerve damage
  • Nerve conduction studies, which use electrodes at various points in the body to measure the success of electrical signals passing through nerves
  • Electromyography (EMG), which uses thin needle electrodes to measure electrical activity in the muscle

Signs & Symptoms of Nerve Injuries

Symptoms can vary depending on which nerves have been affected. 
Damage to motor nerves result in weakness, muscle atrophy, paralysis and twitching.

  • Autonomic nerves are part of the peripheral nervous system that regulates processes including blood pressure, respiration, sexual arousal and heart rate. Damage to this group of nerves results in lightheadedness, bladder and bowel dysfunction, sweating and angina. 
  • Motor nerve damage results in limb weakness, muscle atrophy, twitching and paralysis. 
  • Sensory nerve damage can result in burning, pain, sensitivity and numbness. 

Diagnosing Nerve Injuries

Your doctor will determine the extent of damage to the nerve by using an electrical conduction test—either an electromyography or a nerve conduction velocity. These scans measure the passage of electrical currents through the nerves. Damage is then classified into one of the following categories:

  • First degree: Located at the site of the injury, this block is reversible following a few weeks of healing. No surgery is required. 
  • Second degree: The axons, or the electrical wires within the nerve, are damaged but do not require surgery for repair. 
  • Third degree: Due to more severe damage to the axons in the nerve, recovery is harder to predict. With neurolysis (nerve surgery), the injury site can be cleaned and repaired, sometimes with grafting. 
  • Fourth degree: Axons and the surrounding tissues are damaged to an extent that this injury requires surgery to prevent scarring, which prohibits nerve regeneration. Nerve grafting is required to repair fourth-degree nerve damage.  
  • Fifth degree: This extreme injury results from a nerve being overstretched or severed. Surgery is required.

Treating Nerve Injuries

Depending on the type of nerve injury and damage, doctors will prescribe a range of treatment solutions. Surgery is recommended for nerve damage that doesn’t heal properly. Following an EMG screening to review scarred nerves, a surgery can restore function to muscles using tendons from another muscle group.

Injuries resulting in pain may require medications for pain management. These medications may include antiseizure, depression or insomnia prescriptions, or over-the-counter medicines like aspirin, ibuprofen or Advil. Recovery involves exercise, physical therapy and sometimes braces, splints or use of electrical stimulators.

Living with Nerve Injuries

Severe nerve injury can affect one’s ability to work and perform normal daily tasks. Recovery can depend on lifestyle choices, particularly those that reduce stress. While movement may be restricted, continuing to exercise or work with a physical therapist can expedite recovery. Work with your healthcare professional to develop a recovery plan that won’t put you at risk for further damage.