Shock or Neurogenic Shock: Definition, Causes, Pathophysiology, Symptoms, Diagnosis, Treatment and Overview

What is a neurogenic shock?

A shock or shock is considered a life-threatening condition in which there is insufficient supply of blood flow in the body.

There are five common types of shock and one of the most striking in neurogenic shock , which occurs when there is a lesion in the central nervous system, for example, the brain and spinal cord, alters the function of the nervous system, affecting the distribution of blood throughout the body.

Although these types of crashes may have different specific causes, most of them show the same manifestations.


  • Low blood pressure – usually reaches up to 60 mmHg
  • Increased heart rate – reaching more than 120 beats per minute.
  • Difficulty breathing – the acts of breathing need more effort than the usual and normal pattern of breathing.
  • Pale skin – this happens because there are already a small number of red blood cells in the circulation.
  • Hyperhidrosis – is an abnormal and excessive sweating even when the body is not exposed to the hot temperature.
  • Lethargy – is a manifestation of diminished mental capacity. Most of those who are in torpor can not think clearly and the associated symptoms are the following:
    • Confusion
    • Anxiety
    • Difficulty speaking and walking
    • Hallucinations
    • Depression
    • Memory loss
  • Fainting – this occurs when there is a brief moment of unconsciousness. The symptoms are:
    • Dizziness
    • Sickness
    • Excessive sweating
    • Fast pulse
    • Weakness or fatigue
    • Cold limbs and warm skin
  • Confusion – since the patient has impaired mental capacity.
  • Coma – the individual becomes unconscious and does not react to stimulation

Causes of Neurogenic Shock

Neurogenic shock may be due to severe damage to the central nervous system.

The mechanism is that once the trauma occurs, the body’s sympathetic functions are interrupted, which could lead to the relaxation of the blood vessels, thus decreasing blood flow throughout the system.

If not treated promptly, it can be dangerous to the person’s life due to continued insufficiency in the blood supply causing cell death and organ failure.

Common causes:

  • Decreased blood volume due to secondary hemorrhage or dehydration.
  • Serious allergic reactions
  • Medications that can alter the normal flow of blood through the body.


To diagnose this condition, doctors will first perform a physical exam to detect additional symptoms and control their blood pressure. There is also a series of tests that doctors use to show the severity of the injury that caused the neurogenic shock .

TC scan:

A CT scan uses X-ray images to show images of the body. If you have a spinal injury, scans can help diagnose the severity of the injury. It can also help doctors detect any internal bleeding or additional damage.

IRM scan:

An MRI is an imaging test that is used to show the internal structures of your body, such as your spine. It can help detect any irregularity with your spine. In combination with an evaluation of your symptoms, your doctor may use an MRI to diagnose the source of your back pain and neurogenic shock.

Urinary catheter:

Doctors will also use a urinary catheter to measure your urine volume. With some injuries to the spinal cord, you may not be able to urinate on your own or you may suffer from incontinence. Through urine tests, doctors can also help detect any signs of infection.

Pathophysiology of the Neurogenic Shock

Neurogenic shock is the clinical state that manifests from primary and secondary spinal cord injury.

Hemodynamic changes are seen with a spinal cord injury above the T6 level. Descending sympathetic tracts rupture more frequently due to an associated fracture or dislocation of the vertebrae in the cervical spine or in the upper part of the thoracic spine.

The primary lesion of the spinal cord occurs minutes after the initial impact. The primary lesion is direct damage to the axons and neuronal membranes in the intermediolateral nucleus, the lateral gray matter and the anterior root that lead to an interrupted sympathetic tone.

The secondary lesion of the spinal cord occurs hours or days after the initial impact. The secondary lesion is the result of a vascular lesion, electrolyte changes and edema that leads to a progressive central hemorrhagic necrosis of the gray matter at the site of the lesion.

At the cellular level, there is excitotoxicity due to accumulation of NMDA, inadequate electrolyte homeostasis, mitochondrial damage and reperfusion injury, which lead to controlled and uncontrolled apoptosis.

Neurogenic shock is a combination of primary and secondary injury that leads to the loss of sympathetic tone and, therefore, to the unopposed parasympathetic response driven by the vagus nerve.

Consequently, patients suffer from instability in blood pressure, heart rate and temperature regulation.


Fluid replacement is the best initial treatment for neurogenic shock. Some institutions use the use of pressor agents to maintain the hemodynamic stability of the body.

  • The use of dopamine (Intropin).
  • The use of the antidiuretic hormone , vasopressin.
  • Atropine – this speeds up the heart rate and increases the cardiac output.

Neurogenic shock can cause irreversible damage if not treated quickly. The treatment options are intended to stabilize it and prevent further injury or damage.

First, your doctor will immobilize you to prevent further damage. Then you will be given intravenous fluids to regulate your blood pressure.

If your blood pressure is too low, you may be given vasopressors or medications that help tighten blood vessels and increase blood pressure. Some of the most common vasopressors include:

Also, if you have a slower heartbeat, your doctor may prescribe atropine. This medicine will help maintain a normal heart rhythm


The shock or neurogenic shock can be fatal. If you recently injured your spine and have nausea or dizziness and have chest pain, you should call 911 or visit an emergency room right away.