He Neurogenic shock Is a condition in which there is not enough blood flow in the body due to sudden loss of sympathetic nervous system signals, responsible for maintaining normal muscle tone in the walls of blood vessels.
When neurogenic shock occurs, the blood vessels relax and dilate, resulting in accumulation of blood in the venous system and an overall decrease in blood pressure.
This may be due to a complication brain or in the spinal cord , Particularly in the T6 region and where there was a disconnection between the brain and The autonomic nervous system .
It is a life-threatening condition that requires immediate medical attention to prevent irreversible damage to the tissues or even death of the patient. There are several types of shocks, however, the neurogenic is considered to be the most difficult to manage due to possible irreversible tissue damage.
Neurogenic shock should not be confused with spinal shock, since the second one lasts from one day to a couple of days, and the absence of sensory and motor tone is temporary as well. Neurogenic shock, on the other hand, lasts for several days to several weeks and may result in loss of muscle tone.
Symptoms of neurogenic shock
Decreased blood pressure
Hypotension or low blood pressure results from a reduction of systemic vascular resistance translated into collection of blood within the limbs, resulting in deficiency in sympathetic tone.
The lesion in the spinal cord Usually results in the inability of the blood vessels to contract, and in response to the alteration of the autonomic nervous system, there is a decrease in blood pressure.
Hypothermia
Hypothermia is an excessive drop in body temperature in which the patient has hot limbs and the rest of the body cool to the touch. This feature may be a symptom of neurogenic shock.
It occurs because the spinal cord injury usually results from the loss of sympathetic tone, which in turn can result in the inability to reorient blood flow to the nucleus circulation, causing excessive loss in body temperature.
Bradycardia
Bradycardia is one of the key signs of neurogenic shock, characterized by a resting heart rate of less than 60 beats per minute.
This is because the injury to the spinal cord causes nerve damage, which in turn causes the walls of blood vessels to relax and decrease the heart rate.
Bradycardia is also aggravated by hypoxia or insufficient blood supply.
Other symptoms of shock include: rapid and difficult shallow breathing, pale skin appearance, cold and clammy skin, dizziness and lightheadedness, nausea and vomiting, fainting, rapid and weak pulse.
In severe neurogenic shock, symptoms may also be accompanied by:
- Change in mental state or confusion and disorientation
- anxiety
- Looks blank or eyes staring at nothing
- No response to stimuli
- Low or no amount of urine
- Excessive sweating
- Bluish discoloration of the lips and fingers (meaning deprivation of oxygen in the body)
- Significant chest pain
- unconsciousness.
Causes
Neurogenic shock occurs immediately after a spinal cord injury, so this injury is the main cause of neurogenic shock.
Spinal cord injury can occur with complete or incomplete damage to the bone marrow, defined as the injury to any part of the spinal cord, including the nerves at the end of the spinal canal.
Spinal cord injuries or trauma can be blunt (no spike) or penetrating. They can be caused by a dislocation, rotation and over extension or flexion of the cord. It can also occur as a result of sports injuries, falls, vehicle accidents, gunshot wounds, stab wounds, among others.
In some cases, it can occur as a result of local anesthesia being administered incorrectly. Drugs and medications that affect the autonomic nervous system may also result in neurogenic shock.
Treatment
Neurogenic shock is a life-threatening situation, so it is considered a medical emergency in order to preserve the patient's life.
- Immobilization of the spine is necessary to prevent further damage to the spinal cord.
- Access to the nearest hospital is necessary to ensure the preservation of life. The goal of emergency physicians will be to stabilize the patient and prevent any irreversible tissue damage.
- For blood pressure, the patient should be given intravenous fluids in order to restore values. The Dopamine And other inotropic agents may be infused in case liquid resuscitation is insufficient.
- For severe bradycardia, atropine or a pacemaker is usually given if necessary.
- In the event of a neurological deficit, the high dose of methylprednisolone may be administered within 8 hours following the onset of neurogenic shock.
Spinal cord
What is the spinal cord?
The spinal cord is a long cylinder of nerves that extends from the base of the brain through the vertebral canal and down the spine. In adults it is about 45 centimeters in length and 2 centimeters in diameter.
It is part of the central nervous system (CNS) along with the brain. This has different segments and each contains a pair of roots made of nerve fibers called the dorsal roots (towards the back) and ventral (far from the back) roots.
What is the function of the spinal cord?
Its main functions are:
1- Electrical communication . These electrical signals are driven up and down the cord, allowing communication between different sections of the body and the brain, as the cord passes through different levels of the trunk section.
2- Walking (locomotion) . During the walk, several muscle groups in the legs are coordinated to contract again and again.
Although it may seem simple to put one foot in front of the other while walking, it has to be carefully coordinated by several groups of neurons known as central pattern generators in the spinal cord, which send signals to the leg muscles. This allows them to spread or contract, producing the alternate movements that are involved in walking.
3- Reflections . Reflexes are predictable and involuntary responses of the spinal cord and the nerves of the peripheral nervous system (SNP).
References
- John P. Cunha (2016). Medical Definition of Neurogenic Shock. Medicine Net. Retrieved from: medicinenet.com.
- Elizabeth H. Mack (2013). Neurogenic Shock. The Open Pediatric Medicine Journal. Retrieved from: benthamopen.com.
- Medicalmd (2014). Neurogenic Shock. HubPages. Retrieved from: http://hubpages.com
- Dudek RW (2014). Embryology. Lippincott Williams & Wilkins. Retrieved from: myvmc.com.