How does spinal cord injury cause autonomic dysreflexia?

Injury at or above the sixth thoracic spinal cord segment segregates critical spinal sympathetic neurons from supraspinal modulation which can result in a syndrome known as autonomic dysreflexia (AD).

What is the most common cause of autonomic dysreflexia?

The most common cause of autonomic dysreflexia (AD) is spinal cord injury. The nervous system of people with AD over-responds to the types of stimulation that do not bother healthy people.

Does autonomic dysreflexia only occur in spinal cord injury?

Autonomic dysreflexia is a condition that emerges after a spinal cord injury, usually when the injury has occurred above the T6 level. The higher the level of the spinal cord injury, the greater the risk with up to 90% of patients with cervical spinal or high-thoracic spinal cord injury being susceptible.

What are possible causes of autonomic dysreflexia?

Autonomic Dysreflexia Causes

• Constipation.
• Kidney stones.
• Urinary tract infection.
• Inserting a catheter, a medical tube.
• Hemorrhoids.
• Irritated or blistered skin.
• Pressure sores.
• Sunburn or hot water burns.

Why does T6 cause autonomic dysreflexia?

Patients with lesions above T6 are most susceptible to autonomic dysreflexia because the large splanchnic blood vessels are supplied by sympathetic fibres carried within T6 to T10 nerve roots.

Why does autonomic dysreflexia cause bradycardia?

Dysreflexia is related to the interruption of descending inhibition and the development of hyperresponsiveness of peripheral receptors. Bradycardia resulting from a hypertensive crisis is due to activation of baroreceptors and a vagal-mediated response above the lesion to compensate for the hypertensive crisis.

What is autonomic shock?

Neurogenic shock is a distributive type of shock resulting in hypotension (low blood pressure), often with bradycardia (slowed heart rate), caused by disruption of autonomic nervous system pathways. It can occur after damage to the central nervous system, such as spinal cord injury and traumatic brain injury.

Why does autonomic dysreflexia only occur above T6?

What is a T8 spinal cord injury?

Individuals with injuries from T1 to T8 usually affect control of the upper torso, limiting trunk movement and sensation as the result of a lack of abdominal muscle control. This can affect balance as well as proprioception (where your body is in space).

Why does neurogenic shock occur above T6?

Medical Complications Neurogenic shock can occur in patients with SCI at T6 or above because of the loss of thoracic sympathetic outflow. This results in decreased venous tone, causing pooling of the blood volume in the extremities and hypotension.

Which medications are used in the treatment of autonomic dysreflexia?

Hydralazine, mecamylamine, diazoxide, and phenoxybenzamine might also be used. If an erectile dysfunction drug (e.g. Cialis, Viagra) has been used within 24-hours, other medications should be considered as blood pressure could drop dangerously low. For the most part, autonomic dysreflexia can be prevented.

Which are characteristics of autonomic dysreflexia?

Autonomic dysreflexia is an abnormal, overreaction of the involuntary (autonomic) nervous system to stimulation. This reaction may include: Change in heart rate. Excessive sweating. High blood pressure. Muscle spasms. Skin color changes (paleness, redness, blue-gray skin color)

What is the best treatment for autonomic neuropathy?

Some treatments can relieve the symptoms of autonomic neuropathy. Treatment is based on what part of your body is most affected by nerve damage. Your doctor may recommend: Diet changes. You might need to increase dietary fiber and fluids. Fiber supplements, such as Metamucil or Citrucel, also might help.