OTHER COMPLICATIONS OF SPINAL CORD INJURY: AUTONOMIC DYSREFLEXIA (HYPERREFLEXIA)
Autonomic dysreflexia, also known as hyperreflexia, is a state that is unique to patients after spinal cord injury at a T-5 level and above. Patients with spinal cord injuries at Thoracic 5 (T-5) level and above are very susceptible. Patients with spinal cord injuries at Thoracic 6 - Thoracic 10 (T6-T10) may be susceptible. Patients with Thoracic 10 (T-10) and below are usually not susceptible. Also, the older the injury the less likely the person will experience autonomic dysreflexia.
Autonomic dysreflexia can develop suddenly, and is a possible emergency situation. If not treated promptly and correctly, it may lead to seizures, stroke, and even death.
Autonomic dysreflexia means an over-activity of the Autonomic Nervous System. It can occur when an irritating stimulus is introduced to the body below the level of spinal cord injury, such as an overfull bladder. The stimulus sends nerve impulses to the spinal cord, where they travel upward until they are blocked by the lesion at the level of injury. Since the impulses cannot reach the brain, a reflex is activated that increases activity of the sympathetic portion of autonomic nervous system. This results in spasms and a narrowing of the blood vessels, which causes a rise in the blood pressure. Nerve receptors in the heart and blood vessels detect this rise in blood pressure and send a message to the brain. The brain sends a message to the heart, causing the heartbeat to slow down and the blood vessels above the level of injury to dilate. However, the brain cannot send messages below the level of injury, due to the spinal cord lesion, and therefore the blood pressure cannot be regulated.
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