Neurogenic shock

A type of shock resulting from spinal cord injury

Neurogenic Shock

MRI of the cervical spine, often involved in neurogenic shock

Neurogenic shock is a type of distributive shock that occurs when there is a sudden loss of signals from the sympathetic nervous system that maintain the normal muscle tone in blood vessel walls. This condition is most commonly associated with spinal cord injury, particularly injuries to the cervical or upper thoracic spine.

Pathophysiology

Neurogenic shock results from the disruption of the autonomic pathways within the spinal cord. The loss of sympathetic tone leads to unopposed parasympathetic nervous system activity, resulting in widespread vasodilation, decreased systemic vascular resistance, and subsequent hypotension. The heart rate may also be affected, leading to bradycardia due to the lack of sympathetic stimulation.

Causes

The primary cause of neurogenic shock is acute spinal cord injury, particularly at the cervical or high thoracic levels. Other causes may include severe head injury or conditions that affect the autonomic nervous system.

Symptoms

Patients with neurogenic shock may present with:

• Hypotension
• Bradycardia
• Warm, dry skin due to vasodilation
• Reduced cardiac output
• Possible respiratory failure if the injury affects the diaphragm

Diagnosis

Diagnosis of neurogenic shock is primarily clinical, based on the presence of hypotension and bradycardia following a spinal cord injury. Imaging studies, such as MRI or CT scan, are used to assess the extent of spinal cord damage.

Management

The management of neurogenic shock involves:

• Stabilization of the spine to prevent further injury
• Administration of intravenous fluids to maintain blood pressure
• Use of vasopressors to counteract vasodilation
• Atropine may be used to treat bradycardia
• Monitoring and support of respiratory function

Prognosis

The prognosis of neurogenic shock depends on the severity and level of the spinal cord injury. Early recognition and management are crucial to prevent complications and improve outcomes.

Related pages

• Spinal cord injury
• Shock (circulatory)
• Autonomic nervous system