II. Definitions

  1. Neurogenic Shock
    1. Distributive shock from neurogenic vasodilation mediated by loss of sympathetic tone
    2. Follows cerebral or spinal cord injury (above T6) affecting sympathtic nervous system
  2. Spinal Shock
    1. In contrast to Neurogenic Shock, Spinal Shock is not a true shock syndrome
    2. Results in flaccid paralysis and Deep Tendon Reflex loss below level of spinal cord injury

III. Pathophysiology

  1. Results from Severe Head Injury or upper spine injury (above T6)
  2. Peripheral Sympathetic Nerve denervation results in ungoverned Parasympathetic Nerve activity
    1. Loss of vasomotor tone (vasodilation) leading to distributive shock
    2. Loss of cardiac Sympathetic Nerve activity, leads to paradoxical Bradycardia

V. Signs

  1. Hypotension
    1. Secondary to Bradycardia and vasodilation
  2. Bradycardia
  3. Decreased vascular tone (vasodilation)
    1. Warm extremities

VI. Associated Conditions

  1. See Severe Head Trauma
  2. See Spinal Cord Syndrome
  3. See Cervical Spine Injury
  4. See Thoracolumbar Trauma
  5. Spinal Shock
    1. Flaccid paralysis and Deep Tendon Reflex loss below level of spinal cord injury
  6. Diaphragm Paralysis
    1. C3-5 Cervical Spine Injury resulting in phrenic nerve denervation

VII. Differential Diagnosis

  1. Hemorrhagic Shock (first priority to manage)
    1. Presents with Tachycardia, Vasoconstriction and cold extremities
    2. In actuality, distinguishing from Neurogenic Shock can be difficult
    3. Hemorrhagic Shock is more common, more immediately deadly and more treatable
      1. Address possible Hemorrhagic Shock first

VIII. Pitfalls

  1. Fluid Overload (from aggressive fluid Resuscitation)

IX. Management

  1. Careful Fluid Replacement
  2. Vasopressors (Norepinephrine is preferred)
  3. Target mean arterial pressure of 85 mmHg or higher (maximizes spinal cord perfusion)

X. Prognosis

  1. Neurogenic Shock if due to critical Head Injury may indicate terminal event
  2. Prognosis is often poor

XI. References

  1. (2012) ATLS, ACOS, p. 179-80

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Ontology: Neurogenic shock (disorder) (C0544617)

Definition (NCI_FDA) Shock resulting from neurogenic vasodilation, which can be produced by cerebral trauma or hemorrhage, spinal cord injury, deep general or spinal anesthesia, or toxic central nervous system depression.
Definition (NCI) Shock resulting from neurogenic vasodilation, which can be produced by cerebral trauma or hemorrhage, spinal cord injury, deep general or spinal anesthesia, or toxic central nervous system depression.
Concepts Pathologic Function (T046)
SnomedCT 129577007
Italian Shock neurogeno
English Vasogenic Shock, Neurogenic Shock, Neurogenic shock (disorder), neurogenic shock, SHOCK, NEUROGENIC, NEUROGENIC SHOCK, shock neurogenic, Neurogenic shock (diagnosis), Neurogenic shock
Japanese 神経原性ショック, シンケイゲンセイショック
Czech Neurogenní šok
Hungarian Neurogen shock
Spanish choque neurogénico, choque neurógeno (trastorno), choque neurógeno, shock neurogénico, shock neurógeno, Shock neurogénico
Portuguese Shock neurogénico
Dutch neurogene shock
French Choc neurogène
German neurogener Schock