Autonomic dysreflexia: Somatosympathetic and viscerosympathetic vasoconstrictor responses to innocuous and noxious sensory stimulation below lesion in human spinal cord injury

作者：Brown Rachael^*; Burton Alexander R^*; Macefield Vaughan G

来源：Autonomic Neuroscience-Basic & Clinical, 2018, 209: 71-78.

DOI：10.1016/j.autneu.2017.07.003

• Autonomic dysreflexia
• Somatosympathetic reflexes
• Spinal cord injury
• Viscerosympathetic reflexes

Autonomic dysreflexia is a dangerous elevation in blood pressure in people with spinal cord injury (SCI), produced by a spinally-mediated reflex activation of sympathetic vasoconstrictor neurones supplying skeletal muscle and the gut. Current dogma states that, apart from visceral inputs - such as those originating from a distended bladder or impacted colon - autonomic 'dysreflexia is triggered by noxious inputs below the lesion. However, while selective stimulation of small-diameter afferents in muscle or skin evokes a sustained increase in muscle sympathetic nerve activity and blood pressure, and a transient increase in skin sympathetic nerve activity and decrease in skin blood flow in able-bodied subjects, such noxious inputs have no effects on blood pressure and skin blood flow in SCI individuals. Conversely, weak electrical stimulation over the abdominal wall, which in able-bodied subjects is not painful and activates large-diameter cutaneous afferents, causes a marked increase in blood pressure in SCI but not in able-bodied subjects. Moreover, vibration of the penis in spinal-injured men, which is not noxious, caused marked vasoconstriction and increases in blood pressure, similar to those produced by non-noxious distension of the bladder during urodynamics procedures. This suggests that activation of large diameter somatic afferents, not small-diameter afferents, triggers the increases in vasoconstrictor drive that lead to autonomic dysreflexia, arguing against current dogma on the importance of noxious inputs in triggering autonomic dysreflexia.

• 出版日期2018-1