Global InformationAutonomic dysreflexia information
| Autonomic dysreflexia | |
|---|---|
| Other names | Autonomic hyperreflexia[1] |
| Specialty | Neurology  |
Autonomic dysreflexia (AD) is a potentially fatal medical emergency classically characterized by uncontrolled hypertension and cardiac arrhythmia.[2][3][4] AD occurs most often in individuals with spinal cord injuries with lesions at or above the T6 spinal cord level, although it has been reported in patients with lesions as low as T10.[5] Guillain–Barré syndrome may also cause autonomic dysreflexia.[1]
The uncontrolled hypertension in AD may result in mild symptoms, such as sweating above the lesion level, goosebumps, blurred vision, or headache; however, severe symptoms may result in potentially life-threatening complications including seizure, intracranial bleed (stroke), myocardial infarction, and retinal detachment.[2]
AD is triggered by either noxious or non-noxious stimuli, resulting in sympathetic stimulation and hyperactivity.[6] The most common causes include bladder or bowel over-distension from urinary retention and fecal compaction,[7] pressure sores, extreme temperatures, fractures, undetected painful stimuli (such as a pebble in a shoe), sexual activity, and extreme spinal cord pain. The noxious stimuli activates a sympathetic surge that transmits through intact peripheral nerves, resulting in systemic vasoconstriction below the level of the spinal cord lesion.[8] The peripheral arterial vasoconstriction and hypertension activates the baroreceptors, resulting in a parasympathetic surge originating in the central nervous system to inhibit the sympathetic outflow; however, the parasympathetic signal is unable to transmit below the level of the spinal cord lesion and is insufficient to reduce elevated blood pressure.[8] This results in bradycardia, tachycardia, vasodilation, flushing, pupillary constriction and nasal stuffiness above the spinal lesion, while there is piloerection, pale and cool skin below the lesion due to the prevailing sympathetic outflow.[8] Bradycardia is a common symptom though some patients may experience tachycardia instead.
Autonomic dysreflexia should be treated immediately by removing or correcting the noxious stimuli. This involves sitting the patient upright, removing any constrictive clothing (including abdominal binders and support stockings), rechecking blood pressure frequently, and then checking for and removing the inciting issue, which may require urinary catheterization or bowel disimpaction.[2][4] If systolic blood pressure remains elevated (over 150 mm Hg) after initial steps, fast-acting short-duration antihypertensives are considered,[9] while other inciting causes must be investigated for the symptoms to resolve.[2]
Prevention of AD involves educating the patient, family and caregivers of the precipitating cause, if known, and how to avoid it, as well as other triggers.[4] Since bladder and bowel are common causes, routine bladder and bowel programs and urological follow-up for cystoscopy/urodynamic studies may help reduce the frequency and severity of attacks.[2]
- ^ a b "Autonomic dysreflexia". Medline. NIH. Retrieved 19 March 2019.
- ^ a b c d e Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, Bradley WG (2016). Bradley's neurology in clinical practice (Seventh ed.). London: Elsevier. ISBN 978-0-323-28783-8. OCLC 932031625.
- ^ Solinsky R, Kirshblum SC, Burns SP (September 2018). "Exploring detailed characteristics of autonomic dysreflexia". The Journal of Spinal Cord Medicine. 41 (5): 549–555. doi:10.1080/10790268.2017.1360434. PMC 6127514. PMID 28784041.
- ^ a b c Consortium for Spinal Cord Medicine (2002). "Acute management of autonomic dysreflexia: individuals with spinal cord injury presenting to health-care facilities". The Journal of Spinal Cord Medicine. 25 (Suppl 1): S67–S88. PMID 12051242.
- ^ Vallès M, Benito J, Portell E, Vidal J (December 2005). "Cerebral hemorrhage due to autonomic dysreflexia in a spinal cord injury patient". Spinal Cord. 43 (12): 738–740. doi:10.1038/sj.sc.3101780. PMID 16010281.
- ^ Krassioukov A, Warburton DE, Teasell R, Eng JJ (April 2009). "A systematic review of the management of autonomic dysreflexia after spinal cord injury". Archives of Physical Medicine and Rehabilitation. 90 (4): 682–695. doi:10.1016/j.apmr.2008.10.017. PMC 3108991. PMID 19345787.
- ^ Eldahan KC, Rabchevsky AG (January 2018). "Autonomic dysreflexia after spinal cord injury: Systemic pathophysiology and methods of management". Autonomic Neuroscience. 209: 59–70. doi:10.1016/j.autneu.2017.05.002. PMC 5677594. PMID 28506502.
- ^ a b c Winn HR, ed. (30 November 2016). Youmans and Winn neurological surgery (Seventh ed.). Philadelphia, PA: Elsevier. ISBN 9780323287821. OCLC 963181140.
- ^ Solinsky R, Svircev JN, James JJ, Burns SP, Bunnell AE (November 2016). "A retrospective review of safety using a nursing driven protocol for autonomic dysreflexia in patients with spinal cord injuries". The Journal of Spinal Cord Medicine. 39 (6): 713–719. doi:10.1080/10790268.2015.1118186. PMC 5137561. PMID 26838482.