Autonomic dysreflexia (AD) is a potentially life threatening hypertensive syndrome prevalent among patients with chronic spinal cord injuries (SCI) at spinal segment T6 or above. AD is due to the loss of supraspinal control over sympathetic preganglionic neurons and is triggered by noxious stimuli below the level of injury. The treatment of AD is multifaceted, from conservative management to topical and oral antihypertensive medications. Understanding AD's rapid onset and severity are extremely important for exercise physiologists working with patients with SCI.
A 67-year old male with chronic motor incomplete cervical SCI (i.e., ASIA C4 C) and persistent orthostatic hypotension (OH) was enrolled in a study to determine the effects of biofeedback on blood pressure (BP) modulation when an episode of asymptomatic AD occurred. Baseline and resting BP were recorded at 122/82, with a resting mean arterial pressure (MAP) of 96. The BP was continuously monitored using a telemetric device (Caretaker, Charlottesville, VA). Upon positional changes required to measure OH with a tilt table, the participant showed an antagonist response with a sudden increase in BP consistent with AD symptoms, reaching a maximum level of 199/121. The participant was asymptomatic during the AD episode.
BP returned to baseline levels after the participant was transferred back to a seated position in the wheelchair without using other measurements or medications. The titl test was modified with the participant positioned in a semi supine position (30° incline) and then tilted to approximately 45and remained in this position for 3 minutes.
AD is prevalent among people with cervical or upper thoracic SCI, and often the episodes are asymptomatic. As a part of the training routine, many patients with SCI are placed in a supine position for passive stretching and exercising. We are presenting data on this episode of asymptomatic AD due to postural changes to bring awareness to exercise physiologists of this life threatening condition. Trainers should carefully check for signs of AD in this population and measure BP often during the training sessions if a continuous assessment of BP is unavailable. Seated is recommended over a supine or semi-supine position. This could be accomplished by using physical therapy wedge cushions to maintain blood pressure homeostasis.
First author's contact: firstname.lastname@example.org