Submitted on February 7, 2005
Accepted on March 17, 2005
AUTONOMIC DYSREFLEXIA DURING SPERM RETRIEVAL IN SPINAL CORD INJURY - INFLUENCE OF LESION LEVEL AND SILDENAFIL CITRATE
A. William Sheel1*, Andrei V. Krassioukov2, J. Timothy Inglis1, and Stacy L. Elliott3
1 International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada; School of Human Kinetics, The University of British Columbia, Vancouver, British Columbia, Canada
2 International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada; School of Rehabilitation Sciences, The University of British Columbia, Vancouver, British Columbia, Canada; Department of Physical Medicine and Rehabilitation, The University of British Columbia, Vancouver, British Columbia, Canada
3 International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada; Department of Psychiatry and Urology, The University of British Columbia, Vancouver, British Columbia, Canada
* To whom correspondence should be addressed. E-mail: bill.sheel{at}ubc.ca.
Autonomic dysreflexia (AD) can occur during penile vibratory stimulation in men with spinal cord injury but this is variable and the association with lesion level is unclear. The purpose of this study was to characterize the cardiovascular responses to penile vibratory stimulation in men with spinal cord injury. We hypothesized that those with cervical injuries would demonstrate a greater degree of AD compared to men with thoracic injuries. We also questioned whether the rise in blood pressure could be attenuated by sildenafil citrate. Participants were classified as having cervical (n = 8) or thoracic (n = 5) injuries. While in a supine position subjects were instrumented with an ECG and arterial blood pressure was determined beat-by-beat. Subjects
reported to the laboratory twice and received an oral dose of sildenafil citrate (25-100 mg) or no medication. Penile vibratory stimulation was performed using a handheld vibrator to the point of ejaculation. At ejaculation during the non-medicated trials, the cervical group had a significant decrease in heart rate (- 5-10 beats/min) and increase in mean arterial blood pressure (+ 70-90
mmHg) relative to resting conditions whereas the thoracic group had significant increases in both heart rate (+ 8-15 beats/min) and mean arterial pressure (+ 25-30 mmHg). Sildenafil citrate had no effect on the change in heart rate or mean arterial pressure in either group. In summary, men with cervical injuries had more pronounced AD during penile vibratory stimulation than men with thoracic injuries. Administration of sildenafil citrate had no effect on heart rate or blood pressure during penile vibratory stimulation in men with spinal cord injury.
