A variety of neurologic conditions can cause erectile dysfunction. The most common of these are spinal cord injury, lumbar disk disease, stroke, Parkinson’s disease, multiple sclerosis, Alzheimer’s disease, and pituitary disease (pituitary adenoma).
In addition, certain surgical procedures, such as radical prostatectomy for prostate cancer and surgery for rectal cancer, can injure the pelvic nerves. The incidence of erectile dysfunction after radical prostatectomy varies according to whether the patient experienced erectile dysfunction before surgery and whether a nerve-sparing procedure was performed. Reported rates of erectile dysfunction after bilateral nerve-sparing radical prostatectomy range from 18% to 82%. Other factors unrelated to disease or surgery can also cause erectile dysfunction. For example, long-distance bicycle riding on bicycles with small, hard seats has been implicated as a cause of erectile dysfunction, possibly by nerve or vascular compression.