FAMILY PRACTICE GRAND ROUNDS Male Sexual Impotence: A Case Study in Evaluation and Treatment John G. Halvorsen, MD, MS, Craig Mommsen, MD, James A. Moriarty, MD, David Hunter, MD, Michael Metz, PhD, and Paul Lange, MD Minneapolis, Minnesota R. JOHN HALVORSEN {Assistant Professor, De­ cavernosa. There is also a very important suspensory lig­ D partment o f Family Practice and Community ament—a triangular structure attached at the base of the Health)-. Male sexual impotence is the inability to obtain penis and to the pubic arch blending with Buck’s fascia and sustain an erection adequate to permit satisfactory around the penis—that is responsible for forming the angle penetration and completion of sexual intercourse. Im­ of the erect penis. potence is defined as primary if erections have never oc­ The arterial supply to the penis flows from the aorta curred, and secondary if they have previously occurred through the common iliac, hypogastric, and internal pu­ but subsequently have ceased. The cause of sexual im­ dendal systems. The artery of the penis is a branch of the potence may be psychogenic, organic, or mixed. In the internal pudendal artery and has four branches. The first past, the common belief was that 90 percent of impotence branch, the artery to the bulb, supplies the corpus spon­ was psychological.1,2 Recent research indicates, however, giosum, the glans, and the bulb. The second branch is the that over one half of men with impotence suffer from an urethral artery. The artery of the penis then terminates organic disorder, although often there is considerable into the dorsal artery of the penis (which supplies the deep overlap between both psychological and organic causes.3,4 fascia, the penile skin, and the frenulum) and the deep or A knowledge of the anatomy of the penis and the com­ profunda branch (which supplies the corpora cavernosa plex physiology of erection is necessary to understand the on each side). cause of the problem, the methods of diagnosis, and the The venous drainage consists of both a superficial and treatment options. a deep venous system. The superficial dorsal vein drains into the external pudendal vein, which then connects to the saphenous system. The corpora cavernosa and the ANATOMY AND PHYSIOLOGY corpus spongiosum flow into the deep dorsal vein, which drains into a plexus of veins called the lateral prostatic The three major parts of the penis are (1) the base, which vesical venous plexus, or Santorini’s plexus. is anchored to the perineum; (2) the body, composed of The penis has somatic, sympathetic, and parasympa­ the paired corpora cavernosa located dorsally, and the cor­ thetic innervation. These fibers originate from two areas— pus spongiosum, located ventrally; and (3) the terminal spinal segments T-12 through L-2 and segments S-2 portion, the glans, an enlargement of the tip of the corpus through S-4. The afferent somatic fibers responsible for spongiosum. The corpora cavernosa are separated by an penile sensation travel through the dorsal nerve of the incomplete connective tissue septum that permits free penis to the internal pudendal nerve back to its spinal communication of blood between the corpora and that roots S-2 through S-4. These fibers supply the ischiocav­ allows them to function as a central unit. They are also ernous muscle, the bulbocavernous muscle, penile skin, fused in the body and proximally diverge to attach to the and urogenital diaphragm. The parasympathetic fibers, inferior aspect of the pubic rami. The corpus spongiosum on the other hand, originate from the anterior roots of S- houses the urethra and lies ventral between the corpora 2, S-3, and S-4, and are known as the nervi erigentes. They terminate in the small and large cavernous nerves supplying the penis. The sympathetic fibers originate from Submitted, revised, September 29, 1988 the spinal roots of T-12 through L-2, descending through From the Departments of Family Practice and Community Health, Neurology, the aortic plexus, the superior hypogastric plexus, the in­ Radiology and Urology, University of Minnesota, Minneapolis, Minnesota. Re­ ferior hypogastric nerves, and finally intermingling with quests for reprints should be addressed to: Dr. John G. Halvorsen, 516 Delaware St, SE, Box 718 UMHC, Minneapolis, MN 55455. the parasympathetic nerves as they reach the penis itself. 1988 Appleton & Lange THE JOURNAL OF FAMILY PRACTICE, VOL. 27, NO. 6: 583-594, 1988 583 MALE SEXUAL IMPOTENCE Physiologically, erection involves a neurologically me­ Additional history obtained during his initial visit to diated series of events that subsequently give rise to com­ our clinic indicated that he was sexually competent and plex vascular events that result in increased size and ri­ had achieved orgasm with a normal erection a day before gidity of the penis. The single, most basic factor producing his injury. His previous workup had included a “stamp an erection is that more blood must enter than leave the test,” which is a crude snap gauge test to measure noc­ cavernous spaces. turnal penile tumescence. This test showed no evidence Psychogenic erections are cortically mediated by sight, of tumescence. sound, smell, and thought. The exact neurotransmitter On initial physical examination Mr. J. was moderately mechanisms involved are poorly defined, but it is believed anxious. His blood pressure was slightly elevated at 160/ that both dopamine and serotonin are important. Tes­ 90 mmHg. His heart rate was 72 beats per minute and tosterone is also needed for libido and ejaculation. Cortical his weight 204 pounds. His genitourinary examination stimuli exit first through the preoptic region of the hy­ was normal. Neurologically he had an absent bulbocav­ pothalamus, then through the pons and cord, exiting ernous reflex and decreased proprioception in his left great through T-12 and L-2. Reflex erections occur by way of toe. Vascular examination revealed absent dorsalis pedis the sacral reflex. The afferent limb arises from somatic pulses bilaterally and absent penile pulses even with the fibers S-2 through S-4 by way of the pudendal nerve as vascular doptone. No penile blood pressure was detectable. previously mentioned, and the efferent limb (the para­ His medical history included multiple problems. Med­ sympathetic limb) exits through the nervi erigentes from ications included oral testosterone, as previously noted, S-2 to S-4. There is complex mingling of sympathetic and as well as a ,8-blocker used to treat his hypertension, which parasympathetic fibers so that in the neurologically intact had been only moderately well controlled. He had also individual both psychogenic and reflex pathways act syn- been treated for alcohol abuse in 1970 at the Veterans ergistically for erection to occur. The exact biochemical Administration hospital. Chart notes by the psychologist mechanisms that enable these neurologic signals to in­ at the clinic where he was initially evaluated indicated crease blood flow to the corpora are yet to be completely that he might again be chemically dependent, but he had defined, although adrenergic transmitters seem to be more refused treatment. He had also sustained a back injury at important than cholinergic. Vasoactive intestinal peptides work in 1975 and had undergone a subsequent laminec­ may also play an important role. tomy at the L-4-L-5 level. He had had chronic back pain After this basic science review, Dr. Craig Mommsen, and a stiff knee since that time. Both of these factors pre­ the family practice resident who coordinated the patient’s cipitated his early retirement from his machine shop oc­ evaluation, will present the history and examination ob­ cupation. He also had been a tobacco user at greater than tained on the first visit to our clinic. one pack per day for over 20 years. He indicated that he had experienced some anxiety and possibly a slight ele­ ment of depression; however, these problems had not been CASE PRESENTATION treated. The only other additional information obtained during his initial visit to the clinic was a random blood DR. CRAIG MOMMSEN {Third-year Resident in Family glucose of 105 mg/dL, which was within normal limits. Practice, University o f Minnesota, University Family After the initial visit with him, the problem list, shown Practice Unit)-. Mr. J., a 56-year-old gentleman whose chief in Table 1, suggested multiple possible causes for his im­ complaint was the inability to obtain erections after having potence. These involved psychologic factors, neurogenic slipped and fallen, appeared at the University of Min­ and vascular factors, and the possibility of medication nesota Family Practice Clinic three years after his fall. He side effects. The patient, therefore, had further evaluation had slipped on the ice, fractured his left patella, and driven from a neurological, psychological, and vascular perspec­ his left foot into his perineum. Since that fall he had not tive. Dr. Michael Metz, from the Program in Human Sex­ had any erections, but he had been able to ejaculate with uality at the University of Minnesota, will first address manual stimulation. He had had a partial evaluation at the psychological causes for impotence. another clinic prior to visiting the University Family Practice Clinic. This evaluation indicated a low, or bor­ derline low, testosterone level, and he was given a trial on PSYCHOLOGICAL EVALUATION oral testosterone in an attempt to improve his sexual function. He was also evaluated by a psychologist, who DR. MICHAEL METZ {Assistant Professor, Department thought he did not have a significant psychological cause of Family Practice and Community Health): At this time, for his impotence. Despite these measures, his impotence I will discuss the psychological variables that must be had persisted and had continued to concern him and his considered in evaluating a patient with impotence.