Impotence--recent advances in diagnosis and management.

Impotence is the consistent inability to achieve or sustain an erection of sufficient rigidity for sexual intercourse. It is an age dependent disorder with an incidence of 1.9% at 40 years and 25% at 65 years of age 1 , which increases manifold in certain diseases 2. Recent developments in the field of erectile dysfunction has now improved the understanding of the physiologic mechanisms of penile erection, 3-5 pathophysiology of impotence, its diagnosis and management. Penile erections may be 'reflexogenic' elicited by local sensory stimulation of the genital organs, or it may be 'psychogenic' 6,7 elicited by supraspinal erectile stimuli received by visual, gustatory, auditory, tactile or imaginative stimuli generated within the brain. Probably these two erectile mechanisms act synergistically in the control of penile erections. 6 Neurogenic impotence is usually associated with injuries of spinal cord and its afferent or efferent limbs; 8 it may be partial or complete depending upon the extent of injury, 75% of them may retain erectile capability but only 25% retain adequate erections for penetration 9,10. Suprasacral lesions also cause impotence but the reflexogenic erectile mechanism is preserved in these cases. 8,11 Multiple sclerosis, diabetic peripheral neuropathy, alcoholism and surgical procedures such as radical prostatectomy, cystoprostatectomy and proctocolectomy may disrupt the autonomic-nerve supply to corporal bodies resulting in impotency; that is why surgeons have modified radical pelvic procedures to spare the cavernosal nerves and preserve potency especially in young patients 12-14. Psychogenic impotence may be caused by psychogenic stimuli to the sacral cord, excessive sympathetic outflow or elevated catecholamine blood levels which inhibit reflexogenic erections. 15 It may be due to performance anxiety, relationship conflict, sexual inhibition, sexual performance conflicts, sexual abuse in childhood, fear of pregnancy or sexually transmitted diseases 16. Primary psychogenic impotence is usually of acute onset and related to a specific event, with normal nocturnal erections and on masturbation while an insidious, progressive loss of erection with a constant change for more than a year in the rigidity or ability to sustain nocturnal, coital or masturbation related erections, which can now be measured by latest devices, 17-25 is usually indicative of primary or ganic cause.26'27 Organic causes such as atherosclerosis which is usually associated with hypertension, hyperlipidemia, cigarette smoking, diabetes mellitus, and blunt injury of pelvis, perineum or penis, pelvic surgery or irradiation and priapism may alter the blood flow of penis, 28-34 resulting in decrease in the rigidity of …