Signs of spinal cord injury :
• A spinal cord lesion above the spinal centers of erection or ejaculation causes a disturbance in psychogenic erection, while reflex erection and, under certain conditions, the potency can be maintained. Even with traumatic transverse lesions of the spine in most patients, reflex erection (and ejaculation) remains intact. Potency impairment associated with damage to the spinal cord is observed in multiple sclerosis, amyotrophic lateral sclerosis, spinal cord.

It can be an early sign of a spinal cord tumor, and also develop after bilateral chordotomy. In all cases, a neurological examination reveals other signs of damage to the spinal cord, in most cases – urination disorders.

Signs of damage to the sacral spinal cord or sacral roots or nerves: • Direct bilateral total damage to the sacral center of an erection (tumor, trauma, vascular lesion) causes complete impotence. Moreover, in all cases, there is also a violation of urination (and defecation), other objective neurological symptoms in the framework of cone and epicone syndrome. With partial damage to the sacral spine, for example due to trauma, a psychogenic erection can persist against the background of a reflex erection disorder. 

• The cause of erectile dysfunction is also a bilateral lesion of the sacral roots or pelvic nerves. It can develop, in particular, with trauma or a tumor in the cauda equina (accompanied by impaired urination, saddle anesthesia), pelvic fractures with rupture of the posterior urethra, after volumetric surgery on the pelvic organs (for example, rectum resection), after cystectomy. perineal prostatectomy, etc. Lesions of the pelvic area are always accompanied by a violation of the sensitivity of the perineum and genitals and the loss of the corresponding reflexes.

Signs of damage to the sympathetic and parasympathetic system : • Damage to the sympathetic system in the region of the lower thoracic or two upper lumbar efferent fibers, the border trunk or peripheral sympathetic fibers affects potency only if it is bilateral, and not in all cases. With bilateral sympathectomy at the lumbar level, there may not be a violation of potency. However, this causes a disorder of ejaculation mechanisms. • Perhaps the violation of potency, which is regularly observed in some forms of neuropathy, is associated with the defeat of parasympathetic and sympathetic efferent fibers: this phenomenon is observed, as a rule, in young men with diabetes mellitus, as well as in Shay-Drager syndrome and in acute pandizavtonomy. 

Damage to the anatomical structures of the penis can usually be easily determined on the basis of anamnesis and examination: penis consolidation after plastic surgery, priapism. severe injury.  

Preserved potency , which leads to orgasm without semen, can cause male infertility. It is in most cases based on retrograde ejaculation into the bladder with insufficient closure of its internal sphincter. Among the etiological factors, neuropathy should be mentioned, especially in diabetes mellitus, and transverse spinal lesion syndrome. Usually this phenomenon is accompanied by disorders of the bladder.

Priapism, along with local causes, may also be the result of acute spinal cord injury (at a high level). 

Potency disorder may also be associated with violations of sexual behavior in pathological processes in the brain.