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Contributions: (I) Conception and design: All authors; (II) Administrative support: All authors; (III) Provision of study materials or patients: AN Shridharani; (IV) Collection and assembly of data: AN Shridharani; (V) Data analysis and interpretation: All authors; (VI) Manuscript writing: All authors; (VII) Final approval prescription du viagra of manuscript: All authors. Abstract: Erectile dysfunction (ED) related to compromise of the nervous system is an increasingly common occurrence.

This may be due to the multifactorial nature of ED, the myriad of disorders affecting the neurotransmission of erectogenic signals, and improved awareness and diagnosis of ED.

Nevertheless, neurogenic ED remains poorly understood and characterized.

Disease related factors such as depression, decreased physical and mental function, the burden of chronic illness, and loss of independence may preclude sexual intimacy and lead to ED as well.

The amount of data regarding treatment options in subpopulations of differing neurologic disorders remains scarce except for men with spinal cord injury. The treatment options including phosphodiesterase inhibitors, intracavernosal or intraurethral vasoactive agents, vacuum erection devices (VED) and penile prosthetic implantation remain constant.

This review discusses the options in specific neurologic conditions, and briefly provides insight into new and future developments that may reshape the management of neurogenic ED.

Keywords: Erectile dysfunction (ED); neurogenic; treatment. Neurogenic erectile dysfunction (NED) is a traditional classification of erectile dysfunction (ED) encompassing disorders impairing erections via neurologic compromise or dysfunction. The disorders compromising erections may act centrally, peripherally or both.

The prevalence of neurogenic ED has been suspected to be between 10% and 19% of all causes of ED (1,2). However, several classically defined neurogenic processes may affect several components of the normal pathway to achieve erection e.g., multiple sclerosis (MS), diabetes mellitus, iatrogenic surgical and spinal cord injury. Each disease state has its own unique characteristics that require acknowledgement to fully understand their effect on ED.

Much of the emphasis on erectile pathophysiology has been placed on penile smooth muscle function and cavernosal hemodynamics. The neuroanatomy and neurophysiology of erection can be characterized but its full extent is poorly understood.

Neurologic disease does not always reproducibly affect erections in a uniform manner compared to other types of sexual dysfunction (SD). This offers many obstacles to understanding the role the nervous systems plays in SD and consequently obscures what treatment options readily optimize erections specific to the neurologic insult. Treatment strategies for ED usually target the corporal smooth muscle to augment its relaxation or replace its function via prosthesis implantation. Nevertheless, to treat ED related to a neurologic disorder, assessments of function and disease related factors are recommended, as ED in these men is often multifactorial in origin.

A comprehensive understanding of the neural pathways for erection is necessary for assessing whether neurogenic ED exists and how to appropriately address the ED. As stated previously, neurologic disease may affect multiple neural pathways leading to ED, sensation deficits and ejaculatory dysfunction. Nerves originating in the spinal cord and peripheral ganglia innervate the penis.

There are autonomic (parasympathetic and sympathetic), and somatic separate and integrated pathways.

The autonomic pathways neurons originate in the spinal cord and peripheral ganglia from the sympathetic and parasympathetic systems, respectively. They merge to form the cavernous nerves that travel alongside the prostate, enter the corpora cavernosa and corpus spongiosum to affect the neurovascular events required for tumescence and prescription du viagra detumescence.

The somatic nerves send sensory information from the penile skin, glans, and urethra via the dorsal penile nerve and pudendal nerve to the spinal cord.

The somatic nerves also initiate contraction of the ischio- and bulbocavernosus muscles. The sympathetic pathway originates from the 11 th thoracic to the 2 nd lumbar spinal segments and goes via the white rami to enter the sympathetic chain ganglia. Subsequently nerves prescription du viagra travel through the lumbar splanchnic to inferior mesenteric and superior hypogastric nerves to the pelvic plexus. The T10 through T12 segments are most often the origin of sympathetic fibers, and the sympathetic chain ganglia that innervate

the

Preganglionic fibers pass through

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The cavernous nerves that innervate the penis arise from the portion of the pelvic plexus.

The pelvic plexus also contains nerves that innervate the rectum, bladder and urinary sphincter and the nerve projections can be damaged during radical excision of the bladder, prostate and rectum, leading to iatrogenic ED (4).