Damage to the nerves of the peripheral nervous system is referred to as peripheral neuropathy. The peripheral nervous system is a network of neurons that connect the spinal cord and the brain to the rest of the body. Peripheral neurons are responsible for transmitting physical sensations, like touch and heat, from the skin to the brain. The peripheral neurons also allow the brain to control many processes throughout the body, such as movement, digestion, heart rate and sexual response. Damage to the peripheral neurons resulting from peripheral neuropathy can cause sexual side effects in both men and women.
Damage to Nerves Controlling the Sex Organs
The sexual organs in both men and women are connected to the brain by peripheral neurons. Sexual arousal occurs when the brain registers an excitatory signal and transmits that signal to the sex organs, explains the Boston University School of Medicine. When the sexual organs receive the excitatory signal, neurotransmitters are released that increase blood flow to the sex organs, causing erections in men and labial, vaginal and clitoral engorgement in women, in addition to stimulation of vaginal secretions. If the nerves that connect to the sex organs become damaged, these signals required for sexual arousal cannot reach the sex organs.
Sexual Side Effects in Men
In men affected by peripheral neuropathy, the neurons that connect the penis to the brain may become damaged. As a result, when the brain experiences sexually stimulating input, it cannot transmit that signal to the penis. An erection results from signals reaching the penis that cause its smooth muscles to relax and allow in increased blood flow. Without the signals from the brain, blood flow to the penis cannot be increased, and there is no erection. However, sex drive in men with peripheral neuropathy may remain unchanged. Alternatively, men with peripheral neuropathy may be able to achieve an erection, but they may experience sexual climax without normal ejaculation.
Sexual Side Effects in Women
Similar to men, women require signal transmission through peripheral neurons between the brain and the sex organs to induce the sexual response. When the brain receives a sexually stimulating signal, that signal is transmitted to the vagina. Similar to men, the signal induces the smooth muscles surrounding the vagina to relax and increase blood flow to the vagina, clitoris and labia. In addition to causing engorgement of these organs, the increased blood flow also stimulates vaginal secretions that lubricate the vagina. Women with peripheral neuropathy may not experience physical sexual arousal, leading to vaginal dryness. Women with damage to the peripheral nerves may also have difficulty achieving orgasm.