The answer to this question can get quite complicated. It depends on what spinal level the damage is in, as in which vertebra, as well as how much of the spinal cord in that area is damaged. The spinal cord, just like the brain, is organized into several different areas to do different tasks. Some areas control reflexes, some areas carry sensory signals, some areas carry conscious muscle control signals, some areas carry unconscious muscle control signals.

Erections are primary controlled by reflex neurons in the spinal cord, so even people with rather high up spinal cord damage have genitalia that respond essentially normally to sexual activity.

Being horny is generally controlled in an area of the brain called the prefrontal cortex, so as long as that isn't damaged, theoretically there is no reason their sex drive should have any changes. But, it is also affected by mood, self image, and other things.

I'm sorry I can't give you better answers, but it is really a complicated subject. If you are asking because you are curious about whether you should pursue an experience with someone, I say go for it. It can still be very rewarding regardless of sensation or working genitalia.

I have never thought of that..

saw a show where they talked about his exact thing. I think it was on TLC or something of the like. Some can get erections, some can't. some can feel, some can't. it just depends on the paralyzed person, the damage done, and how. One couple couldn't feel at all, and he couldn't get an erection. But they still had sex, but it was very sensual every time they said. He said he what felt like "mind-gasms" he still felt sexual, and still liked the appeal of it all.

Good question. =)