For Friday Weird Science, there is really nothing better than a good case report. And you guys are getting a GOOD one this week. Partially because it’s really good, and partially because I have just returned from the bachelorette party of a dear friend. So you now get to meet FUN Scicurious! And see how devoted Sci is? She’s so devoted she’s blogging to you in a dubious mental state! It’s because I care. And because, though last week I got to say “vagina”, this week I get to say “penis”. Hehehe.
Namba, et al. “Phantom erectile penis after sex reassignment surgery” Acta Medical Okayama, 62(3), 2008.
Also, I will warn you, I’ll describe stuff, but you probably don’t want to see the pictures. If you do want to see them, check the paper out for yourself.
Sexual reassignment
In all that I have ever read on sexual reassignment surgery, it appears to be easier to go from male to female (or hermaphrodite to female, in some cases), than to go from female to male or hermaphrodite to male. There are a lot of complications with both operations, of course, but it seems that male to female is generally less problematic. After all, it’s a lot easier to take stuff away, than to put stuff there that wasn’t there in the first place, let alone making something that wasn’t there in the first place actually functional. On the other hand, going from male to female, there are probably a lot of problems with sensitivity of the new vagina, the ability to use the muscles that surround it (if they have those), etc. But suffice to say that both operations are incredibly difficult.
This case study concerns a 52 year old who was diagnosed as a male to female transsexual, and then had his penis and testicles removed, and a vagina a clitoris were created. After the operation, she (the authors refer to the patient consistently as ‘he’, but I think it’s more polite to refer to someone as the the gender with which they identify) complained to clitoral hypersensitivity and a sensation known as “phantom erectile penis”.
A bit about phantom limbs
The first reported “phantom limb” phenomenon was described in 1871 by Weir Mitchell (oooh, that would make a GREAT Giant’s Shoulders, I need to keep that in mind…). Basically, this is the sensation that the limb is still there following amputation. Most people might think of this as merely spooky, but it can really disrupt people’s lives. Sometimes the phantom limb is in constant pain, and no pain killer will work. Sometimes the phantom limb itches horribly, and it wouldn’t matter where you scratched. For a lot of good stuff on phantom limb, I highly recommend Ramachandran’s ‘Phantoms in the Brain: Probing the Mysteries of the Human Mind’. This was the book that got me in to neuroscience, it’s very well written and incredibly cool.
When most people think of phantom limbs, they think of phantom arms or legs, maybe fingers. Probably no one thinkgs of a phantom penis. And the phenomenon is very rare. It was first described in 1951, and can result from either amputation of the penis for medical or traumatic reasons (got bit off?) or due to transitions from male to female. The transition from male to female, however, produces phantom penis far more often than penile loss due to trauma.
As far as we know currently, phantom limb works like this: For every part of your body, you’ve got sensory cortex and motor cortex (two different areas), devoted to that part specifically. This is not even counting the supplementary motor areas and other brain regions that can affect movement or sensation. But the motor and sensory cortex are the ones we’re concerned with now. The primary motor and sensory cortical areas are on either side of the central sulcus (a groove which splits the front and back of your brain), and each one has a specific map to it, called a homunculus (latin for “little man”). These homunculii are mapped out according to how much representation each area of your body gets in your brain. Areas that are very sensitive to touch, say, will get a lot more area devoted to them than those that are less sensitive.
As you can see from the picture above, certain things get a LOT more area devoted to them than others. Your hands and fingers, for example, are very sensitive and get a lot of representation. Proportionally, so do the genetalia. So there are a lot of neurons coming up from the genitalia to the cortex. When you cut off the penis and testicles, those neurons don’t carry sensory information anymore, and that area of the brain just isn’t getting all the stimulation that it’s used to. When that happens, and your brain realizes that the condition is permanent, things will start to change. The thing your brain hates most is a wasted neuron. So the brain undergoes changes in its cortical remapping, and sensory information from surrounding areas (say, the new clitoris) will come up to that area of the cortex, a phenomenon called “cross-activation”.
The Case Report
Following sexual reassigment surgery, it’s apparently pretty common to suffer from some phantom penis and phantom erectile syndrome for the first few weeks, while everything settles and cortical remapping takes place. However, in this case, the patient continued to experience the sensation of an erection for over 6 months after surgery. I can imagine that this quickly got annoying. After all, there’s nothing the poor woman can ever DO about it!
The authors performed a second surgery. It turns out that, to perform a male to female transition, you take the penis off, but you leave most of the underlying anatomy intact, the corpus spongiosum, the external urinary, etc. This meant that the nerves going up to the brain were still there, too, and could still be stimulated by the friction and stimulation from nearby areas.
What they had to do was go back in and scoop the extra parts out. Literally. This is very difficult, as the woman still has to be able to pee, and so the urethra has to remain intact, and that’s a tall order considering that the urinary and ejaculatory systems share a duct in the male. But they did do it. By scooping out the underlying tissue, they got rid of all sensory nerves going from the former penis to the brain, which allowed remapping to eventually take place, and the woman stopped suffering from phantom erectile penis.
Hehe. Phantom erectile penis. Try to say that ten times fast. Without smiling. Knew you couldn’t.
And I think it’s about time to put the data together on the post about masturbation and nasal congestion! I will hopefully be presenting the data graphs and stats soon.
Namba, Y, Sugiyama, N, Yamashita, S, Tokuyama, E, Hasegawa, K, Kimata, Y. (2008). Phantom erectile penis after sex reassignment surgery Acta Medica Okayama, 62 (3), 213-216
