Help! My penis doesn't belong to me- is this possible??

[MilesMayhem]

I read about something called hemiasomatognosia, where the patient believes that the left part of the body doesn't belong to him. I wonder, is this exclusive to the left half, or can other parts also be perceived as foreign? What about the penis? A dude on a cyclingforum said his tools felt like they weren't his anymore after long bikerides (wrong saddle, too wide or narrow saddle compared to the pelvis) so I jokingly said that he had to have a brain damage. But would such a thing be possible, even in theory?

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[PMR 4 MSK]

Left hemi-neglect is a common sequela of right CVA - it can be anywhere from mild innattention to what is happening on the left side, to complete lack of awareness that the left side of the world even exists. Patients have been known to push their left leg out of bed believing someone else's is in bed with them. Men don't shave the left side of their face. They won't look to the left unless you make them.

Cyclists periodically get an external compressive to the pudendal nerve, which can lead to genital paresthesias and anesthesia. In some cases, it can be permanent, but usually resolves with staying off the bike. Therre are seats that are made for people that get that, as well as cushion overlays for the seat.

As a funny similarity, my father once had ankle surgery with a spinal anesthetic. In recovery, he kept reaching down below the sheet. My mother finally asked him what he was doing. He said, "I can't feel gonies (gonads) so I kept checking to see if they're still there!" Within an hour or so he could feel them again, so he was satisfied they weren't missing.

There are also psychotic conditions that can cause people do believe certain parts of their body are foreign. Some delusional and dissociative disorders too.

 

[typhoonegator]

What I am about to write is mostly true.

Your dominant parietal lobe (almost always the left) has some degree of bilateral somatotopic representation. Hence, most left inferior division strokes or other lesions do not result in lasting hemineglect syndromes, although in the acute setting they may cause a right neglect. You can, however, get a Gerstmann syndrome from this area, which is pretty neat.

Your non-dominant parietal lobe (almost always the right) has only contralateral somatotopic and spatial integration duties, and so a lesion to the right parietal lobe will result in some degree of hemineglect for the left side of the body. The severity of this neglect syndrome is variable, and depends on the extent of the injury and any other diaschisis that may have resulted. You may also see an eyelid apraxia (not actually an apraxia in the strict definition of the word), as well as anosognosia. Because these patients have a very poor understanding of their left hemispace and difficulty with even understanding that they have a problem at all, they can be very difficult to rehabilitate, even though their language function is, at least cursorily, intact. I recently had a patient that thought that his left side belonged to a guy who was laying underneath him in bed, named "Steve".

Midline structures seem to have bilateral representations, and so I can't think of an organic way in which you could get "aphallognosia" and still be conscious and able to discuss this complaint with a neurologist. However, within the realm of psychiatry, this has probably been seen.

A pudendal block or a conus syndrome is a different story. Sure, your parts might not feel like your own anymore, but if someone pointed to your schlong and asked who it belonged to, you wouldn't say "Steve".

 

[MilesMayhem]

Midline structures seem to have bilateral representations, and so I can't think of an organic way in which you could get "aphallognosia" and still be conscious and able to discuss this complaint with a neurologist. However, within the realm of psychiatry, this has probably been seen.

Sure you can. Open up the cranium, take a spoon, and start digging at both sides of the interhemispheric fissure in the region of the central sulcus. *giggle.

A pudendal block or a conus syndrome is a different story. Sure, your parts might not feel like your own anymore, but if someone pointed to your schlong and asked who it belonged to, you wouldn't say "Steve".

Thanks for the extremely well-explained reply, typhoon (and to PMR). There is one thing that still bugs me. How does the patient react if you take his right finger, and use it to touch his chest gradually in the direction of the neglected arm? At what point does the patient cease to exist, and where does steve appear? When the eyes themselves work, and there is no lesion on the path to the occipital lobe, can you overcome this neglect by looking in the direction of the neglected arm? Can you make the patient convinced by logics, or is this totally like a delusion appearing in the setting of a focal disease of the right hemisphere?

 

[PMR 4 MSK]

Sure you can. Open up the cranium, take a spoon, and start digging at both sides of the interhemispheric fissure in the region of the central sulcus. *giggle.

Thanks for the extremely well-explained reply, typhoon (and to PMR). There is one thing that still bugs me. How does the patient react if you take his right finger, and use it to touch his chest gradually in the direction of the neglected arm? At what point does the patient cease to exist, and where does steve appear? When the eyes themselves work, and there is no lesion on the path to the occipital lobe, can you overcome this neglect by looking in the direction of the neglected arm? Can you make the patient convinced by logics, or is this totally like a delusion appearing in the setting of a focal disease of the right hemisphere?

You've just described one of the approaches to overcoming left hemi-neglect in PT and OT. Pt's with severe neglect will often start to rationalize and/or confabulate at first, but often logic will help. We also try to approach the pt from the left, arrange their beds so that everyone approaches from their left.

You are right in that the visual fields can be intact, except that CN2 can be infarcted along it's path by a high cortical CVA. Visual deficit with neglect is a bitch to overcome.

 

[typhoonegator]

Because the representation of the trunk is much less developed than the representation of the limbs in the CNS, it is likely that you will get variable responses until you get to the arm, when the patient would firmly state that it is not his. Also, while the eyes may work, and there may not be a homonomous hemianopsia (there often is in these cases), there is still visual neglect for the left hemispace, so it is actually very difficult to get them even to look in that direction. However, I often will bring the left hand into the right hemispace and force the patient to look at it, then ask him who the hand belongs to. In his version of reality, it really is not his, and you won't get very far trying to convince him otherwise. Also, because of the anosognosia, he really thinks he is just fine, so of course that limp hand you're holding in front of his face can't belong to him. I had a patient with a full R MCA stroke (and full left sided plegia) a week or two ago trying to convince me to drive him to his office so he could "run upstairs" to pick up some work that needed to get done while he was in the hospital. He just didn't get it. It's actually pretty amazing when you stop and think about it.

 

[OldPsychDoc]

Sure you can. Open up the cranium, take a spoon, and start digging at both sides of the interhemispheric fissure in the region of the central sulcus. *giggle.

Maybe a really well-placed meningioma on the falx?

"aphallognosia"--thanks typhoonegator. I'm going to have to find a way to work that into conversation today.