Where do I start?

[stephanies]

Qrteq,

Have you checked your pelvic MRI for sacral Tarlov Cysts?

Stephanies

[qrteq]

Hello everyone, I am back with some updates. The condition unfortunately is still there, although it has definitely changed in the meantime (has it ever stayed still?). I've been doing various stretches as recommended by the PT plus some that I came up with that seemed to pull on the affected area, and certain aspects of the condition did indeed improve. For one, my perineum is practically pain free at this point. For some time around nov-dec, I've had a noticeable inflammatory sensation at the ischial tuberosity (hamstring attachment, basically) while sitting which has definitely improved. I've had a control MRI done to check on my hips again, and the edema in my quadratus femoris muscle has subsided, and the MRI was pretty much "clean". The penile pain comes and goes still sometimes with pauses lasting hours, sometimes merely minutes, but the sensation seems to be duller and less focused on specific areas now - before it was stinging surface pain as if from an embedded splinter or an ingrown hair... now it's often less of an outright "pain" and more like an unpleasant "pulling" sensation, and the pain is more cramp-like.

What's new is that unfortunately the back pain came back, and I'm feeling pain at my inner thigh (slightly lower than before), and on the backside of my left buttock - right where the sciatic nerve is located. I can trace a direct line of skin sensitivity at the lower edge of my buttock from the sciatic nerve towards the painful inner thigh area, which definitely suggests that these two should be related. So could all of this be a manifestation of sciatica then? I wasn't aware that the sciatic nerve innervated the genitals, but there's been some talk that it might be contributing some branches...? Right now I'm very suspicious that the penile pain could also be related to the sciatic nerve rather than the pudendal nerve (or at least, not the pudendal nerve alone).

Most stretches didn't get any response from me, but there were some notable ones that yielded a painful or pulling response - notably I did a variation of the wide leg hamstring stretch (https://www.youtube.com/watch?v=6L3-BoPEDi4) except I put my legs as wide apart as possible, forming an obtuse angle at the crotch (being careful not to do this on a slippery floor), and when I bent over and reached down, I felt a definite painful pulling sensation right at the "pain epicenter" spot inside the inner thigh (formerly at the perineum), and currently also at my buttock. The other stretch is a bit harder to describe - I stand up, hips rotated out, knees at maybe shoulder width, and I lean over to the side to touch my knee with my elbow while allowing my knees to bend a little; this produces a similar sensation to the previous stretch, but more focused on the inner thigh. Merely flexing my buttock and rotating my hip out produces a response from the sciatic nerve area that's slightly painful but also somewhat relieving, like when somebody massages a painful muscle. (I compare all of these with the healthy right side, which doesn't respond painfully to any of them)

I've dealt with stress a lot in the past few years, but the window when this started occuring was actually a pleasantly stress-free time for me... in fact right now, the only thing truly stressing me out is this stupid annoying condition.

As mentioned in the first post, I've had a spinal MRI done before - there weren't any Tarlov cysts... but since this change happened, I think I might need to get another MRI to see if that slightly bulged disc worsened any. As for where to move the thread, whatever Violet thinks might be the best place would be fine.

[Violet M]

I've never heard of the sciatic nerve causing genital pain, but I have heard of crosstalk between the nerves so I wonder if there could potentially be some crosstalk between the nerves in your case?

Violet

[qrteq]

To illustrate how variable the symptoms are, the aforementioned pain from my last post subsided the very next day, and was replaced with a different pain on my inner thigh, roughly in the area of the semitendinosus muscle slightly below the hamstring tendon. The day after that, this pain was about 50% weaker, and in addition to it I started feeling pain again in the area in the superficial transverse perineal muscle area. Since then, these two painful areas seem to be altering back and forth. I can sit still for hours and the pain will subside, then I start moving and I start feeling it again, as if some two surfaces were rubbing together inside in there and gradually getting inflamed by this action.

The pain itself is definitely superficial - I can pinch my skin at the painful area, pull it and I can clearly feel the pain shooting out from inside the skin between my fingers - somewhere within the subcutaneous fat perhaps. On the inner thigh, where the pain is situated, I can palpate some kind of a hard cord-like structure deep within the skin, perhaps an inch long, mildly painful to touch, feeling like a hard blood vessel; I can feel no such structure on the opposite thigh. I've been wondering whether it was a thrombotic vein perhaps, but I've checked it under ultrasound and found nothing but normal-looking muscle and normal-looking fat, no sign of a dilated vessel or discernible edema. Now I again wonder whether I'm dealing with a "back mouse" in there: like a subcutaneous fat hernia that's being pushed out perhaps by one of my adductor muscles which I tense up while walking. It still wouldn't explain the groin pains I've felt earlier though.

[qrteq]

I've figured it out!
The source of the pain. I'm almost certain it's the posterior femoral cutaneous nerve (PFCN), more specifically the perineal branch that wraps around the proximal thigh towards the groin.

How did I not consider it any sooner. To my credit, not a single orthopedician, neurologist, surgeon nor PT has considered it in my case either.

Now I strongly doubt I can convince the average neurologist in my area of this and get a formal diagnosis on paper (my last call with a neurologist ended with them prescribing 4 different brands of drugs over the phone, despite them not even having a clue about the cause... what else is there to say), but let's consider:
- the course of this branch 100% correlates with all the pains I've felt around the perineum and inner thigh. The nerve is said to share a lot of dermatoma coverage with the pudendal nerve, and variations in its branching and extent have been described as common and not entirely understood. It easily could be the case that my own PFCN contributes to my sensitive genital innervation, even though that's not its "official" textbook trajectory.
- my problems since the start were always purely sensory, never motoric nor autonomous (like often described in many cases of PN). The PFCN is a purely sensory nerve.
- I'm a very sedentary person. PN is most commonly associated with professional bikers and women after childbirth. I've heard of bad posture while sitting to be more emphasized as a possible cause for PFCN, though that might be just reader's bias on my part.
- the pains lateral from my sit bone that I've described as possible "sciatica" - yeah, the PFCN is located immediately next to the sciatic nerve just a few mm apart, and seeing how I don't have pains radiating down my leg, the tenderness felt in this area probably arises from the PFCN.
- the pulling pain in my left thigh I feel while bending forwards during hamstring stretches? That's probably me feeling the PFCN being strained in general.
- the "hard cord-like structure, tender to the touch" on my inner thigh possibly could be an inflamed nerve sheath (as the location actually corresponds to one of the terminal PFCN branches) hence it would be hard to spot within the fatty skin layer under an ultrasound.
- and the kicker. Previously I wrote this: "my left ischiofemoral space is narrower, with some atrophy present in my [quadratus*] femoris which implies a chronic impingement upon the muscle" The nerve courses right next to the quadratus femoris muscle, atrophied in my case. Though I'm not sure about the mechanism by which the atrophied muscle could be irritating the nerve (I'd expect the opposite to be the case, the atrophy actually liberating the nerve somewhat?), it definitely seems very suspect that some interplay between the PFCN and the abnormal QFM could be the source of most if not all of my problems.

What remains is to decide what can be done about all this. There is very little information out there about treating PFCN pain, aside from "here goes nothing" type nerve blocks and surgeries. By trial and error, I've figured out several stretches that seem to be alleviating the pain little by little at least temporarily - especially ones that involve externally rotating the hip and basically squeezing my buttock seem pleasantly relieving at least within the moment. What I don't know is whether I'm not just making things worse in the long term by doing this. Another factor to consider is the quadratus femoris muscle. What can be done about the atrophy? I suppose there should be targeted exercises centered around the muscle. But should something be done about it in the first place? Won't it make the PFCN impingement (if it even is PFCN impingement) even worse?

[Violet M]

I guess you could consider possible impingement on the innervation (L4-S1) and the blood supply (inferior gluteal artery) to the quadratus femoris for why the muscle might be atrophied. I think you said you have a tight ischiofemoral space?

According to the following article: https://radsource.us/ischiofemoral-impi ... -syndrome/
"IFI has been rediscovered as a source of hip, groin, and/or posterior thigh pain.2,3 Prior to that time, edema signal intensity on MR within the quadratus femoris muscle (QFM) was attributed to muscle strains. Using MR, it has been recognized that a narrowed ischiofemoral space may cause impingement or compression of the QFM, resulting in muscle edema and, over time, muscle atrophy."

Violet

[qrteq]

Belated update - treating this entity as a PFCN-related neuromuscular syndrome seems to be bearing some fruit. I don't think I'm entirely out of it yet, but I've definitely made some improvement, via targeted exercises and better and more careful choice of where and how I sleep. Right now the condition only seems to really get aggravated mainly if I sit or lie incorrectly for longer bouts of time (one particularily triggering event is when I catch myself lying on the affected side [which I had a long habit of doing], head propped up by elbow, putting pressure on my left hip), and doing more active stuff like going up a flight of stairs doesn't seem to make the pain instantly relapse anymore. Once in a while I'll push a certain stretch over a limit and I'll feel a (painless) "snap" sensation right around the course of the nerve - these only happen on the affected side, and they ultimately seem to lead to more relief of the pain on the long-term. I wonder, are these adhesion breaks, trigger point releases, something else? I like to speculate that these motions release some amount of pressure on the nerve, but changes this tiny aren't something I could reliably verify by any diagnostic method.

[Violet M]

Thanks for the update. Hopefully you will continue to see improvements. Sometimes it's slow going waiting for things to heal.

Violet