This is a question everyone asks. Don't assume your doctor knows answers either. I was at a conference not long ago and asked the Drug Rep for Lidoderm, and SHE said the company doesn't know either and gives no advice!

Well, armed with that nugget of optimism, I do have some suggestions that I have learned over the years by experimenting with mine. I started with Lidoderm when they first became available in US. I had at that time a severe case of Meralgia Paresthetica that I was enduring with much agony. It was the result of a C-section when I had my son. I had the vertical long incision because they were looking for a tumor at the time. Somehow that nerve -- the lateral femoral nerve--got damaged.

I found the right spot for that problem after a few days, and after about 2 weeks of continuous daily use, the nerve settled down and I didn't need them anymore for that purpose! This told me that nerves might be firing when the original trauma is over, but for some reason they get stuck in the "on" position.

Lidoderms work for sensory pain very well. They do not affect motor functions normally (there might be exceptions to this, but I don't think so). They were originally made for post-shingles pain, which lingers for some patients for life. Slowly other studies came out. One for example comparing knee pain relief with Celebrex and Lidoderm, and the Lidoderms were found to be fairly equal in relief.
http://www.zhion.com/joint_bone/Lidoderm.html

I do not think Lidoderms work at the endpoints where we feel pain. At the tips of the nerves the cells are tiny and spaced around. I think the nerves travel along and conjoin like tree roots to turn into a major sized nerve which then carries the messages to the spine. I found a nice 3D graph of the leg (and other body parts too) at this link:
http://www.healthline.com/vpbody/ner...-spine-to-foot

There is a slide toggle at the bottom which you can move back and forth, to see 360 degrees around the foot and leg.
Moving to the left, rotates the leg showing the inner aspect of the ankle (medial) and this shows the tibial nerve, supplying the heel, arch and big toe. Just above the ankle is the junction for that area, and a patch here (1/2 patch...placed vertically will reach those sensory parts. Turning the picture to the right, lateral aspect of the foot, shows the tibial and peroneal nerves feeding the other parts of the foot. So you can intercept those at the lateral ankle area before they go up the calf.
I sometimes use 1/2 patch on the top of each foot, for burning issues... if you turn the graph facing you --you can see all the nerves on the instep area going to the toes. Sometimes I use that placement for big time global burning(when my Biofreeze does not work well.)

Looking up the leg you can see behind the knee, another junction where the peroneal splits off the sciatic. This is another spot, right above the bend of the knee on the back side of the thigh to try if you have calf pain, or knee pain in addition to foot pain. Sometimes I think foot pain can refer from the knee.
This spot behind the knee is where people get pressure palsies from crossing the legs too much. So it is a good spot to try the patches for some people.

Way at the top of the lower back, is the sacral plexus. I have luck with this location too. But it usually needs a full sized patch.
Leg pain, groin pain, and recently I have noticed some foot pain generates for me at this level too. So for some it is worth trying a patch there too.

Lidoderms are expensive which is difficult for some patients.
So experimenting may be expensive. That is why I put my experiences here, so that you may find quicker relief. I prefer this topical method instead of oral meds for pain. Most of the time it works for me. Sometimes I have to take Tylenol, or Aleve liquigels in addition, but not always.

At that 3D website are other body views, showing nerves as well, and the principles are the same if you want to try shoulder, back etc...use the various views to give you a location for your placement. If you have had EMGs or X-rays showing pathology, get your results, and look them up on the graph.
This will help you map out, your placement and get the most results for your expense and time.

Any questions or comments are welcome on this thread.
The smallest I cut the Lidoderms is into 3rds. For the feet you can get away with that size and save $$. The Ankle needs at least 1/2 patch. The knee works with 1/2 patch, and the back needs a whole one, for me. Keep the rest of the patch not used in the closed zip lock with its backing intact.

I have heard that if your patches dry out some with age..say past the Exp.date, you can rehydrate them with a little fine mist spritz of water. If they don't feel cold going on anymore, they might not work. I have old patches and I've used them successfully. They sometimes don't stick well however. Using medical tape is okay with them to help that. If you have very oily skin you might clean it off with alcohol, and then dry it, and then apply. You cannot wear them in showers or swimming. They will fall off. The adhesive is aqueous and moist. So too much sweating makes them fall off too.

Follow manufacturers suggestions with Lidoderm, the timing of 12 hrs on and 12 hrs off, and proper disposal, since active drug remains in the patches when you discard them. Fold them over sticky sides together so pets or small children cannot get to them. Do not apply over broken or open skin areas either. This would affect the absorption of the lidocaine and expose you to more than allowed.
We don't get many comments about rashes. I've never had them with these patches.

I usually use 1-1/2" [about a 1/4th patch short side] strips around my key pain points.... I've found using more makes the whole area totally numb, or, dangerously so. But, IF one particular area is bad? I'll spead strips around the whole key area, concentrating more on the above the pain than below.
Very strange about the Lidoderm Rep not giving you an answer about key useful sites? Avoiding possible liability issues? Works against them in the long run...I'd think.
Here is a site I stumbled across recently and the neuro aspects as well as the others are very simple and clear compared to some....
http://www.apchute.com/index.htm
Love the mysterious body! Nothing is ever simple - 's to you especially! - j

Thank you!

Both this post and your post for Magnets came at a very good time for me, as I have had 2 very bad days, with both Meralgia Paresthetica and the lower back pain that seems to accompany it. I know what brings it on - sitting too long in one position. But, last week, I was on a mission and couldn't tear myself away from the computer. So have suffered since mid-Friday afternoon. All my own fault.

I have had Meralgia Paresthetica since Aug 2007. Several CT Scans and MRIs revealed no cause of nerve compression. I was told that even without finding a cause of compression, the Meralgia Paresthetica could eventually go away on its own. It has not. Most times it is tolerable. But other times, it immobilizes me.

It wasn't until I saw the GYN for my annual checkup, the most likely reason was revealed: I have had surgery for endo 11 times. Since I had relocated, my current GYN only performed the last surgery, and told me later he had never seen someone with so much scar tissue. He believes the compression is most likely from scar tissue. I think he is probably right.

So, long story long, I have looked at the 3D body map (great site btw) and can find where that nerve leaves the thigh, but can't see where it actually attaches to the spine. I did find the attached image from Wikipedia that shows it splits and attaches to both L2 and L3. So, I looked at the 3D body map Spine...

Vertabrae (spine)

...and found L2 and L3. Is this the location you found worked for you? If not, would you mind sharing the location?

I'm going to contact my doctor today to try and get some Lidoderm patches.

Thank you so much for your timely post. I'm going to also post some questions under your post for Magnets.

Attached Images

Lateral Femoral Cutaneous Nerve.png (94.8 KB, 253 views)

For the MP I cut one Lidoderm in half and place 1/2 in the groin (just at the top of the thigh above the bend),
near the midline of the body, and the other half at the other end of the groin/top of the thigh, almost to the lateral aspect of the thigh. As high up as you can go, before the bend.

This placement really helped me. At the time years ago I had very painful stabbing...like a hundred bee stings often. Then in between stabs I had numbness mostly in the upper middle thigh.
My numbness is almost gone now, and I only get little stabs if I over extend the leg, or sit in a hot tub or steam room. The steam room (which I love for other reasons) sets that nerve off for me within 10 minutes!

Avoid tight clothing with MP...tight jeans are the worst. Girdles are not good either, anything tight across the abdomen, or at the thigh/body junction. I only wear unfashionable polyester, and loose underwear. (combined with my comfy shoes, I am a fashion disaster!!LOL)

This diagram is very good too....from a copyright protected place so I cannot move it here.

http://www.aafp.org/afp/20000401/2109.html
Figure 2b

Thanks again for your help. I'll keep the info until I can get lidoderm. Emailed my neuro today, and he doesn't want to prescribe until he sees me again. He typically has a 5-6 month wait, but fortunately my follow-up is already scheduled for next month.

Yeah, I know all about the loose clothes .

All of my going-out clothes have elastic waists. Around the house and yard, I wear long, loose, cotton or denim dresses, so I have no pressure. I find myself resisting any reason to leave the house, because I know it will only be a matter of hours before I am miserable from sitting in the car, elastic around the waist, and everything else that goes into leaving my comfort zone.

Any relief I can get will certainly make going out easier.

Some people get MP from bone graft harvesting too.

So intercepting it higher near the spine might work. But I have read that there is a genetic variation in which nerve splits off which lumbar to provide the lateral femoral branch. So it varies with people. I did mine on the leg, where the nerve exits the abdomen.

Lidoderms are expensive. If your doctor balks, just tell him that all the nursing homes (where I used to supply) use them now instead of addicting narcotics. That should satisfy him!

I had to provide my doctor with the Celebrex study and some other things I found on the net. She will give me one RX for 90 once a year now. She rolls her eyes, but does it. And that is all that matters.