A message from Dr. Attaman regarding nerve blocks

[Karyn]

Welcome to HOPE, Dr. Attaman!

I have a couple of questions regarding statements you've made in the MRN thread:

"The best way to prove whether you have pudendal neuralgia is an image guided local anesthetic injection (block) of the pudendal nerve. If this gives you excellent pain relief for at least a few hours, the diagnosis is likely.

Therefore I generally only order MRI neurograms of the pudendal nerve if diagnostic blocks have rendered the diagnosis of pudendal neuralgia definitively, but my patient continues to have pain. In that case, I know that the problem is pudendal neuralgia, but I want to see if there is any specific area of entrapment or injury that may explain why pain persists".

Can you please explain how/why these injections are considered to be diagnostic? My unprofessional, simplistic thought process is that if you inject any tissue in the body with an anesthetic, numbness or altered sensation is likely to occur.

The flip side to that is: I'm personally aware of many patients who've had "failed" nerve blocks, yet were indeed severely entrapped at the level of the SSL & STL. Zero pain relief, zero numbness. Not even a bit of tingling. Just a pain flare. In quite a few of these cases, the thought has been that due to profound scarring, the medication wasn't able to penetrate its target.

Secondly, what does your injection cocktail consist of? There seems to be a variation in medications with these blocks, depending on who administers them.

Thank you very much for reaching out to us, and for contributing to our community!

Kind regards,
Karyn

[Dr. Jason G. Attaman]

Welcome to HOPE, Dr. Attaman!

I have a couple of questions regarding statements you've made in the MRN thread:

"The best way to prove whether you have pudendal neuralgia is an image guided local anesthetic injection (block) of the pudendal nerve. If this gives you excellent pain relief for at least a few hours, the diagnosis is likely.

Therefore I generally only order MRI neurograms of the pudendal nerve if diagnostic blocks have rendered the diagnosis of pudendal neuralgia definitively, but my patient continues to have pain. In that case, I know that the problem is pudendal neuralgia, but I want to see if there is any specific area of entrapment or injury that may explain why pain persists".

Can you please explain how/why these injections are considered to be diagnostic? My unprofessional, simplistic thought process is that if you inject any tissue in the body with an anesthetic, numbness or altered sensation is likely to occur.

The flip side to that is: I'm personally aware of many patients who've had "failed" nerve blocks, yet were indeed severely entrapped at the level of the SSL & STL. Zero pain relief, zero numbness. Not even a bit of tingling. Just a pain flare. In quite a few of these cases, the thought has been that due to profound scarring, the medication wasn't able to penetrate its target.

Secondly, what does your injection cocktail consist of? There seems to be a variation in medications with these blocks, depending on who administers them.

Thank you very much for reaching out to us, and for contributing to our community!

Kind regards,
Karyn

Dear Karyn,

Great questions.

It is true that if we injected a massive amount of local anesthetic into the soft tissues along the entirety of the course of the pudendal nerve (in other words, injected many times all along the perianal, perineal, and genital regions), most pain associated typically associated with pudendal neuralgia would go away temporarily. This is otherwise known as topical anesthesia. This would require many tens of cc's and many injection sites. This is NOT what is done for diagnostic injections, pudendal or otherwise.

For diagnostic nerve blocks, the nerve is first located as accurately as possible using image and/or electrical guidance. Then a VERY small amount of local anesthetic is injected in this VERY discreet, very specific location. The medication is distributed over a portion of the nerve deep inside the body. Therefore, this temporarily interrupts the function of the nerve. If this results of alleviation of the typical pain (along the entire course of the nerve distribution), then we can conclude the nerve is indeed the pain generator.

This is similar to using a voltmeter on electrical wiring to identify faulty wires.

You can learn more about the different types of blocks on wikipedia:
http://en.wikipedia.org/wiki/Local_anesthetic

For those who do not attain even short term pain relief from image guided nerve blocks, the diagnosis of that nerve causing the pain is unlikely. In the case of the pudendal nerve, if it is blocked reasonably proximal to its origin, everything from that point distal should be relieved of pain, entrapped or not.

Nobody has determined the ideal injection cocktail for pudendal neuralgia. Typically I use a combination of a short acting (2-4% lidocaine) or long acting (0.5% or 0.75% marcaine, .5% ropivicaine) local anesthetic mixed with a steroid (kenalog or dexamethasone). I like to follow what is called a dual block paradigm, in which I block the nerve on two different days. I have my patient fill out a pain log after each injection. If I see a shorter duration of pain relief from the lidocaine injection, and a longer duration of pain relief from the marcaine injection, that helps to validate the study and rule out placebo effect.

The dual block paradigm is used in certain highly studied and validated spinal injections, and I have carried it over to blocks of the pudendal nerve.

There are always exceptions in medicine that do not follow the rules so keep that in mind.

[wasiscba]

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[flyer28]

good reading. basically agree. I think the most challenging cases are when the pain is clearly generated by pudendal nerve, but there is no classical entrapment. Operation might be detrimental in that case and even blocks might aggravate the situation, but generally are worth the risk I guess. Very difficult decision making process, both for patient as well as for doctors.

[Dr. Jason G. Attaman]

good reading. basically agree. I think the most challenging cases are when the pain is clearly generated by pudendal nerve, but there is no classical entrapment. Operation might be detrimental in that case and even blocks might aggravate the situation, but generally are worth the risk I guess. Very difficult decision making process, both for patient as well as for doctors.

Pudendal neuralgia is one of the most challenging neuralgias to treat, and I treat all forms of neuralgia.

[blightcp]

Welcome Dr.Attaman,

I have had two PN surgeries, by Dr. Conway and there were several issues found:

Code: Select all

Upon entering the ligamentous space, we immediately were able to identify a portion of the falciform process, which appeared to infuse with thesacrospinous ligament near the ischial spine and appeared to be directly compressing the pudendal nerve. The pudendal nerve was identified with the NIMS device and we obtained a latency of approximately 6.3 milliseconds requiring 8 milliamps for stimulation. We then excised that portion of the falciform process entrapping the nerve using bipolar cautery and tenotomy scissors. We were then able to undermine the pudendal nerve, which was flattened in this area, placing a Vesseloop around the nerve. We then skeletonized the nerve in a cephalad direction until it entered the Alcock canal. We then dilated The Alcock's canal with a right angle clamp, incising a portion of the roof of the canal. We then traced the nerve in a cephalad direction and again found it affixed in another area to the remnant of the sacrospinous ligament near the ischial spine. So once this area was freed, we then retracted the nerve laterally and then cauterized and divided the ischial spine at attachments of the sacrospinous ligament and carried that dissection in a cephalad direction. Once the area was completely freed, we then also inspected the vascular bundle, which was lateral to the main trunk of the pudendal nerve and we felt also contained a separate branch of the pudendal nerve as well. Once this was completely mobilized, we were able to transpose the neurovascular bundle medial to the ischial spine.

By no fault of Dr. Conway the surgery was not successful, and now 2 years post op, it has been declared a surgical failure.

I have zero sitting tolerance, and I on a constant stream of prescribed opiates to manage pain. I have a Medtronic Sacral Stimulator installed and that has helped with the motor function issues, but has not worked for pain relief.

I have had 8 or 9 nerve blocks and the local anesthetic works but there has been no lasting relief.
I was wondering if you had any suggestions of what to peruse as a non-narcotic solution to pain management?

Thanks
Carl

[stephanies]

Blight,

I am very sorry to read that the stimulator has not helped your pain. Is there another option for placement of the components or leads of this stimulator or another kind of stimulator that might be able to help?

Wishing you less pain,
Stephanies

[Dr. Jason G. Attaman]

Welcome Dr.Attaman,

I have had two PN surgeries, by Dr. Conway and there were several issues found:

Code: Select all

Upon entering the ligamentous space, we immediately were able to identify a portion of the falciform process, which appeared to infuse with thesacrospinous ligament near the ischial spine and appeared to be directly compressing the pudendal nerve. The pudendal nerve was identified with the NIMS device and we obtained a latency of approximately 6.3 milliseconds requiring 8 milliamps for stimulation. We then excised that portion of the falciform process entrapping the nerve using bipolar cautery and tenotomy scissors. We were then able to undermine the pudendal nerve, which was flattened in this area, placing a Vesseloop around the nerve. We then skeletonized the nerve in a cephalad direction until it entered the Alcock canal. We then dilated The Alcock's canal with a right angle clamp, incising a portion of the roof of the canal. We then traced the nerve in a cephalad direction and again found it affixed in another area to the remnant of the sacrospinous ligament near the ischial spine. So once this area was freed, we then retracted the nerve laterally and then cauterized and divided the ischial spine at attachments of the sacrospinous ligament and carried that dissection in a cephalad direction. Once the area was completely freed, we then also inspected the vascular bundle, which was lateral to the main trunk of the pudendal nerve and we felt also contained a separate branch of the pudendal nerve as well. Once this was completely mobilized, we were able to transpose the neurovascular bundle medial to the ischial spine.

By no fault of Dr. Conway the surgery was not successful, and now 2 years post op, it has been declared a surgical failure.

I have zero sitting tolerance, and I on a constant stream of prescribed opiates to manage pain. I have a Medtronic Sacral Stimulator installed and that has helped with the motor function issues, but has not worked for pain relief.

I have had 8 or 9 nerve blocks and the local anesthetic works but there has been no lasting relief.
I was wondering if you had any suggestions of what to peruse as a non-narcotic solution to pain management?

Thanks
Carl

Dear Carl,

Due to the American medicolegal milieu I cannot provide specific medical advice on a forum, unfortunately. However, for other people suffering with pudendal neuralgia for which all else has failed, sometimes pulsed radiofrequency treatment or spinal cord stimulation at the conus medullaris may provide relief (this is a different location than the sacral stimulator).

As you have read on this forum, there are few certainties with pudendal neuralgia treatment. I am sorry you are suffering.

I wish you recovery, Dr. Attaman

[blightcp]

Thank you for your reply, and I understand your limitations in providing information.

We, my care team, have looked at pulsed RF ablation and have found several issues that make it not feasible at this time, at least here in New England.

Thanks Again

Carl

[desperate]

Hello doctor,

I know this is a little off the topic of nerve blocks but I am just wondering if you can differentiate between pudendal vs the superior hypogastric nerve?

From your years of experience has anyone come into your clinic with absolutely no urge to urinate at all? The reason I ask is because I do not know if no urge to urinate is a symptom of PNE or another nerve like the hypogastric nerve. I know these are the only two nerves that innervate the bladder so I'm curious to hear your thoughts.

Thank you so much
-Dom