The science of craniocervical instability and other spinal issues and their possible connection with ME/CFS - discussion thread

[JenB]

If helpful, here is a DRAFT Venn diagram of symptoms from awhile back. I catalogued symptoms mentioned by Ramsay in his 1990s paper, symptoms reported in the outbreaks literature (I think it had to be mentioned in at least two papers but I forget what criteria I used), along with tethered cord symptoms and CCI symptoms. There may be some errors an omissions of course, but I tried to take great care.

I have done the same with CCC and ICC diagnostic criteria, if that is of interest to anyone.

You can see that there is in fact some overlap.

If patients with CCI and tethered cord are being misdiagnosed with ME, you could see why this could happen if the clearer signs of nerve compression were dismissed or if the patient never reported them. In the beginning, I went to every doctor with a list of 40 symptoms. It was a very challenging clinical picture to tease out, in particular because I had THREE pathologies at once: CCI, tethered cord and MCAS. (I believe MCAS interacts with CCI and tethered cord in some ways we don't yet understand and there is some literature on this, or at least, MCAS + spinal injuries.)

The sadness of all this is that when my neurologist in 2012 (the one who diagnosed me with conversion disorder) asked me to walk, he saw the problems I had with my gait and thought they were hysterical. If he had simply asked me to walk on my heels and toes, it would have been clear I had a tethered spinal cord and things might have happened very differently for me and others like me.

It is also important to note that patients on FB are getting diagnosed with more than CCI/AAI. They have Chiari, *surgical* cervical stenosis, tethered cord syndrome, Eagle's Syndrome, Klippel-Feil syndrome, scoliosis, etc. A lot of missed diagnoses. There is a lot of overlap between these conditions and connective tissue disorders. I'm perfectly happy to view this as a nosological problem, where even the most "strict" definitions are preventing people from getting the investigation they need and deserve.

 

[Jonathan Edwards]

I am afraid that is now as clear as mud Jen.

We need some proper data gathering.

One thing I would like an answer to is whether traction is really supposed to separate the occipital condyles from the atlas, so that fixation takes weight entirely through metal rather than articular surface. That would seem to me very risky indeed in the long term and I do not understand the rationale if CCI is judged on the angles that indicate forward/back slip rather than vertical translation.

If you could explain how any of the anatomy could make sense I would take the whole thing more seriously.

 

[JenB]

EDIT: There are meant to be two images below. One does not appear on some devices.

As far as my understanding is those symptoms, except apnea maybe, are not very normal to see in ME? At least paralysis and syncope would be a red flag for me that there might be something else going on

PS: Im not saying u didnt have ME

Yes, that's quite possible.

Here are all the Venn Diagrams on one post. As you can see there are some symptoms like paralysis, numbness, apnea, dyspnea, vertigo, syncope, visual disturbances that are not mentioned in Ramsay or the outbreaks.

Not everyone with CCI will have any or all of those symptoms but it may be that they are what people who truly require surgery have.

However, some of these symptoms are mentioned in the ICC, for example.


Ramsay, Outbreaks, TC, CCI



ICC, Ramsay, TC, CCI, with my symptoms highlighted

 

[JenB]

Sorry--forgive any duplicates. I have been trouble uploading photos the way mine are formatted

Re: the Venn Diagrams. I want to stress that surgeons are not diagnosing primarily based on symptoms. Yet, symptoms do matter because no matter how abnormal someone's measurements, you don't operate on someone who is asymptomatic or not severe.

 

[JenB]

I am afraid that is now as clear as mud Jen.

We need some proper data gathering.

One thing I would like an answer to is whether traction is really supposed to separate the occipital condyles from the atlas, so that fixation takes weight entirely through metal rather than articular surface. That would seem to me very risky indeed in the long term and I do not understand the rationale if CCI is judged on the angles that indicate forward/back slip rather than vertical translation.

If you could explain how any of the anatomy could make sense I would take the whole thing more seriously.

I am not sure I understand what is confusing about what I said.

Couldn't agree more that we need proper data gathering.

What aspect of the anatomy does not make sense?

And are you talking specifically about CCI or these neck diagnoses as a whole?

 

[Adrian]

I have done the same with CCC and ICC diagnostic criteria, if that is of interest to anyone.

Yes I think that is of interest. One of the additional things that would be interesting is further definition/description of symptoms along with information about severity and frequency (which is an issue with the ME diagnostic criteria).

The one thing I notice is that PEM which we so often describe as a defining feature of ME doesn't overlap. But then that doesn't stop mis-diagnosis with people being told they have ME (or more likely chronic fatigue).

I've long thought someone should look at statistics around mis-diagnosis (i.e. those placed in an ME, CFS or CF bucket when they had another diagnosible condition). Misdiagnosis is encouraged by things like MUS which discourage investigations. But there is a difference between well defined diagnosable conditions and other conditions that are described by sets of of symptoms with little agreed knowledge of mechanism - here we should be pushing for research to understand mechanisms

 

[JenB]

Yes I think that is of interest. One of the additional things that would be interesting is further definition/description of symptoms along with information about severity and frequency (which is an issue with the ME diagnostic criteria).

The one thing I notice is that PEM which we so often describe as a defining feature of ME doesn't overlap. But then that doesn't stop mis-diagnosis with people being told they have ME (or more likely chronic fatigue).

I think that is part of the nub here. Jeff, Julie, Karen and I, along with several others, are all here saying that we DO or DID have PEM, yet these are our diagnoses.

Maybe PEM is not unique to ME. Or maybe it is hard to know if your PEM and mine are they same thing because these are subjective experiences.

I did fail two CPETS miserably, had low NK function, acetylcholine autoantibodies, etc. but who knows? Maybe there is something else different about me.

I never did a 2-day CPET because these studies were not out when I first got sick. However, I would never have even been able to do the second day. I would have collapsed.

@Adrian Venn Diagrams are above

 

[JenB]

Please note that since tethered cord syndrome and CCI are diagnosed based on pathology, rather than symptoms, there are no required symptoms.

 

[Adrian]

Maybe PEM is not unique to ME. Or maybe it is hard to know if your PEM and mine are they same thing because these are subjective experiences.

I think that is an important question not just in these terms but more generally. The survey done by members here found that 2/3rd of patients surveyed said the DSQ questions on PEM didn't represent their experience. So it seems to be one of the things that could do with much more definition as to what it means. Equally, fatigue is quite a vague term which can reflect different experiences - a friend who I think had ME and later post cancer treatment fatigue clearly had a very different experience with the two but they would both be described as fatigue by doctors.

I do wonder if we need to develop a much richer vocabulary to describe symptoms like fatigue and PEM.

I never did a 2-day CPET because these studies were not out when I first got sick. However, I would never have even been able to do the second day. I would have collapsed.

I think these tests are far from ideal they feel like destructive testing. But I do wonder if regular blood testing and monitoring against exertion could give interesting clues.

@Adrian Venn Diagrams are above

Yes saw them after I posted.

 

[Trish]

One thing I would like an answer to is whether traction is really supposed to separate the occipital condyles from the atlas, so that fixation takes weight entirely through metal rather than articular surface. That would seem to me very risky indeed in the long term and I do not understand the rationale if CCI is judged on the angles that indicate forward/back slip rather than vertical translation.

I am not sure I understand what is confusing about what I said.

It seems a straightforward question. Have the surgeons said that traction and surgery separates the occiput from the atlas. That would mean the weight of the head is not held by the atlas, so the metal fixings would have to take the weight.

 

[JenB]

It seems a straightforward question. Have the surgeons who use traction explained how it is supposed to diagnose CCI?

Sorry. I missed this as it wasn’t the question I was responding to.

With traction, they take hard bone measurements (via fluroscopy) and measure the change in your measurements (CXA, Grabb-Oakes, BDI) at progressive pounds of force. They also measure your symptomatic response to traction. I think the idea is to see if your symptoms improve and if your measurements normalize. I believe if you are a candidate for surgery, they then fuse using intraoperative traction, informed in part by your results during this traction test.

The also use an ICP bolt test to see if your intracranial pressure is abnormal and if it normalizes with traction.

EDIT: I am pretty sure I already described this multiple times, here and elsewhere, so perhaps that is not what is being asked?

I also know of someone who did something very similar (on the west coast) and had a neurologist examine them. Their neurological exam normalized while under traction. So that’s perhaps something else that could be considered in a study of people with CCI.

 

[JenB]

EDIT: I think I quoted the old version of your question @Trish!

Re: the specifics of the occipital condyles and fixation, that is way above my pay grade. I do not know anything about the physics of various surgical techniques and how they work.

Also, in this question, re: measurements and how they relate to fixation, Dr. Edwards is asking something VERY SMART. Specifically re: horizontal instability v. cranial settling. Hopefully he will have an opportunity to converse with these neurosurgeons directly in the future.

 

[JenB]

EDIT: I think I quoted the old version of your question @Trish!

Re: the specifics of the occipital condyles and fixation, that is way above my pay grade. I do not know anything about the physics of various surgical techniques and how they work.

Also, in this question, re: measurements and how they relate to fixation, Dr. Edwards is asking something VERY SMART. Specifically re: horizontal instability v. cranial settling. Hopefully he will have an opportunity to converse with these neurosurgeons directly in the future.

My simple answer is I do think traction often corrects the kyphotic CXA

re: condylar screw fixation specifically, Dr. Bolognese obviously has some talks on the topic other have shared on why it is better tolerated by patients in terms of not feeling the hardware, not experience metal fatigue.

However, re: the biomechanics, perhaps the full paper here might answer Dr. Edward's question? It lays out some of the pros (biomechnically equivalent, less bending/metal fatigue) and cons (riskier, harder).

Craniocervical Fixation With Occipital Condyle Screws Biomechanical Analysis of a Novel Technique
https://sci-hub.se/https://journals...rvical_Fixation_With_Occipital_Condyle.2.aspx

Here is a case series: https://journals.lww.com/jspinaldis...cervical_Fusion_Via_Occipital_Condylar.8.aspx

 

[Guest 2176]

One thing I would like an answer to is whether traction is really supposed to separate the occipital condyles from the atlas, so that fixation takes weight entirely through metal rather than articular surface. That would seem to me very risky indeed in the long term and I do not understand the rationale if CCI is judged on the angles that indicate forward/back slip rather than vertical translation

This is a question that I would be interested in the answer to as I don't quite understand the anatomy of cranial settling and vertical instability.

However it seems clear in the literature (https://link.springer.com/article/10.1007/s10143-017-0830-3) that traction can correct a kyphotic cxa, which is a measurement that's a proxy for brainstem compression via the odontoid bone, and that this measurement is associated with pathology, and that intraoperative traction is used to correct the cxa and fuse in a better position.

The Henderson paper suggests that intraoperative traction is used. It even gives a diagram of this process. I don't understand how a surgery like this wouldn't improve symptoms , but simply try and prevent worsening, like @Jonathan Edwards has suggested , if what Henderson is saying is true and they are correcting kyphosis.

So, the cranial settling anatomy is something that I can't speak to. But if many of the people with a CCI diagnosis have a kyphotic cxa I don't see how it is somehow unbelievable that traction would tell us something about their symptoms , and mimic the effect of a fusion.

 

[Guest 2176]

In addition that paper provides justification for setting the range of the cxa how the consensus statement has set it, both from some kind of modelling of neural stretch injury based on angle, and also from the study on patients who have had their cxa surgically corrected.

 

[JenB]

This is a question that I would be interested in the answer to as I don't quite understand the anatomy of cranial settling and vertical instability.

However it seems clear in the literature (https://link.springer.com/article/10.1007/s10143-017-0830-3) that traction can correct a kyphotic cxa, which is a measurement that's a proxy for brainstem compression via the odontoid bone, and that this measurement is associated with pathology, and that intraoperative traction is used to correct the cxa and fuse in a better position.

The Henderson paper suggests that intraoperative traction is used. It even gives a diagram of this process. I don't understand how a surgery like this wouldn't improve symptoms , but simply try and prevent worsening, like @Jonathan Edwards has suggested , if what Henderson is saying is true and they are correcting kyphosis.

So, the cranial settling anatomy is something that I can't speak to. But if many of the people with a CCI diagnosis have a kyphotic cxa I don't see how it is somehow unbelievable that traction would tell us something about their symptoms , and mimic the effect of a fusion.

Interesting. I was a 65% on that Bulbar brainstem disability index post-thyroidectomy but pre-thyroidectomy, was 50%. But there are a lot of symptoms they don’t measure. For example, after my thyroid surgery, I lost the ability to tell the temperature of water and had to always have my husband check how hot the shower was before I went in so I wouldn’t burn myself.

These are obviously extreme symptoms. I had had subtler symptoms for years that the thyroid surgery simply made obvious.

As you can imagine, even though I am upset that the recommendations from some neurosurgeons in the 1990s that people with ME/CFS diagnoses should be in “neck neutral” during surgery was not passed on by my ME/CFS doctors, I am also in a way glad that that information was lost to history as it allowed me to become symptomatic enough to be diagnosed.

 

[Guest 2176]

Abstract
There is growing recognition of the kyphotic clivo-axial angle (CXA) as an index of risk of brainstem deformity and craniocervical instability. This review of literature and prospective pilot study is the first to address the potential correlation between correction of the pathological CXA and postoperative clinical outcome. The CXA is a useful sentinel to alert the radiologist and surgeon to the possibility of brainstem deformity or instability. Ten adult subjects with ventral brainstem compression, radiographically manifest as a kyphotic CXA, underwent correction of deformity (normalization of the CXA) prior to fusion and occipito-cervical stabilization. The subjects were assessed preoperatively and at one, three, six, and twelve months after surgery, using established clinical metrics: the visual analog pain scale (VAS), American Spinal InjuryAssociation Impairment Scale (ASIA), Oswestry Neck Disability Index, SF 36, and Karnofsky Index. Parametric and non-parametric statistical tests were performed to correlate clinical outcome with CXA. No major complications were observed. Two patients showed pedicle screws adjacent to but not deforming the vertebral artery on post-operative CT scan. All clinical metrics showed statistically significant improvement. Mean CXA was normalized from 135.8° to 163.7°. Correction of abnormal CXA correlated with statistically significant clinical improvement in this cohort of patients. The study supports the thesis that the CXA maybe an important metric for predicting the risk of brainstem and upper spinal cord deformation. Further study is feasible and warranted.

 

[JenB]

Abstract
There is growing recognition of the kyphotic clivo-axial angle (CXA) as an index of risk of brainstem deformity and craniocervical instability. This review of literature and prospective pilot study is the first to address the potential correlation between correction of the pathological CXA and postoperative clinical outcome. The CXA is a useful sentinel to alert the radiologist and surgeon to the possibility of brainstem deformity or instability. Ten adult subjects with ventral brainstem compression, radiographically manifest as a kyphotic CXA, underwent correction of deformity (normalization of the CXA) prior to fusion and occipito-cervical stabilization. The subjects were assessed preoperatively and at one, three, six, and twelve months after surgery, using established clinical metrics: the visual analog pain scale (VAS), American Spinal InjuryAssociation Impairment Scale (ASIA), Oswestry Neck Disability Index, SF 36, and Karnofsky Index. Parametric and non-parametric statistical tests were performed to correlate clinical outcome with CXA. No major complications were observed. Two patients showed pedicle screws adjacent to but not deforming the vertebral artery on post-operative CT scan. All clinical metrics showed statistically significant improvement. Mean CXA was normalized from 135.8° to 163.7°. Correction of abnormal CXA correlated with statistically significant clinical improvement in this cohort of patients. The study supports the thesis that the CXA maybe an important metric for predicting the risk of brainstem and upper spinal cord deformation. Further study is feasible and warranted.

Ah. So in other words, traction normalities a kyphotic CXA. Great find!

I've linked to this paper many times before but never thought much about the details of intraoperative traction and CXA.

 

[Daisybell]

@JenB can you please confirm for me that you mean dysphasia as a symptom of CCI - and not dysarthria? That doesn’t make any sense to me. Brainstem compression leads to slurred speech and swallowing problems due to the effect on the cranial nerves. Aphasia/dysphasia results from damage to the cortex....

 

[Guest 2176]

The same paper discusses cranial settling and something called "functional cranial settling" that I don't quite understand the difference between that and cranial settling.
Here's an example: "One large series reported “kinking of the medulla” (kyphotic CXA) in 140 of 364 of Chiari patients [111]; these were recognized as a form of “functional cranial settling” [110] in one series, and cranial settling or basilar invagination occurred in 25–30% of cases of Chiari malformation [26]. Kim et al. described “nontraditional basilar invagination” as the underlying cause of recurrence of pain and disabling symptoms in Chiari I patients after conventional suboccipital decompression, and reported substantial neurological improvement after intraoperatively correcting the CXA from an average of 127° to 147° [81]. Functional cranial settling, such as occurs with connective tissue disorders [110], may invite inordinate aggregate translation and flexion and subsequent basilar invagination with compression of the spinal cord or medulla [53, 54, 61, 64, 65, 116, 165]."

I'd like to dive further through the references to understand cranial settling Better though , but it may be above my pay grade.