Muscle biopsy studies

Hey

We recently had the study which showed impaired glucose utilization in muscle biopsy samples

Anyone know if we have more studies from muscle biopsies?

Im thinking about having one myself out of curiosity, and want some references

I think history might show that the above mentioned study might have been an important part of the puzzle

Thanks

 

Sorry I missed it do you have the S4ME thread link for the study?

 

I can't think of any proper study off the top of my head, but there are many case reports I looked at over the years trying to identify any misdiagnosis.

This case study is a good example.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4748504/

 

The problem with muscle biopsy is that to get a sample that is big enough to be representative it is likely to be painful and to leave a scar. In fact to be representative you might need to have about six samples taken.

It is a useful technique for picking up marked structural changes as in mitochondrial disease or myositis but the hope that it would be useful to show metabolic changes seems to me overoptimistic. A better way to study metabolism in muscle is likely to be MR spectroscopy, which is completely non-invasive and can be repeated as often as you like.

Muscle biopsies done on people with MF/CFS in the 1980s at UCL did not show anything useful.

 

Interesting! Thanks for this input, I guess its hard to find anything if you dont know what you are looking for. Ill ask the metabolic section what they think of MR spectroscopy

 

Newton and co did some work on this. https://meassociation.org.uk/2013/0...ope-for-me-sufferers-the-times-23-april-2013/ The link to the press release is dead. And no link to study.

 

Yea I was about to mention it, but remembered the research got a lot of criticism here, so not sure how good it was

 

For a patient perspective: I had a muscle biopsy taken in an NHS neuromuscular disease clinic. I believe the main indications were my very high resting blood lactate and some moderately wonky CPET results. Long history of non-specific symptoms that appear to overlap with CFS/POTS/MM, for what that was worth too.

The biopsy itself was no big deal, just a single needle biopsy taken from the thigh. Small incision, no stitches and only a local anesthetic required - back on the train home straight after.

The results were unremarkable, minor non-specific changes in the muscle only. If more had come to light they were ready to run genetic screening, but instead it was case closed for neuromuscular disease. The assumption is "just" POTS/SFN as an explanation for those issues, I don't regret having it done to exclude MM etc. as a possibility though.

 

Sorry but what's MM? Maybe I know but it won't come to mind at the moment.

 

Behan did studies on muscle biopsies and found problems with mitochondrial function. At the time, Wessely had published a paper which found something like 90% of people with ME had depression so he said that the percentage Behan had found was not as high so the paper did not prove anything and the subject was dropped.

At the time I felt it was wrong because there should have been 100% of people found to have depression if that was all ME was as it is a yes/no answer but not every muscle fibre would have to have damaged mitochondria to cause the exercise problems we have.

 

Mitochondrial Myopathy

 

Wow here it is https://link.springer.com/article/10.1007/BF00294431

I have to read the whole paper, that seems like important findings judging by the abstract!

 

Would Invasive CPET showing impaired oxygen extraction be useful? I believe it’s done in the US and one hospital in London and in some patients it’s showing that their o2 uptake in muscles is low?

 

I think there will always be difficulties in interpreting oxygen uptake figures. I think we need to see a profile of metabolic molecules actually in the tissue during and after exercise and my understanding is that MR spectroscopy has the best chance of doing that.

 

This paper came up in discussion at the CIBA Conference in 1992, following Edward's paper on Muscle histopathology and physiology in CFS

Komaroff: On the question of mitochondrial myopathies, Professor Behan has published a paper with illustrations of very distorted mitochondria; these findings were not seen in control biopsies (Behan et al 1991) Has anyone else looked for electron micrographic evidence of a mitochondrial myopathy, and is it conceivable that one could see such a myopathy without seeing functional consequences?

Edwards: One can certainly see such morphological changes without consequences for muscle function. We see a range of so-called pathological abnormalities in normal people. Some years ago a woman who came third or fourth in the London Marathon came to my clinic complaining that she was terribly tired and was particularly fatigued after running 18 miles! Electron microscopy of her muscles showed damage to sarcomeres. It could well be that she was doing too much, yet she was still able to do much more exercise than the usual patients complaining of chronic fatigue.

Discussion continued a little before Lloyd was allowed to turn it to "the CFS patient's disordered perception of fatigue". Behan seemed to recognise that he was outnumbered.