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By Timothy Boerger
Reviewed by B.Davies

Neck Muscles and CSM– An Update Part 1 of 2

​This will be the first of a 2 part mini-series on the properties of muscles in the neck and how they impacts outcomes of surgery. We previously looked at this following an early piece of research from North America.  This series will serve as an update on this research. 

Why was this study conducted?
As outlined previously, the amount of fat found within muscles has been linked to the type of symptoms experienced by patients; including the amount of neck pain and walking ability. This new study was done on a separate cohort of patients than the previous study and included measures of neck strength and other quality of life scales not assessed previously which addresses some weaknesses of the previous study.

How was the study conducted?
This study used MRI imaging to measure the size and the amount of fat in muscles in the neck. Neck strength was measured by clinicians using a hand held force sensor. Several questionnaires were performed to assess function, pain, and quality of life. Importantly, this study used what is called a “cross-sectional’ design meaning it only looks at 1 time point. 

What was discovered?
Larger muscles and larger amounts of lean muscle (i.e. muscle without fat) in the neck were associated with increased strength. (We already knew this in general, but it is good to ensure there isn’t something different about patients with cervical myelopathy). More fat in muscles of the neck was associated with more disability measured by the mJOA. Importantly, neither strength, muscle size, or muscle fat were associated with pain, duration of symptoms, neck disability index, or quality of life in this study.

Why is this important?
Between the previous study linked above and this study, it appears that muscle fat may be a biomarker of disability and function in patients with myelopathy.  Currently there are no biomarkers for myelopathy, which makes it difficult to assess how severe it is or give an idea of how things will develop.  More research will be needed to investigate the usefulness of muscle fat as a biomarker, but given that it can be quantified based on existing widely avaliable imaging techniques, it could enter routine clinical practice quickly.
 
Why could muscle fat relate to the severity of myelopathy?
One reason this is being investigated is that fat infiltrates muscle as a response to nerve injury and disuse. For example, if a nerve is injured the nerve doesn’t tell the muscle to contract as much and it allows more fat to become deposited within the muscle itself. 
    
References

1. Fortin M et al. Relationship Between Cervical Muscle Morphology Evaluated By MRI, Cervical Muscle Strength And Functional Outcomes In Patients With

Degenerative Cervical Myelopathy. Musculoskeletal Science and Practice. 38; epub 2018: 1-7 

1. Fortin M, et al. Association Between Paraspinal Muscle Morphology, Clinical Symptoms and Functional Status in Patients With Degenerative Cervical Myelopathy. Spine (PhilaPa 1976). 2016 May 23

By O.Mowforth
Edited by B.Davies

We don’t really know what symptoms a “typical” patient with myelopathy has. 
In fact, the huge number of often quite subtle and non-specific symptoms is probably one of the main reasons why early diagnosis is so challenging (Davies et al., 2018).
 
When medical students prepare for exams they tend to learn stereotypical descriptions of conditions. For myelopathy, this might be a patient with walking problems and clumsy hands.

​However, increasingly symptoms that one might never consider could be linked with myelopathy are emerging from the shadows.

Depressed or anxious mood is one such symptom (Stoffman et al., 2005). 
In recent years we have realised that myelopathy patients suffer from high levels of depressed or anxious mood and that this often improves after spinal surgery. But we have had little understanding of why this is the case.

A recent study from Japan has provided a little more insight (Sawada et al., 2018). The Japanese team studied the activity levels of various sites in the brain in myelopathy patients before and after surgery. They also studied individuals without myelopathy as a control group for comparison.
To do this, the team asked participants to do a simple finger-tapping exercise whilst they observed activity levels in the brain using functional magnetic resonance imaging.

The team found that before surgery individuals in the myelopathy group had a significantly higher activation in an area of the brain called the supplementary motor area compared to individuals in the group without myelopathy.
Next the team found that activation of brain areas, including the anterior cingulate cortex, the supplementary motor area and the thalamus significantly correlated with depression. This meant that the greater a patient’s depression, the greater the activation they had in these brain areas.  
Finally, the team found that both depression and activity in the anterior cingulate cortex and supplementary motor area decreased following surgery for myelopathy. 
Interesting!

The team argue that up to now surgeons have focussed on the “typical” symptoms such as the clumsy hands and walking problems when deciding whether to operate. They believe that their work may lead to future surgical decisions taking more account of the psychological symptoms too!

Davies, B.M., Mowforth, O.D., Smith, E.K., and Kotter, M.R. (2018). Degenerative cervical myelopathy. BMJ 360, k186.
Sawada, M., Nakae, T., Munemitsu, T., and Hojo, M. (2018). Cortical Reorganizations for Recovery from Depressive State After Spinal Decompression Surgery. World Neurosurg. 112, e632–e639.
Stoffman, M.R., Roberts, M.S., and King, J.T. (2005). Cervical spondylotic myelopathy, depression, and anxiety: a cohort analysis of 89 patients. Neurosurgery 57, 307–313; discussion 307-313.

Myelopathy.org and Myelopathy Support on Facebook have been a great help for both me and my wife since my diagnosis in 2016. Since then, life has been difficult to say the least. Cervical myelopathy, and the accidents it has caused, have led to me going under the knife for no less than six major surgeries. These have significantly affected my body and its ability to cope with everyday life.

I created a ‘lucky numbers’ board featuring 1-100. I then made a list of those numbers with spaces next to them for people to write down their names and telephone numbers. It cost £1 per number and I decided on a winning pay-out of £25 which, if all the numbers had been taken, would deliver a tidy profit of £75 for Myelopathy.org. 

I set my table up in the club room. I took along some laminated photos of people’s CT scans, including my own, as visual aids. I also made copies of one of the charity’s media releases about the condition and the need for early diagnosis, and the basic facts about myelopathy. These are part of the Myelopathy.org fundraising pack. 

It was very interesting to see how people reacted to the photographs and then responded to the information in the leaflets and that I was able to supply about myelopathy. 

The fundraising experience was a positive one and the fact that I was able to raise £71.10 (no idea where the 10p came from) was a bonus. I am now really looking forward to taking part in the next fundraising event. So, if you have any ideas or want to hold a fundraiser yourself, please let me or one of the Myelopathy.org team know.

My top five tips for fundraising.
1) Plan where you want to hold your fundraiser and contact relevant authority/fête organiser/owner etc for permission

2) Share, share, share. Use social media, such as Facebook, WhatsApp, Instagram etc, to gain maximum promotion and coverage for your fundraising activity.

3) Make it personal. Tell your own story so that people can understand more about your experiences and your reasons for fundraising. Sometimes that personal touch/story can elicit donations.

4) Remember your inspiration. There’s a reason why you are supporting this cause. Hold on to your inspiration and bring all that enthusiasm to your fundraising activities.

5) Have fun. If you are not enjoying yourself, you will give off all the wrong vibes. So, smile and perhaps rope in a friend or two to help so that you can jolly each other along.

By Timothy Boerger
Reviewed by B.Davies
​
Neck Muscles and CSM– An Update Part 2 of 2
​This second of a 2-part mini-series on the properties of muscles in the neck and how they impact outcomes of surgery. We previously looked at this following an early piece of research from North America.  This series will serve as an update on this research.

Why was this study conducted?
For a short recap of the previous 2 blogs related to this: how much fat there is within muscles has been related to symptoms of myelopathy. Additionally, cervical lordosis, or, the curve of the neck, is believed to be related to outcomes following laminoplasty.1 

How was the study conducted?
This study performed a pre-operative MRI at which they performed measurements of the neck muscles. They then tracked the participants for 12 months post cervical laminoplasty to assess the curvature of the neck with x-ray.

What was discovered?
The main finding was that muscle size at multiple vertebral levels in the neck is related to loss of curve following surgery. The smaller the neck muscle size, the greater loss of neck curve.

Why is this important?
This is further evidence suggesting the muscles in your neck are important in myelopathy.  It should be noted that this study only looked at patients who underwent a laminoplasty, one of many different types of surgical procedure for myelopathy (i.e. it is unclear whether this finding would be applicable to other types of surgery such as ACDF).
​ 
Whilst this link is again being drawn, it remains to be seen whether or not treatments to help neck musculature could make a difference to patients.  The authors in this study suggest it could better advise on the type of surgery that is to be performed.  Drilling down to these questions will be an important next step for this line of research. 

Have you had any therapy to strengthen your neck pre- or post- surgery? Did it help?
    
Reference
Lee BJ et al. Importance of the Preoperative Cross-Sectional Area of the Semispinalis Cervicis as a Risk Factor for Loss of Lordosis after Laminoplasty in Patients with Cervical Spondylotic Myelopathy. Euro Spine J. epub 2018: 1-10

The authors used a national insurance claims dataset of 22 million people in Taiwan and identified 27,947 patients with CS, they then matched this with a similar number of non-CS patients of a similar age and gender distribution, as well as matching numbers of patients with other health problems such as hypertension, diabetes, asthma and stroke. This was to allow them to compare the incidence of ACS between the groups without other diseases invalidating the comparison. 

All the patients were followed up until they had a diagnosis of ACS, died, or the end of the research period occurred at the end of 2011. After this, the number of ACS events in each group were measured as a rate over the number of “person years”. This being the number of times a diagnosis of ACS was made for every year a patient lived.
 
In this paper, the incidence of ACS was measured as number of ACS/1000-person years. These were then compared between various groups to obtain a ratio, to determine the relative risk of ACS occurring in a person with CS compared to someone without ACS in a similar state of health.

Overall, the study showed that patients with CS were 13% more likely to have an ACS, than patients without CS. This was determined ‘statistically significant’, but in real terms this represents a very small increase from 3.9/1000-person years to 4.27/1000-person years in rates of ACS diagnosis. 

Looking in more detail at the patients with CS, for those with myelopathy the risk was slightly higher, increasing by 20% but interestingly, it seems treatment of CS has an effect in reducing ACS risk:
– Patients receiving spinal decompression surgery were less likely to have an ACS (27% reduction)
– Patients receiving rehabilitative therapy were less likely to have an ACS (33% reduction) 

The statistical difference between the form of treatment for CS and reducing ACS risk was not significant.  

This is a good question, and not entirely clear.  The researchers suggested that it may be to do with the sympathetic trunk. The cervical sympathetic trunk consists of collections of nerve cells bodies, called ganglia, aligned along the front of the spine.  The ganglion in the neck are involved in control of the cardiovascular system.  This special group of nerves also connect with the ligaments of the spinal column, such as the posterior longitudinal ligament, and the lining of the spinal cord. Irritation to these structures is thought to cause the sympathetic nervous system to increase its output, for example to fibers in blood vessels around the body, causing them to constrict and causing hypertension, which contributes to a diagnosis of ACS.

This is not the first study to show a relationship between CSM and Cardiovascular health (we have previously described a study specifically looking at high blood pressure), however it is the first to show an increased risk of a heart attack.

There are a number of limitations to this study, and the actually increases in risk are relatively small.  But it adds to the research of CSM and Cardiovascular disease, and once again shows the far reaching impacts of CSM.    

Shih-Yi Lin et al. Risk of acute coronary syndrome in patients with cervical spondylosis ​Atherosclerosis 2018

[1]M. Singh, I. Khurana, Z. Kundu, A. Aggarwal, Link of sympathetic activity with cardiovascular risk in patients of cervical spondylosis, Int. J. Clin. Exp. Pathol. 3 (2016) 41e44 
[2]M. Singh, I. Khurana, Z.S. Kundu, A. Aggarwal, Galvanic skin response in pa- tients with cervical spondylosis, IJHSR 6 (2016) 148e152.
[3] N. Marina, A.G. Teschemacher, S. Kasparov, A.V. Gourine, Glia, sympathetic activity and cardiovascular disease, Exp. Physiol. 101 (2016) 565e576,